Variable speed

[billh]

Bent the gouge tang????? If you are using a spindle roughing gouge - don't. The tangs are not meant for work like that. Bowl gouge tangs are the same or close to the same diameter as the tool unless they are old cheapies. Yes, I know not everybody made their gouges the same.

Your photo appears to show that you are cutting on the outside circumference of the blank to round it. Much better and far less "clunking" to start near the center and basically start making the bowl shape. Your gouge will not be subjected to severe hits when the flat-spot ends and the wood starts again.

billh

[DougLA]

Yes iamtooler, belt slipping is a problem at slow speeds & large blanks with the 70 year old Craftmaster lathe as well.

In prior lathe set up with speed regulated by frequent belt changing (perhaps aggravated by running belts under some tension over next pulley edge) the belts would eventually stretch and start to slip frequently especially on smallest step pulley perpetuating problem by polishing inside of pulley surfaces as well as side of belts. CTC belts also tended to eventually come apart. This is now 3rd time in 2 years that I've replaced both belts. With present incarnation I have used a P. Auto Kevlar 5/8" belt from DC motor to jackshaft over larger diameter cast iron pulleys and have used a Gates notched 1/2" belt from jackshaft to headstock step pulleys with both adjusted to "perfect" tension (err... whatever that is!). I also roughed up inner polished surface of smaller pulleys with sandpaper and all pulleys look to be running true.

I think belt life is likely another advantage of electronic variable speed. With need for belt (speed range) changes much less frequent and future care to change belts with tension completely released, I'm hoping to avoid replacing belts anytime soon. Others experience?

Last night turning a 15", 45 pound blank of wettish beech courtesy of hurricane Dorian, I roughed out a blank starting at ~200 rpm in low speed range. Set up worked well. Motor certainly didn't stall, however with a couple catches (one actually bent gouge tang) there was still slipping of 1/2" notched belt on smallest 2" jackshaft pulley. No slippage with 5/8" belt. Guess, one should look at slipping as a safety feature in this situation!

Agree belt slipping also a potential problem with a drill press at slower speeds but with experimentation as suggested by Rory and attention to pulley quality/size, belt size/type and tension perhaps can overcome if go to electronic variable speed?

Good thing I enjoy eternal tinkering! Oh the joy of retirement!

[iamtooler]

Be aware that the problem with belt driven drill presses is transmitting the torque for low speed applications. It is hard to stall even a 1/2 hp motor because the belt slips below about 700 rpm. I have some English DPs that have a 2 speed final reduction to over come this.
Rob

[tool fan]

Hi Doug, I've seen the same motor as you have. There is no difference between them as far as I can tell. In my anecdotal opinion, the mass of these motors is the most important feature. If you tear apart one of those Weslo's you will probably find a much smaller motor with a label suggesting that it is 2.75 HP. Maybe just before it blows up at top speed at high load, but in reality, not meaningful.

Turning big forstner bits might be problematic with one of these DC motors. Although as I stated earlier, I had one on a Jet tabletop drill press that would blow the 15 amp circuit breaker before it stalled. I used a larger Leeson motor and a DC 51 speed control. I sold it. Since then, I have found that the DC 51 control boxes are not the same and will only output ~ 400 watts at full power.

I think that VFD's and 3 phase motors are better for drill presses and metal lathes and that would be my choice when I get around to converting another drill press.

If you find a free MC 60, hook it up and test its performance with your DC motor. Try it with the flywheel on and off and see what you think. Be mindful that you probably do not need the step pulley, so you might find that there is room with the flywheel on.

To turn down the flywheel I take it off and turn the drive stub down on my metal lathe.

I hope that this helps.

[DougLA]

Rory, you certainly have a lot of knowledge with treadmill motor/controllers conversions and great that pass on your experience. Nice job.

Interesting, I have that same motor down to motor model # but rated for 2HP for some unclear reason.

I have toyed with idea of putting in my tabletop Rockwel/Beaver drill press so as to slow down beyond 700rpm for drilling metal and perhaps large Forstner bits. Wondering about wisdom of using without flywheel as would be a lot easier and neater to install and quicker to shut down without. Drill press only gets occasional and short bursts of use for minutes only - nothing like turning for hours at a time. Wonder what you think? How do you turn down the flywheel - just with motor spinning or do you use a metal lathe?

Have seen a couple older Weslo Cadence (840 & DL40) treadmills with slider potentiometers. From what I could glean on line should have MC60 controllers? altho prices not right.

