[4]

1127 belts

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

ttabbal

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Jun 12, 2017
Messages
729
Likes
723
#1
So, I wanted to switch to high speed and remembered something that was a bit off. The belt came installed in high speed, however, there was no tensioner setup for it. The manual talks about loosening the motor mount, but there don't appear to be any slots etc.. Getting it off was kind of a pain. I would have had to completely remove the motor and twist it to release the tension.

Low range with the 2 belts works fine. There is a tensioner in the machine, but the belts are too short to use it for high range. I'm thinking of taking the belt to a auto parts store and getting one a few inches longer. Just wondered if someone else has seen something like this and what they did.
 

Jeff.64

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Feb 22, 2015
Messages
9
Likes
7
#2
I measured all three belts and they had an average width of 0.384” (9.7mm = 0.382”) and an average height of 0.238” (6mm = 0.236”). I spent a ton of time trying to find information on the Mountianrope M-33, M-27.5 and M-25 belts. I could not find a cross reference. SPZ series belts are 9.7mm (0.382”) wide and 8mm (0.315”) in height. Gates HI-POWER Z section belts are 10mm (0.394”) wide and 6mm (0.236”) in height. I received a PM-1127 a few weeks ago and have the same problem you're having. The M-33 belt was very tight. The belt tensioner idler was not in contact with the M-33 belt. Like you I had to remove the motor to change the belt. I did not want to try rolling the belt off with a screw driver and cause damage to the aluminum pulleys. I think a longer belt will be required. I have not yet determined the length. I intend on making accurate measurements of the vee angle on each pulley and determine if the SPZ series or if the Gates HI-POWER Z section belts will work. The belt tensioner idler on my machine is turned very rough and in my opinion would result in premature belt wear. I plan on making a replacement or cleaning up the original belt tensioner.
Go to page 12 of the attached pdf (page 11 of the manual) and you will see that an M-34 belt is used for high speed. The Warco WM-290V lathe looks to be very close in design to the PM-1127.
 

Attachments

ttabbal

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Jun 12, 2017
Messages
729
Likes
723
#3
Thanks for the detailed info! I find this very strange, but fixable.
 

tweinke

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 24, 2014
Messages
870
Likes
523
#4
Does Matt have any ideas on this issue? I would think he would have some thoughts or should know of the issue so it can be corrected.
 

pacifica

RGL
H-M Supporter - Gold Member ($25)
Joined
Jan 2, 2018
Messages
175
Likes
86
#5
On my PM1340gt the belt and pulleys were substandard. I replaced the sheaves with martins, and the belt with a cogged gates belt; gates belt fits properly in the martin sheaves, no shredding, smoother running. I could've got the sheaves balanced but it didn't seem necessary. Motor movement is difficult.

Before I replaced sheaves and belt I was experiencing about .0003 runout on shaft---but over .004" on the sheave.Probably the most cost effective upgrade you can do. Heavy duty stand will make a big difference, Superior chuck can make a big difference. And leveling. Your choice and budget as to how much you want to do.
 

ttabbal

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Jun 12, 2017
Messages
729
Likes
723
#6
Does Matt have any ideas on this issue? I would think he would have some thoughts or should know of the issue so it can be corrected.
I remembered it on a weekend, so I thought I'd see if the community had run into it. I'll contact Matt as well, but I figured he'd be enjoying his weekend. I hoped someone might point out the adjustment point I missed or something. :)
 
[6]
[5] [7]
Top