DC Motor Brain Trust Questions

Re: DC Motor Brain Trust Questions

Bill Hale / The Wood Spinner

>Baldor is good

Yes you will need a controller for the speed controls. Be sure to add a reversing sw.to the wireing.

I would use a three step florentine , ? sp,pulley set. As motor speed reduced so does HP.

Good turning and be safe

Bill

Re: DC Motor Brain Trust Questions

Don Evans

>DW:

Couple of things:

Minirak makes a controller for DC motors. The Nova 3000 lathes sold by Woodcraft and KMS in Canada used Leeson motors and the Minirak controller.

The controller they used will output 90 volts with 115 volt AC for the controller but the motor you have is 180 armature volts so that same controller can be used by flipping an internal switch in the controller but you'll need a 220 volt AC line feeding it.

You can talk to someone at www.woodcraft. com or www.kmstools.com to see if they have a controller they will sell but being new units, they will be expensive.

You can get the same controller from www.surpluscenter.com but you'll have to do a little work to it, like adding the external heat sink and the braking resistor. All of this is sold by surplus center for about $80 to $100.00 US dollars.

As far as pulleys, yes, you'll want to keep it on step pulleys, not direct drive. You didn't say what lathe you have so the one's you have now may be just fine. Only problem will be if you present motor pulley will fit shaft of the DC Baldor.

Good luck with your mod, variable speed on a lathe makes tremendous difference in turning experience (assuming that is what you end up using it on).

Don

Re: DC Motor Brain Trust Questions

DW

>Don,

Thanks for the info. The motor in question is a $1357 DC Perm. Mag. motor new. It is going for around $300. Swinging the deal will be tight right now, but if I can, it would really help in getting back to turninig.

I have an old generic lathe that I have refurbished more than once. However, the slowest speed I can get is around 700 rpm. Much too fast for anything more than 4-6" in diameter. My arthritis really takes a beating on anything remotely out of balance... so I have done little turinig for several years.

I hope to someday slow the lathe down and a DC motor seems to be the way to go. If I can close this deal I will need more help in working through the mods.

Thanks..

DW

Re: DC Motor Brain Trust Questions

John Lucas

>DW

I would look at variable Frequency drive and motor. If your motor is $300 and a controller will run anywhere from $100 to $300 your in the range for a Variable freqency drive with 3 phase motor.

They run on 220 single phase. They don't lose torque at low speeds like DC motors and the prices have come way down from 3 or 4 years ago.

I just checked www.dealerselectric.com and they have them from $290 for 1 horse and $460 for 3 horse. You will have to either wire it your self or pay your local motor repair place a few buck to wire it but they work really well. I've wire 2 of them and they aren't difficult at all if you have any electronic background. My friend payed the local motor place $100 to wire his up. It looked a lot more professional than mine.

Re: DC Motor Brain Trust Questions *LINK*

John Lucas

>Sorry I meant to put the link up.


http://www.dealerselectric.com

Have you considered a jack shaft?

Clem Wixted Jonesboro AR

>This may not be as good as a continuously variable speed DC motor but you can get quite a few more speeds out of your present setup, especially on the low speed side. I had this on my lathe before my current DC setup. You have two belts to change but it has worked for years on a lot of lathes.

If you want to stay with DC and you don't need a big DC motor you might consider a treadmill motor. I bought a used treadmill for $15 to add variable speed to a mini lathe. There are a few situations to overcome but it will work if your power requirements aren't too high.

Clem

Variable frequency drives

Bob Hackett

>If memory serves me,Chuck Woodruff used to offer a 1 HP set up ready to go for around $400.The prices went up,but not drasticly,as the HP went up(naturally).Chuck is a woodturner and an electrical engineer so he is definately the hot ticket here.He also offers DC drives but I think after talking to him you`ll want the VFD.You can reach him at (206)723-8487.You can contact him online at;woodco@gte.net.

Mainely,Bob

BTW-All my contact info for Chuck is as of 2002.If it`s outdated his add can be found in the back of the AAW journal(that`s how I found him).

Re: DC Motor Brain Trust Questions

Don Evans

>DW:

Your latest information makes thing different. I especially understand the health issue as I have same problem with back and neck. I'd forget the motor you are looking at and go with the VFD from dealers electric or Chuck. (actually, I might buy it for an investment and resell it)

I though you already had this motor so it made sense to use it.

Personally, I would go with the 1 HP unit dealers sells for $290.00. It's all the power you'll ever need from sound of things. It would be easier to wire in also.

