Just found your channel and subscribed. Very nice mill. Nice work

@mwmxcnc

Ай бұрын

Thanks! I’m not much of a video editor, but I’m working on it. I’ll be building a plasma table pretty soon, I’m using mess boards, and Linux cnc for this one, should be a pretty neat build, if you’re into cnc machines and fab work.

I have a Precision Matthews PM940 which is similar in size. I replaced all the bearings in the gearbox with better bearings and it made it run smoother and quieter. I also run Mobil 1 synthetic motor oil in the gearbox instead of 90w gear oil as it allows the gears to turn easier and helps with the power. I also replaced the oil seals with better seals. If you ever take off the lid again, put a strong magnet in the bottom of the gearbox to attract and hold metal shavings. If you drain the oil into a jug, tape a strong magnet to the bottom of the jug so that any shavings in the oil will be attracted and held by the magnet. When you pour the oil back in to the gearbox, any metal shavings will be captured and held by the magnet. Then you can take the magnet off of the jug and clean out the jug. I also removed the oil drain plug and installed a 1/4" valve to make draining the oil a lot easier.

@mwmxcnc

6 ай бұрын

Those are some good ideas, I did clean it out really well originally, but dropping a magnet in there woulda been smart. What oil did you use? I think some 15-40 syn would probably be a good middle ground that won’t thicken up like the 90w conventional gear oil does in the cold. You can hear the motor struggle when to get going when it’s first started and cold. I’m guessing you did the bearings and oil at the same time, so it would be hard to tell which contributed to the noise reduction most. Although both probably helped. I will try changing the oil here in the next couple weeks, I can do atleast that now, and maybe find a drain plug with a magnet. I’ve always suspected quite a bit of power is being lost by the 90w, but I’m also the type that typically listens to manufacture specs unless someone else has had good luck with an alternative. Also, the manufacturer of this mill probably spec’s whatever was cheapest, and not based on living in a Utah garage.

@halfstep67

6 ай бұрын

@@mwmxcnc I think I used Mobil One 5-30. but the 15-40 would be good too. I also added about a half quart of Lucus oil stabilizer to it to make the oil clingier. I have been using the synthetic oil for a while with no problem even at higher RPM. I just recently replaced the 8 bearings in the gearbox and noticed the better quality Nachi bearings are quieter. The old bearings seemed to be in good shape, but the new bearings are quieter. If you ever replace the bearings, you will probably have to open up the gearbox and get the numbers off of the bearings as the parts book probably won't list the bearing sizes. I also replaced the 3 oil seals since I went that far. I converted my PM940 into a CNC and wanted to run at higher RPM so that is why I went with using synthetic motor oil instead of heavy gear oil. I can run at 6000 RPM with no problems. I have very little metal shaving stuck to the magnet in my gearbox, so it is doing fine, and the gear teeth all look good. I have the strong magnet in the bottom near the drain hole to catch any shavings when I drain the oil. The drain plug in mine is a 1/4 NPT thread, so I just installed a 1/4 valve to make it easier to drain the oil. You can reinstall the drain plug in the end of the valve for extra security.

@mwmxcnc

6 ай бұрын

@halfstep67 Luckily when I recorded the video I tried to read out the bearing numbers, I think I can figure them out, but my question is how are you getting 6k rpm? I would love to get mine even to 3k would be awesome. Mine tops at 1500 the PM’s are nicer machines from what I’ve read, what did yours start with and how did you get it up to 6k? I’ve been trying to devise a plan to up the rpm’s for a long time, and other than swapping the gearbox out for some sort of pulley system or adding a pulley system to it, I haven’t really been able to find a way. I don’t know much about 3ph motors, but I have read they can be run at a higher hz to get higher rpms, but I’ve always looked at vfd’s as kind of a headache, seems people run into problems mainly with the cheaper vfd’s.

@halfstep67

6 ай бұрын

@@mwmxcnc Since I converted my PM940 to CNC, I had to buy a VFD and a 3-phase motor so the CNC controller can turn the motor on/off and control the speed and direction. I have a 3 PH 2 HP 3600 RPM motor. I have a tachometer so I can accurately clock the RPM. I can hit 6K pretty easy and even higher with angular contact bearings in the spindle. Even if I didn't do a CNC conversion, I would still want a VFD and 3-phase motor for the ability to control the RPM. It is a game changer for a bench top mill. You will need to go with better spindle bearings. The factory spindle bearings are a tapered bearing, and you can replace them with higher quality, higher RPM tapered bearings. Or you can go with angular contact bearings that are made for higher RPM than the tapered bearings. With a good quality tapered bearing, you can get 6k for short periods. With the angular bearings, you can run all day at 6K. There are some other things you will need to do to set the spindle bearing preload and maintain it and to get good concentricity with little run-out. I replaced the spanner nut with a better one from J. W. Winco.

