Motors Basics

[omar_colocci]

Hi guys!

I've been looking for a motor that I could use as grinder, buffer and maybe, in the future, use it as a general purpose motor, using pulleys, with a lathe ora bench router.

The problem is that here in Brazil I found two kinds of motors: some are sold as grinders only and others as polisher/buffer only (at least in theory).

An example of "grinder" is this one from Black & Decker (what I found very similar here from same manufacturer, but it's 1/2 HP):

http://www.blackanddecker.com/productgu ... yType.aspx

These seem to have screws on both ends of the shaft.

The "polishers" have those conical (removable, help by small screws) tips on both ends of the shaft (which seems blank or with a step) for attaching buffing wheels.

All I found were 1/2HP, 3400-3600 rpm (couldn't find anything slower) and shaft diam. 1/2". Is any of them going to work? I'm most concerned with future uses I can make with it, like I told you before.

Please! Help!!!! 8O

[omar_colocci]

Do you have the space to rig up a pulley reduction setup? That would reduce the speed, if you get a pair of ganged pulleys you would have adjustable speeds. If not, you'd need to use smaller buffs to get the same number of feet-per-second where the buff meets the pipe.

Hi random!

The buffers I found have that "blank" shaft end (all dual shaft) and pieces are help using a set screw (I guess this is how you call it). I'm not sure if I can find step conical pulleys (that's my idea of speed adjust, added to a separate shaft) to fit these.

The bench grinders I found are basically the same as above, but they have screws on both ends of the shaft to hold the wheels. I just don't know if and how pulleys are attached to any of these kinds of system.

The smaller wheel I could find was a 5". I've got a sewn cotton 5" and a sewn flanel 6" for a try (maybe I'll cut off the outer sewing to make it softer).

I no longer use a standard buffer for my pipes, I use the Foredom now; it's nice to be able to see what I'm doing for a change.

If you mean this is like a Dremel, well, I have reshaped one of my pipes a few months ago and polishing with the Dremel didn't feel nice at all (minimum speed of the model I own is 5000 rpm!!!!).

I think I'll end up using my hand drill (2200 rpm) attached to my small bench using a hand drill mount with an arbor to hold the wheels, at least for a first try.

Maybe with the experience a justified need for some extra hardware arises.

[omar_colocci]

Could any of you guys take pics of the details of any similar equipment set ups so I can clearly understand what is needed and how it works?

Thank you all for your patience!

[jeff]

Omar,

I currently use a hand drill with 6" buffs. To tell you the truth, aside from the rig being a bit cumbersome, it works very well. All of my pipes have been buffed this way. I have tried the Dremel route before, but the success has really been limited. Like you, I found that the RPM is simply too great.

I will let you know that I own a 3/4 hp bench grinder with a 3450 no load rpm that I'm going to try and buff with. The 6" buffs should help me approach the correct speed. But, I'm counting on the buff slowing down considerably (1000 rpm or more) with the load. That should work fine. It will be a while before I set it up and use it, but if you'd like I'll let you know how it turns out.

Jeff

[omar_colocci]

I currently use a hand drill with 6" buffs. To tell you the truth, aside from the rig being a bit cumbersome, it works very well. All of my pipes have been buffed this way. I have tried the Dremel route before, but the success has really been limited. Like you, I found that the RPM is simply too great.

Hi Jeff!

I guess I'll give my hand drill a try. Probably I'll go for the grinder if I decide to try grinding my own bits, but it's an idea for the future, I'm still going to try my first kit (which is going to take a couple of weeks to arrive, ARGH!). Like they say: the difference between a boy and a man is simply the price of the toys

Thank you guys for your comments!

[KurtHuhn]

Omar,

If you simply can't find what you're looking for, try washing machine repair shops or even junk yards. A washing machine or dryer motor usually is a 1725 RPM motor, and you can get them for very small money - especially at junkyards. Most of them have mounting plates welded on, so you can attach them to wooden stands you make yourself.

[omar_colocci]

Hi Kurt!

Funny you mention it. A friend of mine who works with antiques (including pipes) suggested me exactly what you did. I can puchase grinders and polishers here in Brazil in a range of about $40 - $50. Now you got me curious on how much would such a motor costs me.

Thank you for the tip.

[KurtHuhn]

The last one I bought was about $15. However, I had to look around to find it that cheap.