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neonman
04-13-2011, 12:25 PM
I have a Clausing 5914 lathe that I'm fond of, but there are a couple of issues about it I am totally fed up with.

The speed control has been problematic since I got the lathe a couple of years ago. It leaks the oil out and I have to prime it every time I want to use it. I have been unable to get it fixed after having taken the system apart several times. I've replaced the pistons and "O" rings In it, which were purchased from Clausing, and have been unable to fix the leaks.

I'm thinking about replacing the lower belt and the hydraulic system with a step pulley system and remounting the motor on a swivel plate. Any ideas or suggestions about whether to go with a 2 pulley or 3 pulley system? Pulley ratios? Has anyone modified the Clausing 5914 lathe this way? I'm looking for some experience with this and what pitfalls I nay encounter.

I also have been having problems with my 3 phase converter and am thinking about going with a VFD. What size should I get? I bought the lathe manual from Clausing and unfortunately there is precious little usable info in there. It doesn't even specify the motor HP or amperage. The motor is the single speed option. Does anyone know the motor HP and amperage?

A little info about how I use the lathe. Nearly all of my work is done at lower speeds and I will need the low end torque. I will be able to sacrifice some high end speed if necessary. I know motors loose torque at the lower frequencies, so the pulley sizes can reflect a ratio that allows the motor to run a bit faster. Any suggestions on pulley ratios or about this modification as a whole?

Neonman

lazlo
04-13-2011, 01:01 PM
The speed control has been problematic since I got the lathe a couple of years ago. It leaks the oil out and I have to prime it every time I want to use it. I have been unable to get it fixed after having taken the system apart several times. I've replaced the pistons and "O" rings In it, which were purchased from Clausing, and have been unable to fix the leaks.

Been there, done that :(

Sounds like you have the square aluminum pusher assembly? Is the hydraulic oil leaking from the pusher, or from the high-pressure oil fittings?

My hydraulic hose was original, and a mess. I replaced the hose, made sure I taped and tightened the fittings, and bled all the air out of the lines, and it works really well.

That said, Reeve's Drives are now archaic -- there are several guys who have gone the VFD route: remove the vari-speed sheave and drive the clutch/brake with a V-belt, or drive the spindle directly with a long timing belt. I'm thinking of doing the former, but upsize the motor to 3 HP so I have plenty of torque without using the back gear.

PaulT
04-13-2011, 01:24 PM
I dumped the vari-drive system on my 5914 for a direct drive/VFD based setup and I really like it. Very quiet plus you get smooth starts, stops and reversing with the VFD. I dumped the clutch setup also.

The only issue is loss of torque at low RPM's, but since I use carbide tooling (CCMT based tools work really well on this lathe) I'm rarely spinning the lathe slowly. The only time I go slow is for power tapping, and then I don't mind not having mondo torque. I also just have a "dumb" VFD, using a sensorless vector VFD would improve low speed torque over what I have but I haven't felt a need to pursue that.

I put notes on how I did the conversion in a file in the files section on the Clausing forum on yahoo, it has part numbers for the motor pulley and belt I used, its a really easy conversion.

http://groups.yahoo.com/group/clausing_lathe_and_mill

Good luck-

Paul T.

neonman
04-13-2011, 05:54 PM
Lazlo, the fittings are fine. Oil is leaking from the pistons somewhere. I did replace the hose too, used a combination of copper tubing and hose. And, yes, I have the square aluminum dual piston pusher on the bottom end.

The top end is also leaking I believe. It was and I also rebuilt that.

On the motor drive part, I want to use the back gear, I turn a lot of cast iron - large parts like flywheels, and need the low speed. Just wonder what pulley ratio to use on driving the intermediate shaft. I was planning to keep the upper
drive belt & associated stuff.

By the way. the hand main spindle wheel is missing on my lathe and was wondering if anyone could send me a sketch with a few important dimensions of it. I thought I'd make a pattern and cast a bronze one for it.

neonman

lazlo
04-13-2011, 05:59 PM
By the way. the hand main spindle wheel is missing on my lathe and was wondering if anyone could send me a sketch with a few important dimensions of it.

Wow, that would be fancy :) I have an extra one (the original aluminum hand wheel), if you're interested. I can measure it, but I'm flying out tomorrow morning and won't have time to sketch it.