On Wednesday 30 May 2018 17:52:03 John Bald wrote: > I picked up a couple of surplus marathon 1.5hp inverter duty 1000:1 > motors awhile back like this one: > https://www.regalbeloit.com/Products/Catalog?model=145THTR5328 > Look around John, that half a horse bigger is costing you over 800 bucks. I suspect Marathon, haveing tested it on an inverter and it worked, expects to make an extra $300 or more just for the word inverter in the sales propaganda.
> My plan is to replace the original single phase/single speed 1hp motor > on my PM727 mill and also add belt drive similar to what cnc4xr7 did > on youtube and bypass the original gearbox. I had thought about using > a set of comet clutches and belt as a simple solution (clutch on motor > varies speed and clutch on driven shaft varies torque) for constant > speed/torque, but will probably just make a couple of multigroove > pulley sets and move the belt over as needed. I don't think I will > have room for the comet clutch setup. Any thoughts on pulley ratios? > Would be nice to be able to make this work with one set of pulleys, > but from what others have posted it looks like a second set is > necessary to be able to have ample low speed torque. I want to be able > to run small high speed cutters for CNC on aluminum etc at say > 4000-6000rpm (maybe 1:1.5 pulleys?) , but also be able to have enough > low speed torque for other operations. Don't know what the biggest > flycutter this size machine could handle, and how much torque is > needed so I'm kind of guessing. Maybe 1.5:1? the specs for Marathon > motor show about 22ft/lb of torque at ~100 rpm. The lowest speed > available with original gearbox and motor is 115rpm, but can't find > any torque specs on original motor to use to calculate torque for > comparison. I can't be much help there, but theres no shame in using a used motor, so look around for a 1.5, I'm sure you can get one for not more than $200 on fleabay or?? So what if the bearings are shot? You can put them in it for less than a $30 bill. Clean out the dirt and dust bunnies with the shops air hose while you are at it. If the windings aren't toasted, if the tips of the stator and/or armature aren't polished from poor bearings letting them come in contact, and the vfd is set to never exceed its nameplate FLA, (thats about the list of if's) it should still be a perfectly good motor 100 years hence. The sheets of iron stacked can become shorted, creating a hot spot that can cook the motor if they are worn and polished as the metal may be smeared enough to defeat the layer of varnish that separates the plates in the stack. That is the one major caveat to buying a used motor, because you have to take it apart to see that sort of damage. [...] -- Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
