# Which Way To Flip The Parts



## Jerry Bowen (Jun 25, 2011)

This thread is associated with the use of the the Incra Jig. It may be a point thal everybody that uses the jig already knows about, but then again it may not be.

The point that I want to cover in this thread has to do with the issue or problem that is created if the end cuts on a workpiece are not perfectly cented on the workpiece. By the cuts I mean the cuts for box joints or dovetail joints.

I mentioned the issue if a correct center cut in an earlier thread and got a couple of responses that indicated that other users have run into the same problem I had, that being the difficutly of getting a perfect center cut to use to set the template on the carriage with.

Let me see if I can explain what I am talking about for those not familiar with the Incra jig without getting it to difficult to understand. First invision all of the cuts on the ends of workpieces that are going to be used to create a small box. Now think about the importance of the edges being flush with each other when the four parts are assembled. You should then understand that if the cuts are not perfectly centered on the ends of the workpieces that the edges will not be flush which is not what one wants.

In order to be certain that the four sides end up flush after assembly, the template in the jig must be set properly. The demo from Incra shows how to do this which I am not going to go into right now other than to say that the procedure that they suggest is not fool proof and the problem that is created when an error is made and how to deal with the error is what I want to speak to in this thread.

At this point I am going to have to assume that the reader is familiar with how the jig works and if the reader does not understand I refer them to the demo on line rather than me attempting to explain it here.

In the demo after the first cuts on one ends of the first two workpieces are completed the demo says that you should flip the parts over and make the cuts on the other end of the workpieces. This is where the rub comes in. If and only if the set up is such that the cuts are indeed perfectly centered it makes no difference if the parts are flipped vertically, end for end, or horizonallly. But if the cuts are slightly off center and the workpieces are flipped end for end a problem is created.

The problem shows up when the parts are laid flat on the router table and the bit of the router is run into each of the cuts so that during assembly the square ends of the opposing work pieces will fit into the round hole that was cut when the first cuts described above were made. If the cuts are not centered, one set of cuts on one end of the workpiece will not line up properly to make the the cuts when the part is laying flat on the router table. I don't know if the reader is following me at this point or not, but if the reader is familiar with using the jig, he or she will know what I am trying to describe. The off-set created by the cuts not be centered will not allow both ends of the workpiece to line up with the router bit when the workpiece lays against the fence an is fed into the bit.

Now again assuming that the reader is following this, here is how to overcome the problem if you don't already know about it. What you do is this, after you make those first cuts on the first end of the work pieces, don't flip the parts vertically, flip them horizonally, sideways, this will cause you to be able to make those "flat on the table" cuts when it is time to do so. Flippin horizonally will cause the the off-set created by the non centered cuts to be able to line with the router bit when the part is laying flat on the router table..

Do the same thing with the secone set of two parts and then when the parts are assembled, match a wide pin with narrow tail at each corner and the edges will be flush.

Now, you may or may not be able to follow all of this jargen and if you are not interested in the subject just forget it, but on the other hand, if this describes an issue that you as a user have had to deal with and would like for me clear it up for you send me a private message or just post to the thread I will try to clearify it for you. 

Jerry


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## Dmeadows (Jun 28, 2011)

Jerry, mark one edge of each piece and always keep that same edge against the fence.
Flip the parts end for end. That way if your off center, at least by always referencing from the same edge, the joinery should still line up.


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## Jerry Bowen (Jun 25, 2011)

Dmeadows said:


> Jerry, mark one edge of each piece and always keep that same edge against the fence.
> Flip the parts end for end. That way if your off center, at least by always referencing from the same edge, the joinery should still line up.



Duane,
Are you saying this from experience or not, What you describe is what creats the problem for me and does not work. Only when doing what I have tried to describe is the only with to deal with the off center problem. I would not have started thred if I did not know that in my experience anyway, is the only way to deal with it.

I the cuts are not the same distance from the edges of the boards at both ends which is what happens if the cuts are not centered, then the distance from the fence to the bit will not line up on both ends when the board is laying flat for the end cuts, at least this has been my experience.

Jerry


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## Dmeadows (Jun 28, 2011)

Yes, from experience. I recently dovetailed 18 drawers for my kitchen cabinet build with my Incra jig... no problems! If you don't keep all of say the top side(or bottom as long as you are consistent) against the fence, then yes poor centering will give mismatched alignment of parts. If you keep the same edge against the fence on all parts, the worst that should happen is the half pins on the board edge won't be equal. 

And yes, Jerry, I have had cases where I was slightly off center, but the tops all align, and the bottoms all align! If done the way I suggested, they pretty much have to!

I even gang cut 6 to 8 parts in one pass whenever I had several the same width!


