Considering a PM-833T or maybe a PM-935TS 3PH

[mksj]

The PM-833TV is a 2 Hp motor and they indicate that it can run off of a 230VAC 20A single phase circuit. Pn the PM-935 with a 3Hp motor on a VFD you should be using a minimum of a 30A circuit, this would require 10AWG wiring. The reason why PM/QMT may suggest 20A/12AWG might be for 3 phase input power, I did not see any indication the PM-935 manual as to fusing or wire gauge for this mill, and running it off of a VFD is a completely different set of electrical requirements. My understanding of the NEC wiring requirements for VFD's is that the input wire current rating needs to be at least 125% of the rated VFD input, and is independent of what the output current is set to. The input current rating of the WJ200-022SF is 22A single phase, so the wiring would need to support 27.5A, thus the 10AWG on a 30A breaker.

 

[ltlvt]

I'm new here and about to pull the plug on a new mill. The 833T is a better fit for my budget and my floor space. However, the 935TS 3P is inticing and I would enjoy building a simple VFD system for it. I read Dave's comparsion between the two. Other than the 833's lacks PDF and no nod adjustment , it seems to be a well made and capable machine. If I went the 935 route, what VFD do you recommend, where's a good place to buy the other components and what is a good total cost estimate?

I have the 833-t and it is a very good Hobby mill for me. There are always tradeoffs between Knee Mills and Bench Mills. Of course, starting with price and ending with Nod. The real plus for my 833-t is I built my own platform from 3"x3" square tubing and put a Vintage Kennedy rolling tool chest in it. I have all the tools I need just below the machine. I used the I-Gage Dro and also converted it to Touch DRO. I love it. I used the Samsung Galaxy 7-inch tablet for my monitor. Most people install a bracket to mount the tablet on, but I chose to leave mine unmounted. This leaves flexibility to move the tablet anywhere so I can view other files at will. Yuri has updated the software to 3.0. I plan to download and install the update soon as I finish the project that is on the mill table now. I do not recommend buying the Mill Table stand that Precision Mathews sells. I did and it was very unstable when moving the table X axis from left to right. I repurposed it for a drill press stand and built this one myself.

 

[Christianstark]

If I had it all to do again I would have gone knee mill, but my 833tv is just fine for my needs.

 

[websocket]

PM-935TS it is. Should be here next week or so.

My head hurts from reading about VFD builds. I'm aiming for simple, ON - STOP - ESTOP - FORWARD / REVERSE - 1 TURN SPEED POT - FREQ DISPLAY. Nice to have would be DCV for tach and quill light and replace FREQ DISPLAY with TACH DISPLAY.

Anyhoo, time to run a 30A circuit and then read some more on VFD builds.

Thanks for all the guidance.

 

[Just for fun]

Good choice! Congrats

 

[davidpbest]

PM-935TS it is. Should be here next week or so.

My head hurts from reading about VFD builds. I'm aiming for simple, ON - STOP - ESTOP - FORWARD / REVERSE - 1 TURN SPEED POT - FREQ DISPLAY. Nice to have would be DCV for tach and quill light and replace FREQ DISPLAY with TACH DISPLAY.

If you want some inspiration on VFD and other customization opportunities for you 935, I posted about some of my embellishments in this post. Lots more details on the build are here.

 

[B2]

These pictures of the PM935 always look so nice .... and impressive. It would seem to be a shame to do so, but I am curious has anyone ever done a CNC conversion to one of these or similar Knee style machines?