Find a turning club near you, I'd bet money there are several electronic guys there. For some reason we gravitate to this hobby. Moths to a flame.

Don

AC all the way!

Steve Mushinski

>If the cost of you DC system is going to be around $300 get the AC system from the link in this thread you will be very happy.

AC system were very costly before therefore were not a option for the home hobby user. Now they are within our means in price and the performance is much better when talking full range of torque.

If the DC system was free or cheap then it is better then nothing. If you are buying then the best choice is an AC system.

I have the 2hp and love it.

Re: DC Motor Brain Trust Questions

Bill Hale / The Wood Spinner

>If dollars are tight consider Surplus Center Treadmill DC motor and controller. I think you can get them for less than $ 100.00. Remember you get what you pay for and they are not the greatest. I hav an old lathe I let other turners use and it has one on it. It works OK. They say 2.5 hp but I would guess 1/2 to 3/4 at best.

As the rest have said AC

Good turning and be safe

Bill

Re: DC Motor Brain Trust Questions

DW

>Thanks y'all...

After doing a minimum amount of research, I agree with the AC route, especially given the stable torque in all RPM's.

I have found some Lathe motor packages from an electrical co., of 1HP with controller, for $244. Will look into the link in this thread as well.

Appreciate you guys and all your help. Will let you know what happens.,, just might post some current work someday! In the meantime, will snap some shots of work when I was young, foolish and didn't know any better.

DW

Re: DC Motor Brain Trust Questions

DW

>John,

Thanks. You confirm something I found a couple of days ago. An local electrical co. is offering a Lathe motor package just as you describe, for around $244+ shipping. Will follow up your link as well. AC seems to be the best choice over DC.

Thanks again,

DW

Re: DC Motor Brain Trust Questions

Don Evans

>How about sharing the link with us for the $244.00 unit? My brother is in the market for one also.

Don

Don - Here is the *LINK*

DW

>Don,

Here is the link to the Friesen Electric eBay store. I sorted the items by the AC Motor link on the left of the page. The 5th and 6th items down are a 1/2HP Lathe package and 1HP package respectively.

I am no electrical guru by any stretch of the imagination, but I think these are what you were talking about.

Scan the three pages of AC Motors/Packages and let me know what you think. Some are "Buy Now" others are open for bid. However, I would submit that we offer them a group purchase and call them on the 1-800 line to make a deal. They most likely will take something "off the table" for a pre-sold agreement.

No connection to them... just thinking outside the box.

DW


AC Motors Link

AC MOtor/Controller Package Deal

DW

>Don,

Just got off the phone the sales rep. for Friesen. He said his boss would be "very" interested in discussing a package deal for a group purchase. The boss is out of the office right now but I plan on calling him later.

Are you interested in your brother with a group purchase? Sales rep said that even the open bid items are available for immediate purchase.

What is WC's policy in posting this opportunity? Maybe I should check with Ellis... don't want him to pull my plug, chain, leg, hair...

DW

Re: Don - Here is the

Rick R, So Cal

>DW,

Go with the lower RPM motor (1140 or 1725). Here's why: with a VFD, you get constant torque up to the motor's rated RPM, then from there on up, you get constant HP. You want to be in the constant HP part of the curve as much as possible in order to get maximum power. To achieve this with a 3450 RPM motor for the lower spindle speeds, the headstock pullies would have to be too large to fit.

As an example, the PM3520 uses a 1725 RPM 2HP motor. The VFD runs the motor from 0 to 120Hz, or 0 to 3450 RPM. So when the speed control knob is at halfway or higher, you get 2HP at the spindle.

Rick

Re: Don - Here is the

DW

>Thanks Rick,

This is going to be a learning curve for me. I am initiating a negotiation for group pricing on packages and will request input from the membership once I get confirmation of interest from the company. Ellis gave the green light so I am not letting any grass grow under my feet... so to speak.

Thanks again, Rick, for the great info.

DW

Re: AC MOtor/Controller Package Deal

Don Evans

>Hi DW:

Thanks for the link. I agree with Rick on the motor rpm so the only motors I saw in the 1750 (approximately) rpm range were $283.00. Also the brand names on some of them I've never heard about. Frankly some of them looked repainted also which would bother me.

I think we'll stick with the $290 with dealers electric for two reasons. One is the controller appears more manageable (larger buttons, etc) and the motor is a Baldor.

Thanks for offering to broker the deal but think I'll pass.

Also, being in NC would make shipping much more than saving. Due to vacation trip the other one will have no shipping cost.

Don