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## Jerry Bowen (Jun 25, 2011)

Dmeadows said:


> Yes, from experience. I recently dovetailed 18 drawers for my kitchen cabinet build with my Incra jig... no problems! If you don't keep all of say the top side(or bottom as long as you are consistent) against the fence, then yes poor centering will give mismatched alignment of parts. If you keep the same edge against the fence on all parts, the worst that should happen is the half pins on the board edge won't be equal.
> 
> And yes, Jerry, I have had cases where I was slightly off center, but the tops all align, and the bottoms all align! If done the way I suggested, they pretty much have to!
> 
> I even gang cut 6 to 8 parts in one pass whenever I had same several the same width!


Duane,
I don't think you and I are on the same page yet, but as long as we are both happy with our technique, what difference does it make. 

Jerry


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## MAFoElffen (Jun 8, 2012)

Jerry Bowen said:


> Duane,
> I don't think you and I are on the same page yet, but as long as we are both happy with our technique, what difference does it make.


I am not sorry to say I agree with Duanne.

My Incra Ultra, which later became the Incra LS Super System... Works from one side and you stay with that side towards the fence. I'm sorry to say that what you (Jerry) described, seems off.

Let me get this straight... You are going by Mark's demo video and not with the Incra Manual? Because what Duane described is that same that is in their own manual. Let me give you another perspective from how that jig works:
You cut a "cut" for a joining... That doesn't matter whether what kind of joint. With me so far? Then use the Incra scales to move the fence to the next index to cut your next cut... The work is on a jig that slides along the fence, that just happens to have the workpiece and a backer board clamped to that jig... Why in the heck would you take the work piece off to flip the work and cut from the other end?

The reason I say that is-- With any joint jig, you work from one side , move to the next index (board still oriented the same direction) to cut the next cut. RT or TS joints...

If you flip the piece and work from another end... Then you lose all refernce from the first cut and the index. I'm sorry I didn't see that demo and I don't understand the why in that. That doesn't make any sense to me and I can't see it in my head. 

We are talking about the same Incra system right? Because the fence part of mine mine "was" called the Incra Jig, but that part of it is now called the Incra LS. What vendors now called the Incra "Original" Jig... is just not the same thing and is (what?) a plastic jig you attach to a fence? Just not the same system.

But still... Joining is joining. I can't see working from two separate ends to the center and hope you get there "centered." That would be a test of cutting to a set length and a whole lot of extra factors that you just don't need to throw in there. That is like saying you are doing that on purpose just to "make" that as challenging as you can make it to see how it comes out... Right? How you described that, is that you put the side that was away from the fence, towards the fence... That is what it sounded like you were describing. I have to admit, I was sitting here scratching my head and wondering how we were talking about the same system... and in what universe that would happen. (LOL)

NOW... What I think you meant to say was-- And what Duane understands, is that you cut all the joints on one side, while that side is facing the table, while leaving the leading edge towards the fence. You move the fence back to make all those indexed cuts.... When through, you then take the workpiece loose, keeping the side that was at the fence towards the fence, as you turn the work piece over, so that the freshly cut joints cuts are now up, the other side that needs to be cut is now towards the table and the leading edge is still against the fence....

Now, if that is really what you are trying to say... then I think we can all agree on that interpretation.


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## Jerry Bowen (Jun 25, 2011)

MAFoElffen said:


> I am not sorry to say I agree with Duanne.
> 
> My Incra Ultra, which later became the Incra LS Super System... Works from one side and you stay with that side towards the fence. I'm sorry to say that what you (Jerry) described, seems off.
> 
> ...





Mike,
One of two things is wrong here, either I'm doing something wrong or you don't understand what I'm trying to say. Let's try this again, and by the way,I reserve the right to be wrong, O.K.

The first thing we do is to take two workpieces and with a backing board clamp them to the right hand fixture and make all of the cuts across the the first end of the workpieces. Now for the sake of this example, let's execrate the error of the centering of the cuts on this first end of the workpieces, say in this case 1/8th of an inch off center.

Now we are ready to make the cuts on the opposite end of the workpieces and we turn the workpieces end for end so that the edges of the both workpieces that were against the fence are still against the fence when the second set of cuts are made. Now the off set is the same on both ends of the workpieces. There is more wood on one edge of the workpieces than the other at the area from a corner to the the first cut due to the off set created by the cuts being made off center.

The next step is to do the same thing with the other two workpieces with the only difference being that the cuts on the first two workpieces is say for the pins and the cuts on the other two workpieces are the tails.

