CVA lathe

[matthewsx]

If it’s a friction material it’s possible you could have someone laser cut them provided you could source the right stuff.

As noted above, probably same as motorcycle clutch.

John

 

[mksj]

You also could get by with no clutch if using a VFD to operate the motor run commands. Might try to contact lathes UK to see what they have, they do have the belts.

lathes.co.uk

 

[Beckerkumm]

Here are two NOS motors i found for $100 each. The Marathon Black Max I intended to use on the CVA has some fitment problems. In addition, the speed range possible with the vector motor isn't really necessary with the gearbox . I expect to only run from 40-75 hz so this inverter duty will be adequate.

I mocked up the gearbox and motor to drill new holes for the plate that the motor attaches to. The holes were drilled on my old Moore jig Bore.

Dave

 

[davidpbest]

Dave, you need more old iron. LOL

David Best

 

[Beckerkumm]

David, or more common sense. Dave

 

[mksj]

Dave had asked me to build him a turn key VFD control system for this lathe, and it was a bit of a challenge in both the design and also trying to source parts for the build. The control system design is a bit different then any other of the VFD control systems I have built, Dave always seems to challenge my remaining brain power with his design requests. The build process has been about 3 months with various changes to the design requests. Sourcing parts was a major problem, and it also required a specific type of proximity sensor that took additional weeks to source (which ended up being a direct ship from the manufacturer). The plan originally was to use the a Yaskawa GA500 VFD, but availability became an issue and there was a several month lag time for inventory. We switched to using a Hitachi WJ200-075LF which is oversized so it can handle either single phase or three phase input.

We discussed various switch configurations/designs, we ended up with a control pod that will be mounted on the headstock which which uses momentary run buttons for jog, forward, stop and reverse. The VFD is configured for 2 wire control but I use a latching relay configuration to sustain the run commands, in addition the proximity bypass is built into the reverse button. The original lathe lower cast iron plate previously had push buttons for the motor on/off and and coolant, the plate was modified with an E-STop and Coolant switch installed, as well as the speed pot. Most of the switch gear is made by Idec, which are very well built and more for industrial applications. They are more expensive and had to be sourced from multiple vendors and the switch blocks reconfigured. The sourcing of parts was a major issue and required sourcing from multiple distributors, a real PTA. A custom made front panel was made for the run controls enclosure.

I was going to build a micrometer for this lathe, but fortunately Dave found the one that came with the lathe and I then had to figure out how to install a proximity stop mechanism, and as mentioned the 30mm proximity sensor was hard to source with the specs/range I was looking for. It was hung below the micrometer stop along with the safety limit switch. I have been adding chip shields over the sensors to prevent inadvertent triggering of the sensor from chips. The micrometer stop is a very unusual design.

The VFD/system control cabinet is 20x12x10" so was a tight fit for all the components, a power disconnect switch was added to the side of the cabinet. The braking resistor is mounted to the underside of the backing plate. Everything was powered up with a temporary power cord, programmed and verified the functions. Overall, glad this build is done.

 

[tjb]

Typically stellar work, Mark.

Looks great.

Regards

 

[Aukai]

For you Mark, the impossible just takes a little longer

 

[Beckerkumm]

Mark is great to work with and really wonderful to put up with me. Old machines and old men present multiple problems. CVA has a clutch but no reverse which with braking makes the vfd conversion a very helpful addition. I can handle old machine electrics but am pretty pathetic at electronics and Mark continues to be a life saver.

CVA is running and many mechanical issues have been addressed. Because the lathe is basically a 10ee with a gearbox and 30" bed, in pretty good condition, I took Richard King's advice and am delivering it to A and D machinery to have them go through the machine and do whatever is necessary to ways, carriage, etc to take the machine back to near it's original precision. It has taken months to find parts in the UK and Martin Nichols has been a huge help through email and through his threads on PM. You can count the number of people with real CVA knowledge on an amputee's hand so I've been lucky although my speed makes Mark look like he is in Warp drive.

Dave

 

[davidpbest]

Mark, looks like a terrific build and learning experience.

Dave, do you plan to actually use this machine?