Hey Iggy - stepper motors ?

Sure you can - but a windshield wiper motor???

snipped-for-privacy@snyder.on.ca fired this volley in news: snipped-for-privacy@4ax.com:

With feedback? You betcha! I not only _could_, I have (yes, with a wiper motor).

LLoyd

Since when were wiper motors made with servos, Lloyd? ;) Apples and Lambos.

Not saying it's not possible, but more complex than necessary to get the required or desired accuracy

Add a feedback loop, and you have a servo.

Larry Jaques fired this volley in news: snipped-for-privacy@4ax.com:

Um... I didn't say they were. They can be made INTO servos quite easily, and if you have an application that won't mind the inherent backlash in the geartrain, they're quite powerful and quite inexpensive for the torque they'll put out.

Lloyd

Richard fired this volley in news: snipped-for-privacy@earthlink.com:

Yup... but so many people are into "buy instead of make", they cannot see that.

Lloyd

My own thinking is, if you are smart enought to make a servo out of a wiper motor and adapt it to a milling machine, you should be able to make enough money in less time to simply buy proper equipment.

Well, he said "wiper motor" and you said "servo", so it was implied/inferred.

Aren't most power runs usually just removing background field material? I would think that backlash wouldn't matter for many runs, though I don't see where backlash would come into it during a run. It would have constant feed, right, with limiters cutting off power at the end of the run?

Quite often true, but it can also depend on which they have more of: money or time. Lack of time can play heavily into that decision. So can the need (or wish) to learn a machining procedure/method.

I'll buy an HF tool to do a quick one-off job. But if I see that down the line I'll need it quite often, I'll either make a better one (if possible) or buy the better brand-name tool for it. That brings value into the equation, too. Those of us with less money are very familiar with this aspect.

It doesn't make much sense to turn a hobby into a religion. Those of us who take the "recreational" part seriously should have an easy answer: if you find it pleasurable to do so, then make it. If it's a chore and if the option to buy is reasonable, then buy it.

Like most people here, I've often made things that made no sense to make, and then took a brief pleasure in having done so, for several reasons. Then, if reason slipped into my consciousness at some later point, asking "why in the hell did I do that?," I sigh and swear to think first, the next time, before sucking up precious hours to satisfy some atavistic urge that made as much sense as tailoring my own underwear. d8-)

Or, as we said in the '60s, "If it feels good, do it."

One issue with typical wiper motors is they're only intended to rotate in one direction and in my experience don't run as well in the reverse direction. The few I have taken apart only have thrust provision for the intended direction. I have used them to run in both direction and it worked OK. Window winder motors are bidirectional and have thrust pads at both end of the shaft on the ones I've dismantled.

Ed Huntress fired this volley in news: snipped-for-privacy@4ax.com:

Yeah, I'll go along with that.

Lloyd

Changing a wiper motor into a servo motor only requires a feedback device. An encoder will do. The wiper motor will probably not make a very good servo motor though because there are not many segments in the commutator compared to a motor designed for servo use. Eric

snipped-for-privacy@whidbey.com fired this volley in news: snipped-for-privacy@4ax.com:

Think "commutator segments per revolution". They're geared WAY down.

Lloyd

I took great pleasure in the building of both my Holes Creek ball turner for the lathe and my home made boring head for the mill . I get even more pleasure out of using them .

snipped-for-privacy@snyder.on.ca prodded the keyboard

Its no more hard or complex than any other servo system. Have a look at how the printer manufacturers do it !

"Lloyd E. Sponenburgh" prodded the keyboard

David Billington prodded the keyboard

Yes that's true ! Which is one reason that I used a tumbler gear mechanism to reverse the table direction. Limit switches take care of running into the ends of the table.

As far as servoing is concerned, isn't that what the DRO is for. Set zero and run to value "X" then stop.