About to pull the pin on a new PM-25

Counter top to top of work surface, just under seven inches.
 
Just circuitous your decision process for the 25 over the 727, I'm stumped as to which is a better choice for myself. I like the idea of gear drive, but it sounds like many (especially CNC people) prefer the belt drive
 
I'm tall (6'3") and was worried that the working height with the stand would be too short. I ended up putting my PM-25MV on a Harbor Freight tool cabinet. This places the table almost exactly at my elbow height which is the general recommendation I've seen in various forums. Very comfortable to use plus I've got tons of storage. I added some simple leveling feet under the cabinet for leveling and stability. Can still move it as needed using the casters but not something I'd want to do on a regular basis.
 
GunsOfNavarone said:
Just circuitous your decision process for the 25 over the 727, I'm stumped as to which is a better choice for myself. I like the idea of gear drive, but it sounds like many (especially CNC people) prefer the belt drive
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For me personally the 25 is lighter and slightly smaller, I know this is a backwards step with mills but its a reality for my small shop (and since i'm coming from a mini-mill its not a backward move for me!), the gear drives also tend to be noisier and potentially more maintenance?... as well as the price difference. I just feel for my situation the 25 will be a better choice. Dont know much about the CNC aspect but I do know there are several conversion kits available for the 25, don't know if they'll work for the 727.
 
Geared head machinery is a carry-over from the days when only single-speed A/C motors were available. In order to get different speeds available, you had to use a gearbox to get a limited range of spindle speeds. Or go real elaborate with DC drives like the Hardinge and similar. Very good, but expensive.

Now with better designed 3-phase A/C motors and VFDs, there is no longer a need for gearboxes. And on smaller lathes and mills that use BLDC motors, there is no need for gears because these are even more efficient and higher torque than A/C motors of a similar size. All the while providing a much larger rpm range than a geared head machine.

And if that isn't enough, the belt driven mills are quieter, and produce a better surface finish than gearheads.

Something to think about.
 
The caveat with a belt drive/electric variable speed drive is you need a bigger motor to cover a wider speed range and as a minimum need at least two speed ranges. CNC is based on much higher RPM's and typically smaller cutting bits, so a single speed range may be acceptable. If used in a manual mode, and finances permitting then the PM-727MV or PM-30MV would be good choices, the latter can use a smaller motor because of more gear ratio choices. Changing belt ratios can be a bit of a PTA, on my lathe I always left it in one range and then ended up with a single belt ratio. The PM-727MV is relatively quiet according to owners, need to change the oil, but I have heard of no long term reliability issues. If CNC conversion is in the future then a belt drive is the only way to go, I would opt for the BF-30 with the larger motor/220V for a future conversion. The limiting factor on the belt drive heads will be the maximum RPM achievable with the stock bearings.

Space wise, at the end of the day, it is a nominal foot print size difference between the PM25 and PM727, going from a 13" to 18 1/4" maximum spindle distance from the table and having an extra Y travel of 1.5" are significant factors in favor of the PM727. Once you start using these machines, you get a much better feel for the need for increased travel. Also adding something like a DRO scale on the back of the saddle you can loose another 1" or more of Y travel, so you have a very limited milling work/travel area. It all boils down to what you plan on machining on your mill, the PM25, PM727 and PM30 are all very good choices withing this price range. The variable speed versions offer a lot more flexibility for dialing in the speeds. Best of luck whatever you choose.
 
Another quick question, what is the actual table to spindle min and max, (without a DRO and with the quill fully retracted)....the website lists both 12" and 13", wondering which is correct, and is the Z travel actually 13"?
Thanks again
 
OK... after talking with Precision Matthews about both the PM25MV and the PM727V i'm even more confused about what the actual specifications are on either one of these machines....On the 25 they said the maximum spindle speed was only 2250RPM and the spindle to table was 13"max, though the spec sheets and manual differ saying 2500rpm and either 12" or 13"??? On the 727V the manual states the motor is 1.5 hp while they stated it was only 1 hp? Can anyone here that actually has one of these machines enlighten me as to what the actual numbers are as it really drives me nuts trying to make a decision when there is conflicting information and even the company that sells the machines does not seem to be too sure of the actual specifications? I realize a lot gets lost in translation sometimes but there has to be a data plate on the motor of the 727V and a ruler measurement of the spindle to table on the 25, also im pretty sure ive seen the speed on the 25 at 2500rpm on a couple videos?
Thanks again!
 
I don't have my PM-25 in front of me at the moment, but my solid model (which I believe I made as close to actual dimensions as I could) shows 11.758" from the spindle to the table. I can double check that.

The stock machine came with a 2500 RPM top speed. I bumped it up to 5500 and the stock bearings did not last long.

The actual Z travel on my machine is closer to 11.5" than 13".
 
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