Pm 25 Vs. Pm 727

B

Buggy Chief

Registered
Registered
Joined
Sep 24, 2016
Messages
125
New to the forum and addiction:) I am currently researching the 727 and 25. I taught myself to TIG Weld Aluminum as well as steel over the past 7 years by asking questions on forums and this seems to be no exception.

With that, I am leaning towards the 25 as I will be working with aluminum and lighter steel. I see that the price difference is about $200. Being new to this, is the fact that the 727 doesn't have a digital readout for RPM an issue? How do you tell what RPM? Do you get a ton more benefits with 727 relative to working capacity by stepping up to the 727? Thanks in advance.
 
I have a PM25 and am content with it.
The 727 has change gears, not a variable belt drive so the gear you are in determines the RPM, no need for a tach. The 727 has almost twice the spindle travel of the 25, this is a plus. The 727 is almost 200 lbs heavier than the 25, another plus, give stability, to eliminate vibrations. It (the 727) has 15 inches of X travel, the 25 has about 18, the more travel you have the longer piece of work you can work on without moving it.
I prefer the variable speed, I can drill a hole at high speed then tap it at low speed with a twist of the dial. To me this is worth some of the difference.
Hope this helps, hope others chime in, too.
 
T Bredehoft said:
I have a PM25 and am content with it.
The 727 has change gears, not a variable belt drive so the gear you are in determines the RPM, no need for a tach. The 727 has almost twice the spindle travel of the 25, this is a plus. The 727 is almost 200 lbs heavier than the 25, another plus, give stability, to eliminate vibrations. It (the 727) has 15 inches of X travel, the 25 has about 18, the more travel you have the longer piece of work you can work on without moving it.
I prefer the variable speed, I can drill a hole at high speed then tap it at low speed with a twist of the dial. To me this is worth some of the difference.
Hope this helps, hope others chime in, too.
Click to expand...
Great points. Didn't consider the weight. I really appreciate the input!!
 
It all comes down to what you intend to do with the machine. Both are capable machines, within their intended work envelope. If you want to work on stuff that requires the larger envelope, then you need the larger machine. I had a PM25 and it worked very well (and accurately) for what I was doing on it. I personally prefer a belt-driven BLDC to a gear head arrangement, but that's just a personal preference. Also, the 727 is a wet-head and may leak/drip if not looked after. The 25 is a dry head and won't have that potential problem. My last bench mill was a 9x40 from Charter Oak. One of the first mods to it was to gut the head/remove the gears and put in a two-speed belt drive. Much quieter and smoother cutting. Or maybe the reduction in noise just made me think it was smoother... ;)
 
The table size on the two machines is the same. There is a decrease of X-travel due to a wider saddle on the 727 which adds stability on the outer ends of the travel. I have the 727 and feel that I made the right decision as I was also leaning towards the 25. I initially thought that only having 6 speeds would limit me but it has not been a problem at all. The torque that you get on the low rpm settings translates into using larger drill bits and end mills with ease. Personally, the only thing that I would like to be different about my machine would be to increase the x-travel a few inches. The extra quill travel is a definite plus with the 727. It really helps when drilling thicker parts.
 
3dshooter80 said:
The table size on the two machines is the same. There is a decrease of X-travel due to a wider saddle on the 727 which adds stability on the outer ends of the travel. I have the 727 and feel that I made the right decision as I was also leaning towards the 25. I initially thought that only having 6 speeds would limit me but it has not been a problem at all. The torque that you get on the low rpm settings translates into using larger drill bits and end mills with ease. Personally, the only thing that I would like to be different about my machine would be to increase the x-travel a few inches. The extra quill travel is a definite plus with the 727. It really helps when drilling thicker parts.
Click to expand...

I bought a 727 this year and am very satisfied, with that said what 3d said is how I feel
 
Both machines are very capable, I was going to go with a PM-25MV initially but decided for the extra bucks more weight and spindle travel would be nice. I do work mostly in steel so top RPM was not a limiting factor. in the future I would like to change over to a three phase motor/ VFD to increase the speed range a bit. For me my PM-727M will always be a manual machine so blazing fast spindle speeds will not be required the way I see it. These words are spoken by someone who knows enough to get into trouble but has the common sense to look here to find the correct answers.:encourage:
 
tweinke said:
Both machines are very capable, I was going to go with a PM-25MV initially but decided for the extra bucks more weight and spindle travel would be nice. I do work mostly in steel so top RPM was not a limiting factor. in the future I would like to change over to a three phase motor/ VFD to increase the speed range a bit. For me my PM-727M will always be a manual machine so blazing fast spindle speeds will not be required the way I see it. These words are spoken by someone who knows enough to get into trouble but has the common sense to look here to find the correct answers.:encourage:
Click to expand...
Thanks for the feedback. Being a novice and beginner, I will be doing a mix of aluminum and Steel. Question is, I keep seeing folks say they would like to change motors to a three phase VFD...What does that entail relative to cost and modifications?
 
You would need a new 3 phase 1 Hp metric C face motor (Leeson, Marathon, etc. with the same mounting specifications or some adapter plate) and a VFD, most likely a single phase input of 120V and an output of 240V 3 phase. You could remove the high voltage from the contactors and use one set of contacts on each contactor to control the VFD direction. Providing you can find a motor that fits this machine, you are probably looking at around $350-400 in parts to do the conversion. There is no need to up-size the motor with 6 gear speed gearbox. You also do not have the issues of the capacitors going south, and I would expect more torque out of a 3 phase motor. Probably top out at 2100 RPM with the VFD set to 80Hz. If you can get a drop in motor replacement, you are looking at a few hours to do the conversion. Would make for a very nice mill.
Example:
http://www.electricmotorwholesale.com/MARATHON-R373.html
https://www.automationdirect.com/ad...ts_(115_-z-_230_-z-_460_-z-_575_VAC)/GS2-11P0
http://www.electricmotorwholesale.com/LEESON-174605/
 
You must log in or register to reply here.
Back
Top