[tool fan]

The tach was from ebay and it's powered by a small dc transformer (wall wart) that I have strapped onto an electrical outlet that I wired into the AC circuit.

[al.m..]

There is a DPDT switch for Forward and Reverse. I have since labeled it. Here is also a picture of the motor with the pulley. Outside of the KB electronics control boxes, I believe that the MC 60's are the best...……...and its hard to beat free.

whaere did you get the tac? Is it powered off the mc60?

[tool fan]

There is a DPDT switch for Forward and Reverse. I have since labeled it. Here is also a picture of the motor with the pulley. Outside of the KB electronics control boxes, I believe that the MC 60's are the best...……...and its hard to beat free.

[al.m..]

I just finished another one. This time a Delta/Milwaukee Homecraft from the late 1940's. It was pretty rough when I got it, but cleaned up nicely. The only thing I don't like is the exposed pulley belt and I may build a cover. What I do like is the indexing pin. There seems to be lots of torque at low speed.

This one has a 2.25 HP Johnson variable speed DC motor and the control board is an MC 60. On the lowest pulley configuration rpm ranges from a crawl to ~ 1900 rpm. On the fastest pulley configuration the upper range is around 7,000 at least that's where I chickened out as I turned the speed dial

For a 70 year old lathe it runs surprisingly smooth.

nice.
i just acquired two more treadmills with the mc60 board,both free.May convert my drill press .
did you add reverse to the Homecraft? I would like to see you motor pulley arrangement

[tool fan]

I just finished another one. This time a Delta/Milwaukee Homecraft from the late 1940's. It was pretty rough when I got it, but cleaned up nicely. The only thing I don't like is the exposed pulley belt and I may build a cover. What I do like is the indexing pin. There seems to be lots of torque at low speed.

This one has a 2.25 HP Johnson variable speed DC motor and the control board is an MC 60. On the lowest pulley configuration rpm ranges from a crawl to ~ 1900 rpm. On the fastest pulley configuration the upper range is around 7,000 at least that's where I chickened out as I turned the speed dial

For a 70 year old lathe it runs surprisingly smooth.

[DougLA]

While sanding I am in habit of switching direction with every change of grit. Guess i'd live in fear of accidentally going from forward to reverse without fully stopping and destroying DC brushes or worse.
Wasn't a problem if that happened with prior Leeson that had a centrifugal switch. If flipped drum switch into reverse and hadn't slowed down sufficient to activate centrifugal switch than motor just continued on merrily turning in forward direction.

[tool fan]

I do not recall adjusting the trip pots on the KB controller that I had but I do remember that the motor sounded pretty good at full speed. Hopefully the guy that bought it has not had any problems. Also, I believe that the one I had was 110 only.

I was thinking about your comment on the DPDT switches with DC motors. I can't imagine a situation where the operator of a wood lathe would want to flip from forward to reverse while using. My experience is that you either turn in forward or sand in reverse. It would be different tor a metal lathe or a drill. And in that case your controller with the brake or a VFD with a 3 phase motor are pretty nice.

[DougLA]

Controller has a switch for "115"AC / "230"AC with corresponding top DC outputs of 90+ and 180+ volts. Using 220v I placed a voltmeter on DC output that goes to motor and you can see the voltage change as turn potentiometer knob. As motor badge specs say it gets up to ~ 180 volts at 4200 rpms. I went above that for 10 seconds and there was bit of an electrical burning smell plus sounded as if something might blow up!

As I understand it, voltage to motor relates linearly to speed and HP.

I have set the controller max motor speed(voltage) trimpot presently to ~3500 rpms as must certainly be healthier for motor longevity. This gives a maximum lathe spindle speed of ~3000 using high gear with step pulley, I forget exact number but at rpms of 3500 motor DC voltage was somewhere around 150 volts and thus HP would be less than badge spec rating of 3HP at 4200. BUT at top speed setting of 3500 motor hums along comfortably.

Lathe spindle speed range with step pulleys presently ~200 to ~3000 rpm. Hope not but depending on turning performance no doubt there will be further fine tuning of controller max speed and "tinkering" with pulley ratios from motor to jackshaft.

[tool fan]

I actually had forgotten that the dpdt switch is on the DC side. Having said that, I'll bet you are right and that instead of the usual 90 volts, you have 180 with the 220 circuit

[DougLA]

Sorry, misunderstood. With 220 guess DC output was too much for that particular Princess Auto switch.