Converting to variable speed

[gbeersjr]

Just wondering if anyone can give me any suggestions about converting a 4 speed Rockwell/Delta 11" (46-140) lathe to variable speed? Any websites/personal knowledge on how to do it? And would it be worth the time and effort? Or should I continue to save and purchase a newer lathe?

Thanks,
Gary

 

[Bill Boehme]

It's sorta' like putting lipstick on a pig.

Save your money for a new bigger and better lathe. If you go with a variable frequency drive (expensive), it means that you will also need to get a three-phase motor and it will need to be larger than the one that you currently have to make up for lost power at slow speeds. Count on several hundred dollars for that approach. If you go for a lower cost SCR type controller, you still will need a different motor -- either a universal wound motor or a DC motor. You will still have a low speed lack of power problem.

The benefit that you derive from making a variable speed mod is very subjective and really amounts to a feeling of, "I think that I gotta' have it". In reality, you will find that you still have the same old lathe with all of its warts.

 

[colinsp]

Gary

I did this to a Record lathe a couple of years ago. Depending on where you buy the pieces from depends on your costs. There are some photos and instructions on my site at http://www.turnspain.com/lathe_upgrade.html

Hope this helps

 

[odie]

I converted my Woodfast lathe last summer to VS. It's not a difficult conversion to do, but pretty expensive, since I went for the 1 1/2hp Leeson. For me, it was worthwhile, since I've been happy with the lathe......you should ask youself the same question......Is this a lathe you will be happy with in the years to come?

I purchased my VS motor and controller from CSUSA.

Here's a link....click:
http://www.woodturnerscatalog.com/store/Lathes___Attachments___Variable_Speed_Drive___vs_drive?Args=

One benefit to the conversion is you have a motor you can now use for a polishing station.

otis of cologne

 

[MichaelMouse]

Though not a monster like the Woodfast, you are several steps above a pig with lipstick. You have the features, save the MT head, of any Thoroughly Modern Mini in an ageless overbuilt package.

I'd countershaft it 2 for one, halving the speeds. Makes a simple job to use a couple of pillow blocks and put your lower cone pulley on there with a drive pulley twice the size of the one on your motor. Use of a link belt for the 2:1 allows really close mounting, allowing you to swing the whole package on the existing hinge in the same place it is now, if you have the factory stand, or drop it down to the shelf below as the lathes furnished with countershafts used to.

Take the money you would have spent and get a chuck and some jaws for it. Make sure you hedge the future by getting one with a replaceable insert.

I can't remember the last time I turned over 1000 rpm, but you'll have more than that at the top end, so as long as you look at your shavings instead of someone's "rules of thumb" you should be fine. .

 

[George Van Beynen]

Though not a monster like the Woodfast, you are several steps above a pig with lipstick.

Thanks for the morning chuckle from Phyllis and I!

 

[Steve Worcester]

Just wondering if anyone can give me any suggestions about converting a 4 speed Rockwell/Delta 11" (46-140) lathe to variable speed? Any websites/personal knowledge on how to do it? And would it be worth the time and effort? Or should I continue to save and purchase a newer lathe?

Thanks,
Gary

While the underlying sentiment here is you can do it, by adding a VFD (variable frequency drive) and motor, would the cost be worth it to you.
By trolling through ebay and places like that, you can probably do it for the $300 range.

(The budget explanation) A VFD allows you to control a 3 phase motor with single phase power and varying the frequency and "stuff" to allow for (theoretically) 0-full speed. An alternative would e to get a DC motor and power supply.

So, if you are willing to do some digging, it can be done. The Leeson is a good turnkey package, but it might cost more than piecing together a setup.

 

[GeorgeH]

Will this work?

http://www.pennstateind.com/store/tclvskit.html

 

[john lucas]

