Gross Motor Skills

I’m still not able to use my new belt grinder. Not really.

For a long time, I wanted a 2″x72″ belt grinder, because it’s a powerful tool for removing metal and other materials from stuff. If you want to change the shape of something fast, a 2×72 grinder (I am reverting to the typical lazy expression without quotation/inch marks) is your best friend.

As people who actually read this blog know, I bought a pretty yellow grinder, and I rigged it up with an old motor and VFD I had lying around. So far, so good. But there are some issues.

First of all, do not ever buy Dupli-color water-based pickup bed paint (“Bed Armor”). It’s horrible. They make a poisonous (probably) solvent-based bed paint which is magnificent, but I bought the water-based type because my local Advance Auto Parts didn’t have the version that works. The results were not good.

I intended to use it on the wooden platform I made for the grinder. I guess I should point that out. The solventy stuff makes a rock-hard finish you could probably pressure-clean, and it dries fast. It’s useful for lots of projects. I hoped the water-based version would work just as well.

I made the platform and started spraying it. The paint came out in globs and big droplets. It didn’t want to adhere to the wood, so I had to use a lot. There were big globby areas when I was done. It self-leveled to some extent, but when it was over, it looked bad. Also, it takes over a day to cure.

When it was cured, the surface was like fresh concrete, only without the durability. It was gritty. It attracted and held onto grease and dirt. Worst part: I could scrape it off with a fingernail.

Avoid.

That being said, I decided to use the platform until I got the grinder set up, with the intention of stripping and fixing it later.

The motor I intended to use had some problems. Mainly, it was caked with black grease which was not far from wax in consistency. The grease was inside the motor as well as outside. How did that happen? Don’t ask me. It appeared as though someone had operated the motor near a mysterious, implausible source of flying grease, and the motor’s fan had sucked it in through one end of the case.

Also, the case was rusty and peeling. It was like that when I got it, but I made it worse by storing capped muriatic acid near it. You can’t have muriatic acid in a room with iron. Even if you cap it, the acid will get out into the air and make things rust.

The motor was free, sort of. I bought my first lathe (used) from an outfit called Plaza Machinery, and in addition to promising me one model of lathe and sending a different one, the owner sent me the wrong motor. He made some truly pathetic, grudging efforts to make up for what he did, and sending me the crusty motor was among those efforts.

I offered to send it back to him at one point, but he had my money, and he was no longer willing to talk to me, so I kept it.

He also sold me micrometers that didn’t work. Then people got mad at me when I criticized him on a machinist forum. Amazing. Obviously, if you’re part of a hobby, your loyalty should be to your fellow hobbyists, not to characters who promise you one thing, insist on cashier’s checks so you can’t fight them through your credit card company, and then send you something else.

Forum people tend to suck up to vendors, and that’s sad. They’re like church people who try to rip out the throats of honest individuals who criticize crooked pastors. It’s a mindset I can’t comprehend.

The lathe guy was obnoxious, and his business methods were suspect, to put it kindly (more like euphemistically). I forgive him and all, but that doesn’t change what he was. I don’t care if every Internet machinist on earth gets mad at me.

I guess they’ll all stop sending me big weekly checks to pay my bills.

I felt bad putting my crusty motor beside my beautiful grinder, so I decided to paint it. I took the end shields off (that’s what the ends of motors are called). I sprayed chemical stripper on the case (outside of the motor) and used a plastic spatula to remove the crud. That stuff is amazing. It takes about ten minutes to work, and if you’re not inept, you can spray it very accurately.

I cleaned the excess stripper off in the kitchen sink. It’s good to be single.

I finished up with an angle grinder and wire knot wheel. I would guess that the whole depainting process took 45 minutes, including wiping it down with DNA (denatured alcohol). I gouged one of the motor’s wires, but I was able to perform microsurgery on it and fix it. About half of the strands were cut. I cut the rubber back on each side of the gouge. I wrapped thin wire around the remaining strands to build them up. Then I buried the joint in solder and covered it with shrink tubing. It’s really nice. I was shocked that I was able to do it at all.

Having panned a brand of paint and a machinery dealer, I will now offer some praise.

Hammer-finish paint is great for tool restorations. It has little dents and dimples in it when it dries, so it masks scratches and dings in a machine’s surface. It looks snazzy. I decided to try it. I got me a couple of cans of Rust-Oleum Forged Hammer Finish paint. This stuff includes primer, and it’s about a dollar more than the regular Rust-Oleum hammer finish paint. It has a neat spray nozzle that works in all positions.

