# My PM25 Frankenmill



## wrmiller (May 27, 2014)

Hey all,

Most here probably didn't know that I had problems with the column on my PM25, but after a bit of talking back and fourth with Matt and Ray, I received a replacement for the column that is much better machined that the one it's replacing.

I had also joined a small group that ordered the first offerings of BenchTopPrecision's pulley conversion kit. He offers them for the G0704 and the PMs (he has a older PM25 that he used to do the prototype on). I finally got the pulley kit and upgraded spindle bearings, so this last weekend was going to be the weekend to get everything converted over, with the new column. Almost a brand new machine. 

Things started getting weird when I pulled the gear carrier out and went to install the bearings onto the new pulley carrier that replaces it. The lower bearing didn't fit. It's ID was 35mm. The pulley carrier bearing surface was 40mm. Crap.

Ok, I have a part for a different machine. 5mm isn't that much, but it's a bearing surface that has to run pretty true to the other bearing surface. It's Memorial Day weekend, and I'm not going to be able to reach Scott, so I figure what the heck, if I ruin the pulley carrier I can always purchase another.

I managed to pull it off and got the bearing surface turned down to where I need some moderate tapping with a 1" brass drift to get the bearing on. Perfect. Got the quill/spindle assy and the pulley carrier installed back in and noticed the threaded spindle end cap that Scott supplies to replace the goofy c-clip retainer for the spindle spring is too big. It easily slips over the threads, over the splines, and all the way down to the pre-load nut for the spindle bearings. It even has the same thread pitch/diameter. Hmmm...

Wasn't sure what to do about that, so while I was thinking, I tried to install the base plate for the adjustable motor assy. It won't fit. The plate sits on top of the intermediate shaft sticking out the top of the head. Scott had told me I didn't have to mess with taking out the intermediate shaft, and could leave it in. Not going to happen.

Everything comes back apart so I can get the intermediate shaft and gears out. I didn't know those gears were plastic also. Glad to get rid of them. Put everything back together, get the base plate mounted, then try installing the motor plate to the motor. Holes don't line up. Not even close. Now I'm just getting ******, and started thinking that Scott had shipped me the wrong kit. Just to see what happens, I tried putting the motor pulley on the shaft to see if it fit. Nope. Hole is too big.

I shut off the lights and came into the house to tell Scott what had happened via email.

This morning he replied (he's East Coast) and told me that from everything I had told him, I had a PM20. NOT a PM25. The PM20 and the G0704 share the same internals. The PM25 has a significantly larger spindle, with appropriately larger splines, gear carrier, and bearings (at least the lower bearing of the gear carrier).

So I checked the mill when I got home. Yup, has a 27" wide table, and a PM25 sticker on the head. But apparently I have the smaller spindle/bearing carrier/bearings of the G0704 or PM20.

It's not Matt's fault, as from the outside it looks and feels like a PM25. It's almost as if someone at Weiss built a PM20 head and someone stuck a PM25 label on it.

Tonight I measured the gear carrier, including the spline major and minor dimensions, the motor mounting holes and motor shaft so Scott (bless his heart) can make some parts for me that will fit this Frankenmill I have. And he's not even going to charge me for this, even though it isn't his fault. Gotta love him for that. 

I will eventually get this little mill up and serviceable, and will use it for the foreseeable future. But when I eventually wear it out or just get tired of it, it's replacement is coming from Taiwan.

Thanks for letting me vent.  )
Bill


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## ChipsAlloy! (May 27, 2014)

Wow! You got it right  its a frankenmill. Hope everything gets fixed pretty soon. 

Sent from my Arc using Tapatalk


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## wrmiller (May 27, 2014)

As Matt at PM is no longer carrying the 20/25/30 machines (he told me that right after I bought mine...) It is unlikely I'll ever know for sure if it was built this way intentionally, or as I described. Maybe Weiss was short the PM25 parts and needed to make that one last shipment. Who knows?

I will get this thing operational, this time with Scott's help. It's just taking a lot longer than I had figured.

I was originally going to get the G0695, but talked myself out of it. Can't remember why exactly, probably tried to save myself some bucks, but I think I need to stop listening to myself.  

Bill


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