CDCO 5C Collet Chuck Review

lazylathe said:
Hi Charlie,

Watching the video I saw one thing that I have been corrected for on a few other forums that could lead to some issues.
Tool overhang.

Wen you are turning the backing plate there is way too much tool overhang.
This causes flexing and could be part of the problem.

Just something I have had drilled into me and thought I would mention!
Good luck with Frank!!
Let us know how it goes!

Andrew
Click to expand...

The gear issue was a problem from day one even before I did anything but turn the chuck T handle. As far as tool overhang and flexing I don't think it was an issue with anything as the chuck back was turned perfectly flat and verified on a surface plate and dial indicator. I took very light cuts. I know it's not a good idea to do it that way but my only option at the time.
 
Im not sure as why you went the route you did?
If this was me, If the chuck didnt feel right, I would have sent it back , after inspection.

Lets start from scratch here. You bought a new chuck, and new back plate. Assuming from the same seller, not that it matters. The back plate would be the first thing to fit up on your lathe. About all you should be required to do is take a skim cut to ensure it true. Second, cut the register step to fit the chuck. Both these operations on your lathe spindle. This would make both operations as accurate as your lathe is.

In some cases, you may be required to put the bolt pattern on the back plate to mount up. After all three of these things are done, mount it up, and check for run out. Now after indicating , you have run out issues, it can only be in a few places.
First thing would be a bad collet, it is possible. Id pull the collet,and indicate the ID of the chuck it self. Narrow it down, collet, or the chuck!

Providing you have trued the back plate as mentioned above, and indicated it to prove your work is accurate, the only places to check are the collets, and or the chuck its self. In either case, ship it back. I would not hang the chuck off your 4 jaw like that, and do any cutting. I have seen guys do this, only to learn later the run out is in the collet, or debree in the assembly. From what I understand this chuck/ back plate/ and collets are new. The only thing you should be cutting is the back plate, thats un avoidable. Past that ship the items that cause issues back.

Charley, just another thing comes to mind. Have you ever checked your spindle bearing ajustment? Might want to get the indicaters out, and just check this, make certain your spindle isnt floating around on loose bearings. Dont be surprized if they are in need of ajustment. Good luck with this.
 
8ntsane said:
Im not sure as why you went the route you did?
If this was me, If the chuck didnt feel right, I would have sent it back , after inspection.

Lets start from scratch here. You bought a new chuck, and new back plate. Assuming from the same seller, not that it matters. The back plate would be the first thing to fit up on your lathe. About all you should be required to do is take a skim cut to ensure it true. Second, cut the register step to fit the chuck. Both these operations on your lathe spindle. This would make both operations as accurate as your lathe is.

In some cases, you may be required to put the bolt pattern on the back plate to mount up. After all three of these things are done, mount it up, and check for run out. Now after indicating , you have run out issues, it can only be in a few places.
First thing would be a bad collet, it is possible. Id pull the collet,and indicate the ID of the chuck it self. Narrow it down, collet, or the chuck!

Providing you have trued the back plate as mentioned above, and indicated it to prove your work is accurate, the only places to check are the collets, and or the chuck its self. In either case, ship it back. I would not hang the chuck off your 4 jaw like that, and do any cutting. I have seen guys do this, only to learn later the run out is in the collet, or debree in the assembly. From what I understand this chuck/ back plate/ and collets are new. The only thing you should be cutting is the back plate, thats un avoidable. Past that ship the items that cause issues back.

Charley, just another thing comes to mind. Have you ever checked your spindle bearing ajustment? Might want to get the indicaters out, and just check this, make certain your spindle isnt floating around on loose bearings. Dont be surprized if they are in need of ajustment. Good luck with this.
Click to expand...