The Penn state hit is a DC motor of about 1/2hp I think. The speed of650 is dependant upon the pulley system you already have on the lathe. I think 650 is too fast for bowls but is fine for smaller things.
I've gone through all the conversions on various lathes from Step pulleys to jack shafts to DC and then finally the VFD. I've also had lathes with Reeves drives. The Jack shaft is the lowest maintenance of the 3. There's really nothing to go bad except bearing, belt and motor. All of which can usually be purchased locally. It's fairly simple to change over unless there's no room to run another belt.
The Reeves drive is something you can't really install yourself. It usually comes on the lathes. It's 2 biggest problems are lack of low speed and the pulleys sticking. You have to perform a periodic maintenance on them to keep them running well. The do hold up if it was a quality machine to begin with. There also isn't anything in there that you can't have a good machinist fix, so these lathes will usually last forever. At least on the old good cast iron jobs. Can't say that about the cheaper versions.
The DC is the simplest to convert but fairly expensive. If the DC controller dies your dead in the water until you can get a new one. They aren't that hard to come buy but can be a little difficult to locate locally. You also lose a lot of power at the low speed which is where you need it most. To compensate you put a bigger motor on which of course runs up the price. Been there done that.
The Variable Frequency Drive is the way all manufacturers have gone. You get high power at low speeds, adjustable speeds, and soft start and electronic braking. It's moderate to quite expensive depending on how you go. The downside is if it dies your dead in the water. You can buy the units locally but it won't be the same brand and you will probably have to be somewhat electrically verses to change it over. The same is true for the 3 phase motor. You will probably have trouble finding one the right size locally.

All said and done it's usually better to just get a lathe that already has variable speed. I did have fun rebuilding my various machines and wouldn't give up the experience but I could have purchased my Powermatic a long time ago if I hadn't spent all that money on fixing up old lathes.

 

[Steve Worcester]

In this case the 1/2hp would hurt you. Personally I don't think it is enough for a lathe that you intent to go out to the full swing. 1HP would be much better.

I would love to upgrade my mill drill the same way, but I would want 3HP there!

 

[Bill Boehme]

.......The Variable Frequency Drive is the way all manufacturers have gone. You get high power at low speeds, adjustable speeds, and soft start and electronic braking. ..........

Actually, you don't get high power at low speed -- the power falls off linearly as a function of speed from full power at full speed to zero power at zero speed. That is the big disadvantage of systems with variable speed drives. The way around that problem is through stepped pulley drives (you just can't get away from them without a big performance penalty) and by using larger motors to make up for the lack of low speed power. Depending on the design, some VFD drives are able to maintain constant motor torque when operating below base speed, but most people misunderstand torque and and equate it to power.

Most of the systems that you would encounter for use on a lathe do not actually have electronic braking -- rather it is a programmed deceleration profile although it can behave in much the same way as true braking.

 

[Bill Boehme]

Will this work?

http://www.pennstateind.com/store/tclvskit.html

I just looked at it and I wouldn't touch it with a 10 foot pole. They avoid giving any specs for the motor, but judging by its size, I would say that 1/10 HP would be closer to its real rating. Depending on how the universal motor is wound, its output power could fall of as the normalized square root of the speed (i.e., 1/4 full power at 1/2 speed) rather than linearly.

 

[john lucas]

You are correct as always. Whatever you call it you have plenty of torque or felt power at low speeds with the VFD. With DC you have almost none of the above.
On the variable frequency drive that I programmed for my last lathe you had a choice between what they called electronic braking and deceleration. If I remember correctly it also had something else that resembled what they called ramp up time. I did not understand how those two differed either. I did not understand the difference and played with both settings. I couldn't tell the difference.
Either way VFD beats the sox of DC drives in my opinion.

 

[gbeersjr]

So a VFD is not always the same as a VSD?

 

[MichaelMouse]

You are correct as always. Whatever you call it you have plenty of torque or felt power at low speeds with the VFD. With DC you have almost none of the above.

Either way VFD beats the sox of DC drives in my opinion.

Hmm, you and the EEs have a basic disagreement. Also the MEs who use DC motors for applications requiring greater torque at slow speed.

Worth mentioning that the current crop of drives are best described as DC, since they use square waves. Gives them more torque.

 

[odie]

Hmm, you and the EEs have a basic disagreement. Also the MEs who use DC motors for applications requiring greater torque at slow speed.

Worth mentioning that the current crop of drives are best described as DC, since they use square waves. Gives them more torque.

Huh? What's EEs and MEs?......and square waves?.....all way above my knowledge........but, I guess I don't need to understand the specifics of why......only that I'm not seeing a slower speed torque that's a problem in turning with my DC variable speed drive.

You still do have your step pulleys, and it's a snap to change them (just like I've been doing prior to the switch) when a lower speed torque is desired. I have run across that with larger bowl blanks and taking big heavy cuts, but it's not a problem to increase torque dramatically when switching to the "lower gears"!

otis of cologne

 

[Bill Boehme]

Just to clarify things, both the simple SCR controllers used for universal and DC motors along with the sophisticated PWM VFD controllers all use square waves as the output to the motor, but the mechanical inertia of the motor and the electrical reactance of the motor effectively helps to blend the square wave pulses into a sinusoidal waveform.

