[cowanrg]

I am currently looking to upgrade my X2 clone (MicroMark) that has been converted to CNC. It's just too small for what I want to do. When I converted it, I bought all the electronics and motors necessary for a bigger mill, so I already have almost everything I need for a conversion (controller, motors, etc). I use 570 oz/in steppers, 5060D drivers, etc.

I was originally planning on the G0704 based on how much documentation there is on it. But the more I started looking, the PM-30MV seems like a better mill. It now uses the KB Electronics speed control board, has a bigger motor than the G0704 (a common upgrade/complaint it seems), and the price isn't that much more.

I mostly do alumunum, and really only use my mill for fun. I don't need insane accuracy/precision, or need to cut exotic materials. But, I also want to make a wise investment and not regret buying the wrong mill either. My shop is also relatively small, so the 30MV is about as big as I could go (I would probably not even get the longer table, because it takes up more room, and I don't need that much x travel).

I bought Hoss' DVD like everyone else, and it looks like MOST everything would translate to the PM-30MV. But at the same time, I don't want to go on a wild good chase trying to shoe-horn everything into a different mill. I was planning on buying the C7 ballscrews from automation technologies, and using my X2 to mill all the other parts. Any thoughts? Is the PM-30MV really worth the extra few hundred?

[arizonavideo]

I have three mills a IH(big RF 45 clone) a Weiss 30 /PM30 and a G0704 mill.

All are good but I really like the Weiss 30. It is almost twice the size as the 704 and the motor is big enoughf out of the box. It is no IH but it a perfect size for hobby use that you wont outgrow vary fast. The table is biger than you might think.

The main problem wit the 30 is it is priced so close to the RF45 so most just go for it. The 45 will mow through metal way faster then the 30 but it is much louder and has a lower spindle speed and it not nearly as nice to use untill you add a belt drive to them.

You will be happy with the 30 so go for it.

And I'm going to make some CNC kits to fit the 30 too.

[hoss2006]

cowanrg, have a read thru this thread if you haven't yet, same scenario.
http://www.cnczone.com/forums/bencht...onversion.html
Hoss

[cowanrg]

cowanrg, have a read thru this thread if you haven't yet, same scenario.
http://www.cnczone.com/forums/bencht...onversion.html
Hoss

I have. I just finished reading every post in that thread before I started here. I've read that and many of the recent G0704 threads over the past few weeks. What I'm seeing is that the G0704 has a weak link, and that's the motor. I haven't been able to find nearly as much information on the PM-30MV, it seems like a lot less people get it, even though it's not THAT much more than the Grizzly. I am just curious why, since they do seem pretty close to one-another.

arizonavideo, that's good to know. I figured if someone had both, and they had the space, they'd probably prefer the PM-30MV, but there's not a lot of comparison done.

Really, I'm just a BIT nervous about choosing it over the G0704 because of the lack of documentation. Hoss' DVD, and others' builds give me all the information I need to not make a mistake, or buy the wrong thing when doing a conversion. But there are so few PM-30MV conversions that I feel like I might run into snags along the way. I was really hoping to just buy the ballscrews from Automation Technologies and not have to think much about it, but that might not be the case with the PM-30MV.

[AVRnj]

Cowanrg, I may be mistaken but I don't think you can use the ballscrews from automation technologies for the PM-30MV. I believe there are too many differences, but again I may be wrong.

In all honesty, buying the ballscrews from linear motion is not really a big deal, you send them your drawings they invoice you and you get them a few weeks later, many have bought from them.

There definitely is not as much documentation on the PM-30's, and there are some definite differences.

That said, I think Hoss' DVD plus the existing threads by digits, longrat and hopefully mine in the future will provide enough info if you are willing to make some tweaks.

I was in the exact same boat, I have an SX2L that I converted and wanted something bigger. For me I knew if I bought the G0704 I would want to upgrade the motor, and depending on how much you spend, you start getting closer to the PM-30's in cost.

