# Trouble Pattern Routing - Help Appreciated



## marc82much (May 8, 2011)

I want to fabricate some parts for a chair. I made a pattern out of 1/2" MDF. That is the first picture.

I am using a Whiteside RFT5125 Spiral Flush Trim Solid Carbide bit, with two bearings. Two flute up cut 1/2" shank. This is the Whiteside choice for pattern routing on a router table, which is what I am doing. Second Picture.

I am using 3/4" white oak. The first pass went fine, see Picture three.

Then came the problem. See Picture four. On another portion of the pattern, the bit immediately grabbed the grain and tried to rip the workpiece out of my hand. I spared you the picture of the blood. It does not matter which direction I rout, because I don't even get to that. I put the pattern and workpiece flat on the table, then push it real slow until the bit engages the wood, and it grabs and tries to throw it. I don't have the workpiece against the bit to try routing in either direction.

Any thoughts?


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## Quillman (Aug 16, 2010)

Double sided tape is your clamp, right?


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## marc82much (May 8, 2011)

Quillman said:


> Double sided tape is your clamp, right?


Yes.


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## JOAT (Apr 9, 2010)

How deep was the cut? You need to rough cut as close to your cut/rout line as you reasonably can, I would say under 1/8" with oak, and proceed slowly. Sounds to me like you might have been trying to take to much at a time. Need more details.


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## MAFoElffen (Jun 8, 2012)

I can see that is in end grain... Which as you hinted at (trying different feed directions) one direction would be easier than another... But my question is: 
What did the piece look like before you started?

I guess I should explain that question... 
- I noticed that is one of two small braces, to support the arms of an Adirondack styled outdoor chair 
- You didn't mention what kind of wood you were making that out of, but from the pictures, it looks like a well seasoned hardwood, such as oak... and you were doing a pattern that would involve lots of end grain. Is that close to what that was?
- By picture one, and from the tear out, I'm gauging that piece as being fairly smallish in size.
- You didn't mention what sized bearings you were using before you went to a flush cut or any of the prep you did before going to your flush cut.
- You mentioned "blood"... Which previous to reading that sentence, I already had worried about that before reading that...

Here's what I would have done with that piece and see if it opens some creative ideas. I probably have 2 tooling methods I would have approached that, both based on safety and depth of cut on end grain. Both have similar prep before the actual flush cut.

On prep, I'm assuming with your cut list that these 2 pieces started out as 2 pieces from one square, each piece bisecting that square to make the two braces. So you didn't have to route out a whole lot to start with. After double taping to the pattern, you could take a bandsaw, scrollsaw, jig saw, hand coping saw (etc.) to trim the pieces down so that you don't have to route as much at a time to get it down to finished size.

Next is how it is routed. It's a small piece. This is where the safety and control part of it falls together or apart. Instead of trying to hold onto a small piece on a router table while routing (without a fence). 
*Hand router:*
I probably would have either screwed a lug to the off back side of the pattern to mount it into a vase or mounted the pattern to a larger piece to clamp it down to a table, then hand routed it. If you start routing it with a larger bearing, then you can step the depth of cut into a finished flush cut. 
*Router Table:*
Mount the pattern onto a larger backing piece so it is controllable and so your fingers/hands are away from the bit. Use the same bearings to step into your finish cut. 

Either method would give you move control, with your hands and fingers away from the bit.

Using the second method, one problem is that if you use too large a squarish piece as the backer, you are doing the cut blind. That could be done that way by feel and checking it often. But maybe better than doing it blind, the larger backer could be rectangular, with the cut side of the pattern moved over it's edge, so you can actually see that that edge as it's being cut... Definitely more work that way (reattaching the pattern to the holding piece...)

That is just what first came to mind from reading your post and seeing the pic's. (Trying to hold onto a small piece of wood, trying to route it's endgrain...)

