Which lathe to upgrade?

[Lee Alkureishi]

Hi all,

I currently own a harbor freight 34706, which I've been reasonably happy with, except for the terrible 3/4hp motor (Chinese no-brand, probably actually more like 1/3 - 1/2hp, bogs down easily with anything over 5" or so).

I've been thinking about upgrading the lathe's motor for a while now, in particular with a VFD and 3 phase motor. This weekend, I found a 2hp 3phase leeson TEFC motor at a yard sale ($40!), and now have a VFD on the way from ebay.

But, I also recently found an older lathe on craigslist - a myford ML8. It was a bit rusty, but after cleaning up it runs just great. There's a bit of vibration from the current motor (1hp), but otherwise seems to be in great shape.

So, now I'm wondering which lathe to slap this new motor on? I'm leaning toward the myford, as it's pretty sturdy, allows outboard turning (I turn mostly bowls, and would like to go a bit bigger than the 8" inboard limit), and is just "cooler" than the 34706. On the other hand, the 34706 is a clone of the Jet 1236, newer, probably equally sturdy and has a swivelling headstock. Choices!

I do understand neither of these lathes is going to handle an unbalanced 20" blank, and 2hp is way overkill for their capabilities. All I'm looking for is to be able to turn mid-size pieces (say up to 12" or so), get very low speed capabilities for out-of-round blanks and sanding/finishing, and have easy speed changes. I think this will do it - just want to figure out the best option!

[Eric Holmquist]

I'd go with the HF, it is probably sturdier and less likely to produce needless drama if you start doing more aggressive cuts that the larger motor will allow.

Just because you are not turning something big does not mean you are not putting a lot of load on the lathe. If you get too aggressive, you can stall a 2HP motor with an 8" bowl. Not sure I'd like to see if the myford does something exciting under that sort of load.

[Jim Burr]

I'd get out of the HF syndrome like white on rice. Delta, Jet, lot's of choices for reasonable prices and far more stable with greater longetivity. It may however, be more reliable than my spelling! Give some serious thought to where you want to be in 1-2-5 years Lee and extrapolate your needs from there.

[Steve Schlumpf]

I agree with Jim - there are lots of options when it comes to upgrading to a larger lathe. Having a 2 hp motor on a small lathe - or any lathe not designed to handle that kind of stress - could become a real hazard. Seriously take some time and think things through.

[Bob Bergstrom]

While the Myfoord is an awesome spindle lathe, it is what it is bolted down to that would be a major weakness. The harmonic of wood and sheet metal stand can cause some detrimental vibrations. If the harbor Frieght has Gast iron legs that is a asset in turning bowls. The Myford also only goes down to 750 rims. You could install a jack shaft to solve that. Put the end of a piece of wood on the headstock of the Myford. Put you ear on the other end. If you hear any rattelly sound, the bearings are dry and need to be replaced. They probably are considering the age.

[Lee Alkureishi]

Fair enough. As I mentioned above, it wasn't my intention to find a huge motor but the deal was too sweet to pass up. I do recognize the limitations of these smaller lathes, and am just looking for a way to improve performance to acceptable on the size pieces I am currently turning.

From asking around, it sounded like setting the belt tension loose, to allow it to slip before anything can bend or break is an acceptable way of using a higher rated motor on smaller/lighter equipment. I had planned to use that as a safeguard.

Re: Jim's comment about HF - I agree with that for many of the machines produced by HF, but many reviews also state that the 34706 is an exception. It is a near identical clone of the Jet 1236, likely made from the same castings and sharing all the features of a lathe sold for $900 - including its flaws. Now, I recognize that the Jet is by no means a great lathe either, but there are multiple websites demonstrating how to upgrade the motor for just this reason. These upgrades seem to be fairly well tolerated - albeit not with a 2hp motor.

I would love to upgrade my lathe to a better model, and I will, in time. It's just not feasible at the moment.

I appreciate all the advice given here - this is a learning process for me, and the many answers I've received over the last several months have helped immensely.

Thanks again,

Lee

[Lee Alkureishi]

Hi Bob,

I understand what you're saying, but I'm not sure why I would need a jackshaft with a VFD in place. The VFD would allow infinite speed control down to effectively 0rpm. I could install a matched step pulley directly on the motor, and that would give me multiple speed ranges for different torques at lower speeds.

Thanks for the tip about the bearings - I'll check it out when I get home. The HF lathe stand is stamped steel - I built a sturdier workbench which it's currently bolted to.

[Eric Holmquist]

Not sure if this is an option, you would need to study the VFD programming manual to make sure, but if you can throttle back the max power delivered to the cheap but overkill 2HP motor via VFP parameters that may be the best bet to ensure that you don't dump too much force into the lathe if you use the big motor.

This might take the form of current limiting the VFD output, but if you are lucky, you can tell the VFD that you have a 1HP motor instead and the VFD will ensure that the motor does not generate too much power.

[Lee Alkureishi]

Hi Eric,
that's a fantastic suggestion - can't wait for the vfd to arrive, so I can figure out if that's an option...

The vfd is a huanyang one from Ebay. Reviews are generally favorable, but anyone here have any experience with them?

Lee

[Roy Turbett]

I didn't have any trouble programming a used Reliant 2 HP VFD to use with a 1 HP Leeson three phase motor on my Powermatic 90. At 20 Hz, the lathe turns at 220 RPM. One thing to consider is that a 2 HP VFD draws about 18 amps.