Now, all of the cuts have been made and it is time to lay the workpieces with the pins cut in them flat on the router table and run the bit into the pins so that the tails will fit to create a 90 degree corner. So when the edge of one of the workpieces that is laying flat on the router and the the bit is in line with the first pin you make the cut and advance all the way across the end of that workpiece, 

Now it's time to do the same thing on the other end of the workpiece, but when you rotate the workpiece around 180 degrees on the router table and and put the edge of the workpiece against the fence, the bit will not line up with the cuts due to the off-set created by the cuts not being centered. 

I could have a mental block here, but that has been my experience from the get go and is what I have tried to explain and of course I may be out in left field.

If what I am saying is wrong and it may be, why even worry about centering the workpiece to start with expect for appearance sake??

I'm waiting for you to show me where I'm wrong and am willing to let you show me. I am well aware that you know more about these things than I do. I'm not insisting that I am right, I'm just trying to tell you how I see it.

Mark and I have talked about this at length in regard to dealing with the assembly of the four parts after the cuts are made with the off set existing and he didn't have a problem understanding what I am trying to say. I may have misunderstood him too for that matter. The fact that you are emphatic about it makes believe that I have indeed been doing something very wrong.

Jerry


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## greenacres2 (Dec 23, 2011)

Jerry--the only reason to use the center of the workpiece to position the fence is EXACTLY for appearance. So that when the jointing is done, the pins on top and bottom are near enough to the same width that they look the same. Once the fence is positioned, then the cutting begins but not from the center. I keep the "top" of the box against the fence all the time so i don't end up being off on the top. Having the "bottom" away from the fence allow me to run a pencil line across it that i can see as a reference and to know i have the right side against the fence. Works well for me.

earl


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## MAFoElffen (Jun 8, 2012)

Agreed with Earl. 

Jerry-- just like the "last part" of my post. Then we are saying the same thing, but you are going into too much detail and too much extra work. It's really easier than that. I think you are making it a bit harder than it really is.

This is what I usually do... I cut two sides at a time. I leave the length of the jointed edges long until after fitting. That way I don't waste time worrying if the adjacent sides line up exactly with the other edges. It's faster just to mark where they are, in relation to each other, then trim them in respect to that reference mark. That way evrything is then magically the same size.

It's not rocket science. And the Incra System makes that even easier to do, more accurate and faster for me. Use the strength of the system, which is the repetitive indexing between the cuts.


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## Jerry Bowen (Jun 25, 2011)

MAFoElffen said:


> Agreed with Earl.
> 
> Jerry-- just like the "last part" of my post. Then we are saying the same thing, but you are going into too much detail and too much extra work. It's really easier than that. I think you are making it a bit harder than it really is.
> 
> ...




Mike,
I must really have a mental block, I don't have a clue what you are talking about, I know the problem is with me, sorry, I just can't follow you.

All I am seeing is that if the cuts are not centered the distance from the fence to where the cuts begin on one end of the board cannot be the ssme distance when the opposite edge is against the fence after the workpiece has been rotated 180 degrees while laying flat on the rouger table. This is where I am confused I guess. The distance from the edge of the workpiece to the cuts at both ends of the workpiece cannot be ths same if the cuts are off center. I don't know how much plainer I can say that. The problem is overcome, in my mind if the workpieces are rotated horizonally instead of being flipped end for end when going from one end of the workpiece to the other. I know that I sound like I'm being stubborn, I am not doing so on purpose, I just don't see what you are doing to negate this point. I don't doubt you, I just don't see it yet.

Jerry

Jerry


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## Dmeadows (Jun 28, 2011)

Jerry Bowen said:


> Mike,
> I must really have a mental block, I don't have a clue what you are talking about, I know the problem is with me, sorry, I just can't follow you.
> 
> All I am seeing is that if the cuts are not centered the distance f*rom the fence to where the cuts begin on one end of the board cannot be the ssme distance when the opposite edge is against the fence after t*he workpiece has been rotated 180 degrees while laying flat on the rouger table. This is where I am confused I guess. The distance from the edge of the workpiece to the cuts at both ends of the workpiece cannot be ths same if the cuts are off center. I don't know how much plainer I can say that. The problem is overcome, in my mind if the workpieces are rotated horizonally instead of being flipped end for end when going from one end of the workpiece to the other. I know that I sound like I'm being stubborn, I am not doing so on purpose, I just don't see what you are doing to negate this point. I don't doubt you, I just don't see it yet.
> ...


That's the point.. you should *NOT HAVE* opposite edges against the fence! If you do you are not flipping the parts correctly. 

Try this... cut all 4 pieces for your box. stack them all 4 together with the top sides you want all up. put a mark on the top of all 4 boards. Make *all* cuts with that marked edge against the fence. Yes absolutely if you make cuts with the unmarked edge against the fence, you indeed will have problems if you are not perfectly centered... I guarantee it!

