# Help with bit height limitation bosch 1617 / RA 1181 table



## Old Bull (Aug 28, 2020)

I am very new to routing. I installed an RA 1181 aluminum top in my Delta 36-725T2 saw. I used the fixed base from my Bosch 1617 as a lift which has an above table adjustment. It has to be me not knowing something. I have so far;

1. Removed the original black base.

2. Installed 1/2" shank bits.

3. Moved the major adjustment ( 3 settings) to the top.

4. The router is physically striking the bottom of the base and can not go higher.

5. The microadjust is also as high as the base will allow. The angled portion of the router is striking the bottom of the base and will go no further.

6. Mount is flush with bottom of plate.

Have I found a reason why the fixed base is not a good lift ??? The bottom of a slot bit is only appx 1/8" above table. I set the bit in and raise it appx 1/16th inch.

Thanks any help.

.


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## Old Bull (Aug 28, 2020)

It has to be my ignorance as the collet is showing at the surface.


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## Stick486 (Jan 4, 2013)

How deep are you setting the bit into the collet???..


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## Old Bull (Aug 28, 2020)

I am afraid this misunderstanding is entirely my lack of experience. The bits are set in and then raised 1/16th off the bottom.
In order to rectify my ignorance let me ask this in a different way.

How do I adjust the height of the cut. If I want a slot 1/2" up from the bottom of a jewelry box how do I adjust the cutters height?? use a different bit ??


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## Stick486 (Jan 4, 2013)

1st... looks like you are setting the bit way too deep...

adjust for depth of cut using the router...
use the coarse and or fine to adjust for depth of cut...
look to your owners manual.. start reading at page 12....


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## Nickp (Dec 4, 2012)

Donny...based on your pictures everything looks right.

Your collet nut is extended above the table a bit, that would be right for the 1617 in the 1181 (mine is about the same)...makes me wonder which slot bit you're using ?

Is it adjustable like the Freud...? What brand bit are you using...?


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## Old Bull (Aug 28, 2020)

I am using MLCS. I think my failing may be that I am assuming the bit has to go to the bottom. 

I am starting to get the idea the bit does not have to go to the bottom. Would it be correct to say the shank can be raised up from the collet as high as I like (safely) and that is part of the height adjustment. The manual says that at least 5/8" of shaft must be gripped by collet, that may be the answer and my failing.

I was just basing bit installation by all the videos I have seen that said the bit always goes to the bottom then raise 1/16th inch. The bit you see in the bottom image is as high as I can get it which is to low.


thanks for the help, I sort of feel like a fish out of water here.


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## Cherryville Chuck (Sep 28, 2010)

There is no advantage in having the bit sticking past the bottom of the collet but you do want to use 100% of the collet to hold the bits. If you take the collet out of the router and stick the bit you want to use it and set it so that the end of the shank is flush with the bottom of the collet and then mark where it comes out of the top of the collet with a fine line magic marker. Now you know how much bit to insert.

Someone came up with a simple jig for setting bits at optimum depth. They just took a block of wood and drilled a 1/2" and 1/4" holes in it that were the same depth as the length as the collet and they would start an o-ring onto the bit and shove the shank in the hole. That would push the o-ring up the shank to where it should sit in the collet. If you don't have any o-rings you could still use the jig and just mark the right spot with a marker.


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## Nickp (Dec 4, 2012)

Old Bull said:


> I am using MLCS. I think my failing may be that I am assuming the bit has to go to the bottom.
> 
> I am starting to get the idea the bit does not have to go to the bottom. Would it be correct to say the shank can be raised up from the collet as high as I like (safely) and that is part of the height adjustment. The manual says that at least 5/8" of shaft must be gripped by collet, that may be the answer and my failing.
> 
> ...



If you're using the MLCS 7668, you will notice the shaft is thinner right under the cutter. The bit only needs to go in as far as the bottom of the collet...or 1/8" or so above the collet at the point where the bit tapers up to the cutter...

Can you post a picture of the bit only just to make sure we're talking the same bit...?


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## Old Bull (Aug 28, 2020)

Thanks for being patient and helping as there is no doubt the problem is me. The bit is in fact a 7668 1/2" shank, 3/8 deep, 1/4 tall.

The bit ( as you both stated correctly) needed to go down to the where the 1/2" shank ended (the grey recessed area starts). That would have raised it up. I was going all the way down and then up appx 1/16th. 