Part II:
The next part is that if you had followed a cut-list and cut the square "squared" that both those two braces would be cut from... that the two edges were square and the those two edges were 90* from each other... then you would have just needed to line the pattern to those edges and had one curved edge to route. Meaning, that end grain edge that blew out, could have been cut out with a saw and not needed to be routed to get that pattern... 

It's an outdoor furnishing project, not a roccoco revival parlor chair. The clearances do not need to be exact. Even if you did, after a short time, weathering will affect that.


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## boogalee (Nov 24, 2010)

Marc

What tools do you have?

I would have cut it on a band saw then use a spindle sander to finish the piece.

Al


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## marc82much (May 8, 2011)

boogalee said:


> Marc
> 
> What tools do you have?
> 
> ...


I could do this (I have a spindle sander / belt sander) but I am going to make several and I thought pattern making was the right way to do it. I thought that is exactly what this bit is designed to do.


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## Mike (Nov 22, 2004)

Marc, are you placing your wood against a safety starting pin and pivoting it onto the bit?


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## Semipro (Mar 22, 2013)

My opinion I think it is small piece, he lost control, try mounting a handle to the pattern so that you can get a better hold. If you are not comfortable with what you doing find a better way. You probably back the pressure off and it kick back


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## JOAT (Apr 9, 2010)

boogalee said:


> I would have cut it on a band saw then use a spindle sander to finish the piece.


I hadn't realized just how small that piece is. I think you've got probably the best idea for doing it yet - except I don't have a spindle sander.


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## jw2170 (Jan 24, 2008)

I agree with Mike. A starter pin is required.

Can you flip it so the grain runs downhill?


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## Shortslvs (Jan 13, 2013)

Funny but my thought was like many others. As I read description it was missing "starting pin".


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## dmja49 (Aug 15, 2013)

Those sides should already be flush,use a bandsaw or jigsaw to cut the pattern for the curved portion but leave 1/8 inch extra to rout,it could be the bit,try another bit;a straight one.


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## malb (Sep 15, 2008)

I have looked at the pics provided. My take on the situation is that you are making small(ish) corner brackets with the grain on the diagonal. The corner is a right angle, which suggests that you could cut the two straight sides with a table saw or similar with a decent crosscut blade and mitre gauge or jig. In that case you should be able to avoid having to route those two sides. Because both are secured to elements of the chair, the surfaces are not visible and an absolutely smooth surface is not essential.

My read on the issue is that you managed to trim the first edge safely because the bit was cutting down grain. Move to the second edge and you had problems because the bit is cutting against the grain, digging into and raising the grain to cause the breakout in the picture and difficulty in controlling the cut. You will probably experience a similar issue on the third (curved) side because part of the cut will be down grain, and part will be up grain, and the bit will break out chunks of material on the up grain portion.

One solution to the problem is to use a bit with two bearings, one on the shank and one on the tip. Then you can trim the first (down grain) side and the down grain part of the third side with the template on top of the part, and flip the job and template and raise the bit (and guard it) and complete the second side and third side in 'template following' mode, (pattern between table and work), which cuts these two sections down grain.

Using a starting pin if practical will help, but it may not be practical if the pin has to be 1 inch or more from the bit and the edges are only a couple of inches long as there is no real mechanical advantage available.

I would also investigate methods for allowing you to make the cuts with the controlling hand(s) kept clear of the bit. One approach would be to use an extended pattern with remote grips or handles, and blocking to locate and secure the job. With this type of setup, it is easy to insert the work, cut the down grain elements, release the job and flip it in the template, then down grain route the elements that would be upgrain for the initial cuts. 

For the part you are trying to make, you could have a 3 station template about 15 to 18 inches long with a setup for each of the edges you need to finish and hand grips at either end, or if you were able to do the right angle edges on a table saw, a single station template about 10 -12 inches long to cut the curved edge. Either way you would use a pattern routing bit with the bearing on the shank, rather than a flush trim bit with a tip bearing.


