Motor speed control

TreverT · Post by **TreverT** » Wed Sep 21, 2005 9:00 am

Has anyone ever installed any sort of motor speed controller to adjust speed on a single-speed motor? I've got a big 2HP 2800 rpm motor on a belt-drive drilling rig that only has room for one pulley (no using stepped pulleys) and I was wondering if it was possible to wire in some sort of speed control to slow the thing down when needed. I haven't had any luck so far looking around online, where all my searches find are large industrial speed controllers that cost $900+. The only other alternative I can see is to get another pair of pulleys machined to slow the thing down, but then I'd be stuck with the one new speed all the time.

bscofield · Post by **bscofield** » Wed Sep 21, 2005 9:21 am

Trever, we were just discussing something similar:

http://www.pipemakersforum.com/modules. ... pic&t=1236

Not sure if that is exactly what your talking about or not... Perhaps your talking about doing it without messing with the voltage?

TreverT · Post by **TreverT** » Wed Sep 21, 2005 9:48 am

That's it exactly - too bad, as it sounds like electric speed control won't work. These are big capacitor-start motors, I hadn't thought of that as the problem. It looks like getting some custom-made pulleys may be the only answer, unfortunately. Hate to think what that will cost!

ArtGuy · Post by **ArtGuy** » Wed Sep 21, 2005 10:12 am

Trever,

My buddy knows someone who works with small electric motors. He once told him he could put a speed control on just about anything. Let me see if I can get his contact info for ya. He may be able to help.

magruder · Post by **magruder** » Wed Sep 21, 2005 3:27 pm

Trever:
can you turn your own pulleys on a lathe? It seems like that is the operation (turning a wheel) that I see most discussed on small lathe boards and news groups.
Just a thought.:dunno:
Best,
Steve
BTW- I can't remember if you said you would be @ CORPS.
Are you attending?

bscofield · Post by **bscofield** » Wed Sep 21, 2005 4:50 pm

ArtGuy wrote:Trever,

My buddy knows someone who works with small electric motors. He once told him he could put a speed control on just about anything. Let me see if I can get his contact info for ya. He may be able to help.

I'd love to hear the outcome of this if anyone gets anywhere with it!

TreverT · Post by **TreverT** » Wed Sep 21, 2005 5:48 pm

magruder wrote:Trever:
can you turn your own pulleys on a lathe? It seems like that is the operation (turning a wheel) that I see most discussed on small lathe boards and news groups.
Just a thought.:dunno:
Best,
Steve
BTW- I can't remember if you said you would be @ CORPS.
Are you attending?

Nope, can't afford the cost or the time to do CORPS this year - next year, I hope. I don't think I'm up to turning my own pulleys, especially since the one I really need needs a key slot to fit the motor shaft. Also, the drill shaft is as thick as my arm, which is a wee bit more than my lathe can handle. It's a big setup - the 2HP motor is the size of an office trash can.

bscofield · Post by **bscofield** » Thu Sep 22, 2005 2:33 pm

I just talked with an electrician friend who told me that you should be able to harmlessly do this to any motor. There IS a something to keep in mind. There are two ways to limit the power flow to the motor: Reducing the Amperage or Reducing the Voltage. If you reduce the voltage (a common device to be found) the Amps will increase. He (electrician) said this was because power will remain constant no matter what, so if you decrease amperage the volts will increase and if you decrease voltage the amperage will increase. Decreasing the volts, and therefore increasing the amperage, will kill the motor. However, decreasing the amperage will slow it down safely. He said the thing to do it can be found out Radio Shack even (that's for something like 110 volt sander, not sure about Trever's mamoth machine). He also said he had purchased one from Dremel because they made one for their tool to slow it down.

There ya go!

TreverT · Post by **TreverT** » Sat Sep 24, 2005 3:24 pm

Firstly, thanks to all who replied to this question! I just posted a description of what I ended up doing to ASP, and am pasting it here also. Please note that the pic link is changed every couple of days, so if someone reads this a week from now, the same pic won't still be up. Eventually I want to create a photo-book of the steps I use in drilling a pipe, but that will have to wait for more time.

_______________________
What I did do was the simplest option - had a nearby machinist make me a new, smaller drive pulley to try out, and it is working terrifically. Drills a glossy smooth hole in anything, with enough torque to uproot a tree.
I have posted a pic of the machine I've been talking about here:
http://www.talbertpipes.com/11photo.shtml

The chuck apparatus has very adjustable jaws to hold pre-shaped stummels (I shape the pipes before I drill them), and can be rotated, raised, lowered, or moved in any way in an X/Y axis, onto either a conventional drill or a set of spinning cutters for quick shaping and multi-step-in-one operations. Pretty neat for a 100 year old gadget!
I should point out here, before any rumors get started, that I do NOT use this to "machine cut" any Talbert Briars - all the Talbert Briars continue to be fully handmade, and I just use this to drill them. However, I'm working with the adjustable cutting heads with the intention of being able to do some custom sets of Ligne Bretagnes, making them in batches to my own personal designs instead of being limited to the existing shapes we got when we bought the business. That way I could design things like, for instance, my own monster-fat bulldog shape and cut ten or twenty of them at a time, to keep them in the affordable Ligne Bretagne price range.

achduliebe · Post by **achduliebe** » Sat Sep 24, 2005 8:16 pm

Trever,

I would love to see a close up of that chuck apparatus, if you ever have a chance to fit it into your schedule.

