Robert Yates Posted August 3, 2012 Share Posted August 3, 2012 What to do with it / slow it down and not burn it up , or get rid of it / Help me out a Bit please . Sam Quote Link to comment Share on other sites More sharing options...
jeremy k Posted August 3, 2012 Share Posted August 3, 2012 Sam - if its made that way use it, or step it down with pulleys to a slower speed for your use that's needed. Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted August 3, 2012 Share Posted August 3, 2012 Yes, you can step down with pulley sheaves and belts to whatever you want. Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted August 3, 2012 Share Posted August 3, 2012 It would drive a kick butt industrial duty flex shaft. All you need is the the flex shaft. Quote Link to comment Share on other sites More sharing options...
ironsmith Posted August 4, 2012 Share Posted August 4, 2012 if it's ac , you can use a variac to slow it down, just make sure it is rated for the hp or wattage. if you had the money a motor controller would be awesome as well. you will lose torque slowing it down though. Quote Link to comment Share on other sites More sharing options...
clinton Posted August 4, 2012 Share Posted August 4, 2012 Use this to figure rpm's http://gadi.agric.za/software/renting/pulley.php Quote Link to comment Share on other sites More sharing options...
Robert Yates Posted August 4, 2012 Author Share Posted August 4, 2012 It came that way 110/115 AC 1 1/4 horse motor turning 7500 Rpm it was on an ol Tire balancer that sits on the ground . I would like to use it on a belt grinder I am making . I am thinking a controller to slow it down a bit and a good one , I don't want to burn it up . what would be the best one to use ? Sam Quote Link to comment Share on other sites More sharing options...
r smith Posted August 4, 2012 Share Posted August 4, 2012 Dont most grinders use 3600 rpm? Ideally 2 or 3 hp? if you slow the rpm of the motor to that you will likely loose power as well. 1/2 the speed= 1/2 the power. Think about belt reduction to slow the speed and use electronics to fine tune it. Nice to have such a fast motor. :D Quote Link to comment Share on other sites More sharing options...
Robert Yates Posted August 4, 2012 Author Share Posted August 4, 2012 Well I really did not to admit or let it be known , However , here it is : I have neurological , memory issues ,and the ability to comprehend some of the simpler things in life as of now due to injuries Sustained while in the Military . Some folks on here know it already as I have spoken to them on the phone . Sorry for being so inquisitive about how to go about using this motor and how to set it up If some one will Pm me and take the time to explain the how too's for me I need the help . Thank you Sam Quote Link to comment Share on other sites More sharing options...
fluidsteel Posted August 4, 2012 Share Posted August 4, 2012 If it's single phase AC, you'll ruin it turning it down. If it's 3 phase get a VFD. If it's single phase you'll need to use step pulleys to slow it down. It might be easier to just get a new motor. I run a 1.5Hp 3Ph 1725 RPM motor through a KBAC27D VFD. I have the VFD set at 2x speed and have that mounted on a GIB grinder from Jamie at Polar Bear Forge. I also have a 9" disc grinder with a 3Ph motor running off of the same VFD via a switch. I'd recommend getting a 3Ph motor and VFD if you can. One thing to consider, my VFD was $400+ from Wayne Coe, but, plenty of people have had success with the TECO VFD's for a fraction of the price. They aren't a NEMA 4 rated enclosure and are potentially damaged by steel dust.... Quote Link to comment Share on other sites More sharing options...
Robert Yates Posted August 4, 2012 Author Share Posted August 4, 2012 it is a single phase the RPM is very High the prints of the Grinder i am making are BY : by Michael Clerc I just don't know how to get them on here ? Quote Link to comment Share on other sites More sharing options...
ironsmith Posted August 4, 2012 Share Posted August 4, 2012 those plans are really well done sam, I did some figuring on a pulley calculator, and if you put a 2 inch v belt pully on the motor, and a 4 inch pully on the grinder shaft you will get 3500 RPM for the grinder. if that turns out to still be too fast you can increase the diameter of the grinder side ( driven) pully to slow it down. This would be the cheapest solution. and the motor would run without modification. hope that helps... Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted August 4, 2012 Share Posted August 4, 2012 You don't need to slow it down to use it for a belt sander. My belt sander a Bader space saver has 6" drive pulley and a 3600 rpm motor. If you were to install a 3" drive pulley on the your 7500 rpm motor you would be in the right ballpark with your surface feet per min on the belt speed. No jack shaft or electronics needed and a 3" drive pulley is much cheaper. You can also find grinding wheels that work in that RPM range but they will probably be in the 6" range. Bench grinders are cheep and easy to find I would not try to make a duel purpose machine. Quote Link to comment Share on other sites More sharing options...
Robert Yates Posted August 5, 2012 Author Share Posted August 5, 2012 Thanks guys for the help copied this and will get help from pop-in-law to set it up . Blessings and Best regards Sam Quote Link to comment Share on other sites More sharing options...
ciladog Posted August 5, 2012 Share Posted August 5, 2012 Sam, I would be very careful with what you spin up to 7500 RPM. The centrifugal force is enormous and if you use sheaves that are not designed, dynamically balanced, and rated for that speed, it can be dangerous. Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted August 5, 2012 Share Posted August 5, 2012 Sam, I would be very careful with what you spin up to 7500 RPM. The centrifugal force is enormous and if you use sheaves that are not designed, dynamically balanced, and rated for that speed, it can be dangerous. Bader sells balanced drive pulleys. Quote Link to comment Share on other sites More sharing options...
Robert Yates Posted August 5, 2012 Author Share Posted August 5, 2012 the Plans are based on the KMG set up here is what I found http://www.beaumontmetalworks.com/index.html I am looking at installing this to my grinder also However don't know just yet It is a freebie I have got from a friend . The very same one . http://www.beaumontmetalworks.com/index.html Quote Link to comment Share on other sites More sharing options...
ciladog Posted August 5, 2012 Share Posted August 5, 2012 Bader sells balanced drive pulleys. But Tim, those are designed for use at 3450 RPM not more than twice that speed. I would check before using them at 7500. Quote Link to comment Share on other sites More sharing options...
Robert Yates Posted August 6, 2012 Author Share Posted August 6, 2012 I am chatting with Balder for my set up and use (Safety) I do not want hurt or anyone round me . Sam Quote Link to comment Share on other sites More sharing options...
BIGGUNDOCTOR Posted August 7, 2012 Share Posted August 7, 2012 What about a variable speed pulley? The type that you just turn a handwheel and the speed adjusts? We had them on many of the winery machines we worked on. Quote Link to comment Share on other sites More sharing options...
David Gaddis Posted August 8, 2012 Share Posted August 8, 2012 If you save that motor for another project you would do yourself a favor. Purchase another used motor of better design and save yourself a lot of problems. Any belt that has a 2" diameter shaft that is spinning at 7500 rpm is gonna be toast in short time. The surface feet per minute that is required for the belt to acquire tractive force and remain in contact is a problem. In short the sheave will be throwing the belt away from contact. Very few operations have power belts in excess of 3600 rpms for that reason. Yes there are a few...like specialized grinder operations...and they have expensive belt following tension-izers. Even the automotive industry realized this phenomenon after a gozillion years and went to the serpentine belt..which is designed to travel at very high feet per minute. Those grinder kit designering guys have pretty much perfected the system...so consider using their information. in my life I too have re-invented the wheel because it was not round enough...and yes...I ended up at the wheel store to make a good purchase. Just saying.... Now for proof one can look at my junk pile and see many mistakes. The good stuff is on a piece of machinery being used. Carry on Quote Link to comment Share on other sites More sharing options...
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