As far as efficiency goes, three phase AC motors are far more efficient than DC motors which, in essence, have to use commutation to take DC and turn it into something resembling a sinusoidal waveform. Since the rotor is chasing a rotating phase angle vector around a circle, the ideal waveform is sinusoidal for the greatest efficiency (which translates directly into torque and power). There is always a performance penalty when using square wave excitation to a motor and this is one of the design parameters that I would have to take into account in the design of of a variable speed control system.

One might ask, "why do we use drives with square wave output if sinusoidal output is more efficient". The answer is simple -- with square wave output, the cost of the electronics is far less and the efficiency of the electronics is greater. And, there are some tricks that can be done in the electronics to fool the motor into thinking that the input is actually a sine wave. The most significant is that by increasing the square wave frequency up above 5 kHz (even as high as 30 kHz, in certain situations using BLDC motors), and using a scheme known as pulse width modulation, the motor performance begins to approach the efficiency attained using pure three phase sinusoidal alternating current.

Oh, by the way, I have my own "lipstick on a pig" project involving a Delta 1440 lathe that uses a true closed loop drive system via an optical encoder on a 2 HP Baldor industrial three phase motor designed for operation up to 6,000 RPM (that's the motor, not the lathe, although in actual use about 4,000 RPM will be the maximum motor speed) and matching Baldor vector drive controller. I was able to obtain them as industrial surplus for only about $300 total (they were almost new) and the new cost from Baldor would have been right at $5,000. So, my pig is also wearing diamonds!

 

[odie]

The DC is the simplest to convert but fairly expensive. If the DC controller dies your dead in the water until you can get a new one.

Question.....

How common is it for the DC controller to fail? Can I reasonably expect my Minarik controller to last me a lifetime? (For me, I hope to have 25+ years left before I meet my maker! :cool2

otis of cologne

 

[odie]

Wow, boehme........What do you mean by "clarify" things?

For someone like me, who can barely do a few basic algebra problems, your post was like trying to understand Einstein's theory of relativity! heh,heh,heh!

I think I'm probably not the only one here that needs to know a few things on a more basic level.........like, will it work, or won't it.......and how well.

OK.....I'll now put back on my dunce hat, and go back to the stool in the corner!

otis of cologne

 

[Bill Boehme]

Wow, boehme........What do you mean by "clarify" things? ............

.........or, as Ronald Reagan used to say, "There you go again ...". My wife would have said, "I just wanted to know the time ... not how to build an atomic clock". I am afraid that it is a chronic condition that afflicts many engineers.

My FIRST POST on this question probably summed up things the best.

As I mentioned, I also have one of those "lipstick on a pig" projects. If you love to tinker with mechanical things, it can happen and there is nothing inherently wrong with that. Another engineer in our club, the Woodturners of North Texas, modified his mini lathe into a full-blown ornamental lathe that also has the capability of functioning as a rose engine lathe -- if you look hard, you can still see the mini lathe at the heart of his machine. Our January 2008 program featured his ornamental lathe.

The bottom line is that converting a lathe to a drive system that has a variable speed motor will work, but you might be disappointed in the results after spending a lot of money and time because the results will not be dramatic. For the benefit of those who don't want to earn an engineering degree in the process of modifying their machine, here are a few tips that may be of help:

