Buffing question

[Wallbright]

Hmmmm those seem to run the same price as the unit. Would it be better to just return it and buy an adjustable one? I have not ever modified power tools before.

[Dixie_piper]

I just realized Sas was responding to your first post (I referenced that in your second )
Check on the price of a variable speed buffer/grinder first, may still be cheaper to add a rheostat.
As far as wiring it, should be fairly simple and a good "first project" for modifying power tools. It would most likely come with instructions, and if not, there are many "how-to's" online available.
I would think at most it would require wire nuts, wire cutter/strippers (all available for a few bucks) and... that should be it aside from knowing which wire is which on your motor. Another question easily answered by a google search or tech support from the company that makes your grinder

[KurtHuhn]

You can get a rheostatic sorta thingy that will allow you to control the speed of that grinder by altering the voltage it sees. Google "speed control, power tools" or something like that. 3,400 is about 2 times faster than ideal.

It is my experience that these only work on certain motors, and don't work at all on induction motors - motors with two sets of windings, start and run. Basically, if the motor has a capacitor, these are useless. They work on routers, dremels, or other motors with replaceable brushes, but things like bench grinders will pretty much refuse to run - or if they do run, the torque would be so low that you could stop them with your hand.

The reason is that a single phase motor is constructed, within the windings on the rotor and stator, to expect a specific voltage at a specific frequency, wherein it will draw a specific current. That's why electric motors have plates on them identifying input voltage and frequency, as well as current draw in Amps. If you change input frequency on a single phase motor, it won't run. If you change input voltage, you get very strange behavior like non-starting or seriously reduced torque.

I have been told that you can use these $25 speed controls on bench grinders if you switch the speed control to full power, start the motor, then switch the control to variable power and dial it down. I am leery of this however, since even Harbor Freight warns against this practice. And the guy who told me about this, wasn't what I would call an experienced tradesman of any kind.

My advice, such as it is: Get a buffer/grinder that has a running speed, or a variable speed unit that has minimum speed, of about 1700. This is closer to what you need for pipe work. It's not ideal, but you may find it will work for you.

[Wallbright]

So this grinder is useless? Does anyone have a link to a pipe buffer? Or do people only modify bench grinders to make them?

[KurtHuhn]

I personally do not like high speed bench grinders. They might be okay for some, but I find they spin too fast, and it's easy to mess up a piece of steel with them. I prefer to use a slow speed belt grinder to sharpen my lathe tools. I would not say it's useless, since maybe you could use it to sharpen lawnmower blades or something, but it wouldn't work for my purposes at all. You could maybe add a stepped pulley to one shaft and use it as a motor that would then drive a second shaft - but that would be serious overkill, and not all economical.

My pipe buffer is my lathe:


Some folks use a motor with a shaft and stepped pulleys to create a buffing station.

There are fixed RPM buffing machines designed for plastics. Caswell Plating sells one that runs at 1100 RPM:
http://www.caswellplating.com/buffs/34hpbuffkit.html

This one is more affordable, and has two speeds - 1800 and 3600 RPM. It could be used for rough shaping with a resin disk, and then the disk swapped for buffs. 1800 is a bit fast for applying carnuba, but it can be done with a 6-inch or smaller wheel to reduce surface speed. Not ideal, but...
http://www.eastwood.com/ew-buff-motor-3 ... speed.html

The simple fact is that there's no such thing as a "pipe buffer" that you can plunk down a credit card for. You use the tools you have available and make the most of them.

Check out what this guy did. He even gives parts from Grizzly.
http://www.tdpri.com/forum/tele-home-de ... erday.html

[Wallbright]

I see, well I am going to have my engineering friends help me out. Hopefully we can figure it out. That makes me think though, is there no market for an official pipe buffer? Or do people just use their lathes or hand drills? Seems to me a company that already makes bench grinders and such could benefit from coming out with a pipe buffer.

[KurtHuhn]

The potential market is so incredibly small that I can't imagine it would be worth the marketing expense. Lathes are just about ideal for this, since they're variable speed and it only costs a couple dollars for the parts to mount a buffing wheel. If you have a lathe, I'd suggest using it. If you don't, you can build your own buffing station for less than $100-ish.

[Wallbright]

The potential market is so incredibly small that I can't imagine it would be worth the marketing expense. Lathes are just about ideal for this, since they're variable speed and it only costs a couple dollars for the parts to mount a buffing wheel. If you have a lathe, I'd suggest using it. If you don't, you can build your own buffing station for less than $100-ish.

I suppose that is true. I don't have a lathe though and I was thinking of just buying some arbors and buffing wheels for my cordless drill. It gets up to 1000 - 1500 rpms I believe. I would LOVE to own a lathe and get into pipe making but I just don't have the money right now.

[staffwalker]

Check out what this guy did. He even gives parts from Grizzly.
http://www.tdpri.com/forum/tele-home-de ... erday.html

That's what I use, the buffing mandrel cost about $100 bucks from Grizzly, I pull it with an old washing machine motor, plate says 1025RPM. Don't know how accurate that is. I use 8" buffs, works great. Been running for about three years now. Probably took about $20 bucks in bolts, pulley and what not. Motor was free from a friend but any junkyard has them for a few bucks. bob gilbert

[Wallbright]

What about using this hand drill? I see that PIMO has arbors for hand drills for very cheap and then I would only need to supply the buffing pad for them. Do you know what size the chuck is though for those? http://www.harborfreight.com/power-tool ... -3670.html

[KurtHuhn]

Again, that won't be ideal. However, I suppose it would work.

The arbors that PIMO sells, and that pretty much everyone else does, have a 1/4" shaft.

[Sasquatch]

You can build an arbor with a bolt and some washers and nuts. Just make sure the direction of the spin of the machine vs your bolt is "correct", or use some locktite.