Thread: My DIY belt sander

About 20 years ago I started making knives but could not afford a decent belt sander, also the Internet was not much help back in those days so I spent several years finding the parts to build this beauty. I only made a few knives and was just getting started when I went through a divorce. My knife collecting and making days were over.

Recently with my life settled and a bit of free time my blade collecting and desire to start making them again has kicked in. Right now my lack of tooling has got me interested in just simply restoring straight razors, so I went over to my folks house and dug around, and lucky I thought it was lost forever, but my old sander is almost back in action. Eventually I will re-work it a bit with a new idler pulley and a few other design changes, but it worked "good enough". Back then it should be good for basic stuff at the moment.

So here is my questions. I know I can find some old 1/2-3/4 hp motor around to get started. But what I always wanted was a variable speed motor. Now as you can see I figured out how to build the sander so I think imcan figure out some form of cheap DIY type motor. So far I have a few ideas but not sure if they would work.

1) old treadmill motor, free.... Not sure how much HP
2) I have a very old gas generator with a bad gas motor, it probably 3500 watts or so, and I know the generator is basically a DC motor, but google turns up nothing on who to change one back to "just a motor". Any thoughts or ideas?
3). Some random item from an industrial facility?? I can't even think what item might have a large DC motor...
4). Ok thats all the ideas I have... Anyone got any?

My first thought is retro fitting that to a variable speed grinder/buffer. Take the big shaft and attach it to the arbor of the grinder, viola! It would take a big grinder to move all that weight, but I'm sure you could make it work.

For those interested here is what I have come up with. My best option is to go with a 1hp 3phase 1800 RPM motor. I am going to look locally for one that fits the bill for free. I have many sources and feel reasonably sure I can find one. I emailed the guys at Variable Frequency Drive, AC Motor Drives, Pool Pump Motors, Marathon 3 Phase Motor, Teco Westinghouse Dealer for advise, they told me they would sell me a
1hp 1800rpm Weg 3/60/230/460 TEFC 56C with feet for $160

and to drive it using a VFD(Variable Frequency Drive) this has a dial on it, that changes the frequency and speed of the motor. and also converts 220volt house wiring into 3 phase industrial.

Teco JNEV-201-H1 1HP 230 Volt -- USE AS A PHASE CONVERTER PLUS GET VARIABLE SPEED, Model JNEV-201-H1, Single Phase Input ONLY, Three Phase Output, variable frequency drive, variable frequency drives, ac drive, vfd, afd, frequency drive, drive, inverter, adjustable sp
or a
Teco N3-201-CS for the drive. 1HP 230 Volt -- USE AS A PHASE CONVERTER PLUS GET VARIABLE SPEED, Model N3-201-CS, Single Phase Input ONLY, Three Phase Output, variable frequency drive, variable frequency drives, ac drive, vfd, afd, frequency drive, drive, inverter, adjustable spee
Really they are the same, one is just $40 bucks more and built stronger.

So I am thinking I will go with the cheaper one for $131.00 plus free surplus motor, and I am rocking and rolling. worst case I add $160.00 for a motor online.

The vfd's mentioned above are what I am in the market for, but I made a score on a 2hp 3-phase motor for cheap.

The treadmill's have been used by many. I think they usually start with a 3/4 hp motor & go up, so you should be ok since you don't need a lot of torque at the slow speeds as you wouldn't be adding a lot of pressure at the slow speeds anyways...due to the heat. Secondly you can help it along with a small drive wheel and larger secondary wheel to keep the speed down and the torque up.

Back to your treadmill motor idea - that is what I used on my KMG. It is a 2 hp DC, and I got it free - the whole treadmill - from a local (Minneapolis, MN) used sports equipment store. I had to use all of the controls, since I am not an electrical engineer, so it is a bit odd looking - the entire control panel is mounted to the left of the KMG, but it works great. Just something to think about.

I couldn't remember who had one, but yours was the one that I was thinking of...thanks for jumping in!

Thank you for the help everyone. I believe I found a 1hp 3phase motor for free. So I should be good to go. As soon asi acquire it and test to make sure it works, I will order the phase convertor. I will keep you posted.

I'm building a no-weld grinder and am using a 2hp 3-phase motor...haven't ordered the vfd yet. Sounds like we are on the same page. Actually all I need is the vfd and a drive wheel to be ready to go.