Re: Variable speed

[DougLA]

Tool fan,

Looks good and no doubt a fun project. My opinion would be if you want some idea of rpms - it's there.

I have a 10,000 watt SCR on the way from Amazon. Hope to gear up with a treadmill motor on my Beaver 3400 as a 2nd lathe or perhaps a bandsaw. Looking forward to messing around with it and answering question as to how many DC volts this controller puts out.

Doug

[tool fan]

Tool fan,

Looks good and no doubt a fun project. My opinion would be if you want some idea of rpms - it's there.

I have a 10,000 watt SCR on the way from Amazon. Hope to gear up with a treadmill motor on my Beaver 3400 as a 2nd lathe or perhaps a bandsaw. Looking forward to messing around with it and answering question as to how many DC volts this controller puts out.

Doug

Thanks Doug, It was fun and I think I should have kept the heart monitor hardware so I can measure that while I use the lathe.

I sure hope the 10,000 watt SCR works. Free treadmills are becoming a scarcity around here. About a year ago I could pick one up whenever I needed one. Now, they are gone within a couple of hours of posting. Right now I have loads of the little motors but no controllers that can deliver enough power to be effective. Keep us informed when you try the one you ordered.

[DougLA]

tool fan & Braz-in-the-Peg,

I've set up one of the 10,000 watt SCR's as a self contained controller in a recycled 4X6X6" PVC junction box and incorporated a voltage meter and reverse polarity DPDT switch. Same regulator as Braz-in-the-Peg a few posts back. (10000W AC110V 220V 75A SCR Voltage Regulator Speed Controller via eBay) As he said maximum voltage he calculated does appear to be 130 volts at least on motors I tried it on. Not sure what I will do with it - if nothing else, useful to have a variable DC voltage power supply. Must say it is not as "smart" a controller as treadmill MC-60 or KB electronics controller that I am presently using on my lathe - as it does not have any voltage or current compensation when under load. Guess would be OK with a smaller lathe and I'll likely rig it up with my old Beaver 3400 I have on a shelf.

Just threw together a Flickr album:
https://www.flickr.com/photos/767624...57714856974796

[tool fan]

I like the setup, very tidy and I like how you have incorporated a voltmeter. I f you find that it produces enough torque at low speed for your Beaver lathe I will be copying you. Thanks for sharing the details.


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[DougLA]

Thanks Rory.

Out of interest I had tried this controller with my lathe which uses same model treadmill motor as in last post and is set up with a KB Electronics controller. I have been roughing out wet beech into 16" bowl blanks and it was easy enough to temporarily wire in new SCR controller.

Comparing the two, my present set up does work hard turning these large items but is quite satisfactory. Using the new SCR controller it is much easier to stall, I presume as no voltage or current compensation under load. I'll see how it works doing lighter, smaller stuff either again temporarily wiring it back in to present lathe or set up with my unused Beaver 3400. Might be after the summer before get a roundtoit. As per Braz-in-the-Peg I guess it will be fine with smaller items.

Doug

[tool fan]

Wow that's quite a large bowl!  Your experience with the SCR controller is what I remember.  My conclusion was that it was about the same as the already packaged DC 51. 

Here's my latest project.  I actually found two of these old Rockwell lathes with what look like original Preston Leland 3/4 HP 3 phase motors. 

 

[DougLA]

Nice!