Hi Radek,
thanks for sharing your power drawbar build. I too have a PM932-PDF that I received about two weeks ago. As it turns out, I've had other obligations so haven't had much time on the mill yet. I am a complete novice when it comes to metal working machinery so I read with interest your description of the trials you went through to get your mill working the way you'd like it to.
As far as I can tell without taking things apart, I don't have the contamination or gears binding in the PDF gearbox that you encountered. If I get brave enough at some point I may take the cover off and take a look.
You out mentioned the difficulty tramming the head without an adjustment mechanism to fine tune things. I share your frustration. I will be interested to see what you come up with. I would also be interested in any details you'd like to share about the power drawbar design and build. I have the same issue that DarkZero reported with his original drawbar. The adjustment nut is several degrees out of square and very noticeable. I guess it works OK but it totally bugs me every time I use it so I am going to do something about it when I get a chance. I am leaning toward the power drawbar route. Is it a reasonable project for a beginner?
I should probably mention that I have ordered a PM1236 that should arrive in the next few weeks so I will have access to a lathe too. Anyway thanks for sharing your nice build and the story on your mill. It has given me some confidence that while these machines are not perfect, they are capable of precision with a little effort.
You are welcome Lynrob. Congratulation on your new PM932-PDF. Despite my critical review of the mill I am happy to see you take it in stride and put things in right perspective. I am sure you will find the machine to be a good purchase. For a home use, or even the small commercial enterprise, I do not think you will outgrow it.</SPAN></SPAN>
I know it is easy for me to take things a part due to my trade. However I still stand behind my statement of looking into the feedbox, especially if you will use power down feed. If you turn the power feed selector to off, you will not damage anything even if sand is present as nothing is turning. To take the feedbox of is not a big deal as all you have to do is remove the hex screw on the end of the feed operation handle. Take a note of couple discs. You do not have to remove the individual handle which are retained by knurled pins. If you do, as I did, they are tapered pins and you knock them out with a pin punch. If you remove them you may be rewarded (like I experienced) by a find of insufficient grease which caused both levers to bind. You can take the manual feed handle off. It is basically self explanatory, as if you accidently drop it you don’t brake the handle. Then remove four bolts with 6mm Allen key. Now do not be afraid, just pull the assembly strait out. You may use small sharp chisel with hammer to help you get it started. The feedbox casting has two dowel pins so do not try to twist it off. Don’t baby it too much, under that white paint it is just an ugly piece of cast iron.</SPAN></SPAN>
When you pull it off look at the front edge if you find piece of aluminum strip, throw it in the rubbish bin and read my other post. If unsure send me a private message. I will help you over the phone. If not see that the mating surface is clean. There is no gasket, unless of course they made a shim to fix their screw-up. Look at the gears, scrape some grease off and rub it between you fingers. If you feel no grid reassemble it in reverse process and be happy. If you feel grid, take it all apart and I mean all, including the bearings and wash it in the solvent tank. Advertisement indicated that all bearings are sealed for life. There is four of them and only one included dust shield. Rest were open ball bearing full of gritty junk. Dump then in the solvent tank except the ones that have a dust seal. Should your machine suffer from same sand syndrome as mine one of the most difficult pieces to disassemble was the change “gear lever set” item #22 in the owners manual. The second irritating pieces were part of the clutch and tiny little springs #14, 17, 68 and 19. Take your time with the little springs, forget about the time, go for walk, what ever, just do not bend them or damage them, I would think they are quite critical, unless of course Matt has them in stock, they would be somewhat hard to find. The whole process is not a black magic. Figure out what each part does and you will be rewarded with knowledge what is going on when you move levers or turn the wheel.</SPAN></SPAN>
When you ready to put the cast iron feedbox back on, locate and identify the part #10. It has two tabs on it and has to sit horizontally. It fits into the slots in the cast iron feedbox. Tap the cover back on lining up two dowel pins and reinstall the feed operation handle. You will sleep better.</SPAN></SPAN>
I purchased new drawbar from Enco. 20-1/4"LONG USA DRAW BAR part number 505-2179. I made a bearing bronze collar with the lip to support the drawbar in the center of the spindle. Since the thread on the draw bar is larger then the smooth part, I made the bushing diameter couple thousands larger and threaded. I also made a spacer 1-5/16” long so the bar does not go too deep into the collet should I use double sided end mills. Power drawbar socket now slides nicely onto the ¾” nut. I use 12 point socket as six point binds. I think some old worn out socket work better.</SPAN></SPAN>
I think to make a power drawbar is a nice project as aluminum is cheap and easy on tools. </SPAN></SPAN>
You will be happy with PM1236. I have one for over couple of years and it suits me fine.</SPAN></SPAN>
If one has patience, time and love for machinery it is amazing what can be done with the two machines you own.
Cheers,
Radek</SPAN></SPAN>