Dumb people do dumb things & what's done is done now I just have to fix it. I checked my lathe spindle for runout and had none. All of the collets I have checked have the same runout so I would assume all my runout issues are in the chuck it's self and I'm sure I'll get it to .001 or less TRO with a little work. I read some articles on this and in a nutshell it's kinda how they did it. As far as the "Register" on the back plate I know nothing about that topic and only was brought to my attention by Benny after I had done everything. Still not sure about what it is or really means. Enlighten me on "Register"
 
"Register" is the term referring to the close fitting interface between two separate pieces of an assembly. In the case of a back plate and chuck, once the back plate is firmly in position on the spindle, however it is mounted, be it tapered, pins, threads, or whatever, there is a turned and faced feature of the back plate that should have virtually zero runout (TIR, or Total Indicator Reading, or Total Indicated Runout). The chuck, whether a collet, 3 jaw, 4 jaw, or 6 jaw, has a precision machined (ground in some cases) bore that fits very closely on the mating feature on the backing plate. This interface is often called the "register". It is of the utmost importance that this interface be kept clean and burr-free, and fit with a very few tenths of clearance.
 
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Charley
Tony has done a good job explaining what the register is. Now let me ask you a few questions here. The register that sticks out on your back plate, and fits into the back of your chuck, is it a tight fit? Did you have to draw the chuck up to get it on, or did you have to use a dead blow hammer? Or did your chuck just slap right up against the back plat, and you bolted it up?

Ok enough questions,, here is a few things to look at.
The register that protrudes out from your back plate, should fit snug, not a pressed fit , that you would need to pull the chuck up to the plates with the bolts. If that is the case, then you need to take a skim cut on just the edge, the same edge that fits into your chuck. If it allready fits ok, then use a DTI and run it on that edge, if you havnt machined it ye, you might find there is the source of runout.

Anothe thing to be aware of. The register on the back plate, should have a decent chamfer on it, and should not be just cut squared . The chamfer is needed to help get the chuck started on the register, and is allso needed to prevent carving metal off as you install your chuck. Inspect the ID of the back of the chuck, see any scratches? Now in the event that the chuck just slipped right into place, and just bolted up. That would be a different thing. In that case, loosen the mounting bolts, just a tad. Then set up you indicater again, bring the hi reading up to 12 o clock. The strike the chuck with a dead blow hammer to bring it down. If the chuck has enough play on the register, you can take the runout away , by shifting the chuck. Just think of how a set true type chuck is (set true).

Her is another thing to look at.
You most likely had to drill the bolt pattern on the backing plate, for the chuck.
Does any of the bolts bind at all ? And yes, just a little makes a differance. You should be able to screw all the bolts in with your fingers. If your using the bolts to draw the chuck up to the plate, you should be able to unscrew all of them with your fingers.The next thing, did you chamfer the holes on the back plate? and I mean the side that rests up against your chuck. These should be chamfered, and check with a light stoneing to ensure there is no hi spots pushing your chuck out of true.

I know this is long winded on my behalf, but,,,I have learned over all these yrs. There is a multitude of ways to have a chuck install bite your ass. These may not be anything that is effecting you. I just want you to be aware of the common things that bite most of us. How do I know? lol Dont ask! Been there, done that, got the key chain, the bumper sticker, the T-shirt,,,,,,,,,
 
All good points, Paul. I was giving the abbreviated version. I'm glad you filled in some of the gaps. I think many people overlook something that seems so basic as chuck mounting. It it isn't right, it's nearly impossible to do precision work.
 
All those things were pretty much done (Accidentally) for the most part but were done. I forgot to mark the mating pieces when I took them apart to fix the gear issue but that turned out to be a blessing in disguise. After reassembling it and checking runout tonight I got .0005 on the ground surface of the collet holder & .0025 on the 1/2" collet with a pin in it, .003 with 1/4" collet with a pin in it both about 1" out from the collet. So the runout now seems to be the collets themselves.

Checking the lathe spindle I got .0002 on the inside dia. and .0000 on the outside.
 
I would consider that unacceptable for collet work. I'd be looking for <0.0002 TIR. If it's the collets, and they were spec'd to be <0.0002, I'd return them as rejects. RTV
 
called Frank this morning while waiting on someone on the job site, told him about the gear issue and he said he was sending 2 new gears out to me today:thinking: If he does as he says I guess I have no real beef about the holder it's self. Would like to know what material they are madse of so I could heat treat them.
 
Buyer Be Ware

After a month & a 1/2 of constant hounding & lame excuses I finally got my gears, I do not believe I would have gotten them if I had not been persistent. With the overall bad quality of the tool & the poor service I would say you should steer clear of CDCO & Frank all together. JMHO:whistle:
 
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