Flip the boards end over end, not top over bottom! Maybe I will do a video showing that


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## Shortslvs (Jan 13, 2013)

I am not an expert but I bet if you guys were standing in the same room you would have this worked out in two minutes and have a laugh.

I don't want to get entangled but is it possible Jerry that you are making center cut first? Then trying to make the rest of the cuts?

Center is only for looks and we find it so that we can select which marks on layout ruler to use for that board. Then slide the fence back to the first cut working to the center then past it. Flip so that the same side that was originally against the fence is still against the fence. Slide fence back to first cutting mark, work to center then past center.

Only problem I've had is getting a flush cut on the actual joints. Just a matter of raising and lowering the bit.


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## Dmeadows (Jun 28, 2011)

Shortslvs said:


> I am not an expert but I bet if you guys were standing in the same room you would have this worked out in two minutes and have a laugh.
> 
> I don't want to get entangled but is it possible Jerry that you are making center cut first? Then trying to make the rest of the cuts?
> 
> ...


Yep, Fred. Would indeed make it easier to be in the same room!

One of the beauties of the Incra system is.. it doesn't make any difference what order you make the cuts in. I usually do as you say, cut from the fence to the far edge. Then flip the boards and cut the second set back toward the fence The "economy of motion" thing! But either way keeping the same edge to the fence is essential.

Also it is important to be sure the boards are flush to the fence.. any tilt toward front or back will really mess things up. Don't ask how I know that!


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## Jerry Bowen (Jun 25, 2011)

Dmeadows said:


> That's the point.. you should *NOT HAVE* opposite edges against the fence! If you do you are not flipping the parts correctly.
> 
> Try this... cut all 4 pieces for your box. stack them all 4 together with the top sides you want all up. put a mark on the top of all 4 boards. Make *all* cuts with that marked edge against the fence. Yes absolutely if you make cuts with the unmarked edge against the fence, you indeed will have problems if you are not perfectly centered... I guarantee it!
> 
> Flip the boards end over end, not top over bottom! Maybe I will do a video showing that


Duane, 
I don't understand what you mean by "end over end" compared to "top over bottom" both terms sound the same to me. At least you agree with me when you say that you guarenctee that that I will have a problem if one of the marked edges is not against the fence and that is what I'm referring to. When the workpiece is rotated 180 degrees the marked edge is turned away from the fence as I see it, and somehow that is where I am confused I guess. Don't give up on me, we are getting closer to the issue I think.

Jerry


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## Shortslvs (Jan 13, 2013)

Dmeadows said:


> Yep, Fred. Would indeed make it easier to be in the same room!
> 
> One of the beauties of the Incra system is.. it doesn't make any difference what order you make the cuts in. I usually do as you say, cut from the fence to the far edge. Then flip the boards and cut the second set back toward the fence The "economy of motion" thing! But either way keeping the same edge to the fence is essential.
> 
> Also it is important to be sure the boards are flush to the fence.. any tilt toward front or back will really mess things up. Don't ask how I know that!


Confession time: My first cut went into the plywood guide on the bottom of the sled. Please don't ask me to explain how I did that....


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## Jerry Bowen (Jun 25, 2011)

Shortslvs said:


> Confession time: My first cut went into the plywood guide on the bottom of the sled. Please don't ask me to explain how I did that....


Fred,
Boy do I understand that. In fact I am planning on phoneing Incra today and ordering a new set of those parts for the right had fixture as well as the fiber center knob that locks the fixture to the fence when the fixture is parked. 

I did not actually do what you did but I have run the bit into the edge enough to cut off that material that adheres to the plywood. I know that I could make new ones but I'm just going to buy new ones instead of messing with them.


Jerry

The new parts cost $3.95, can't mess them for that.


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## Dmeadows (Jun 28, 2011)

Jerry Bowen said:


> Duane,
> I don't understand what you mean by "end over end" compared to "top over bottom" both terms sound the same to me. At least you agree with me when you say that you guarenctee that that I will have a problem if one of the marked edges is not against the fence and that is what I'm referring to. When the workpiece is rotated 180 degrees the marked edge is turned away from the fence as I see it, and somehow that is where I am confused I guess. Don't give up on me, we are getting closer to the issue I think.
> 
> Jerry


Jerry, I will do a video to show you what I mean. Won't get to it till this evening... babysitting today!


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## Jerry Bowen (Jun 25, 2011)

Dmeadows said:


> Jerry, I will do a video to show you what I mean. Won't get to it till this evening... babysitting today!




Duane,
I just watched the demo again and the guy doing the demo is definitely rotating the workpiece when it is flat on the router table 180 degrees when doing the end cut into the pin boards which puts the marked edge on the opposite side away from the fence. This is what I am talking about.