• If you are modifying the lathe to eliminate the inconvenience of shifting the drive belt to change speed, you may find that you will still need to have at least two pulley speed ranges, if not more. Take a look at the commercially available machines and you will see that there are very few that do not still have multiple speed ranges. The good news is that on a well thought out machine like the Powermatic 3520, you will find that you can stay in the low speed range almost all of the time.
• Below what is known as "base speed" (motor speed at 60 Hz), power decreases linearly with decreasing speed for AC induction motors and for permanent magnet DC motors. For universal AC/DC motors, the power decreases much more rapidly (as the square root of the speed). By contrast, the power available at the spindle from a stepped pulley speed control arrangement is always constant for all speeds. This also means that the torque increases with decreasing spindle speed. That is a very important consideration to take into account when designing your variable speed drive system. You would like to still have the same or better low speed torque.
• In order to accomplish the above, one of the things that you ought to consider doing is to use a motor with a higher HP rating. Doubling the motor HP is what I would suggest as a simple solution. The other thing would be to change the drive ratio so that you "gear down" the spindle -- meaning that the motor must run faster. Without going to very expensive motors, there is not much leeway in that option as the typical AC induction motor doesn't like to be operated much more than 125% or so above the motor's base speed.
• There are some electrical and mechanical compatibility issues to consider -- the average three-phase AC induction motor may not fare very well in a variable speed drive. Motors need to be rated for this type of service and here are the reasons why --
  • At slow speed the motor will not receive much internal cooling so it must be able to withstand higher temperatures than standard motors.
  • You may need a motor to operate at 200% or more of base speed which reduces efficiency (more heating) and exceeds the bearings maximum speed rating.
  • The voltage input to the motor from a VFD controller has high amplitude spikes that may exceed 1000 volts and this may lead to internal arcing between the windings in the motor. This is a very gradual incipient type of failure mode and may not be noticed for a long time until it is evident that the motor seems to be "weak" and running hot. Therefore, it is strongly recommended that motors rated for inverter duty (class F or class H windings).
• Design the pulley drive ratio so that the motor will be operating most of the time between 50% and 125% of base speed (base speed is typically 1750 RPM).
• For anything other than a mini lathe, design the drive so that the top end spindle speed is around 2500 RPM (and definitely not more than 3000 RPM).
• If you have what is known as a "sensorless vector" type of VFD, you can probably design the low speed limit to be around 100 RPM and still get reasonable power output. For a more basic (lower cost) Volts/Hertz VFD, performance at low speed will not be as good so the lowest practical speed might be around 300 RPM at the spindle.
• You can hardly go wrong with a big motor! (except that it will cost more).
• "A man's gotta' know his limitations ... ". Remember that your little Jet 1236 and similar lathes just are not very strong mechanically and you can't turn one into a Oneway 2436 by adding a big honkin' motor and using risers under the headstock and tailstock.
• I have put more hours of design work into my project than it would ever possibly be worth, but then, that is what hobbies are for! Why did I do it? Well, I am cheap, my time was free, and I got an great deal on some industrial surplus equipment that was nearly new. Sometimes, I think that I do woodworking just so that I can twiddle with my machines. Next on my list is my drill press. It is an ideal candidate for variable speed because changing belts on it is a real PITA.

I hope that I did a little better job of answering your question this time, but, if not, I will try to help with whatever questions that you have.

Bill

 

[GeorgeH]

Does anyone know if something like this would work on a lathe?

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/speedcon.html

 

[Bill Boehme]

Does anyone know if something like this would work on a lathe?

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/speedcon.html

Definitely not!

 

[Bill Boehme]

So a VFD is not always the same as a VSD?

It looks like nobody has address your question about the abbreviations. VSD stands for "variable speed drive" which would be the all-encompassing term that would include the various types of motor controllers. The term VFD stands for "variable frequency drive" and is the type of VSD used to control three-phase AC induction motors. Since the speed of AC induction motors is governed by the frequency of the applied alternating current, this class of controller synthesizes three-phase power at a frequency that will produce the desired RPM. A typical frequency operating range for a VFD would be in the neighborhood of 10 to 200 Hz.

Within the VFD category, there are several variants.

• The low cost budget VFD is a type known as a volts per Hertz controller. Basically, it varies the frequency to the motor, but does not have any sort of feedback sensing to check the motor speed to see if a correction needs to be made. This type of controller suffers from poor speed regulation and shouldn't be used where that would be very important.
• The mid-range VFD controllers usually go by the name "sensorless vector" or something similar depending on the brand. While this type of controller does not have a true feedback measurement device to determine motor speed, it tries to estimate motor speed by trying to detect the motor slip frequency based on the results of a self-initialization test that characterizes the motor parameters and creates a look-up table in software. It does a fairly decent job except at very low speeds where its performance goes to pot.
• The top of the line VFD controllers are "vector drives" that utilize a hardware feedback device mounted on the motor to provide precise speed and position information to the controller. The device normally used is a rotary optical position encoder that typically provide motor shaft angle feedback to the controller with an accuracy of better than 0.1 degree. That means that this type of drive not only provides very precise speed control, but also precise controls the shaft rotation angle at all times. This type of controller is very expensive and would be used in very specialized applications that require precise control where motion must be synchronized with the operation of other systems.