What if I wanted it higher, say 3/4 of an inch, would I need a different bit or can I raise the 1/2" shank up out of the collar a little safely? I think I don't see the limitations to some bits.

What if you needed a slot 2" inches high?

And in reference to "start reading at page 12", I am thinking I need to start reading at page 1 ! ! !

Again, thanks for all the help.


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## Nickp (Dec 4, 2012)

Old Bull said:


> Thanks for being patient and helping as there is no doubt the problem is me. The bit is in fact a 7668 1/2" shank, 3/8 deep, 1/4 tall.
> 
> The bit ( as you stated correctly) needed to go down to the where the 1/2" shank ended (the grey recessed area starts). That would have raised it up. I was going all the way down and then up appx 1/16th. *Correct...*
> 
> ...


...


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## Cherryville Chuck (Sep 28, 2010)

In a pinch I think you could raise the bit up to where only 85-90% of the collet is being used to hold the bit without damaging the collet. I wouldn't make a habit of it and I wouldn't do it with a large diameter bit. You need all the holding power you can get for those. Generally you could make a mark at the 1" mark and that would be the right amount to stick in the collet. I do have an older DW router that has a collet that is only a hair over 3/4" long. I don't know of any over an inch.

If you need a slot that is higher than the bit can reach you'll have to look at alternate methods such as on a table saw or by using a straight bit instead.


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## Old Bull (Aug 28, 2020)

Thank you all for your patience and help. There are different ways to do things and I can not see them at this point.

Chuck thank you. I haven't yet begun to learn enough to use alternatives. I had that one way and that one bit stuck in my brain and could not in my mind turn the board a different direction and cut it a different way. 

Thanks again.

Donny


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## Cherryville Chuck (Sep 28, 2010)

We all put the blinders on at times both unwillingly and unwittingly.


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## sreilly (May 22, 2018)

Somehow I think the meat of this question was missed entirely or I'm up too early with too little coffee. The bit being inserted properly is indeed important but as for height adjustment with the 1617 no one has mentioned that the motor must manually be raised and lowered using the base lock and manually moving the motor. The minor adjustment can be made otherwise as explained. Or was this all about a very minor adjustment. Not having this table I can't say for sure but I would hope the manual would cover this topic thoroughly. But then again I may have missed the entire point in the 1st place.


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## Old Bull (Aug 28, 2020)

Yes @sreilly, I had already used the 3 position height to it's max, that is why the collet actually stuck above the table. I think the two things here are I followed generic instructions I had seen and read about to bottom out the bit then raise it up 1/16 to 1/8. I was inexperienced with bits that have shoulders, so my bit was in to far. The other problem being I just didn't expect the height limitation of routing and routing tables.

Thanks for the reply and help.

Donny


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## DaninVan (Jan 1, 2012)

The point that Donny is really getting at is 'are all slot cutter shafts the same length?' ie are there brands with LONGER shafts?
The one Donny posted the pic of seems rather stubby, or am i wrong?
Here's one from Lee valley...no detail of total shaft length given...
https://www.leevalley.com/en-ca/sho...its/102526-shafts-for-3-wing-slotting-cutters

As has already been mentioned (and picture posted) his collett nut is visible at the surface of the router plate; you can't go higher than that. The only other option is to either raise the bit in the collett (already discussed) _or use a longer shaft_.


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## Cherryville Chuck (Sep 28, 2010)

Donny CMT makes a bit extender https://www.amazon.com/CMT-796-001-00-Router-Extension-Collets/dp/B000P4NQCK and it isn't all that expensive but I recommend caution using it. A few members have said they bought and used one and it worked okay. I never have as I think they could be hard on the router. The longer a bit is essentially you also have a longer lever that is putting more pressure on the bottom bearing. I have a couple of really long bits but I have to be careful with depth of cut and feed rate with them. One is a bowl carving bit from Onsrud that is about 4 1/2" long and the other is a Bosch 1/2" straight bit with a 3 inch cut. I've used it once to deepen some mortises for a door I was building. That bit sticks out the bottom even with the router raised all the way up so I had to have the mortises half done before I could use it. I just thought I would add this to the discussion to point out one more option in case a router is going to be the best option you have you could get a little more reach out of it.


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## Cherryville Chuck (Sep 28, 2010)

DaninVan said:


> The point that Donny is really getting at is 'are all slot cutter shafts the same length?' ie are there brands with LONGER shafts?
> The one Donny posted the pic of seems rather stubby, or am i wrong?
> Here's one from Lee valley...no detail of total shaft length given...
> https://www.leevalley.com/en-ca/sho...its/102526-shafts-for-3-wing-slotting-cutters
> ...


