Building A Set True ER 40 Collet Chuck

M

Mark_f

Registered
Registered
Joined
Jan 16, 2020
Messages
5
I saw a thread on here (can't find it now) about making a set true ER 40 Collet chuck. I got to thinking, that is exactly what I need to solve a problem. I made a ER 40 chuck a while back for my lathe and it holds .0002" TIR on my lathe, but when I move it to my dividing head or rotary table, I get .002 to .003" TIR. This is not acceptable, especially when cutting a gear. Soooo ... I decided to make a set true collet chuck that can be "zeroed" when moved to another machine or fixture. This is my version of the Set True ER 40 Collet chuck.
I started with a 4" diameter X 2 1/2" long piece of CRS 1018. This will make the collet chuck. A 5"diameter X 2 1/2" long piece of CRS 1018 will make the back plate.
20170907_132658_HDR.jpg
I roughed the chuck to around .040" over on all dimensions. Once this is done, I will finish machining to size.

20170908_165832_HDR.jpg
This is the chuck with all surfaces finished to size and polished. I will next thread the end for the nut and cut the 8 degree taper. All the machining is done in a single setup so everything is perfectly concentric. I will post the prints as soon as I get finished drawing them.

There will be more but I only get to work a little a few times a week right now. Many of you know I am facing a severe heath crisis right now, but I am trying to finish some projects before anything happens to interrupt my favorite activity.
 
Today I am close to finishing this part of the chuck.
20170909_121151_HDR.jpg
I threaded the end. It is a 1.5mm pitch. I also cut the 8 degree taper. The threads and taper came out as close to perfect as I could ever expect.

I used my transposing gears I made to cut the metric threads.
20170909_105608_HDR.jpg
The transposing gear is made from regular change gears for the SB 9 lathe. I bought two spare gears off eBay for about $20. This will cut all the common metric threads. It is a 56 tooth and a 44 tooth gear bolted together.
20170909_105603_HDR.jpg
This is the transposing gear mounted on the lathe.

20170909_121125_HDR.jpg
I put a 5/8 end mill in the collet chuck and checked the runout. There was .0001" measurable TIR. I am happy with that.

Next will be to drill the 4 bolt holes in the flange. Then turn it around and machine the back of the flange.
 
Mark, you are an inspiration to hobby machinists around the world. Many of us will never be able to do what you do, but it sure is fun to watch!

Bill
 
Withe the collet chuck finished, I need a way to face the back of the chuck so that it is exactly perpendicular to the collet. To accomplish this, I center drilled a piece of drill rod and machined .003" off the diameter to ensure it is perfectly true. Then put the collet chuck on the drill rod and faced the back with a .001" finish cut.
20170909_154937_HDR.jpg
I indicated the front face of the chuck to be sure it was true before machining the rear face. By my calculations, the rear face is within .0002" of being flat with the face. This is important for accuracy.
 
Mark awesome job as usual! You certainly are an inspiration to me and I'm sure others here feel the same way.
 
I too admire Marks wonderful builds. He really puts all he has into each one. Not just make it a usable tool but a beautiful tool to own. I'm still praying for our hurting machinist here. Even tho we've never met I call him friend and mentor. God bless you buddy
 
Oh no , if I make one how in the world am I gonna cut metric threads on my old logan . Something else to do first yuk sure is costing me .
 
You must log in or register to reply here.
Back
Top