Clausing 100 mk3 lathe

[Pacer]

What Robert D said ---

A threaded chuck shouldnt back off under routine uses - which in reality reversing is seldom used. The threads should be very clean - no chips, etc and the chuck should seat at the spindle with a very noticeable click/pop/clunk, using the method Robert described.

In my own experience and reading thousands of posts, this is just not a common problem. I recently rebuilt an old 13" Sheldon with threaded spindle and an 8" chuck. I added a VFD to it and using my standard 2-3 sec stop/start setting I could not get the chuck to come off.

Hopefully you just have a slightly worn backing plate and one of those new ones from shars will cure it.

 

[COMachinist]

However, if you do need to run your threaded spindle machine in reverse and cut while it is doing so, you do need to lock the chuck to the spindle nose. I recently bought a locking chuck that was made in Germany for one of the European built lathes. The threaded nose of the backing plate is split in six places and has a locking collar around it.

Robert D.

Gee Robert
I guess like minds do think a lot a like I had the same thought just last night while tinkering around in the shop. My thought was to thread the outside of the backing plate boss with a NPT, split it, twice and use a collar to squeeze it down after seating the boss normally on the spindle nose. Most of the backing plates I have seen use a nice thick tread boss. Just my 2cents. I need to keep thinking on this. Does anyone make a replacement spindle for more modern chucks and a larger center bore? With as many of these fine old machines floating around it might be worth doing something about this. No I don't need to thread left hand threads so turning backwards is not high on my bucket list. I just don't want to have a chuck come off again, unless I want it to. Right now I'm doing some cleaning and lubing getting ready to set the lathe in it's place. I'll get some pix up of the lathe when it ready for use.
Take care for now
CH

- - - Updated - - -

Damn, looks like somebody had my idea before me again

LOL my thought as well)
CH

- - - Updated - - -

What Robert D said ---

A threaded chuck shouldnt back off under routine uses - which in reality reversing is seldom used. The threads should be very clean - no chips, etc and the chuck should seat at the spindle with a very noticeable click/pop/clunk, using the method Robert described.

In my own experience and reading thousands of posts, this is just not a common problem. I recently rebuilt an old 13" Sheldon with threaded spindle and an 8" chuck. I added a VFD to it and using my standard 2-3 sec stop/start setting I could not get the chuck to come off.

Hopefully you just have a slightly worn backing plate and one of those new ones from shars will cure it.

Sound like good advise. I want be using the Dayton FRW/REV switch that is on it now, when I get VFD on and use soft starts.
Thanks
CH

 

[COMachinist]

Hi All
New day new problem I was cleaning and adjusting the compound slide today and found out the point of the cutter was at center wit slide (perpendicular) to lathe axis, then set 45deg left it was +.005 high and 45 to left it was about .005 low. So I took off the compound and disassembled it and found some looseness and wear on the machined surfaces. I decided to hand scrap ever thing back to flat, square and parallel and flaked the surfaces to hole lube, replace the gib, and now every thing is tight and square and parallel. And it looks great. Sorry I didn't take any pix of the job it 21deg and 40-50mph winds out today. I'll snap pix of it when it warms up a bit.:drink2:
Top of the day to all
CH

 

[COMachinist]

Hi All
I know this is trivial, but here is my hand scraped compound slide. I also have a question, what are the back gears and lever for on a series100 mk 3 and how are they used? I have Clausing reprint manual for a 100 mk3 4800 but it don't say much about the back gears and what they are used for?
Thank
CH

 

[COMachinist]

Hi
Well got the back gear thing figured out. The old leather V belt was so loose it would not drive any setups very well slipped a lot. Put on one of the HF Link Belts and thing seam to work much better. So yep got he back gears work right now. Got the slide gear figured out and the feed direction lever worked out. Feed rate and thread selection. still tring to get my head around cross feed, I know the cross feed rate is 3/10th to 1. but that pull push knob is strange.:nuts: Looking for a larger 3 jaw chuck all I have now is 6" which is ok, but but will need a bigger chuck, 8-10". I checked Fleebay and saw an 8" Westcott but it looked used and abused. I think I'll try to find a Buffalo or a factory chuck that is in good shape. Your input is appreciated.
Have a Good weekend all.
CH

 

[COMachinist]

Hi All Got the Lathe all setup and have used it to make a few things that I need. Now just trying new tools and things
I got with it.
I have 5C collet holder, and it works great problem is it needs tuning up it has way to much run out so I will be using the info from the chuck tune up thread to it on the usable side.
I also got this with the lathe and have no idea what it would be used for I know it is some kind of Collet holder but this collet does not come out and I can't really figure it out. The out side sleeve moves forward and back on the piece that holds the collet. The inside threads are 2.187 which is like 2 3/16 and the threaded collar is threaded out side to screw in to the collet holder and the inside of the collar is threaded to mount on my 1 1/2"x8tpi spindle on the Clausing. Any ideas what this may be? Collet is stamped .588 and the holder is stamped Huff**** CO. Los Angeles Pat Pend. no number. There is a number 1248 but that number looks to have been the tool room number because the threaded collar has the same number scribed on it as well. The Holder fits my Clausing but Can't figure it out?????
Thanks
CH

 

[COMachinist]

Well I guess no one else has seen one of these either, which makes me feel less stupid. Oh well it's kind of useless, unless your part is .588. no big loss. I have thought about it and it could be from a scrap yard or some place. I figured it is a part production die and was most likely air actuated, the outer sleeve has a grove in it for a yoke or fingers to pull it rearward tightening the collet when held. I'm just guessing here and don't really know, this to be a fact. Thanks everyone for looking. I may try to deconstruct it to see how it works and why the collet will not come out. The collet has no threads on it or in it like a 5c. When I get some more info I'll post it here.
Thanks all
CH:allgood:

 

[34_40]

I haven't seen one of those either! But I think you're right about how it is actuated, either air or hydraulics probably ran the closer for a high production type setup.

just a guess..:roflmao:

 

[COMachinist]

Hi All been running the Clausing with out any problems so far. I just really like this lathe. I found one of these for the threaded chuck. I have not tried it but this should work if the threaded back plate is split a little ways down. It has not been a problem but just incase. I know a fix for some thing that does not need fixing, right) Any way this is what I came up with.
Have a good one.
CH

 

[Newmetalmark]

I'll be watching this thread with interest, I have a 100 Series Model 110 Mk3a with the heavier apron that ended up on the 200 and 6300 lathes. It's waiting patiently for me to restore it, but I haven't been able to get near my metalworking machines for 4 months. Sigh. Work sucks.