@mwmxcnc

6 ай бұрын

Alright, now I’m gonna need more info, your machine sounds awesome, did you come up with everything on your own, or is there some sort of write up somewhere? looking at the pm940, it appears to have a quite a few differences, so I’d bet the gearing and bearings are different. But knowing what you went with, and had success with for spindle bearings, motor and vfd would be a good start. I haven’t searched the web lately for someone who has done the conversion, so maybe there is a write up somewhere now. Being able to control the spindle with the control would be nice.

I am doing mine right now. These machines, have huge amounts of casting sand left in them from the manufacturer. I replaced all the bearings AND found a couple keyways way too loose, which might be the problem with your noise in reverse. There is a 7 part series from a guy named "John Workshop ZX7045" on a rebuild for these machines, what he found was pretty much what i found in mine. Cheers

@mwmxcnc

6 ай бұрын

Yeah I took mine apart and cleaned everything when I first purchased it, but I didn’t know to look for loose keys I’ll be back in there again soon. It was loaded with crud in the gearbox. I’m having a hard time deciding which route to go with to get the spindle seed up. Do you have any plans for that? It’s a killer whenever I have to use a small tool at 1500rpm’s.

@lahoz84

6 ай бұрын

@@mwmxcnc how do you guys adjust the setscrew on left side of the head in wich the quill keyseat rides on? Im totally lost there.

@frankk8018

6 ай бұрын

@mwmxcnc sorry missed your reply. I have no answer on how to speed up the machine, but I have heard rumors that people remove the gear set and go for a belt drive in conjunction with a VFD to control speed. That would open up a lot of options, but after this teardown, see what I saw, I am not sure if the machine is worth the effort. Cheers

@frankk8018

6 ай бұрын

@supla84 horrible system! If I had endless time and money, I would rethink that whole system. I just go by, feel, and lock it down where I think is a good compromise between having too loose of a quill and tearing the crap out of it. Cheers.

Heb jij een tenische tekeningen van de tandwielkast A.U.B ik ben daar opzoek naar

@mwmxcnc

5 ай бұрын

Sorry, I do not have drawings.

@user-ej3ss7lr6d

5 ай бұрын

Bedankt voor uw bericht

Salut camarade j'ai la même machine et je viens de changer tous les roulements à billes et il m est arrivé le même problème que toi et je ne voulais pas démonter à cause du joint qui devait avoir séché 😢 et il me restait ce put... de circlips en fait il te suffit de prendre une tige en acier de 60 centimètre de la faire rentrer par le dessous et tu tapes par le dessous sur le pignon qui remonte😮 Et tu vois la gorge du réapparaître hourrrrrrrrrrrrrrrrrrrra 😅😅😅😅😅😅😊😊😊😊😊😊😊🎉🎉🎉

@mwmxcnc

4 ай бұрын

Well that is good to know for next time! Thanks

Uhmmm unbelievable dude! I've got one of these animals too. But, being a life-long mechanic, there's some things I wouldn't do like you did. Sorry. Let me make my own! Like getting it all back together for a 3rd time and find some extra parts laying on the bench? And let's see, didn't you say you knew after the fact what was binding without doing what you did? That's a PITA! And didn't you know these machines are supposed to sound like a bunch of junkyard dogs arguing over who gets the shinbone? Hey if you do do a headstock modification, let us know.

@mwmxcnc

Ай бұрын

Yeah that was definitely an unnecessary rebuild haha. But it did let me get the bearing numbers, and video of how it all goes together so I will have a better idea of how to convert it to a higher rpm motor. Which I plan to do someday. Also, as a mechanic, you’re saying you don’t end up with bonus parts after most jobs? I have a whole mountain of them! Haha

Why does everyone use the word "is" when they should use "are"? "there is... two" (In this case it's understandable because the sentence might have been "There is one.")

@mwmxcnc

7 ай бұрын

They both sound proper to me, but you are right, depending on the plurality of following noun in the sentence, determines which you use "there is" or "there are".

@drstrangelove09

7 ай бұрын

@@mwmxcnc"there IS two" is wrong... it is "there ARE two"

@paulypaulypauly8011

3 ай бұрын

You is right,

@drstrangelove09

3 ай бұрын

@@paulypaulypauly8011 hahaha