Ultimately for me I wanted to go as big as I possibly could fit, afford, handle this time around as I don't want to do another one after this one, 2 mill conversions and a lathe conversion is enough for me. I was very close to going with a RF45 clone, but my concern was the weight of that beast would be just too much for me to handle on my own.

That led me to the PM-30-LV. I will say it is heavy. The head, column and table are all very heavy. I can manage them by myself, but they are not easy at all.

As of now, I am happy with my choice, but until I am done I don't know if that means anything. I can tell you without a doubt that I have spent a lot more time just working through the design of the conversion than had I gone with a G0704 and used Hoss' plans straight up. For me, that is part of the fun of it though.

Good luck.

[cowanrg]

Hey AVRnj. I've been following your recent thread, and that's one of the reasons why I've been thinking about the PM-30MV over the G0704. It really sounds like the PM-30MV is a better machine, and worth the extra money. I'm just sorta new to all the mechanical stuff, so I'm very nervous about ordering custom ballscrews. I liked the G0704 because of the "just buy exactly these parts and it will work" documentation. I don't know what size bearings to get, etc. Also, with Hoss' DVD, I had planned on building many of the parts before the mill arrived (on my current mill) so the transition would go a lot quicker.

I saw you are getting close to ordering some ballscrews. I know the ones for the G0704 run around $200-$250, do you expect yours to be in the same range? I also want to make sure the conversion side of things isn't twice as much money. I already have the motors and electronics, but I was budgeting around $500 for ballscrews, hardware, and other materials for the conversion. Does that seem reasonable?

Weight isn't THAT big of an issue. I full intend to disassemble the mill and re-assemble it on the stand, and I don't really need to move it around once it's placed. I might even do a heavy-duty mobile stand for it as well... But as long as each piece is around 100-150 pounds, that's fine by me.

[ruffle]

For my 30LV, I used the ballscrew dimensions posted by Longrat in his build thread. They were spot on.

Obviously you do need to check your machine as there are differences between the various versions of the 30's.

Re moving the parts around - yes it's possible but you do know if you've needed to move the column or the table; the other bits are easy(ish).

[AVRnj]

Hey AVRnj. I've been following your recent thread, and that's one of the reasons why I've been thinking about the PM-30MV over the G0704. It really sounds like the PM-30MV is a better machine, and worth the extra money. I'm just sorta new to all the mechanical stuff, so I'm very nervous about ordering custom ballscrews. I liked the G0704 because of the "just buy exactly these parts and it will work" documentation. I don't know what size bearings to get, etc. Also, with Hoss' DVD, I had planned on building many of the parts before the mill arrived (on my current mill) so the transition would go a lot quicker.

I saw you are getting close to ordering some ballscrews. I know the ones for the G0704 run around $200-$250, do you expect yours to be in the same range? I also want to make sure the conversion side of things isn't twice as much money. I already have the motors and electronics, but I was budgeting around $500 for ballscrews, hardware, and other materials for the conversion. Does that seem reasonable?

Weight isn't THAT big of an issue. I full intend to disassemble the mill and re-assemble it on the stand, and I don't really need to move it around once it's placed. I might even do a heavy-duty mobile stand for it as well... But as long as each piece is around 100-150 pounds, that's fine by me.

I am pretty new to all the mechanical stuff as well. My X2 conversion was using a cncfusion kit, so I am coming from a similar place. For the most part, it seems to me that converting a mill whether it is a G0704 or a PM-30/BF30, RF45, X2,X3 etc. with dovetail ways for the most part is a very similar process. You are dealing with 3 axis, a base, a saddle a column and a table. The measurements vary, the shapes vary, and you have some choices you can make like ball screw type, single nut vs double nut, AC bearing type and size, etc, but I feel like there is a lot of similarities between the conversions when you really break it down.

I guess it ultimately comes down to how much you want to design your conversion vs. just do the conversion and your apatite for learning this stuff. For me, I wanted to learn all this stuff, and I was actually kind of let down after doing my X2 in that I just put the parts on the mill but did not really understand what was there or why it was there. But I can certainly understand the appeal to a G0704, following Hoss' DVD and spending more time using the mill than converting it as well.