Jerry


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## Dmeadows (Jun 28, 2011)

Jerry, I just watched one of the demo videos also. Indeed the operator is doing it wrong! The centering must be perfect for it to work that way.

Let me try to explain it. 

1. Cut 2 boards normally.
2. Remove clamp.
3. Grip boards from the top and lay them down along the fence with the edge that was against the fence still against the fence.
4. Pick up the cut end of the boards, keeping the same edge against the fence. You should now have the cut ends up in the air, with the same edge against the fence.
5. Reclamp.
6: Cut the other end of the boards.

You can either repeat for the 2 remaining boards or do the 4 at once as in the demo. If you do 2 at a time, use the A cut on one pair, B cut on the other pair

Then with the edge that was against the fence up for all four boards up, assemble box. the joinery should line up even if the centering is off.

I will try to get a video on youtube either tonight or tomorrow.

Bset of luck, Jerry. we'll get there!:yes4:


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## greenacres2 (Dec 23, 2011)

Shortslvs said:


> Confession time: My first cut went into the plywood guide on the bottom of the sled. Please don't ask me to explain how I did that....


+1 on that. I'd watched a lot of video before my used Incra Pro arrived, so i knew when i saw the gouge on the rail of the right angle fixture that the original owner had erred--and i snickered about it. I think i was doing my second or third cut when i made the divot deeper--but i haven't done it since!!

earl


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## Jerry Bowen (Jun 25, 2011)

Dmeadows said:


> Jerry, I just watched one of the demo videos also. Indeed the operator is doing it wrong! The centering must be perfect for it to work that way.
> 
> Let me try to explain it.
> 
> ...



Duane, 
This is getting really interesting. You now see what was bugging me due to the demo. In your explanation in this post you are not addressing the end cuts where the bit cuts into tails or am I still am missing something. You are saying, or I think that you are saying that you are making all of the cuts with all four edges against the fence so that the cuts on each workpiece on each end of each workpiece line up from one end of the board to the other which they would not do if they had been flipped horizonally like I described in the original thread. Let's keep going, you really have my attention now.

Jerry


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## Shortslvs (Jan 13, 2013)

I feel much better about my error and after Jerry shared the price to replace I may order a couple stand-bys.


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## Jerry Bowen (Jun 25, 2011)

Shortslvs said:


> I feel much better about my error and after Jerry shared the price to replace I may order a couple stand-bys.


Fred,

I considered buying a second set, but did not for two reasons, first, now that I know about the potential of making the mistake, I probably will be more careful. The other thing is that I'm now thinking of adding sub plate to the fixture that protect the parts that we are talking about.

Way off subject, but kind of interesting. Our garbage disposal service had been going steadily up until I finally decided to check into some other service. I first phoned the company that we are with and asked I they had any other options for less money, our dumpster is larger than we really need. Well, they had no lesser priced service so I told them that I would just change services as my neighbor is paying considerable less but does has a much smaller container. All of a sudden they cut the price from $138 down to $67. Strange how that price changed.

Jerry


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## Dmeadows (Jun 28, 2011)

Jerry, I'll do the video, I think that will clear it up totally, but you're getting there. I went to a demo near Cleveland when I bought mine. They did it right back then. Watching that video did give me a better understanding of where you are coming from! Been wanting to play with making some youtube videos anyway.

Guys, I need to order a set or 2 of those plywood runners, also. I have rather chewed up mine. Setting a stop to limit the travel will stop that, I have found. If Incra has a design flaw, I think that is it. However I have use my Incra pro(not LS) for something like 15, 16 years or so without replacing them, so I won't complain about that too much! I have used mine on the router table, table saw, and my drill press. Still one of my favorite tools. I do want to upgrade it to an LS and a wonderfence one of these days.


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## jw2170 (Jan 24, 2008)

Please let us know when the vid is online, Duane.

The board had a discussion recently of finding members that may be able to make short videos showing techniques for the members...


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## Dmeadows (Jun 28, 2011)

jw2170 said:


> Please let us know when the vid is online, Duane.
> 
> The board had a discussion recently of finding members that may be able to make short videos showing techniques for the members...


James, I'll be happy to post a link. Just ask you to remember, although I am a fair to middlin' woodworker, I am a relative newbie to making videos:yes4:

I think I would enjoy doing a few here and there, though!


