# New Guy, New Lathe, need a little help.



## Iron-Iceberg (Dec 25, 2018)

Hello, I’ve been lurking here for a while. First I just wanted to thank everyone for posting their knowledge. I’ve already learned a lot.
I have picked up a new to me lathe. It’s a Clausing 6922 it was originally sold to a company back east and then to a company in Santa Barbara, it was then bought by a guy who was I believe a gun smith. After he died all of his tools where purchased by the guy I bought it from. The guy I bought it from never used it as he had another lathe and just got it as part of the deal. 
Sorry for the long story but it’s just a little background that kinda lets you know that quite a few people have had their hands on it. The gun smith has quite a few recites for parts so I think he took good care of it and replaced things as needed. Unfortunately things get changed and modified over the years so if you see something out of place please let me know.


----------



## SubtleHustle (Dec 25, 2018)

Wow! Beautiful machine! It looks VERY well taken care of! The only thing I see out of place, right off the bat, is its location. It needs to be at my place. No worries though, I will even help you come move it!


----------



## benmychree (Dec 25, 2018)

Very nice!


----------



## NortonDommi (Dec 25, 2018)

Verrrry nice!  What did it come with?


----------



## killswitch505 (Dec 25, 2018)

Man that’s a score I’m seriously jealous........ I’d love to come up on something like this!!!!


----------



## mmcmdl (Dec 26, 2018)

You are starting out with " the best " ! Sweet looking lathe . Congrats .


----------



## higgite (Dec 26, 2018)

Iron-Iceberg said:


> ........ if you see something out of place please let me know.



Yes, there is definitely something out of place. The lathe. It’s sitting in the wrong shop. But, I can help you out with that and I’ll even pay for half the shipping. No, no. No need to thank me. It's the least I can do. 

Welcome aboard. That looks like a very nice find.

Tom


----------



## Iron-Iceberg (Dec 26, 2018)

Thanks for the thumbs ups guys. 
The gunsmith changed out the 3 phase motor for a 3 HP 230V single phase. It has reverse but no high and low range like the 3 phase original. Here is the data plate and a picture of the motor. It looks like he made some custom mounts to make it fit. 
I took the drive out to clean it up and install a new belt. The clutch seems to work good. So I didn’t touch it. 
The vari-drive seem to be tight. I’ll check it again when I get it up and running.


----------



## Iron-Iceberg (Dec 26, 2018)

It came with a three jaw chuck but I’m not sure of the brand. Here is a picture of it.




And a 4 jaw Tambertini


----------



## Chipper5783 (Dec 26, 2018)

Could you post additional pictures of the 3 jaw chuck?  It looks like a style of set true (meaning the chuck can be shifted slightly). I have a 4” on my T&C grinder, which looks similar.

David


----------



## NortonDommi (Dec 27, 2018)

I'm very, very slowly turning Green!


----------



## Iron-Iceberg (Dec 27, 2018)

Couple more of the 3 Jaw


----------



## Downunder Bob (Dec 27, 2018)

Very nice looking bit of gear, lucky you. it should serve you well.


----------



## Janderso (Dec 27, 2018)

I’m a bit green with envy myself.
I hope you know how fortunate you are Mr. Iceburg.
I would give my, well, you get the idea.
Welcome!


----------



## jbobb1 (Dec 27, 2018)

Ran that same lathe off and on for over 30 years. Pushed it pretty hard at times. Always did the job without complaining! 
You scored big time!


----------



## BGHansen (Dec 27, 2018)

Nice score and very nice lathe.  I have a Clausing 5418 which my dad used in the high school shop he taught at.  I'm sentimental toward them as a result and have favored Clausings over other "old iron".  Plus you have the 27 tpi setting in your QCGB that a lot of us covet.  You've got a really nice, solid lathe there!  Enjoy!

Bruce


----------



## bfd (Dec 27, 2018)

I live close to you, In Nipomo, email me if you need machining help. bfdolen@gmail.com bill ps I also changed my lathe from a 3 phase to a 1 phase motor with help from an electrician friend of mine, you can get the high low range back with a quick pulley change bill


----------



## Iron-Iceberg (Dec 28, 2018)

Thanks again, I do feel very fortunate to have found this lathe. Took a couple years of looking on Craig’slist local and pretty much the whole state. 
Sorry I’m a little slo on reply’s but a lot of OT this week and family in town. I’ll get some pictures up of the rest of the tooling that came with the lathe in a few days. 
I’ll also have a few questions on the vari-drive, once I have time.
Thanks for the offer BFD, I have a retired machinist friend who is chomping at the bit to help me out. But I will need all the help I can get. LOL. Once I get a few things sorted out come on over and check it out.