I did order my ballscrews. I ordered 2005's for all 3 axis with a double nut for each. I wanted to go with a 2505 for the Z, but the double nut was not available so I opted for the 2005 with a single nut. I think this will be Ok since the PM-30 comes with a shock spring to help with the load of the head. Shipped to my house, X axis ground and I have the longer table so my x screw was very long, I was UNDER $250.

The bearings I will be using for all axis will be the 7202B from VXB, about $10 a piece and I need at least 7.

I have not figured aluminum costs yet, but I don't think it will be too bad.

Because I am going with the bigger ball screws for the X I wanted to use bigger bearings which will mean more parts I need to make for my mounts as I cannot use the x parts from my mill like Hoss does in the G0704, so that will add price as well.

I think if you have the motors and electronics, $500 seems very do-able, and by going with the 1605's on X at least you can save even more money and not have as many parts to build as well..

I don't think anything was over $100 lb.'s. The head was very heavy, the table was very heavy, and the column was very heavy, but I was able to move them all by myself and I am not overly strong, not weak either.

[Fastest1]

Until recently I dont believe most of us were aware of the availablity of the combined double ballnut Chai is offering. We have seen builds were 2 ballnuts were used but that is a much larger overall package and limited travels a bit more. I am sure the builds from now on will see their use much more often.

I did see the same double nut in a 2005 recently on Ebay (no screw) though it wasnt Chai. In reality the 2005 spec should be enough to get a compatible part from many manufacturers. I would still say buyer beware unless the entire assembly was built and purchased at the same time. I know Chai did not want to sell them separately (he probably would have sold them to me if pushed but he was very concerned that they might not work). Knowing that I had just purchased a set from him with little time for use, he did offer a very good price if I was to order. I will hold off for the moment. Too many unfinished projects right now. The mill works, not finished but it is running just fine.

[cowanrg]

I am pretty new to all the mechanical stuff as well. My X2 conversion was using a cncfusion kit, so I am coming from a similar place. For the most part, it seems to me that converting a mill whether it is a G0704 or a PM-30/BF30, RF45, X2,X3 etc. with dovetail ways for the most part is a very similar process. You are dealing with 3 axis, a base, a saddle a column and a table. The measurements vary, the shapes vary, and you have some choices you can make like ball screw type, single nut vs double nut, AC bearing type and size, etc, but I feel like there is a lot of similarities between the conversions when you really break it down.

I guess it ultimately comes down to how much you want to design your conversion vs. just do the conversion and your apatite for learning this stuff. For me, I wanted to learn all this stuff, and I was actually kind of let down after doing my X2 in that I just put the parts on the mill but did not really understand what was there or why it was there. But I can certainly understand the appeal to a G0704, following Hoss' DVD and spending more time using the mill than converting it as well.

I did order my ballscrews. I ordered 2005's for all 3 axis with a double nut for each. I wanted to go with a 2505 for the Z, but the double nut was not available so I opted for the 2005 with a single nut. I think this will be Ok since the PM-30 comes with a shock spring to help with the load of the head. Shipped to my house, X axis ground and I have the longer table so my x screw was very long, I was UNDER $250.

The bearings I will be using for all axis will be the 7202B from VXB, about $10 a piece and I need at least 7.

I have not figured aluminum costs yet, but I don't think it will be too bad.

Because I am going with the bigger ball screws for the X I wanted to use bigger bearings which will mean more parts I need to make for my mounts as I cannot use the x parts from my mill like Hoss does in the G0704, so that will add price as well.

I think if you have the motors and electronics, $500 seems very do-able, and by going with the 1605's on X at least you can save even more money and not have as many parts to build as well..

I don't think anything was over $100 lb.'s. The head was very heavy, the table was very heavy, and the column was very heavy, but I was able to move them all by myself and I am not overly strong, not weak either.

