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What alternatives are there to the Shopsmith 1/4" speed increaser router adapter

Posted: Tue Mar 20, 2012 1:27 pm
by tmoltzan
I want to router some small sliding dovetails using a 1/4" shank dovetail bit, but I don't have the 1/4" adapter for my speed increaser. Shopsmith does not currently have a supplier for their part. Would a 1/4" shank adapter/Collet Extension like this:

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/router_collet.html


work in the speed increaser? I am not too worried about a few inches of table height, but more safety and performance concerns. I have a handheld router, but no dedicated router table. I jigged something up last weekend for the hand held router, but it was pretty inefficient. I am jointing pieces of different thicknesses and don't think I can get the precise depth of cut I need If I use the shopsmith to route vertically, but I am open to any suggestions on a better way to do this.

Thanks,
-Terry

Posted: Tue Mar 20, 2012 2:21 pm
by JPG
tmoltzan wrote:I want to router some small sliding dovetails using a 1/4" shank dovetail bit, but I don't have the 1/4" adapter for my speed increaser. Shopsmith does not currently have a supplier for their part. Would a 1/4" shank adapter/Collet Extension like this:

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/router_collet.html


work in the speed increaser? I am not too worried about a few inches of table height, but more safety and performance concerns. I have a handheld router, but no dedicated router table. I jigged something up last weekend for the hand held router, but it was pretty inefficient. I am jointing pieces of different thicknesses and don't think I can get the precise depth of cut I need If I use the shopsmith to route vertically, but I am open to any suggestions on a better way to do this.

Thanks,
-Terry

Although I am sure it is balanced, I would be a bit leery.

I would be more inclined to make an adapter from a 1/4" id x 1/2" od bronze bushing. A hole for the set screw to contact the bit would need to be bored and deburred in the bushing. Steel bushing would be better.

P.S. Not having a speed increaser at hand, I assumed a set screw secures the bit. If a collet type method of securing the bit is used, the bushing would need to be split to allow 'squeexing'.

Posted: Tue Mar 20, 2012 2:39 pm
by reible
Hi,

I don't have a speed increaser so I can not be sure how well this would work but I know for sure they work with routers. You would used the 1/2 to 1/4 adapter bushing.

http://www.mlcswoodworking.com/ordersta ... rings.html

The items you were looking at are for extending the "depth" and are not so much for changing the bit size but might work better if the speed increaser is a none standard chuck to start with.

Many moons ago there were plans floating around for 1/2" to 1/4" adapter for the shopsmith 1/2" router chuck.... I had one machined for me as an alternative, not sure where I have it but it was relatively simple design.

Ed

Posted: Tue Mar 20, 2012 3:09 pm
by JPG
reible wrote:Hi,

I don't have a speed increaser so I can not be sure how well this would work but I know for sure they work with routers. You would used the 1/2 to 1/4 adapter bushing.

http://www.mlcswoodworking.com/orderstatus/html/smarthtml/pages/bushing_ball_bearings.html

The items you were looking at are for extending the "depth" and are not so much for changing the bit size but might work better if the speed increaser is a none standard chuck to start with.

Many moons ago there were plans floating around for 1/2" to 1/4" adapter for the shopsmith 1/2" router chuck.... I had one machined for me as an alternative, not sure where I have it but it was relatively simple design.

Ed
For $4 NOT making one is a no brainer!!!:)

Posted: Tue Mar 20, 2012 3:25 pm
by tmoltzan
Excuse me for my ignorance, but I assume that the bushings that were linked to were only for use inside a collet since it was split and did not have a set screw. Is that correct?

The speed increaser does use a set screw to hold the 1/2" shank sized router bits. It is not a collet type chuck. I will search the forums for the adapeter plans reible mentioned.

Thanks for the replies.

Posted: Tue Mar 20, 2012 5:52 pm
by SDSSmith
reible wrote:Hi,

I don't have a speed increaser so I can not be sure how well this would work but I know for sure they work with routers. You would used the 1/2 to 1/4 adapter bushing.

http://www.mlcswoodworking.com/orderstatus/html/smarthtml/pages/bushing_ball_bearings.html

The items you were looking at are for extending the "depth" and are not so much for changing the bit size but might work better if the speed increaser is a none standard chuck to start with.

Many moons ago there were plans floating around for 1/2" to 1/4" adapter for the shopsmith 1/2" router chuck.... I had one machined for me as an alternative, not sure where I have it but it was relatively simple design.

Ed
The speed increaser uses two set screw diametrically opposed to each other. So it does not tighten like a regular collet. Care would need to be taken with the 1/2 to 1/4 collet reducer to ensure the set screws are not landing on the slots and precluding the adapter from tightening.

The router chuck uses a single set screw and so it would be interesting to see the plans Ed mentioned.

Posted: Tue Mar 20, 2012 6:16 pm
by JPG
SDSSmith wrote:The speed increaser uses two set screw diametrically opposed to each other. So it does not tighten like a regular collet. Care would need to be taken with the 1/2 to 1/4 collet reducer to ensure the set screws are not landing on the slots and precluding the adapter from tightening.

The router chuck uses a single set screw and so it would be interesting to see the plans Ed mentioned.
So a set screw hole in a bushing would need to be a hole all the way through. Using half dog(full dog or pins?) set screws would reduce the hole diameter to less than 5/16". A bushing might still work.

I am assuming the opposed setscrews are 5/16-18. ??

Posted: Wed Mar 21, 2012 1:13 am
by tmoltzan
I just got a chance to reread the posts and a solid steel bushing seems like it should work and be easy enough to find. I am going to call around some industrial supply places and see what I can find.

try Whiteside

Posted: Wed Mar 21, 2012 1:33 am
by forrestb
I had the same issue with SS 'unobtainium' reducer. Someone suggested Whiteside 6400 1/2 to 1/4 reducer and it has worked for me.

Posted: Wed Mar 21, 2012 1:45 am
by tmoltzan
forrestb wrote:I had the same issue with SS 'unobtainium' reducer. Someone suggested Whiteside 6400 1/2 to 1/4 reducer and it has worked for me.
Thanks for the insight. Do you have to be careful of the orientation in the speed increaser to ensure a good grip when using the Whiteside reducer as someone else has suggested? That part looks to be functionally the same as the MLCS bushings linked to previously. Is there a reason why one would be better than the other?

Thanks for all of the responses.