 

[MichaelMouse]

Donning beat-up field jacket and flapping the arm held high. Uh,Uh, Uh!

Is this the place to mention that optical controllers like those on the Nova DVR are vulnerable to dust and Hall effect sensors to magnetism?

People who have 'em should make themselves aware of their location and the symptoms produced when they're dirty or otherwise impaired.

Nuturner, my first lathe had a universal motor on it with about an eight to one geared belt reduction. It used one of those controllers. Don't believe anyone, certainly not anyone major, would even think of using such a setup today.

 

[odie]

Question.....

How common is it for the DC controller to fail? Can I reasonably expect my Minarik controller to last me a lifetime? (For me, I hope to have 25+ years left before I meet my maker! :cool2

otis of cologne

Thanks boehme for all the fine input. I muddled through it and think I may have learned something from it.

I'd still like to have this question of mine (quoted above) addressed by someone in the know.

BTW: I've found that for each successive bowl, I may have to change pulley speeds, but usually don't have to vary too much for scraper and gouge work. Species, moisture content.....and SIZE are all important factors to consider before selecting a speed range. Sometimes I initially guess wrong about the proper speed range, and need to make a belt change in mid-stream, but, that's far from the inconvenience it used to be when I only had the step pulleys and no variable speed. It's a great convenience to be able to slow it down to a lower speed for sanding.....and switch back and forth without the need for changing belts. It should be noted that sanding at slow speeds does not require much torque, so using an entire speed range of a particular pulley setting is where the real benefits to the turner are.

I was a pretty stubborn guy prior to installing a variable speed. I had been changing belts on step pulleys for a long long time, and had gotten set in my ways. Now that I have been able to use it for the past four months, I kick myself for not doing this long ago!!!!:mad::mad:

Thanks to all who have contributed to this thread.

otis of cologne

 

[Bill Boehme]

Just making a WAG based on the fact that DC controllers are fairly simple devices with a low component count, it should be very reliable and I wouldn't be surprised if it had a MTBF (mean time between failures) of 5,000 hours, or more. Failure does not mean that it is toast ... it just means that some component has failed, but the bad part could be replaced and then be good for a few more thousand hours.

BTW, the most likely part to fail, by far, is the speed control potentiometer simply because it is a fragile mechanical part with a small wiper that rubs on a carbon resistive element. The tiny wiper will eventually break or will rub a hole in the carbon element. Fortunately, it is low cost and easy to replace.

The motor is very likely to wear out well before the controller fails, especially if you use it very much. I don't think that I would bet the farm on the motor making it for another 25 years.

I hope that doesn't alter your options in a negative sense WRT it lasting the rest of your life.

 

[Ken Grunke]

Does anyone know if something like this would work on a lathe?

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/speedcon.html

One of my early experiments with lathe power was a speed control unit like this, controlliing an AC/DC motor from a lawn mower. It was underpowered, and very loud. The idea is doable for a mini lathe if you protect the motor from dust and yourself from the noise. The controllers are meant for universal brush-type motors only, as found in portable power tools like routers.

 

[Dan M. Appel]

Totally different but related

Someone just gave me a 46-140. I have just about worn out a Jet Midi doing bowls much too large and heavy for the bearings and they are starting to wobble. So, #1 can anyone tell me how to replace the bearings on that lathe and, if possible, how to upgrade the bearings while I am at it. Second, a free lathe is better than no lathe at all. But, there are some very odd things about this lathe. The accessories appear to be a smaller Morse taper than the #2 on my Jet. Is there any way to change them out? Second, while it came with a couple of faceplates that had never been used - everything is a very different thread count and size than my Jet for which I have bought two scroll chucks and a number of different faceplates through the years. Is there any way to either change the threads on the lathe or to get an adapter? Finally, there is no wheel on the headstock end to rotate the headstock. I found a schematic on the web and it doesn't appear to even come with one - just had threads. What was the intent -that you turned your own or is there something I am missing?

Thanks in advance for any help you can give me. It's a cute little lathe with at least a 6 foot bed with extensions. I turn mostly bowls, and figure at 11" it is at least 2" larger than my Jet - that is of I can get it working.