Some slot cutters are longer. I have a stackable one that came with different spacers and shims and 4 different sized cutters. You can put two cutters on it with a spacer between and cut the tongues for tongue and groove joints. It's probably twice as long as that MCLS one. You see some of the sets of bits on Amazon and ebay that are basically no-name brands that have very short shanks too. You need to put almost all of it in the collet.


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## DesertRatTom (Jul 3, 2012)

I long ago started dropping a half inch grommet into the bottom of the collet. Not a O ring, a grommet which are about 1/8th inch thick. I no longer use my 1617s in the table (Triton), but I remember that in the fixed base, I had to twist the motor a bit to get it to slide all the way up. Never used the key (lift), but I think it only made a limited amount of raising or lowering, and that you had to do a coarse adjustment with the clamping motor mount and use the key for fine tuning that.


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## Old Bull (Aug 28, 2020)

"""Donny CMT makes a bit extender https://www.amazon.com/CMT-796-001-0.../dp/B000P4NQCK and it isn't all that expensive but I recommend caution using it"""

Chuck the first thing that popped into my mind when I read that was me at the router table and it starting to shake

@DaninVan, yes, and I wasn't expecting the one I had to be 1/8th" from the table top, but thanks to others I now know this particular one has a shoulder, but it is still not that tall.
.
.
.


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## DaninVan (Jan 1, 2012)

Donny; for some reason the sellers don't seem to think *total shaft length* is a piece of info that potential customers need to know...
It's a mystery to me.


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## DaninVan (Jan 1, 2012)

DaninVan said:


> Donny; for some reason the sellers don't seem to think *total shaft length* is a piece of info that potential customers need to know...
> It's a mystery to me.


If I'm reading this right, DIMAR's is a total length of 3 1/4"
http://dimar-canada.com/pdf/SlottingCutters2.pdf


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## Steve Pack (Jan 1, 2014)

I have a Bosch 1617 mounted in a Ts router table. Sometimes I find the will no high enough or low enough so I remove router and adjust cutter accordingly. I bottom bit and then raise it 1-/6 to 1/8 inch. the I ca get eongh travel using Vernier, MLCS bits are not that tall.


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## DaninVan (Jan 1, 2012)

Further to Steve's comment, I scanned my LV cutter shaft. From the underside of the cutter to the base of the shaft is 1.5". Charles mentioned marking off 1"' on the shaft; this would leave 1/2" of ht. from the table to the underside of the cutter. 
Incidentally, the cutter bore is .30" ...is this a universal standard?


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## Herb Stoops (Aug 28, 2012)

Old Bull said:


> It has to be my ignorance as the collet is showing at the surface.


I just checked mine and with the plastic base plate on, the collet protrudes 3/16" beyond.
So without the base plate it should be around 5/16-1/4" beyond the aluminum. So the table thickness is the only other factor. How thick is the table?

Herb

You guys already answered it, I didn't see the extra pages before I posted.


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## DaninVan (Jan 1, 2012)

Herb; Donny's picture shows the collet nut clearly visible at the top surface of the table, ie he hasn't run out of vertical adjustment ht., just shaft length.


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## Cherryville Chuck (Sep 28, 2010)

DaninVan said:


> Further to Steve's comment, I scanned my LV cutter shaft. From the underside of the cutter to the base of the shaft is 1.5". Charles mentioned marking off 1"' on the shaft; this would leave 1/2" of ht. from the table to the underside of the cutter.
> Incidentally, the cutter bore is .30" ...is this a universal standard?


I think 5/16" is the standard and you are very close with that measurement. I bought a bunch of PC brand arbors and cutters cheap on ebay a couple of years ago if you need a replacement or backup.


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## DaninVan (Jan 1, 2012)

Good to know, Charles. Donny could simply pick up a new shaft assembly from Lee Valley,and continue to usehis existing cutters, assuming that they do indeed have the 5/16" (.3125") bore size
https://www.leevalley.com/en-ca/sho...its/102526-shafts-for-3-wing-slotting-cutters


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## Old Bull (Aug 28, 2020)

My plate is 3/8th's


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## Herb Stoops (Aug 28, 2012)

Old Bull said:


> My plate is 3/8th's


So when you have the router topped out ,the nut should be about flush with the top of the table, like it should be.
Herb


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