5C Collet Slide Mount for Lathe Faceplate

Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.

Moderators: Harold_V, websterz, GlennW

User avatar
Richard_W
Posts: 1933
Joined: Fri Jan 10, 2003 1:00 am
Location: Molalla, Oregon

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by Richard_W » Fri Sep 21, 2012 10:56 am

seal killer wrote:Richard and All--

Richard, aaah. Yes. I agree. That is why I am contemplating those three adjustment screws shown in red, above. I don't have enough experience to know if they might work, though.

--Bill
I don't think your 3 adjusting screws will work well. For them to work well you need to be as close to 120 between the screws as you can get. Then you could only get to with in .0005. I would try 4 screws at 90 degrees so it would move much the same as a 4 jaw chuck. You may have to make some additions to your fixture to do this?

Richard W.

User avatar
Richard_W
Posts: 1933
Joined: Fri Jan 10, 2003 1:00 am
Location: Molalla, Oregon

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by Richard_W » Fri Sep 21, 2012 11:07 am

Another thing I noticed since my last reply. You made the fixture from 1018 CR which has lots of stress in it. Then only milled the features you wanted in it. This would cause the material to bow and when you tighten it down, you are trying to pull it flat. I think you should have taken a light cut with a fly cutter and machined the fixture all over to remove most, if not all the stress before you cut the features. With your adjusting screws you should be able to get it to work yet.

Richard W.

pete
Posts: 1856
Joined: Tue Feb 10, 2009 6:04 am

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by pete » Fri Sep 21, 2012 12:36 pm

Hi Bill,
I'd most certainly agree that your run out is a stack up of various minor inaccuracies. In fact I'm real impressed with what your getting for results so far considering nothing was stress relieved, or ground. Nice 5c fixture also, Eagle Rock make some nice equipment. I have a couple of their knurling tools. But that is going to be a lot of off center weight to be rotating, Your going to need some fairly hefty blocks to counter balance it. And quite possibly your own shop built separate D-series spindle nose for proper static balancing off the lathe.

AFAIK, It's an older English designed tool that isn't all that well known in North America, You might try Googling "Keats Angle Plate", it can be used for a lot of the same work your fixture can, but possibly digging through the Keats info would give you a few more design ideas? The Keats is pretty well a 90 degree angle plate with a male and female work holding V in it, and it can be bolted into position with the correct offset on the faceplate. Your design with it being screw adjustable would be far easier and quicker to use though.

Most crankshaft work like your doing is done in home shops usually by clamping bored and reamed square or rectangular end blocks to a roughed in embryo crank, those end blocks are usually center drilled very accurately for the exact off set required, and all work is done between centers. Multiple throw cranks of very high precision can be done this way. Rough milling or even hack sawing off the majority of the waste material first will help a lot with the torque needed to hold the crank in the correct orientation without it slipping. The outer ends of the crank can be machined oversize in diameter and length to start, and then final machined to size as a last operation before parting to length. Probably there's a bunch of this you already know though.

I'm a bit under the weather right now, or otherwise I'd scan some material for you.

Pete

User avatar
GlennW
Posts: 6851
Joined: Sun Apr 15, 2007 9:23 am
Location: Florida

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by GlennW » Fri Sep 21, 2012 1:28 pm

Don't forget that the collet itself can exhibit some error on top of everything else.

I have seen cheap 5C collets with as much as .0015" total indicated runout.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

Jose Rivera
Posts: 3803
Joined: Wed Feb 21, 2007 9:21 pm
Location: Vallejo California

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by Jose Rivera » Fri Sep 21, 2012 9:29 pm

Nice work Bill ... I see that you have been advancing very well.
As an observation ... Seems to me that this devise may not be perpendicular enough to the face-plate that may cause a little wobble.
Also balance could be a problem at high spindle speeds. Since collets can only hold a sixteenth over one inch, means that high-speed turning may be necessary for a descent finish.

I would like to hear about performance if you don't mind.

Jose
There are no problems, only solutions.
--------------
Retired journeyman machinist and 3D CAD mechanical designer - hobbyist - grandpa

User avatar
seal killer
Posts: 4515
Joined: Sat Aug 18, 2007 10:58 pm
Location: The Land Of Oz (Ahhh, Kansas!)

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by seal killer » Fri Sep 21, 2012 10:23 pm

Jose and Richard and Glenn and ctwo and Pete and Inspector and Ron and Lew and All--

As usual, i learn a tremendous amount from you. I will take your suggestions into the shop and see if I can improve the run out. I'll keep you updated.

Jose, if I can turn it at 300 RPM, I should be able to cut a 3/4" diameter work piece with HSS. I think. :)

--Bill
You are what you write.

Jose Rivera
Posts: 3803
Joined: Wed Feb 21, 2007 9:21 pm
Location: Vallejo California

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by Jose Rivera » Sat Sep 22, 2012 12:42 pm

seal killer wrote:Jose and Richard and Glenn and ctwo and Pete and Inspector and Ron and Lew and All--

As usual, i learn a tremendous amount from you. I will take your suggestions into the shop and see if I can improve the run out. I'll keep you updated.

