New PM-25MV Mill

[shooter123456]

I was thinking of going with 2 shaft steppers so as not to lose manual mode but with a pendent fitted I think I can do the same thing as manual but using each motor to wind the handles.

I have heard a lot of people saying the same, but I wouldn't really bother. It doesn't end up being too practical to turn handles through the motors. You need to turn the motors off so that they aren't holding their position anymore, but that means the controller loses its position and you will need to re-touch off or rehome before using CNC again. Even then, the steppers have detent positions so while you turn the handles, you feel clicks as it moves. Simply jogging manually does the same thing, just through the controller.

For th OP shooter123456, the newer pm25mv have been modified, the X and Y endplates now have 70mm centres on the fixing bolts to table so dont rush out too many kits at the old measurment of 120mm between centres as you might get stuck with them for a while.

That change must have been made before I got mine as mine is roughly 70mm (I measure in imperial, I am actually getting about 71.8mm spacing). But thanks for looking out, that would have been rough if I made a bunch of parts that no one would ever need.

If you would sell a copy of your drawings, especially the fastening nuts that fasten ballnut to table/sled, I would be interested as I'm not looking forward to modeling especially Z axis, disasemble check fit, reasemble and modify a couple of times to get it right, then repeating same on other axis. Let me know.

Shoot me a private message with your email address and I can send you some models.

I've been thinking of using 5.5nm(778 oz/in) nema 24 al round or even next size down for X and Y, the nema 24's fit nema 23 mounting plates that I have so thats not a problem

Those motors might be a bit overkill, but nothing wrong with going bigger than needed. I had great success with 400 oz in steppers for X and Y and their limitations were limited to speed which stronger motors wouldn't have helped. Also, make sure you double check the dimensions for whichever motors you use. I just had an issue in the past few weeks where I had to make some new parts for someone because they were using Nema 24 motors and the mounts didn't have the correct hole spacing. Even though it is supposed to be standard, some manufacturers take liberties with the standards.

 

[kered]

Message sent, i think/hope, as to the motors i was a bit woried that the 3nm(424oz) might not be powerful enough for X&Y and definately not for Z but the 5.5nm gives me 778 oz which acording to david at arizona video is ample and even 650oz are fine, most nema 24 are hole compatible and to get them otherwise you have to ask, on the places I've looked they all say they are nema 23 hole pattern, also some of the nema 24's are 3 phase and AC, another posibility
Most of the 424 oz nema 23 I've seen have very high inductence well over the recomended max of 3.5 so heat will affect them, thats probably why your new drivers gave better performance as they use only the necesarry holding amps hence less heat

Jimrk, thanks for the video link, I have sean it but the files are dificult to load in fusion and try to get meassurments from, its probably just me as I'm lost a bit in fusion, I manage to make the odd model for 3d printing but managing other files no so much. I was hoping to be able to print them in pdf with measurments but not yet found how, even if possible. I also think its the older model by the endplates.
thanks
Derek

 

[kered]

I think I should start a new thread of the conversin rather than hijack this one any further.

 

[jimrk]

Message sent, i think/hope, as to the motors i was a bit woried that the 3nm(424oz) might not be powerful enough for X&Y and definately not for Z but the 5.5nm gives me 778 oz which acording to david at arizona video is ample and even 650oz are fine, most nema 24 are hole compatible and to get them otherwise you have to ask, on the places I've looked they all say they are nema 23 hole pattern, also some of the nema 24's are 3 phase and AC, another posibility
Most of the 424 oz nema 23 I've seen have very high impedence well over the recomended max of 3.5 so heat will affect them, thats probably why your new drivers gave better performance as they use only the necesarry holding amps hence less heat

Jimrk, thanks for the video link, I have sean it but the files are dificult to load in fusion and try to get meassurments from, its probably just me as I'm lost a bit in fusion, I manage to make the odd model for 3d printing but managing other files no so much. I was hoping to be able to print them in pdf with measurments but not yet found how, even if possible. I also think its the older model by the endplates.
thanks
Derek

I'm no wizard in fusion but sketches are your friend. if you turn them on you will find dimensions. also inspect-measure is good.

you can also export to other formats.. Good luck.

and file-new drawings you can create your own pdf with demensions

 

[kered]

As I mentioned I'm not so good with fusion, I'll give that a go and se what i can deduct from them.
I have measured my endplate bolt centres and they are 70mm, in francos drawings they are 120mm, the above images/drawings one is 70mm the other is 72, to be sure I think I will take mine of and draw round them then stick the drawing onto a piece of plate to get them exact, but just on this example there are differences, I would imagine the others too so which is correct, with the ballnut mounts its an industry standard size other than fisical size and the fixing holes to the table or Z sled and can be/are slightly slotted I hope.
thanks again
Derek

 

[kered]

Just come across a problem, all the plans I have are for 1605 ballscrews and my Z axis is 2005 ballscrew, the problem is the block that fixes the ballnut to the head of the mill, it calls for a start block of 85.5x40x25mm, the 1605 ballnut is only 28mm but the 2005 ballnut is 36mm, when you put a hole of 36mm through a 40mm block you only have 2mm either side holding the full weight of the milling head, I doubt its enough, if you updated to a 2005 ballscrew what was the dimentions of the block you used or did you just bore it out and have it like mine, very thin. I might just make another one out of toolsteel just in case but a bigger block would be better A quick sketch with dimentions would be handy as if I make it too big it might get hung up somewhere.

 

[shooter123456]

Just come across a problem, all the plans I have are for 1605 ballscrews and my Z axis is 2005 ballscrew, the problem is the block that fixes the ballnut to the head of the mill, it calls for a start block of 85.5x40x25mm, the 1605 ballnut is only 28mm but the 2005 ballnut is 36mm, when you put a hole of 36mm through a 40mm block you only have 2mm either side holding the full weight of the milling head, I doubt its enough, if you updated to a 2005 ballscrew what was the dimentions of the block you used or did you just bore it out and have it like mine, very thin. I might just make another one out of toolsteel just in case but a bigger block would be better A quick sketch with dimentions would be handy as if I make it too big it might get hung up somewhere.

Flip the ballnut around. Then you only need the hole through it to be enough to clear the screw.

 

[kered]

even flipping arround its only support is 2mm either side, although it does have 2 thin bolts in each half if it breaks. Having said that it also only bolts onto the head with a single cap screw. I think i'll try a one out of 46mm stock instead of 40mm, that will leave 5mm either side.

 

[shooter123456]

even flipping arround its only support is 2mm either side, although it does have 2 thin bolts in each half if it breaks. Having said that it also only bolts onto the head with a single cap screw. I think i'll try a one out of 46mm stock instead of 40mm, that will leave 5mm either side.

Are you thinking something that looks like this?

 

[kered]

yes, the bottom piece