Lathe speed

Re: Lathe speed

Fred in NC

>I would be interested in knowing what kind of lathe, and what kind of motor and speed control for the motor. That loss of power does not make much sense for an AC motor. Is it a single phase, AC motor? It could be that the controller is driving a DC motor, in which case it will make more sense.

Re: Lathe speed

Fred Le Bail

>The motor is a 1/2 hp single phase AC motor. If I could find a simple way to post pictures to this site I would do so.

Fred

Re: Lathe speed

Bill Grumbine, Kutztown PA

>Hi Fred

This is a little different than the answer you are looking for, but I core at 750-800 rpm on a regular basis. Catches are not a result of the speed the blank is turning but rather how the coring tool is set up. If you have it set up so that the tip is at center when the tool is snug up against the gate, those wild bucking catches are reduced to almost nothing. From that point on it is a matter of the feed speed.

Even something as nasty looking as this can be successfully cored at high speed. I did this one at 800 rpm and it was bone dry to boot.

Good luck with it.

Bill

Re: Lathe speed

Bob Persing (Skillman NJ)

>Fred,

Although not nearly as popular these days with the availability of low cost, high-powered, AC motors, a "jack-shaft" setup was a popular accessory for the lathe. The motor drives the jack-shaft and the jack-shaft, in turn, drives the lathe. In one of its simplest forms, one could make a jack-shaft using two pillow block to support the shaft and the fasten two pulley to the shaft, one at each end. A large diameter pulley on one end to be driven by the motor and a small diameter pulley on the other end that will drive the lathe. If your motor has a 4-step pulley on it, use the smallest dia. position to drive the jack-shaft. Then use the largest diameter position on the pulley of the headstock. Depending upon the size difference of the two pulleys of the jack-shaft, you will reduce the OVERALL speed of the lathe. The Delta supplied jack-shaft that I had used with my VERY old Delta lathe was equipped with step pulleys. This provided a very wide range of speed adjustments.

Many drill presses sold today make use of a very compact jack-shaft arrangement to get the 12 or 16 speed range they offer. Perhaps something like this could be adapted for your use.

HTH,

BobP

Re: Lathe speed

George Van in WI

>Fred, when I first started coring I used 200-250 rpm to avoid catches and uneven feeding. I had catches and uneven feeding! I stepped things up to 400 and feeding went much better and considerably smoother. Chips were ejected better. I now use about 600 for starting the feed and if things are going good get up in the 800rpm as Bill states. It seems the speed gets the chips out of the way much better.

Greg Johnson, the McNaughton rep gave me good advise, make sure you are pushing straight in, not pulling in, the blade will create the curve. It helped me.

Re: Lathe speed

Fog Tanner

>When using the McNaughton system on my 16" Delta I run the lathe at 600 rpm in the low range. This is the halfway point and where thre motor is making its most power. On my 24" Vic, its whatever I feel big enough for, power is not a problem. I tried down at 400 on my Delta, but that was painfull. It was slow and the power was down. When I picked up the RPM, the process went much smoother. I also am using the original square end blades, which I preferr over the newer ones with the point. It takes more power, but I like them better.

You need to find what rpm your motor is making its max power and target for that. With 1/2hp you will be pushing it. Its doable, just going to take a while.