PM's Mills

[jwmay]

@jwmay, I've been using a harbor fright mill that might on a good day be good to a thou. There are a number of things wrong with it, and were I to keep it, the whole tool would have to be torn down, examined, and worn parts replaced. Any mill on the market today would do for me, however, i'm calling their bluff...so to speak. I want to know what they mean by 'ultra precision' and what @davidpbest calls FUD fighting words (whatever that acronym stands for). I'd call their description laced in technobabble or ad-speak. It's meaningless verbiage when they could have said exactly how the 728 is better than the other mills they sell. Give me a good comparison, please. They don't have a showroom. Why should I buy their mill and be disappointed by something that does not meet expectations or is difficult to use (like the top mounted Z axis wheel on the 728*) when I can ask you guys here and get good answers to my questions.

I guess you came to the right place for answers then.
I can empathize with you on the technobabble stuff. I personally regard it as meaningless sales jive for people with money to burn.


Maybe it does mean something, and maybe if you keep at it, somebody will tell you. I won’t be convinced it matters, but I’m not
the buyer.

Good luck!

Actually having read David Bests reply, I’m pretty sure he gave you what you asked for.
That’s not technobabble. Those are useful descriptions, which when absent would lead me to believe they aren’t included.

 

[matthewsx]

What HF mill do you own? If it's one of their mini-mills then you're probably ready to upgrade. If it's the RF30 clone it may be worth putting a little work into it if for no other reason then making it better for the next owner.

If PM has offered to un-crate and show you whatever machine you're interested in, and you're driving distance I'd be tempted to take them up on the offer. If you like what they show you then have it loaded up and be on your way. I have a Fender bass that was demoed to me at Guitar Center. Played a bunch of them and settled on the one I have. The salesman said, "great, I'll go in the back and get one for you" I told them no, I want the one I've tried out. This may be something like that situation, no matter how much effort PM puts into it they will have some that slip through that aren't up to snuff. It's their commitment to customer satisfaction that differentiates them from what I see. I think every successful business has to employ a measure of "salesmanship" to keep the lights on. The fact that PM has a backlog of orders speaks not only to that, but also their after the sales support.

Lastly, are you really sure a bench mill is what you want? Have you had the chance to run a Bridgeport or clone? I've finally settled on an older 8x35 knee mill that takes up little more space than a similar sized bench mill and I'm happy I made the room in my little shop. @davidpbest does a good job of explaining the differences between his former RF45 and current PM 935 I think. There are definitely good and bad things about both but taking the time at this stage to make sure you'll be happy in the long run is worth the effort.

Glad you're here with us now and best wishes for getting the machine you really want.

John

 

[davidpbest]

@davidpbest, I've read the PM descriptions and what you quoted is not news, however, how does this translate into the quality of the end product? If not hand scraping the ways does not yield any benefits that folks here have seen using PM's other mills, why do that? If it does give better machining results, quantify them, please.

From my own experience, after scraping in the X & Y axis ways on my RF-45 (the original real square-column benchtop) I was able to consistently improve tolerances of machined parts from ±0.0015 to ±0.0003". That may or may not be significant to you, but for the type of parts I was making, it was the difference between "acceptable" and "reject." Of course you can't control tolerances without experience and using best practices in how you set up and operate the machine - even if the ways are on air-bearings.

I want to know what they mean by 'ultra precision' and what @davidpbest calls FUD fighting words (whatever that acronym stands for). I'd call their description laced in technobabble or ad-speak. It's meaningless verbiage when they could have said exactly how the 728 is better than the other mills they sell. Give me a good comparison, please.

"FUD" = fear, uncertainty, and doubt - exactly what you are feeling at the moment comparing descriptive copy for the different machines.

They don't have a showroom. Why should I buy their mill and be disappointed by something that does not meet expectations or is difficult to use (like the top mounted Z axis wheel on the 728*) when I can ask you guys here and get good answers to my questions.

If you really want a showroom to compare different quality machines, Grizzly in Springfield Missouri would do a fine job of that.

I doubt the attached will be of benefit, but since one of the other posters mentioned it, I'm including my write-up. Warning - it might give you more FUD. LOL

 

[wrmiller]

No machine tool for sale today won’t hold .001”. Asking for that level of detail is akin to asking a car dealer to point out that all the cars have steering wheels.

