Product Craig's Chinese collet chuck cockeyed

[trlvn]

Crappy online pictures:





Am@zon kept showing me 5C collet chucks at lower and lower prices until I finally took a flyer. "Findmall" brand. It arrived in 2 days (no Prime) and it looked good. Super smooth ground finish and virtually impossible to see the line between the upper and lower halves of the body.

I took it apart and there was some fine swarf that fell out. The usual filthy brown 'grease'. The parts looked good on the inside though too. The pinions and ring gear that tighten a collet into the chuck *look* fine.

After cleaning, lubricating and reassembling the parts, the trouble started. The chuck would turn freely _until_ I tried to tighten a collet. I had to press the collet into the chuck a little to get it to start threading. Within a few turns, it would get very hard to turn the T-handle. Then it would free up and turn easily for a couple of turns of the handle. Eventually it would get too hard to turn--before the collet was fully engaged in the taper.

I havent measured to verify but I believe the threaded hole in the ring gear is slightly eccentric. As the collet is drawn in, the tolerances stack up so the collet binds against the front body of the chuck. Note that the ring gear rotates smoothly as long as no collet is engaged. Also, I verified that a collet will easily thread into the ring gear while disassembled.

So I'm returning this chuck and I've ordered another. If I read the reviews right, the problem I have happens from time to time. The majority of people with these chucks report that they work fine. Fingers crossed for the next one.

BTW, mine came with a threaded backing plate. I didn't intend to use it but it was a big free piece of metal. It is threaded 1-1/2 x 8 even though the listing title says "2-1/4 x 8". Glad I wasn't depending on that!

Craig

 

[gerritv]

And sometimes it is the collets. Most have sharp edges everywhere, especially where the anti-rotation slot meets the threads. Some of my colets need a wiggle to get them started as well.

 

[trlvn]

Yeah, I checked 4 different collets. One would actually lock in (an emergency collet) but it still had sticky moments well before the taper pulled tight. I did ease the edges on the anti-rotation thingy but that didn't make a difference.

Hopefully the second one will be better.

Craig

 

[Susquatch]

All of my 5C collets need a push to get them started in my Bison chuck. Once the thread starts to grab they are fine. It has never bothered me. It was like that when I bought it. I have always thought it was normal. I am not planning to fix it.

The runout on this chuck has always been amazing. For most work, I don't even need to index parts, just take them out and put them back in anyplace and go. If I am working in tenths, I just put an index mark on the part at a gap in the collet and it is fine.

I LOVE MY COLLET CHUCK!!! It gets used more than all my other chucks combined.

TIP - One of the first things I did was to get rid of the spring on the key. I hated that thing! The next thing I did was to grind a 1/4 hex to 3/8" drive adapter to fit the smaller chuck key hole and then assigned a Milwaukee 12V Driver to permanent duty on the lathe. I don't use the key anymore - I don't even know where it is! The driver drill is always there handy and makes short work of opening and closing the collet chuck. The driver drill torque is adequate for most purposes. When you need a bit more torque, just use the driver like a real comfy wrench and tighten the chuck up a bit more turning the body of the driver drill by hand.

 

[PeterT]

As others have said, starting the collet into the threads with a light finger push is normal.
If its turning freely without a collet that probably eliminates a distorted ring (green) or pinion threads (yellow) which I've read are usually formed by a forging/stamping method.
If I had to guess its probably the threads (red), like incomplete threading form or the diameter is distorted. Just be careful trying too many of your known good collets because it might just bugger them up, especially under torque. I'm not sure if it would have been post hardened but it should be pretty hard.

I'm not sure how would salvage that issue without a 5C thread die presuming its not too hard. Not exactly cheap or available. If you were lucky & it was an incomplete thread or shrapnel, you might stand a chance of working it with super fine lapping compound on a sacrificial collet but this is getting sketchy & might affect you returning/exchanging it? That's kind of the problem with these things. Nice & shiny on the outside, but they have a habit of cutting corners on the important stuff. Sometimes its just a numbers game, the exact same model can be perfectly fine & good value. The Monday model - not so much.

Before you turf it, put a tenths indicator on the 5C taper surface & see what you get for TIR

 

[trlvn]

I already dropped the chuck off with Staples for return.

Note that the ring gear would easily thread onto a collet when by itself (ie disassembled). A collet would slide right into the front portion of the chuck when disassembled. But when assembled and a collet inserted*, it would start by alternating between being easy and hard to turn. From this, I believe the centre of the ring gear was not concentric with the centre of the front portion of the chuck body. In fact, I believe both were slightly off. Thus as the ring gear turned, it would move into and out of alignment with the chuck body. If just one was off, then the collet would drag constantly as it was being tightened.

Fingers crossed that the replacement chuck is better. For that one, I won't put in an hour+ cleaning it before testing!!

* When assembled but no collet inserted, the chuck key would spin the ring gear with one finger. Yes, the spring before I inserted the chuck key for the first time. 😉

Craig
(I am a bit concerned that the price these chucks is so low that they're trying to sell items that should be scrapped. Still, returns are super easy so it is no big risk to me.)

 

[Susquatch]

(I am a bit concerned that the price these chucks is so low that they're trying to sell items that should be scrapped. Still, returns are super easy so it is no big risk to me.)

That was my concern with my Vevor 6jaw too. But @Mike R seemed happy with his after some Cleanup, so I took the risk. In the end, it wasn't as low cost as it seemed be cause they didn't sell it with my backplate. I doubt I can sell the backplate anywhere near what I paid for the one I bought.

In any event, I am very happy with it so far. No return required.

 

[trlvn]

The replacement has already arrived...and it seems to work fine!!

I tried it out before disassembling it for cleaning and lube. I can spin the chuck key with one finger until the tapers start to lock up.

I sure see why @Susquatch uses power to run collets in and out. That is a lot of turns on the wrench.

Anyway, I won't be able to test run-out for a while. I need to drill and tap holes in the backing plate to work with my lathe's oddball bayonet mounting system (3 holes on 75mm pcd). Then skim the backing plate in situ and make it fit the chuck's registration flange. Shouldn't be a big deal...but there are ribs to slow cook this afternoon!!!

Craig
(BTW, the chuck really did come with a 2-1/4 X 8 tpi backing plate this time. Wonders never cease!)