Converting a PM-728VT or PM-833TV - Questions and Discussion

Grizzly industrial is another option and they are probably just as good. they are all import machines but some brands are better than others but Grizzly are made in ISO factories so you have quality control to a degree. parts are fairly easy to get if something breaks and they stock quite a bit of stuff.

the prices have jumped quite a bit on these machines i have noticed over the past few years too. i see less people converting in the future if things continue to rise like they are going now.

After 4 months of waiting, I finally got the Power Drawbar for my PM-833TV from Greg Priest.

The holes on the mounting plate were off. I drilled new ones.

The controll box was mis-drilled so now the wires stick out front of the machine and the switch is hidden behind it.

The thing would bind up until I added washers to level it.

Still waiting on a wiring diagram to install EStop.

The plus is a guy in a wheelchair can change end mills from his wheelchair with a press of a button.

The negative is:
4 months delays with a constant broken promise of “just another two weeks”.

The instructions are horrible. No parts diagram so good luck figuring out what part he’s referring to.

You loose the use of your quill! There is a lot of hardware hanging off your mill that no longer works. This is really bad.

You can’t use anything but Tormach tools. Your entire set of R8 collets are now worthless. Argh.

The front cover of the PM-833TV is now floating in the air without support. WTH.

If you dont really need a power drawbar, I would avoid this one.

Not sure how they are advertising the PDB but this is the most common one. Sucks that the quality is off. Seems like the others I have seen from PT were pretty good. Posts some picks if you have them. I had a similar PDB on mine that I desiged and made myself with some help from other designers and it worked pretty good but you loose some rigidity with the Tormach set up.

I haven’t seen a PDB that retained the quill. By design it would be difficult if not impossible to do. For the most part, people who are using PDB’s are converting to CNC and the quill is no longer utilized anyway.

I have since converted mine to a Bridgeport style PDB. Not quite as quick as the Tormach setup but retains the rigidity of the R8 system. It works well and I am still figuring out the safety circuits and a few other small things. Adding an encoder to the mix makes the design challenging as well but well worth it.

Hope you get yours working well. I have a bunch of Tormach tool holders that I am going to sell if you are interested. Mostly ER and tapers for drill chucks.

Did you send Greg the position of your holes on top of the head of the mill? He asked for those when he created the plate. They were difficult to measure because they were more or less drilled randomly by the factory.

I have not heard of that problem with the control box, but if you had a 3D printer you could print a new box. I know that you spent quite a bit of money on the kit and are expecting a turn key system, but I have found that to rarely be the case when purchasing from mom and pop shops.

The most expensive part of the PDB conversion is purchasing tormach tool holders. The money is well worth it though. Fixed tool height and quick swapping tools - even if some rigidity is lost.

Thanks for replying. Love your work.

Greg never asked for my drill holes.

You should put a note on your power drawbar video that installing it:

  • disables your quill (bad for a manual mill)
  • breaks your faceplate (love your new one)
  • obsoletes your existing collet investments
  • takes 3 months to order

Being that I’m in a wheelchair and can’t reach the manual drawbar, this unit is still a must-have for me.

Thanks for sharing. I just rec’d my PM-833TV and Greg’s power draw bar kit. I just moved into a new house so it will be a few weeks before I get a chance to setup the mill and install the draw bar. I will keep you posted if I run into similar issues. If I end up printing a new control box, I would be happy to share ti with you.

Hello Lenny,

Not sure if you are interested but I just posted a plan I have to somewhat improve this problem.

Thanks… Richard