Dan

 

[Bill Boehme]

Someone just gave me a 46-140. I have just about worn out a Jet Midi doing bowls much too large and heavy for the bearings and they are starting to wobble. So, #1 can anyone tell me how to replace the bearings on that lathe and, if possible, how to upgrade the bearings while I am at it. Second, a free lathe is better than no lathe at all. But, there are some very odd things about this lathe. The accessories appear to be a smaller Morse taper than the #2 on my Jet. Is there any way to change them out? Second, while it came with a couple of faceplates that had never been used - everything is a very different thread count and size than my Jet for which I have bought two scroll chucks and a number of different faceplates through the years. Is there any way to either change the threads on the lathe or to get an adapter? Finally, there is no wheel on the headstock end to rotate the headstock. I found a schematic on the web and it doesn't appear to even come with one - just had threads. What was the intent -that you turned your own or is there something I am missing?

Thanks in advance for any help you can give me. It's a cute little lathe with at least a 6 foot bed with extensions. I turn mostly bowls, and figure at 11" it is at least 2" larger than my Jet - that is of I can get it working.

Dan

The spindle socket taper is probably a #1 Morse if it seems smaller than a #2 Morse and it can't be "changed out" since it is an integral part of the spindle. There are adapters that can be found from some woodturning dealers, but they are simply extensions that plug into the existing spindle socket. Their advantage is that they are a simple and quick fix. Their disadvantage is that it will increase the runout of the spindle which would be a major concern if turning pens.

The spindle threads might possibly be 3/4 X 16. A ruler and calipers should give you a pretty good idea about the size. You can also get a two-bit thread-pitch gauge at a hardware or auto parts store for about six bits that would simplify the process of measuring the thread pitch.

There is no handwheel because the headstock is designed for both inboard and outboard turning. Assuming that you do not want to do outboard turning, you can make your own handwheel. Find a nut to fit the threads (they might possibly be LH threads) and epoxy it into a piece of wood that you can turn to the desired shape.

Replacing the bearings shouldn't be a biggie -- it might require you to loosen the set screws on the spindle pulley and, most likely, the bearings are being retained in the headstock by internal snap rings. If you do not already have a pair of good snap ring pliers, get a decent pair and don't be tempted to get the "under five bucks cheapo" because they will cause you to do a lot of cussing which will be followed by buying a better pair anyway. Finding "better bearings" doesn't really have an answer until you find out what you have currently. I would suggest going to the technical documents section of the NTN web site at http://www.ntnamerica.com/catalogs.htm to download tech manuals along with some introductory information that is essential to removing and installing bearings.

 

[Joe Greiner]

Delta 46-140

In addition to size, Morse tapers generally have different angles of taper. If you order an adapter, make sure the clerk understands your needs. "Adapters" usually adapt large sockets to small plugs, not the other way around, which you need. Like Bill says, it will increase the cantilever from the spindle and will increase runout. For pens, a new mandrel (for #1 taper) would probably be better, and not very expensive.

Your scroll chucks may be amenable to replacement of the inserts.

You may also find manuals at Old Woodworking Machines ( http://www.owwm.com/ ).

 

[kenvalaska]

"Someone just gave me a 46-140"

Memory is that it is a 3/4 by 16 threaded headstock. The good news is that there is a lot of tooling around for that sized thread and the nuts, bolts, etc are stocked in most hardware stores. Taig and Sherline micro machine lathes have used this headstock thread for years - and the old craftsman lathes were threaded this way too.

The Bonnie Klein late uses a Taig headstock and has that thread. (I have several micro lathes threaded that way). Small three jaw and 4 jaw machinists chucks (both scroll and individual jaw chucks) and a fair amount of tooling is available. Little Machine Shop has MT1 tooling and inserts as does Sherline.

3/4 by 16 is not heavy duty as you may be able to see from these nylock nuts from the hardware store. I take out the nylon insert and use thes in wood block as face plates. The smaller nuts on the loop are 3/4 by 16 from the hardware store - and that loop of nuts weighs about the same as one nut for the 1 1/4 by 8 for the big lathe.

 

[Paul Bennett]

VFD speed control

I just wanted to add my experience with the VFD. I installed a GS-2 on my Hapfo lathe. It works very well. Much cheaper than the DC motor which I have played with. The GS-2 cost about $200 and I got it from Automation Direct.
www.automationdirect.com . You can find used VFD's on Ebay but the best thing about Automation Direct is they have excellent techniccal support. Call them with the size of the motor you want to put it on and they will walk you through the whole process. These things are amazing. You can use it to replace a 3Phase converter. It will brake your lathe, run backwards etc.

Paul Bennett
www.woodworkersnetwork.com