TreverT · Post by **TreverT** » Sun Sep 25, 2005 8:21 am

achduliebe wrote:Trever,

I would love to see a close up of that chuck apparatus, if you ever have a chance to fit it into your schedule.

I just posted another, closer pic of the drill where you can see some more of the chuck. Dunno how much good it will do you since it is a highly specialized thing, but maybe it will be interesting anyway.
http://www.talbertpipes.com/11photo.shtml

Post by **KurtHuhn** » Sun Sep 25, 2005 3:07 pm

What an incredible gadget! Wow. That would cost a fortune to make today!

TreverT · Post by **TreverT** » Sun Sep 25, 2005 3:42 pm

KurtHuhn wrote:What an incredible gadget! Wow. That would cost a fortune to make today!

What amazes me the most is that it hasn't broken through the steel table it's mounted on. The drive shaft is so heavy that I can curl it, just, but it takes me and another person together to barely lift just one of those green steel "girder" that make the framework. It produces a great case of staggering back and forth with it 5" off the ground. Dunno why it is so heavy unless it's all made of lead, but it predates 1950 and may be as old as the 20's. Makes a stable drilling mount though...! Which should actually be obvious given that I was previously using it to drill my stummels at 2800rpm prior to the speed reduction, and the only problem I was having was some chattering and chipping. Imagine drilling a briar block at 2800 rpm on a typical lathe! :O

StephenDownie · Post by **StephenDownie** » Sun Sep 25, 2005 4:01 pm

Wow! That looks like a very heavy duty and versatile tool.

Post by **KurtHuhn** » Sun Sep 25, 2005 5:31 pm

TreverT wrote:What amazes me the most is that it hasn't broken through the steel table it's mounted on. The drive shaft is so heavy that I can curl it, just, but it takes me and another person together to barely lift just one of those green steel "girder" that make the framework. It produces a great case of staggering back and forth with it 5" off the ground. Dunno why it is so heavy unless it's all made of lead, but it predates 1950 and may be as old as the 20's. Makes a stable drilling mount though...! Which should actually be obvious given that I was previously using it to drill my stummels at 2800rpm prior to the speed reduction, and the only problem I was having was some chattering and chipping. Imagine drilling a briar block at 2800 rpm on a typical lathe! :O

And here I am thinking that 500 RPM is a tad too fast. Crikey! What a magnificent piece of equpment.

MEPerryng · Post by **MEPerryng** » Mon Sep 26, 2005 12:44 am

In my humble opinion, why don't you step it down through a secondary shaft, mounted with several pulleys? Unless you are working with extraordinarily limited space, you could even drive a mainshaft with that which could run many tool simutaneously. As far as your capacitor-starters go, they ony need full voltage at first, and then the motor can be stepped down to just above it's start level. I wouldn't use a variac to set your speed... get something that gives you a smooth waveform so you avoid overheating.

Matt

TreverT · Post by **TreverT** » Mon Sep 26, 2005 8:02 am

MEPerryng wrote:In my humble opinion, why don't you step it down through a secondary shaft, mounted with several pulleys?

Matt

Well, the simple answer is that I have nowhere near the mechanical ability to think about adapting this tool for such a setup, not to mention the costs of machining extra parts and such. Way too much unpaid work.....!

MEPerryng · Post by **MEPerryng** » Fri Sep 30, 2005 11:27 pm

Mr. Talbert

It is an old motor... it will handle a variac... try running it for 15 minutes on normal power, and then hook it up to a variac.... I bet it will handle the half-wave very well. Let me know how it goes.

Matt

MEPerryng · Post by **MEPerryng** » Fri Sep 30, 2005 11:37 pm

Mr Talbert,

By the way, most of Europe os on 50 cycles instead of 60 here in the states, but the principles are the same... you should be fine controlling your motor speed with a variac.

Matt.

pipemanruss · Post by **pipemanruss** » Sat Oct 01, 2005 1:40 am

on the varic idea i dont know if i agree with that. the setup he has looks to work fine for him and it is a bit of a specialty tool in itsself. so would mr talbert realy need to spend the money to have various pullys made when he just needs only one speed anyways??