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## Jerry Bowen (Jun 25, 2011)

Dmeadows said:


> Jerry, I'll do the video, I think that will clear it up totally, but you're getting there. I went to a demo near Cleveland when I bought mine. They did it right back then. Watching that video did give me a better understanding of where you are coming from! Been wanting to play with making some youtube videos anyway.
> 
> Guys, I need to order a set or 2 of those plywood runners, also. I have rather chewed up mine. Setting a stop to limit the travel will stop that, I have found. If Incra has a design flaw, I think that is it. However I have use my Incra pro(not LS) for something like 15, 16 years or so without replacing them, so I won't complain about that too much! I have used mine on the router table, table saw, and my drill press. Still one of my favorite tools. I do want to upgrade it to an LS and a wonderfence one of these days.




Duane,
You sure do have my curiosity up, I am also glad that you see why I have been so insistant with what I have saying. 

You mentioned that you would like to make some youtube videos. I am familiar with video work, I made my living for several years in Alaska making Video Demos for guides and Bed & Breakfast businesses. I dropped off of keeping up with technology when HD came along. My Canon XL 1 is old technology now, but it is still a great camera, I never use it any more.

You are right about the skids on Incra's right angle fixure being a weak design, an extra set should be standard as I suspect that most new users of the tool make the mistake of letting the bit contact them.

I am surprised that Incra would do a technique at a show that is different than the video that they distribute as an instructional tool.

I am surprised that more members have not chimed into this thread in regard to their experience with the subject of this thread. 

I'm waiting to hear from you in regard to how you do the "lay flat on the table end cuts into the pin cuts".

Jerry


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## jw2170 (Jan 24, 2008)

Jerry, if you get to see any of the "Router Workshop" videos, you will see that Bob and Rick always mark a face side and bottom when required.

The face side is always down on the table and bottom is always against the fence.

This is to ensure alignment.

First you must make sure the pieces are all the same height.


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## Jerry Bowen (Jun 25, 2011)

jw2170 said:


> Jerry, if you get to see any of the "Router Workshop" videos, you will see that Bob and Rick always mark a face side and bottom when required.
> 
> The face side is always down on the table and bottom is always against the fence.
> 
> ...



James, by height, do you mean thickness. It would have to be thickness if the face is on the table. 

The only two ways to cut into the pin cuts with the face on the table and keeping the same side against the fence, as I see it would be to first re-set the fence and the template to deal with the error created by not being centered, or second cut them by feeding from the workpiece from the opposite side of the bit. 

I am waiting to see if Duane can show me another way to do it without rotating the workpiece as shown in Incra'a video demo. This rotation won't work if the center is off unless the workpieces are flipped horizonlly instead of end to end. By flipping them horizonally, the eddges that were against the fence for the first cuts would be away from the fence when cutting the pins on the opposite end of the workpieces.

I'm waiting to be proven, should say shown, why I am wrong.

Jerry


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## Jerry Bowen (Jun 25, 2011)

Really, all of this back and forth is a moot point if you just be certain that the centering issue is done right and is dead on center. Using the TS to adjust any error in that first center cut on the test piece is so easy to do and when the set up is centered, all is going to go well with no hassle in regard to an off center set up to start with. This is why Incra's demo shows how to do what they show as they must just assume that the centering is indeed set up correctly.

Jerry


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## jw2170 (Jan 24, 2008)

*My bad...*

Hi Jerry,

I just realised that my post may seem a bit confusing {a lot confusing....LOL}.

In your operation, the bottom has to ride against the fence, disregard the mention of the face side.

Do not get too pedantic with the centering, as has been pointed out, this is just for aesthetics. This is only to get the exact same size pin each end of the piece. ( a red flag at a bull )...As soon as I wrote this, I knew how you would re-act.....

On my Gifkins Jig, this is just done by eye. 

By height, I meant the final height of the box. Length x height x thickness.


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## Jerry Bowen (Jun 25, 2011)

jw2170 said:


> Hi Jerry,
> 
> I just realised that my post may seem a bit confusing {a lot confusing....LOL}.
> 
> ...



James,
I think that this thread has really pointed out, to me anyway, the vast differnces in how different people process information and see things differently. Also, it demonstrates how difficult it is sometimrs for a person to grasp the fact that another person sees the same issue in an entirely different way. By just writing our thoughts down on the formum we are limeited to a degree compared to face to face communications. 

An example in my case is that I am not good at following written instructions but can figure out how to assemble something better by just looking at it. That is not to say that I'm really good at it and when I get in a spot I do have to refer to the written instructions. On the other hand, my brother for example, never thinks of starting on something that has instructions without reading them and he just flys through them and ends up with the project done quick and correct. Of course it helps that he isn't blind like I am, but so many things go into the way we see things, be it life, world views, and certainly woodworking projects, and tools.

Thanks for your clearification on the matter at hand, you had me scratching my head. I still am so surprised that Incra would show a procedure in their video that is contrary to the way that other people do the same thing. I am still waiting for the explanation of how to accomplish the subject of this thread. 