I taped the motor off (the way people who actually care about their work do), and I blasted it with paint. Over the next day, I would say I ended up with three coats. It looked wonderful. It’s hard. It’s shiny. It makes the motor look smooth. Excellent. Buy it. It does take a long time to cure, though.

The end shields on the motor are aluminum, and I was not able to make them look good by buffing and sanding. They were too beaten up. I cleaned them using electrolysis (and by boiling them in cleaning-strength vinegar), and then I hit them with black hammer finish paint. The results are beautiful.

The grease was a real problem. I cleaned the motor on the outside using DNA and turpentine, but I couldn’t do much to the inside. The stator (the wiry bits that don’t move) was bonded to the case, so I couldn’t remove it to clean. I wiped off whatever I could and let it go.

Turpentine takes grease off in a hurry. It dissolves it instantly. Then it evaporates. Highly recommended.

The motor had a broken wave spring (washer that functions as a spring and holds the rotor in place in the shield), so I ordered one from Ebay. I also put a clamp fitting in the hole where the wires come out, to provide strain relief and keep the wires off the sharp threads in the hole.

This motor has no junction box. A junction box is a little sheet metal box the wires go into when they leave the motor. Another nice present from Plaza? I don’t know. I can’t believe the motor was made that way. Because it has no junction box, there is no place to connect a ground screw. I’m thinking I may buy a galvanized box from Home Depot and attach it.

So anyway, now I have a beautiful motor that runs like new. That’s a problem. The motor isn’t really suited to grinder use. It’s not sealed against dust, so abrasive and/or conductive stuff from the grinder will get sucked into it. Initially, I didn’t care about this. Free motor. And it was old and beaten up. If it blew up, so what? But now that the motor looks like a rock star, I don’t want to ruin it.

Now I have some wonderful facts about motors, for your enjoyment.

Far as I know, there are two types of motor that work well in dusty environments. One is TEFC, and the other is TENV. TEFC means “totally enclosed fan-cooled,” or something close to that. TENV means “totally enclosed non-ventilated,” or something similar. Look it up. What am I? Your nanny?

The motor I have is more like TOTC, or “totally open to crap.”

If you decide to put a grinder or sanding machine together, think about grit and try to keep it out of your motor. I already have a little belt grinder with a TOTC motor, but I at least arranged the fan so it sucks air from the clean side.

I couldn’t stand the thought of my painted motor eating grit, so I went on Ebay, and I found a TEFC motor for the low, low price of $65, with an ad that practically said, “We will take almost anything for this.”

The motor is a Mitsubishi. I kept looking at the photos, trying to figure out whether it was bulletproof, better-than-American, Japanese Mitsubishi or crappy, depressing licensed Mitsubishi from China or Nigeria or something. I sent the seller a question, and he said he didn’t know, and he offered to take fifty bucks. SOLD!

So now I have that on the way. I have to wait for it before I can do the final setup on the grinder.

The motor has a 145T frame, and the old motor is a 184-something, so I’ll have to put different holes in the platform.

More motor information: motors can be described by frame designations. These are numbers like 145T, 184, 156, and so on. An organization called NEMA created specifications for various frame numbers. If you know a motor’s frame number, you can look it up, and no matter who made the motor, you will be able to determine the motor’s shaft diameter, feet pattern, and so on. This is very helpful when you’re trying to install a motor in a machine you already have. If NEMA says it fits, it fits.

My new motor and my old motor have the same horsepower rating and speed, but the 145T is smaller (nice), and the base is different, so the 184 holes won’t work. With luck, one of them will be okay, but I’ll have to make three more, which is more aggravation than you would think. When you’re Carlos the carefree Cuban self-taught handyman from Hialeah, you just grab your Harbor Freight drill and one of your three rusty drill bits, and you make crappy holes surrounded by tearout. Then you demand payment in cash and run away before your work explodes. When you’re trying to do a good job, you have to use at least two bits per hole, and you have to clamp stuff under the work to prevent tearout. So I have that to look forward to.

When all this is done, I have to make some kind of housing for the VFD, to keep crud out of it.

In about 8 days, I should have a grinder that works. Exciting.

I realize no one read this, but I write what makes me happy, so I suppose that’s okay. If you made it this far, your prize is the photo I post below. In the photo, the motor is only mocked up, but you get the idea.

Enjoy. You lucky, lucky few.