Dropped my PM-935TS (successfully)

[RandallsRaceShop]

I had been looking for a knee mill for over a year on FBM, CL, and industrial auctions; almost every day, twice a day. A few minutes after the heartbreak of being the second best bidder on my fourth Bridgeport (4 times the 2nd best bidder), this PM935 popped up on FB 500 miles away. I had almost pulled the trigger several times on an new 935 so I was very familiar with the quality and value. After "waiting" to think it over on several FBM and CL machines and loosing them in the matter of hours, I jumped right in with a full price offer, which I felt was very fair. About 10 years old, barely used by a hobbyist, with a PM vise, a PM installed VFD, aftermarket DRO, a box of unused USA end mills, collet and rack, fly cutters, and a box of parallels that only had 2 sets showing use. The add went up and I was the first person to respond at 14 minutes. The kind seller offered to hold it for 2 weeks despite plenty of other local buyers. Seller loaded it with me with an engine hoist and 1100 miles and 5k poorer, I was in business. Wonderful seller and wonderful drive.

Step1: Getting it off the trailer was a different story and I thought posting this might be helpful if anyone else wants to give this a try. Because of the angles and heights involved, another engine hoist was no longer an option. When I first loaded the mill, I dropped it onto two full dimension 2x12"x 6'. To get it out, my dad and I jack-knifed the trailer into my shop (20 foot urban alley), ratchet strapped the mill onto the skids and wedged it between blocking, bolted an anchor into a 24"x24" footing, and used a come along to drag it out of the trailer, with ratchet straps on the backside to keep it somewhat supported. I did the next part solo, slow and deliberately.

Step 2: Next tricky part was getting it in the air without a gantry or engine hoist. I had some free 1/4"x2x2.5 angle laying around the shop. I finished through-tapping the 3/4" mounting hose on the PM's base, ran 3/4" all thread into the base, and rested the angle within drillpress-precise holes over the allthread. I then used blocks and a floor jack to get it up in the air for a few days while I could build my best conglomeration of the David Best & Firestopper mobile base that I could, sans using a brake as shown in this thread : https://www.hobby-machinist.com/threads/mobile-base-for-a-mill.53405/. The base gets me about 3" over stock height, with all the holes tapped and the M14 leveling feet going through 1/4" tubing plus an 1" of extra matereial I turned on my lathe and welded under the 1/4". I was going to have the all thread go straight into tapped 3/4" holes on the base, but I didn't want to test my luck on my measuring abilities, so it runs through 7/8" holes with lock nuts underneath the base.

Thanks everyone for your support over the last year. A special thanks to Firestopper for all the compliments I have received from friends and family on my stand, and to Mr. Best for prepurchase support and excellent documentation/write-ups on the PM935 and the design difficulties of the combined wood/metalwork in a small urban shop.
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Great score! Nice work, man. Have fun & be safe.

 

[davidpbest]

Sounds like you got one heck of a sweet deal. Adding a power draw bar would really enhance your convenience. Ditto for power feed.

 

[MensaPE]

I don't mind cranking and counting with the knee, it's not too awful to live with, but I agree that the horizontal axis needs power feed. It used to be an expensive thing to upgrade and now it's not, the chinese power units aren't half bad at 1/5th the price of a high end unit.

When I dropped my PM935TV on it's face, the z axis motor was the only damage. Got a new one from PM, about 400 bux, made in Taiwan, not China. Quality is very good.

 

[netmagi]

Those 935's are really nice. Some day i'll upgrade from my 728

 

[Winegrower]

Personal comments based on my experience: I added a Vevor knee feed unit and this has made a huge contribution to ease of use. I like it! The X axis power feed is basically mandatory, in my opinion. I spent more for a "name brand" unit, Align or such, and it's basically indistinguishable from the $125 Vevor. I've added a 4" riser and this makes a big difference in the available Z height, important for me since I've gone to Kwik Switch holders, probably about 25 of them now in different sizes, capabilities and pre-loaded tools..chucks, end mills, face mills, edge finder, tap guide, center drill, etc. While in some cases they use an extra 1" of headroom, they makes common operations like locating a part, center drilling, pilot drill, drill, chamfer, tap...fast and easy compared to changing either R8 collets in the spindle or tools in a Jacobs or keyless chuck. Also, a friend has a Bridgeport with a power drawbar and it is just not for me, and makes little sense with the Kwik Switch setup.

 

[Larry$]

I've added a 4" riser and this makes a big difference in the available Z height

Wish I could do that! Low ceiling!

 

[ClayPort]

I wanted to wait a bit before adding any upgrades so that I could get to know the mill personally. I also ended up driving back to mill's prior owner to pick up an equally unused 1236 Eisen (same as PM's 1236T) so I have been a little cash strapped. But after putting in some more overtime I am going to venture into ER40 collets and the ER system still requires a power draw bar. My hope is it will add some of the simplicity of the Kwik Switch system. I'm in Japan right now, but I will have a Vevor X-feed on my doorstep when I get home. I had been saving for an Align but it is great to hear they are indistinguishable and 1/3 the cost.

As for a previous commenters question about the angle iron bending; I assure you that it lost no more than an 1/4-1/8" across 8 feet. The bowing seen in the picture is an optical allusion created by the panoramic photo style. Here is a better picture, holding steady for the 3-4 days it took for me to weld the stand. Also, for anyone interested, I started to design a stand for the 1236 lathe, while 700lbs less than the PM935, it still is a hefty 1000lbs. I thought I would need a mobile stand in order to access it from the rear but I found to my suprise that it can be moved by hand an inch or so at a time, creating enought room to access the rear for service and cleaning (I do understand this requires a releveling).