The wild card here is the hands at the controls. Without hard stops, I doubt many of us are capable of repeating to .001” anyways.

If you need greater precision then .001”, then you need to start looking at surface grinders.

Most professionals I’ve met get by just fine with equipment that’s been hard used by uncaring and random operators for decades. Hobbyists ought to relax a little probably.

And some of us 'hobbyists' can, and have repeated to a thou. On my old PM935 mill. And I repeated to +/- a few tenths on my PM lathe. Pain in the ass, but sometimes it's called for.

Once you learn a machine, it's amazing what you can do on it.

 

[Geswearf]

@matthewsx, I have the smallest mill HF makes - it cost 600 originally, I paid half that to a friend when he was finished with it. HF says they have only 4 parts available for it and everything is loose/worn. Tightening up gibs does not solve the problems.
I will take PM up on their offer, but I feel its asking too much for them to uncrate two or three machines for me to look at. My understanding was its an unpowered look...I'm not going to be using the machines so unless I mike every part I won't know if the machine is out of tolerance or not. Their facility is basically a warehouse and a mill is not the same as a guitar (but you know that). I would love to have a Bridgeport, but I simply do not have room for one. I did see one at an estate sale about a mile from my house in the guy's garage. I could have had it for pennies - they had no idea how to move it out but the constraints prevented me from pursuing it. Besides, my needs are for something smaller. As I said in another post, a university nearby has a complete machine shop that I have access to - a genuine B-port, three full size knee Jets, a huge Clausing lathe, 4 jet lathes, a water jet machine, welding shop, wood shop, etc... It is a big pita to use that facilty because of parking and the need to work on someone else's schedule (not to mention work around students' needs for the machines) but it is a last ditch option for me when I need something bigger.
@davidpbest, thanks for the link...I'd already seen that because it is posted in another link elsewhere on this site (I tend to do at least a little reading before opening my mouth...er...keyboard.). At this point in my life, I have no need for such tight tolerances, and really have my doubts about ever needing that.
@wrmiller, you have echoed my feelings and questions about the 728VT vs other mills. If you can do that on a Chinese (not Taiwanese) PM935, then the real difference is the operator. I'm not so naive to think a good machine won't give one better results than an ok machine, but maybe the 728, if it really is built to tighter tolerances, will be easier to use by a novice. On the other hand, the 728 costs the same as the heavier and somewhat larger 30MV and 932V (the latter weighs in at 1000#...pushing it for moving it into my shop).

 

[matthewsx]

I have nothing more to add to this discussion.

Hopefully you’ll get what you need for your shop, we all go through a process figuring what our budget, space and time will allow.

John

 

[verbotenwhisky]

I don’t own any PM products so you can dismiss my comments if you like.

Asking questions and reading this forum will get you most of the way towards answering the questions you asked in this thread.

In general, all machines built in Taiwan will be better fit and finish than China. Quantifying how much more accurate they are is probably beyond what any manufacturer or reseller is capable of doing. There are just too many variables including the biggest one, the operator.

PM has been a forum sponsor since before I joined here and from what I’ve seen has earned the reputation they have. People here do great work with both their Taiwan built and mainland machines. Also with tools from other suppliers.

Mostly your decision should come down to your expectations. If you want a supplier who supports what they sell then PM will probably not disappoint. If you value a higher standard of workmanship then go for Taiwan built.

However, if you desire perfection from the machine itself you may be disappointed no mater what you get. Precision is something to work towards, not something you can buy. There’s a reason drawings have tolerances called out, and although getting closer is good it’s not always worthwhile.

Good luck in your pursuits here, no matter what your passion you’ll find someone on the forum who shares it.

Cheers,

John

It isn't the accuracy that is the issue as much as the quality of castings and the amount of body filler. Things like the DRO mounted to far back on the machine. I added an extra section of arm to the DRO mount to move the display forward. When it comes to quality I know B2 had issues with his PM940M-CNC but I know of at least 1 individual on this forum that had issues with a Taiwanese machine as well. The biggest thing in my opinion is certainly fit and finish. I have a PM940V-PDF, got it with all the options and then made a few adjustments to make it mine, I would buy it again.

I know this isn't the machine you are looking at but it is the machine I have, hope that was a little help.

