Modifications of Emco Maximat V10-P

[r3292c]

Some of these mods are applicable to Emco V10-P lathe, but most of the mods can be applied to many other machines.

I found this lathe 3 years ago on a local craiglist and bought it. I used to have a lathe with VFD before, so the installation of VFD was on the top of my TO DO list. However, V10-P had a 1-phase motor, so the original 1-phase motor has to be replaced either. I didn't really like the original motor because it became hot even after short runs. Original non-reliable (after >30 years of using) motor switch also didn't make me happy.
So I found 3-Phase 1HP Reliance motor and Teco VFD on ebay. Since the original motor doesn't comply with current standard (has different footprints than modern motors), I made a mounting plate from 5/8" aluminum plate.






I put VFD into plexiglass box to protect it from metal chips.


And made a simple control box using original one

 

[r3292c]

3-axis optical scales with display were installed

 

[r3292c]

1-1/2" thick steel plate replaces the upper carriage, the last one is used for taper machining only.
Using this steel plate improves rigidity and makes a very smooth cut-off.

 

[r3292c]

I use air springs to unload Z-axis screw and nut.


Since the weight of the vertical head is roughly compensated by the force of the air spring, just a small force is needed to move the head up and down. So I installed a small DC motor to drive the head. The power supply for DC motor is inside the main electrical box.

 

[r3292c]

And one of the latest modification - the milling head motor.
I wasn't happy about the vertical head motor. Mine vertical head has just four speeds set by gear combinations. But the low RPMs are still too high, and the torque is too low. I wanted to have more powerful motor with variable speed control for the vertical head. I didn't like using these plastic gears either - always need to care about them. Limit flycutting because the gears may break. Finally I decided to replace the milling head motor and convert it to a timing belt drive.

I bought Enduro "servo" motor for industrial sewing machine. This motor is not "true servo" - it doesn't have an encoder. It's a brushless 600W AC motor having three Hall sensors for control. It's VFD uses sewing machine-specific pedal to adjust RPMs, but it can be easily modified with a potentiometer for convenient RPM adjustment. Motor speed can be adjusted in 100RPM to 4500RPM range.

 

[r3292c]

All the gears were removed from the head.


HTD-3M timing belt with 1 : 4 timing pulleys are used.


With current timing pulleys the spindle can run at 25RPM to 1125RPM. I can consider changing pulley ratio if I see a lack of RPMs. I cared about torque at low RPM first. Will see how it's going to work.

 

[stobl]

Very interesting. I'm in the middle of converting my maximat 7 & mill over to a couple of treadmill motors and pwm control. Have you tried the mill yet? I've thought of doing the same thing in terms of eliminating the gearing for a fixed pulley system, but am still up in the air as it would give me the ability to keep the motor wound up to maintain power while achieving the lower rpms. Good thinking about the air spring- I'm definitely going to have to do the same now.

 

[r3292c]

Yes, I've tried the mill on some quite simple tasks. It works great! Will have more milling, including flycutting of cast iron, soon.