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## Bushwhacker (Jun 16, 2009)

Could it be that you are attempting to take out too much stock on the first pass?


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## Lemuzz (Jul 25, 2008)

As Mike said above

"Hand router:
I probably would have either screwed a lug to the off back side of the pattern to mount it into a vase or mounted the pattern to a larger piece to clamp it down to a table, then hand routed it. If you start routing it with a larger bearing, then you can step the depth of cut into a finished flush cut.
Router Table:
Mount the pattern onto a larger backing piece so it is controllable and so your fingers/hands are away from the bit. Use the same bearings to step into your finish cut."



I am inclined to agree Two hands on the router is much safer on fingers. Plus the weight of the router helps as well. Fix your pattern to the wood and firmly clamp to a rigid bench and you should have no problem hand routing the pieces. Also sharp cutters, light cuts and enough power in your router to make the cut without the router stalling. I prefer 1/2" shanks if I can get them in the bit profile I require as there is no flex in the shaft and the risk of a broken shaft and the cutter flying about is eliminated


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## Woodtek (Feb 5, 2012)

Marc,

Rather late than never.
In Namibia I work with hardwoods like teak and rosewood. Since your pattern have a right angle, I would cut all parts with that angle in mind. Trace your template from that angle and cut the irregular shape with (preferably) a band saw to about 1/16" from the line.

Now take it to the router table with still very light passes. 
This should prevent the Boo-boo and the blood.

I use a straight bit fitted with 2 bearings, one top and one bottom. Got it from MLCS. That way you don't have to take the template off, just flip the piece and keep going with the grain.

Regards
Alwyn


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## st8yd (May 10, 2011)

It does appear that you have it cut to within a 1/16" so that probably isn't the problem. However as mentioned above cutting within an 1/8", sometimes is still to much for hardwoods, I try to cut to a 1/16", easier on the router and less chance for burns and tear outs.

Also you can hold a larger board against it (push stick principle) so that it has a solid support and you have more to hold on to.


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## sunrunner (Apr 17, 2014)

*Template Trouble*

When working with different sizes of templates I don't limit myself to any one set of router or bits. Generally I have a tiny dremel router table for fine detail work, a trim router for work that is medium in nature, and a full size 3 1/4 router for more challenging pieces. I find it is much safer this way matching the size of router and bit to the workload. 

Although I realize not everyone has a set of different routers, but since you mentioned blood was spilled I learned a long time ago using the right tool for the right job saves your fingers. 

There was a time in the past where I had no choice but to match the job to the tool I had whether it made sense or not but as I got more experienced you just learn that saftey first is more important.

I teach several router courses and have emphasized this point in all my classes. I used to be a powerhaulic on the tools but these days I just find the right tools with the right bits give much superior results then trying to make one machine fit all whether it is a Dremel router or an Oversized 10 horse Pin Router. Horsepower does not always give you the best results. It's really using the right tool and how well you can handle it.

If you can't follow this mantra at this time then my best suggestion is to limit the depth of cuts and build jigs that get your hand away from that router bit to avoid the tear out. Also make sure the problem isn't dull bits. I've bought new from reputable manufacturers and found what they consider sharp and what I consider sharp are not the same. There are plenty of articles on the web about how to do this although I would suggest buying el cheapo bits at first for practice till you get the hang of it. Don't try learning how to sharpen on your better bits for you may dull them worse. Sharpening in itself may solve your tearout problems.

Victor.


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## dmja49 (Aug 15, 2013)

Correction: try a pattern bit with the bearing on top(after shank,before blade)


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## JOAT (Apr 9, 2010)

I make templates/masters for some pretty small stuff, and rout them with no problems. But for something like those braces, I would cut them out, then sand to the finished size. For me that would be easier, faster, and I think safer, than routing them. But, your fingers, not mine.


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## dmja49 (Aug 15, 2013)

You have tried different grain directions right? Is it the straight portion that is giving you the problem? What kink of wood is it?


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