CVA lathe

[mksj]

Great to see it getting near completion and really looking very nice. Very time consuming and not an inexpensive project when one does a proper restoration. There is something about they way they built these old machines, that makes them keepers and glad you were able to do these restoration. Must be a real joy to use them.

 

[Beckerkumm]

The earliest version looked almost exactly like the 10ee which to my eye is more pleasing. The English machines went to the " modern " square styling in the 50s and 60s. Smart Brown is similar and I think their round head is better looking than the later square head but at the end of the day how the lathe turns is more important. There are quirks though, the feed levers are opposite from those on the Monarch 60. Up engages on the CVA and down engages on the Monarch. I don't know if that can be changed or if the 10ee is also opposite from the larger 60/61.

Dave

 

[tailstock4]

Glad to see you got it back. Looks good from what I can see. I know you will enjoy using it.

I wouldn’t worry about it not being a Concours type of restoration. For me painting is the last thing I do and probably the least important to the machine. However, trying to do it well is certainly as hard to do as any other part of a restoration and can require just as much thought and planning. These old high-end machines are fun to use and provide great insight into what can be achieved where quality and function were the priorities. Yes, they are probably overkill but that’s the fun of it.

 

[Beckerkumm]

Did a little more work on CVA. Installed the VFD enclosure and control boxes. I didn't want to drill holes in the headstock so I used magnets. The DRO location isn't ideal but there were existing holes and I didn't want to put in more so I'll live with it. First night in the shop building ( located beyond the middle of nowhere ) with hearing aids and I've never heard so many creepy sounds, but I survived.

Dave

 

[Beckerkumm]

A little more work on CVA. I installed a Tachulator. There was no great place to mount the hall sensor on the spindle but the double belt pulley is non standard and has about 1/2" between the two sheaves. I drilled twelve 3/16 holes for magnets and was able to mount the sensor using existing holes for the spindle lock bracket. I had swapped the motor pulley as the gearing was based on a 50 hz system so the numbers were off 20%. There are six gears on open belt and six with the back gear. The vfd will cover the rpm spacing which equates to 40-90 hz. The Baldor ECP 5 hp motor should deliver 3.35-5 hp through that range. Top end could be close to 3300 rpm but I doubt I'll ever need to go more than 2500.

I don't know if I'll change the tach mounting until I use the machine more but it works for now. The first sensor i bought had issues with goofy readings, worked part of the time. The wires are so small I suspect there is a break somewhere and they occasionally touch but it made for head scratching. Fortunately Mark Jacobs is my Head and Shoulders guy and came to my rescue.

Dave

 

[Beckerkumm]

CVA is running with Mark Jacob's VFD control system in place. Machine is leveled. It came with leveling shoes that are pretty neat to use. Like the 10ee, the CVA relies on only three points so leveling is very simple. My floor has radiant heat and I suspect isn't poured as thick as I would have done so I use patio blocks to spread the load. They are very flat and dense. I'm now within .0001 which is a good as I can measure and the finish quality is better than I am used to. The lathe, again like the 10ee, uses belts to operate the power feeds unless threading and those feeds are set very fine. That allows for a fast final pass with slow feeds and a very nice finish. The gearbox in the base and an open belt to the spindle also remove the gears from the headstock which improves the finish as well.

If I were designing a VFD driven lathe, ( that no one would want to buy ), 4-6 speeds in a separate gearbox would be my choice. Most of the new smaller machines rely on two ranges which sacrifices hp in the 500-1000 rpm range ( or the very top end depending on machine ). A few lathes have three or four ranges. I like my clutch as well but could give that up with a vfd.

Note Mark's work. It is second to none in function, safety, or beauty.

Dave

 

[Firstram]

Beautiful machine!

 

[Joe Calhoon]

Exceptional job on the lathe Dave!