----------



## Chipper5783 (Dec 29, 2018)

Iron-Iceberg said:


> Couple more of the 3 Jaw
> View attachment 283403
> View attachment 283405




Hi Iceberg, I can't tell you what the manufacturer of your 3J is.  I believe the 5" 3J that came with my T&C grinder is the same make (pictures attached) - and the counter bore that likely held the manufacturer's sticker is also blank.  Everything else (right down to the font) seems very similar.  The chuck has a separate mounting plate that you can shift the main chuck body (or perhaps it shifts the jaw carrier?) using the 3 wedges that are around the outside.

I had mine all apart and mucked around with it.  Mine was very stiff and needed cleaning and I made an adapter for the #50 adapter to use on the T&C grinder's live head.  It seems like a real pain to adjust the chuck, since I think you have to slack the first back plate so that the wedges will be able to shift the chuck body - except the mounting plate covers the SHCS (bolts) that secure the first back plate so you can't really spin it to check the run out.  If you find any instructions, or figure it out (or someone else can enlighten us) - please share the information.

David


----------



## Iron-Iceberg (Dec 31, 2018)

Chipper, it does look the same. Mine does seem to move freely so I have let it be for now. If I find anything out about it I will post it here. 
Thanks.


----------



## Iron-Iceberg (Jan 5, 2019)

Ok I have a question on the variable-drive. I’ve looked over many threads and haven’t found an answer to my question so here it goes. 
First I bled this thing every way I could find Instructions too. I gave up and ordered new seals and packing.  It has the newer, I think, unit with the square master cylinder not the round one. After the new seals and bleeding it again I think I finally got it working good.
 However I can not get the dial to match the speed of the belt. After a couple of days looking at it I decided to take the top of the variable-drive apart and try to figure it out. 
So I found the push rod that rides on the cam is adjustable with a set screw in the end. (See pictures) I’m not sure if this is a stock piece. Seems kinda hokey that the set screw would push on the piston. The Manuel I have shows the old style round master and it looks like the pushrod is not adjustable. Is this the right piece?
Anyway, when I adjust the push rod so that the cam runs the full distance around, it will push the drive too far. It will go so far on the high speed side the belt will run off the pulley.  
I bought a tach to check the rpm and I have adjust the low speed nut on the variable drive pulley to 42 RPMs and then adjusted the push rod until I get 230 RPMs. This is great however the dial does not match up to the RPMs. When I set the dial to 42 RPS at the slow speed it tops out about 210 RPM on the dial. 
Am I missing something? The only thing I can think of is that the cam is wrong and ramping up too fast and pushing the rod too far too soon. But I can’t imaging anyone changing the cam, but who knows.

Thanks for any help.


----------



## Iron-Iceberg (Jan 12, 2019)

Well I guess no one here has dealt with this problem before, or maybe it just doesn’t matter. The dial seems to be just a pretty rough estimate of speed anyway. Sense I only have the high speed due to the motor change. I’m thinking I might just make sticker with new graduations to match the speeds and call it a day. Anyone see a problem with this?


----------



## Nogoingback (Jan 12, 2019)

I don't have a Clausing so I have no clue on that drive, but is it possible the speed of the new motor is different than
the OEM motor?  Is the difference between actual speed and dial speed consistent across the speed range of the 
machine?


----------



## Dhector (Jan 12, 2019)

I've got a 6913 with a similar variable but it was disconnected before I got it so I never used it. I do have the old parts still. I could look at them and photo them if you think it might help you in any way. Just let me know. Not sure if they are the same either, but they LOOK similar.


----------



## francist (Jan 12, 2019)

It would be interesting to hear from some any other guys out there who own the same lathe if their speed ranges correspond closely to the dial increments or not.

I have two variable speed drive systems here, one on my power hacksaw and one on my shaper. And in my experience with these things, the transition between the low-high limits is not necessarily a straight line. I suspect mathematically it should be, but when push comes to shove there are nuances and tipping points in the physical system that causes some slight inconsistencies in the transition.

The lathe in question though is not a mickey-mouse machine, and I figure a good deal of engineering went into making things right. When I look at the speed range and the increment spacing on the dial, it would seem to me that there should be tighter accuracy. I mean, we're not talking about 20 rpm on a 42-2300 range, we're talking 20 rpm on a 42-230 range.

Back to my experiences with less than linear transition, if some of those might be inherent to design (as opposed to being induced by wear) an ideal way to compensate would be through the lobe shape on a cam. Right now the OP has set the low speed limit of 42 and notes the discrepancy at the high end of the range. Are the results consistent if the cam/pusher are set up to achieve a correct top end speed of 230, does the low end then suffer by the same amount? Where I'm going is does the lobe shape on the cam maybe compensate on one end more than the other?

The other thing I know can be a little tricky is getting the belt tension right to produce the desired range. It can be a bit of back forth to set the limits on the variable drive, check the range, tweak the tension, reset the limits, check again, etc. At least that has been my experience with the two I've played with. Is it the correct belt both in profile and size to match the variable drive pulley?