I do agree with you of course that ehe centering of cuts is pretty much a matter of appearance, but the issue of cutting the pins so that the opposing part with the tails cut in it can fit in and create a 90 degree corner is certainly still puzzling to me if done in the way shown in the video if the centering is not perfect as the width of the pin on one side is not going to be the same as the pin on the opposite side of the set of cuts on the end on a board. If both ends have the same off set, rotating the workpiece as it lays flat on the router table as shown in the video cannot work. Of course this is where Doug says that they have done it wrong. So, I'm still anxiously waiting to be shown how to do it the right way. Until them I completely thoroughly without a clue. The only ways that I can see to get around the problem is to either flip the workpieces sideways instead of end for end, reset the fence and the template, or make the cuts from the opposite of the bit feeding left to right instead of right to left? Probab ly a good example of what I said above about people seeing things differently than others.

Jerry


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## MAFoElffen (Jun 8, 2012)

I think what that demo did not show was setting up the cuts for the adjoining sides..

For adjacent sides, I move the cross-slide to the bit... and but the edge of the stock against the forward edge of that bit. The i reset my indexscale. Or It ake the first 2 against the fence, aligned with the back of the bit... then without moving the fence, but moving the cross-slide to the bit, but the 2 adjacent sides aginst the forwar edge of the bit. All four pieces aligned to cut the joints. Clamp and cut.

If the normal first cut was lined up with the fence lined up to the back of the bit, Then above method will start where the first one left off. Perfect alignment with no gauges to fool with. 

No math//no centering//no mess. (K.I.S.S.) Seems to work fine for me. Try that and see how that does for you.


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## Jerry Bowen (Jun 25, 2011)

MAFoElffen said:


> I think what that demo did not show was setting up the cuts for the adjoining sides..
> 
> For adjacent sides, I move the cross-slide to the bit... and but the edge of the stock against the forward edge of that bit. The i reset my indexscale. Or It ake the first 2 against the fence, aligned with the back of the bit... then without moving the fence, but moving the cross-slide to the bit, but the 2 adjacent sides aginst the forwar edge of the bit. All four pieces aligned to cut the joints. Clamp and cut.
> 
> ...


Mike,
Once again, there is more than one way to skin q cat. I suspect that anybody that is interested in making dovetails on the Incra jig is commited to it enough to figure out which approach to centering is best for them to use.

My thread was started to suggest how to make things work when the set up was not centered and a procedure to deal with making the cuts and assembling the four parts so that the edges after assembly were still flush top and bottom. The procedure works just fine but is to complicated for me to explain without soliciting all of the advise that I got. I should have never entered that water obviously, I was not looking for advice as my system works just fine for me. I do appreciate the suggestions and attempt to help me. I wasn't looking for help, I was trying to give it and was not adept enough to explain it without getting everybody confused. 

I find that I can eye ball center close enough that the error is in thousandths and the error can be sliced off with the table saw without causing the workpiece to narrow for the the project. This option is only usable if the TS is accessable without moving the setting on the router fence.

Then there is the option of simply after making the test cut just part way into the test workpiece and then rotating it 180 degrees on the router table and try to feel the bit into the test cut from the opposite side of the bit, this will indicate the error. I can then make an adjustment and use the band saw to cut the end off of that test cut and repeat until the exact center is found. The trick her is have access to either a band sas or the table saw to cut the end off. Once the center is found and the template set the rest is easy as long you are very careful that the router fence is dead sqare with the router table top and that the workpieces are perfectly square and that they are tight against both the router table and the fence. Any error here will create problems that will cause the cuts to not work. Just basic common sense but easy to overlook when learning how to use the jig. I added this just for the sake of anybody using the jig for the first time. 

Jerry


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## Jerry Bowen (Jun 25, 2011)

+


MAFoElffen said:


> I am not sorry to say I agree with Duanne.
> 
> My Incra Ultra, which later became the Incra LS Super System... Works from one side and you stay with that side towards the fence. I'm sorry to say that what you (Jerry) described, seems off.
> 
> ...


Mike,
I just read your post again. Nobody has yet explained what you do to make the cuts into the first cuts that were made with the workpieces when their faces were 90 degrees with the router table. The second cuts that are made with the faces flat against the table are the one I'm talking about. 

One end of the workpiece will line up with the bit as you go from cut to cut, but the other end of that same workpiece will not line up if first cuts were made and not centered. 