 

[verbotenwhisky]

@matthewsx, I have the smallest mill HF makes - it cost 600 originally, I paid half that to a friend when he was finished with it. HF says they have only 4 parts available for it and everything is loose/worn. Tightening up gibs does not solve the problems.
I will take PM up on their offer, but I feel its asking too much for them to uncrate two or three machines for me to look at. My understanding was its an unpowered look...I'm not going to be using the machines so unless I mike every part I won't know if the machine is out of tolerance or not. Their facility is basically a warehouse and a mill is not the same as a guitar (but you know that). I would love to have a Bridgeport, but I simply do not have room for one. I did see one at an estate sale about a mile from my house in the guy's garage. I could have had it for pennies - they had no idea how to move it out but the constraints prevented me from pursuing it. Besides, my needs are for something smaller. As I said in another post, a university nearby has a complete machine shop that I have access to - a genuine B-port, three full size knee Jets, a huge Clausing lathe, 4 jet lathes, a water jet machine, welding shop, wood shop, etc... It is a big pita to use that facilty because of parking and the need to work on someone else's schedule (not to mention work around students' needs for the machines) but it is a last ditch option for me when I need something bigger.
@davidpbest, thanks for the link...I'd already seen that because it is posted in another link elsewhere on this site (I tend to do at least a little reading before opening my mouth...er...keyboard.). At this point in my life, I have no need for such tight tolerances, and really have my doubts about ever needing that.
@wrmiller, you have echoed my feelings and questions about the 728VT vs other mills. If you can do that on a Chinese (not Taiwanese) PM935, then the real difference is the operator. I'm not so naive to think a good machine won't give one better results than an ok machine, but maybe the 728, if it really is built to tighter tolerances, will be easier to use by a novice. On the other hand, the 728 costs the same as the heavier and somewhat larger 30MV and 932V (the latter weighs in at 1000#...pushing it for moving it into my shop).

I understand limits and confined space issue; but on these machines mass is king. the 940 bed mills weigh in the neighborhood of 1300 pounds with the base, the mass makes them very stable and rigid.

 

[Aaron_W]

Blondihacks upgraded from a PM25 to a 728T. That is probably the best direct comparison I know of, they are very similar in size so a good example of the differences between Taiwan (728T) and China (PM25) made.

 

[wrmiller]

@matthewsx, I have the smallest mill HF makes - it cost 600 originally, I paid half that to a friend when he was finished with it. HF says they have only 4 parts available for it and everything is loose/worn. Tightening up gibs does not solve the problems.
I will take PM up on their offer, but I feel its asking too much for them to uncrate two or three machines for me to look at. My understanding was its an unpowered look...I'm not going to be using the machines so unless I mike every part I won't know if the machine is out of tolerance or not. Their facility is basically a warehouse and a mill is not the same as a guitar (but you know that). I would love to have a Bridgeport, but I simply do not have room for one. I did see one at an estate sale about a mile from my house in the guy's garage. I could have had it for pennies - they had no idea how to move it out but the constraints prevented me from pursuing it. Besides, my needs are for something smaller. As I said in another post, a university nearby has a complete machine shop that I have access to - a genuine B-port, three full size knee Jets, a huge Clausing lathe, 4 jet lathes, a water jet machine, welding shop, wood shop, etc... It is a big pita to use that facilty because of parking and the need to work on someone else's schedule (not to mention work around students' needs for the machines) but it is a last ditch option for me when I need something bigger.
@davidpbest, thanks for the link...I'd already seen that because it is posted in another link elsewhere on this site (I tend to do at least a little reading before opening my mouth...er...keyboard.). At this point in my life, I have no need for such tight tolerances, and really have my doubts about ever needing that.
@wrmiller, you have echoed my feelings and questions about the 728VT vs other mills. If you can do that on a Chinese (not Taiwanese) PM935, then the real difference is the operator. I'm not so naive to think a good machine won't give one better results than an ok machine, but maybe the 728, if it really is built to tighter tolerances, will be easier to use by a novice. On the other hand, the 728 costs the same as the heavier and somewhat larger 30MV and 932V (the latter weighs in at 1000#...pushing it for moving it into my shop).

My 935 was a TV, with DRO and VFD. I've had many Chinese machines, and they were not even close to the fit/finish and accuracy of my Taiwan machines. The one exception was my Charter Oak 9x40, but I spent about a year and a fair amount of money to get the accuracy I wanted. YMMV of course.