You're right, for the most part, it's all the same thing. There's not a lot of room on an X2, and I like the idea of having extra room on the PM30. It looks like enough people have done ballscrew conversions on the PM30 that I don't have to reinvent the wheel, so I'm OK with that. I'll probably just copy what others have done :-)

Aluminum cost should be negligible for me as there is a screw aluminum place near me and I can get stock for next to nothing. And I already have some stock that should work fine as well.

It really does sound like less than $500 should be just fine. I might upgrade the z-axis motor down the road, as it's only ~700oz/in I think, but that's easy enough. It looks like I might be getting a PM-30MV then! It sounds like the mill to go with if you can handle the size and extra cost.

[arizonavideo]

If your ways are smooth the 700 oz stepper is way big enough for the Z.

The PM-30 is really the best small mill out for the money. The motor is not too big but you can work with it just fine just watch the face mill. The fit and finish on mine was great but I did fine the the Z ways were not ground all the way smooth. The table is great and the mill is just easy to use stock.

I still find myself using the IH more and more now that it has the belt drive. I used to use the 30 for any part I did not CNC but now I find that the IH is quiet so I just use it unless I have parts running and need to do a op.

Perhaps it time to get the 30 CNC'ed too.

[hoss2006]

It's been my experience here that it doesn't matter what spindle motor the mill comes with, people will seek to upgrade it to something bigger eventually, usually double the output.
Hoss

[cowanrg]

Yes, I've seen that happen a lot. But it seems to happen more as a result of people buying an underpowered mill for their needs, rather than upgrading for the sake of upgrading.

[hoss2006]

Most people buy the machine for it's work envelope, the motors on these machines are conservative for their size partly because of safety concerns.
I run the bf30 motor on my g0704 which is more on par with it's capabilities, I'd expect the BF30 mill can do with a stronger motor still.
Hoss

[LongRat]

Hoss is right. More motor on the 30 would not hurt at all - chances are it will fail anyway so there you go!

[cowanrg]

Yeah, I get it, motors can fail, and I might be upgrading it someday. But it sounds like the motor and controller that come with the PM-30MV are at least decent. At the very least, I can keep the controller, since it's what a lot of people upgrade to on the G0704.

I think I'm going to go with the PM-30MV. I think the BF45 variants are just too big and heavy for me.

[arizonavideo]

If you have dreams of massive material removal with a 5HP motor going 6K then get the RF-45 and add the belt drive. The 30 just wont do what the 45 can in that way.

But if you want to do some cuts with a 1/2" EM and have lots of different ops to do the 30 is IMHO the best hobby mill for the money. The table is larger than you think and the mill don't look that big, then you try to move it and OMG this thing is heavy! On my Weiss 30 I am always happy just looking at the big perfect table it has.

A bigger motor would be nice but the stocker is OK out of the box. I'm looking at the one of the larger 3HP tread mill motors and perhaps changing the output drivers in the controller with higher amp units and a bigger heatsink and a fan of some kind. Its a bit of a hard call as I have a extra 2HP 56C sitting here and you can a OK VFD for $120. I don't know how much more I will use the 30 when I CNC it, right now its like a second Op mill. Some drilling tapping a small surface and such.

[cowanrg]

hum, interesting. From what I've read, it looks like you'd have to rebuilt the spindle if you wanted to do higher RPM. I think it was longrat that had some heat issues when going over 3k RPM.

Honestly, as long as it cuts cleanly with reasonable depths, I'm fine. My X2 is just ridiculously slow, and there's just some things it can't do because it's not rigid or powerful enough. I don't mind going slow.

[arizonavideo]

My spindle came with a lot of preload and took forever to break in. I mean I ran it for hours and hours at lower speeds and it still ran really hot at higher speeds.

It must have been at least 30 or so running hours at higher speeds before it started running cooler.

I to think they set the preload too tight sometimes.

The bearings can be set with vary light preload and will run fairly cool and still be OK for milling it's just is hard to find the correct spot.

Break it in a slower speeds and do short high speed runs watching the temps closely. You should always be able to touch the housing without burning yourself.

[cowanrg]

ah ok. how is yours running now? do you still run the belt drive at higher speeds?