That's not been answered as far as I know, and is what I was referring to originally in the thread. I said that by rotating the workpieces sideways instead of end over end after making the first set of cuts on the first ends of the two workpieces and then making the cut on the second end that this would allow the bit to line up with the cuts when the faces are flat on the table. The bit will line up properly on both ends of the work pieces this way. The pins will be wider on one side that the other at each end. A pin at one end will be wider that the corresponding pin at the opposite end. Cutting the tails reqire that you do the same thing and then when assembled, you put wide pins with narrow tails in order for the edges to all be flush. I know that I am repeating mhyself, but the only reason is due to a second solution that has not been forth come to my knowledge, maybe I missed it. I think that Duane said that he understood what I was saying and agreed with my thinking but that what I was doing was wrong and that what was shown in the video demo was wrong too. He was going to make a slide show to educate me on the matter. 

I'm still sticking to my guns unless shown otherwise, but only because I don't see another solution other than, as I said before, resetting the fence when making the cuts on the second end with face against the router table.

I have a feeling that I'm frustrating you, if so just say "Hey Jerry Cut It Out" and I'll drop it. I was only trying to help when I started the thread and somehow I must have just started some unwanted confusion.

Jerry


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## MAFoElffen (Jun 8, 2012)

I'm no doctor. But I thought I did explain that. So did Duane. But, as you said- Communications is actually the understanding of two people, not just one-sided.

I have more patience than most. More than you probably can imagine. Hard to read that in a post. No frustration here. Just still trying to get that two-sided understanding, that we haven't seemed to find yet.

What I said, have said in different ways... and will say again... (still being patience with you, LOL) to try to explain the same thing:
If you are cutting from one edge (the fence side) to the other edge... then flipping the piece over, keeping the same edge to the fence- Both sides that have pins cut into them mirror each other across that piece of work. The "pins" as you described, are across from each other. Each start from the same edge and work back.

If you offset the other pair of adjoining pieces to start your cut on those same respective sides, where the other adjacent sides' cuts end... then the opposite ends at the corners of those should also be the same offset.

As long as you've cut your workpeices the same width (as you have demonstrated prowess at) the edges of the "sides" should line up. If off by a little, they could be trimmed, planed or sanded to blend them in.

I'm somewhat of a perfectionist on some things... but even If I'm in a hurry and plan on just being off, so starting out by cutting oversized... even that is not a big deal. The medium is wood... not ferrous stock. It's easy to trim. It you want a perfect fit with perfectly lined edges, cut it over-sized, trim, then plane. You are not going to get... It's not going to get any better fit visually than that. And planning to do it that way will save you time and effort. If it's getting it as close as you can by doing it other ways... at some point, you have to say "It's close enough." <-- That close enough is subjective to you... on how close that match is.

There "are" other ways I do that, one as sort of described.. Centering the cut so the ends do end up even on each corner, but I am holding back on mentioning that method. I will mention that even with that, I might eyeball where that is going to place the center cut on the first pair, but the actual cutting of all pieces, I do from one end to the other, never changing the "orientation" from the fence.

Maybe it is me misunderstanding what you are trying to describe. Am I? Are we talking about the same thing, but from different translations of the same thing? I don't know, Duane and I sound like we are in the same perspective. I am still trying to completely understanding why you would want to change the orientation of your workpiece away from the fence. "WE" both know we must flip the sides to cut the other side for the joints... It's just that changing of orientation thing that doesn't make sense to me.

You are correct in that there are many ways to do the same thing. But some of what you said just doesn't make sense to me. There we are again without that both-sided misunderstanding between us. 

Could you please explain that reasoning to me? (Changing orientation.) Not in someone else's words... In yours. Or... wait one... maybe in this time in short simple words. Not in detail. Just basic.


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## Jerry Bowen (Jun 25, 2011)

MAFoElffen said:


> I'm no doctor. But I thought I did explain that. So did Duane. But, as you said- Communications is actually the understanding of two people, not just one-sided.
> 
> I have more patience than most. More than you probably can imagine. Hard to read that in a post. No frustration here. Just still trying to get that two-sided understanding, that we haven't seemed to find yet.
> 
> ...


Let me ask a simple question that might clear all of this up. Are you saying, if there is a slight error in the centering, just fix it with the TS or a planer before doing the jointing cuts. There would be no centering issue to deal with any longer. Everything will fit just fine. If the error is very slight, it won't matter, I can agree with all of that and I do. Actually that is what I do now.

Earier, when I made larger errors in my centering procedure is when I had to find procedure to deal with it. That procedure is what you aren't grasping, and is not evern worth discussing since errors large enough to cause a problem can simply be avoided. 

If we are on the same page here, let's agree and drop it as it is not worth trying to explain any further. I am unable to communicate it to you, if it were important, I would send photos to explain my point. Wish I never had stepped into this can of worms. I do appreciate your patience.

Jerry


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