Stuck Chuck And Head Cleaning

[echesak]

I've got a Clausing 4914 that I've been using and working on for about 5 years. I picked it up for $150. It was very complete, including a 3 phase Baldor brake motor. I've been looking for a 4 Jaw chuck for the odd-ball 1-3/4x8 headstock threads. I finally located one and began work to fit the chuck. But the original 6" 3 Jaw had never been removed. I wanted to be careful not to break gears or the 3 jaw chuck. So I looked around on the web for options. I saw someone that had a similar situation, on a similar lathe. So I used his technique. Once I had the chuck properly blocked, I tried all manner of wrenches to loosen the chuck, to no avail. I finally ended-up machining a custom spanner wrench, which would hold nearly my entire 180 lb frame, without un-sticking the chuck. Finally after applying a little heat to the base of the chuck, and using the custom spanner, the chuck finally broke loose. Here's a couple photos, in case they are useful to someone else, with a similarly stuck chuck.







In hind site, I think applying a little heat, earlier in the process might have been helpful. It takes a lot of heat to warm a 6" chuck, but it didn't seem to take much to get the chuck to finally break loose.

On a side note, while I had the lathe apart, I pulled the head and all the gearing and gave everything a thorough cleaning. It appeared that the previous owner had use it to machine phenolic or some similar material. The dust of this material had caked all over the gears and stuck in the grease. I also located one of the problems with the head jumping out of gear, while threading. So after the clean-up and re-assembly, it's much quieter and smoother. So what turned out to be a chuck re-fit ended up being a head cleaning.

Eric

 

[BGHansen]

Hi Eric,

Good solution for a sticky situation! I'd of probably broken by back gears tugging away, your idea leaves the gears out of harm's way. My 5418 has 2 1/4 x 8 threads, are you sure yours is 1 3/4" x 8?

Best regards, Bruce

 

[Kernbigo]

kroil

 

[MuchMach]

I've got a Clausing 5914 that I've been using and working on for about 5 years. I picked it up for $150. It was very complete, including a 3 phase Baldor brake motor. I've been looking for a 4 Jaw chuck for the odd-ball 1-3/4x8 headstock threads. I finally located one and began work to fit the chuck. But the original 6" 3 Jaw had never been removed. I wanted to be careful not to break gears or the 3 jaw chuck. So I looked around on the web for options. I saw someone that had a similar situation, on a similar lathe. So I used his technique. Once I had the chuck properly blocked, I tried all manner of wrenches to loosen the chuck, to no avail. I finally ended-up machining a custom spanner wrench, which would hold nearly my entire 180 lb frame, without un-sticking the chuck. Finally after applying a little heat to the base of the chuck, and using the custom spanner, the chuck finally broke loose. Here's a couple photos, in case they are useful to someone else, with a similarly stuck chuck.







In hind site, I think applying a little heat, earlier in the process might have been helpful. It takes a lot of heat to warm a 6" chuck, but it didn't seem to take much to get the chuck to finally break loose.

On a side note, while I had the lathe apart, I pulled the head and all the gearing and gave everything a thorough cleaning. It appeared that the previous owner had use it to machine phenolic or some similar material. The dust of this material had caked all over the gears and stuck in the grease. I also located one of the problems with the head jumping out of gear, while threading. So after the clean-up and re-assembly, it's much quieter and smoother. So what turned out to be a chuck re-fit ended up being a head cleaning.

Eric

Yes Eric, that is the way to do it; in your case you were lucky to have a connection point for a spanner wrench. I went through the same thing with my Logan 825 recently and I want to add the following: The chuck and a rod holder in my lathe were really stuck. I read several threads in other forums and the most powerful way to clap the shaft is to use a split collar. I used to pieces of aluminum stock, 3/4"thick, and bored a hole a few thousands smaller that the diameter of the shaft where I was going to hold it; I also cleaned everything with alcohol to prevent slippage. Some people clamp a 1.2x1.2 square bar to the collar, using the two screws that tighten the collar, to provide torque. In my case I was lucky enough that the plates of the collar hit a solid feature on the headstock and prevented it from spinning. On the chuck side a got a piece of 2" hex bar and used a big pipe wrench to remove the chuck. Yes Bruce, NEVER, EVER, EVER use the gears to remove a stuck chuck !!!

 

[echesak]

Bruce, I had a little typing dyslexia. My lathe is actually a 4914. The smaller spindle threads are indeed 1-3/4 x 8. I'll correct the original post.

Thanks for the additional information, MuchMach... I guess it's a pretty common problem. On the bright side, when the chuck was stuck, I could easily machine on the back side of bores, with the machine in reverse. I'm a little nervous to do that any more, now that the chuck is un-stuck...

 

[Kiwi]

Are Rohm chucks standard on clausings ?

 

[echesak]

Hi KI,

I'm not really sure. I bought this one used and it's the chuck that was on it.