Jose, if I can turn it at 300 RPM, I should be able to cut a 3/4" diameter work piece with HSS. I think. :)

--Bill

The balancing can be corrected with counter weights, but it will be time consuming.
If I was to be using C-5 collets in my lathe these are the ones I would buy: ( the first one uses the 3 or 4 jaw chucks and the second requires a mounting plate.

http://www.ebay.com/itm/KALAMAZOO-5C-Co ... 416ab79fa8

http://www.ebay.com/itm/EAGLE-5C-COLLET ... 5895ce6817
There are no problems, only solutions.
--------------
Retired journeyman machinist and 3D CAD mechanical designer - hobbyist - grandpa

User avatar
Richard_W
Posts: 1933
Joined: Fri Jan 10, 2003 1:00 am
Location: Molalla, Oregon

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by Richard_W » Sat Sep 22, 2012 4:00 pm

Jose Rivera wrote: The balancing can be corrected with counter weights, but it will be time consuming.
If I was to be using C-5 collets in my lathe these are the ones I would buy: ( the first one uses the 3 or 4 jaw chucks and the second requires a mounting plate.

http://www.ebay.com/itm/KALAMAZOO-5C-Co ... 416ab79fa8

http://www.ebay.com/itm/EAGLE-5C-COLLET ... 5895ce6817
Jose I must respectfully disagree. He is trying to buid a slide fixture for the throws on a crank shaft, which he has done. Just needs to be tuned up a bit yet, but should work fine.

On another note I think this 5C collet indexer would have saved some time and trouble for him. Since once mounted to the correct offset the part could be indexed to the next throw, much like a crankshaft grinder. The face plate could have been mounted to the mill and center found. Then offset the table the required amount. Then center this 5C indexing fixture to the spindle and bolt it down. Then take the setup to the lathe and mount it on the spindle. Check location of the off set in the lathe. Then cut one crank throw and index the collet to the next crank throw. Repeat as necessay until done. This would eliminate the need for off setting each throw with a slide fixture.

http://www.ebay.com/itm/Horizontal-Vert ... 4842bba149

My thoughts.

Richard W.
Last edited by Richard_W on Sat Sep 22, 2012 7:23 pm, edited 1 time in total.

Jose Rivera
Posts: 3803
Joined: Wed Feb 21, 2007 9:21 pm
Location: Vallejo California

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by Jose Rivera » Sat Sep 22, 2012 5:36 pm

Richard_W wrote:
Jose Rivera wrote: The balancing can be corrected with counter weights, but it will be time consuming.
If I was to be using C-5 collets in my lathe these are the ones I would buy: ( the first one uses the 3 or 4 jaw chucks and the second requires a mounting plate.

http://www.ebay.com/itm/KALAMAZOO-5C-Co ... 416ab79fa8

http://www.ebay.com/itm/EAGLE-5C-COLLET ... 5895ce6817
Jose I must respect fully disagree. He is trying to buid a slide fixture for the throws on a crank shaft, which he has done. Just needs to be tuned up a bit yet, but should work fine.

On another note I think this 5C collet indexer would have saved some time and trouble for him. Since once mounted to the correct offset the part could be indexed to the next throw, much like a crankshaft grinder. The face plate could have been mounted to the mill and center found. Then offset the table the required amount. Then center this 5C indexing fixture to the face plate and bolt it down. Then take the setup to the lathe and mount it on the spindle. Check location in the lathe. Then cut one crank throw and index to the next crank throw. Repeat as necessay until done. This would eliminate the need for off setting each throw with a slide fixture.

http://www.ebay.com/itm/Horizontal-Vert ... 4842bba149

My thoughts.

Richard W.
I apologize, I did not read the whole thread. Sorry Bill :roll: :roll:
The same can be achieved with a four jaw chuck.
There are no problems, only solutions.
--------------
Retired journeyman machinist and 3D CAD mechanical designer - hobbyist - grandpa

shootnride
Posts: 241
Joined: Tue Jun 05, 2012 12:31 am
Location: Sacramento, Ca.

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by shootnride » Sat Sep 22, 2012 7:37 pm

Bill,

Coming from a 65 year old apprentice, it looks to me like you've done a really nice job making this fixture. I was thinking about your situation and wondering how I would have attacked it. Since I likely have an inherent lazy streak and generally seem to look for what I think is the simplest solution, I probably would have used the square 5C collet block that I have and just chucked it in my 4 jaw chuck. That way I could offset it as needed. I've never done this, so I don't know if it would provide the accuracy you need, but it is certainly easier and cheaper. Maybe some of the more experienced guys could comment on the feasability of this idea since I may need to do something like this myself some day.
Just thinkin :|

Ted
Some people raise the IQ of the room when they enter.........others when they leave.

User avatar
seal killer
Posts: 4515
Joined: Sat Aug 18, 2007 10:58 pm
Location: The Land Of Oz (Ahhh, Kansas!)

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by seal killer » Mon Sep 24, 2012 9:59 am

All--

You guys are a gold mine! There are so many good ideas posted that I can stay busy for a long time.

I guess I should take a little time out and finish that engine, though. :)

--Bill
You are what you write.

Jose Rivera
Posts: 3803
Joined: Wed Feb 21, 2007 9:21 pm
Location: Vallejo California

Re: 5C Collet Slide Mount for Lathe Faceplate

Post by Jose Rivera » Mon Sep 24, 2012 2:04 pm

Bill, I have never done a crank yet, but seeing videos of people that are machining cranks for small engines they create the off-set by putting four center drill spots, one on each end, and machine between centers.
In this way it will repeat exactly at ever set-up change.

Another of my two-cents !!
There are no problems, only solutions.
--------------
Retired journeyman machinist and 3D CAD mechanical designer - hobbyist - grandpa

Post Reply