I really like variable drives, they're cool to run. But they can be fiddly to get set up and even harder once a few of pieces start to get changed. Good luck with it. Oh yeah, and I don't like the looks of the set screw bearing on the cam either. That seems less than ideal, but it may have been a factory compromise at one time. Again it would be nice to hear from someone else who has the same machine.

-frank


----------



## Iron-Iceberg (Jan 13, 2019)

I believe the original motor to be 1800/900 RPM from a sales brochure I found. The motor in there now has a data plate that reads 1735 RPM so it’s pretty close. If anything I think would need more travel on the Variable Drive to make up the 65 more RPM. Not less travel.

Dhector if you had a picture of the push rod and the master cylinder that might show me if this is the right part. Thanks.

The old belt was shredded so I put on a brand new belt from Clausing. The pulleys on the drive are really smooth (no groves from running in at one RPM it’s whole life) so I think the speed stays pretty consistent threw the range. 
The cam would seem to be the obvious choice to me, that is just ramps up too fast. With so many owners over the years the cam could have been changed out to a different one, but I wouldn’t think it is a wear item that would be replaced. But who knows.
Does anyone know if Clausing made multiple different cams? Maybe some one along the way swapped a different one in.  
In an endless search on the web about this I have seen a few people talking about RPM discrepancy’s on their lathe but no responses or follow up on how to change it.


----------



## Dhector (Jan 13, 2019)

Iron-Iceberg said:


> Dhector if you had a picture of the push rod and the master cylinder that might show me if this is the right part. Thanks



I'll get pics for you next time I go to the shop. Might be today, if not, I HAVE to be at work tomorrow and I'll get some then.


----------



## francist (Jan 13, 2019)

Iceberg -- have you seen this video series by Randy Richard? Again, not the exact same lathe as yours -- his is a 6903 -- but maybe something there that can help. I also understand he's a pretty good guy, so maybe a comment on his channel might get a helpful response. The link below is for part 1 of three, I only watched a portion of Part 3 where he puts it all back together.


----------



## Iron-Iceberg (Jan 13, 2019)

Dhector said:


> I'll get pics for you next time I go to the shop. Might be today, if not, I HAVE to be at work tomorrow and I'll get some then.


That would be great to eliminate one variable. Thanks For the help.


----------



## Iron-Iceberg (Jan 13, 2019)

francist, yes I have watched his videos. He sure has done a lot of work to get his lathe working. His lathe has the older round master cylinder and he doesn’t take it apart on the video to see much. I might have to shoot him an email to see if he has any ideas.


----------



## Dhector (Jan 13, 2019)

Here are a couple pics. It was not installed when i got my lathe so I have no advise on this but I do have a camera and if you would like some other pics, let me know.


----------



## P. Waller (Jan 13, 2019)

Iron-Iceberg said:


> Ok I have a question on the variable-drive. I’ve looked over many threads and haven’t found an answer to my question so here it goes.
> First I bled this thing every way I could find Instructions too. I gave up and ordered new seals and packing.  It has the newer, I think, unit with the square master cylinder not the round one. After the new seals and bleeding it again I think I finally got it working good.
> However I can not get the dial to match the speed of the belt. After a couple of days looking at it I decided to take the top of the variable-drive apart and try to figure it out.
> 
> ...


I owned the same lathe for 20 years, it is a mechanical V- belt driven variable speed drive and therefore will be inconsistent by its very nature. If you are a modern person that requires fixed speeds you will be disappointed.

The answer is, you can not control the speed of the spindle using a V-belt drive without a control and feedback such as an encoder. You may spend the rest of your natural lifespan trying to get such a simple drive to run at +- 10 RPMs from the indicated speed (-:


----------



## Iron-Iceberg (Jan 13, 2019)

Thanks so much Dhectorfor taking the time to take those pictures.  That looks exactly the same as mine. I’m going to have to look else where.


----------



## Mitch Alsup (Jan 15, 2019)

Dhector said:


> Here are a couple pics. It was not installed when i got my lathe so I have no advise on this but I do have a camera and if you would like some other pics, let me know.
> View attachment 284704



This looks to be the tailstock stop.
There will be a threaded hole near the end of the bed if I am correct.


----------



## Dhector (Jan 15, 2019)

Mitch Alsup said:


> This looks to be the tailstock stop.
> There will be a threaded hole near the end of the bed if I am correct.



No idea. It was installed in the hyd part when I got it. Its been laying around since I got it. Looked at my lathe and didnt see any threaded hole on the bed. Not sure.


----------



## Iron-Iceberg (Jan 16, 2019)

It’s a dead ringer for the pushrod on the variable drive. See my picture above. It’s good to know mine had the stock pushrod and master. Thanks Again.


----------

