Ok so if 600 rpm is too fast....

[Jim Kountz]

I posted a thread yesterday about safe turning speeds and got a wealth of information so first let me say thanks once again to the Creek for that! Along those same lines another question comes to mind.
When I look at most of these older lathes for sale on the net (the old deltas, powermatics and olivers as well as others) I notice that a good many of them dont go much lower than 800 rpm or so. So how did one turn larger items before the advent of VFD lathes? Were there ways to mod the older lathes to make them slower without the use of a VFD?? What did our grandfathers do in this situation? (wish mine were here to ask, rest his soul)

Thanks!

Jim

[Ron Coleman]

I think the advent of electronic speed controls has allowed the increase in work size. If you look at most of the older lathes you won't find many that can turn bigger than 12 inches. Lathes with larger capacity usually had mechanical transmissions to slow them down. New lathes have larger capacity as a direct result of modern low cost speed controls.

Remembering back to the early 60's when I was in high school, bowls were never larger than about 12 inches and back then nobody turned thinner than about 3/8 inch so the work had plenty of strength for the higher speeds. Everything we made back then was glued up from flat stock, nobody ever thought about putting half a log on the lathe.

Before the 1970's there were very few turners doing anything that resembled art. Even greenwood turning is new for the hobby turner, it was used in production turning for many years before it caught on for hobby use.

Ron

[Jim Becker]

Jim virtually all, if not all, of those old lathes were designed for spindle work and many of the current machines that "share heritage" with them are really "best" for spindle work. It's only in the last 20+ years that more and more folks got serious about bowl and spindle work the way that things are now. Prior to folks like David Ellsworth and his contemporaries, there really wasn't anything happening in work like hollowforms and other turned art like the activity has evolved to.

In other words, the majority of turning on those old lathes was not bowls and vessels...if you were a turner, you made table legs, newel posts, balusters, chair spindles and other functional items or were a patternmaker.

[Jim Kountz]

Ahh I see, things are becoming clearer to me now. This world of turning still eludes me but not for long!!
Thanks guys!

[Curt Fuller]

Most of the older lathes you've mentioned have a 12-14" swing. My Oliver has a 14" swing and the slowest speed on it is 700 rpms. As long as I have the the wood mounted securely I've never had any problems or even a close call that I would consider speed related. On the other hand, most of the newer lathes with the exception of the Jet mini EVS have a much larger capacity and need the the slower speed to utilize that capacity safely. Another difference with the older machines is the weight. The headstock on my Oliver weighs much more than the entire weight of my Delta midi. An out of balance bowl blank on my Oliver barely causes any noticeable vibration while it would shake the Delta off the workbench. Also the Reeves drive on the Oliver uses a 1.25" wide belt and works as smoothly today as it did 53 years ago when it was new. When you consider that you can get an old, reliable, American made 500 lb hunk of iron with a strong reliable reeves drive for about the same price people are paying for Chinese imports today, I feel the old machines are a heck of a good deal.

[Dennis Ford]

You have already recieved good answers to your question, if you are looking at a used lathe and considering adding a VFD, check out the tips section at East Texas Woodturners website. http://www.easttexaswoodturners.org/

[Jim Kountz]

Thanks Dennis, wow now I know why more people arent just adding a VFD to their lathes. This seems like alot and kinda pricey too. Am I understanding right in that you need a three phase motor but you do not need three phase supply in your shop to make it work? The three phase motor is needed to respond correctly with the VFD??

[Paul Engle]

Yep you got it Dennis. there are VFD's that run on 110 and 220 single phase, but one needs the three phase winding in order for the drive to select which " winding " gets the juice.

[Bob Hallowell]

Jim,
As I said in the pm I sent you, you can do it for 2-3 hundred if you are patient and buy on ebay. i would still go with the vfd from factorymation
http://www.factorymation.com/s.nl/sc.2/category.32/.f You can get them in 1 phase in 3 out. and then pick up a motor on ebay 3 phase and inverter ot vecter duty. I got my remote switches at www.mcmaster.com (http://www.mcmaster.com) for a whooping total $20 and mounted them on some flat conduit, all together with new pullys a used $2000 baldor vecter motor switchs and vfd I have less the $300. and boy is it great!

Bob

[Jim Kountz]

Hey Bob, thanks again for the info, I have been scouring the bay this afternoon and its true you can get some nice 3 phase motors pretty cheap I was surprised. So with your switch setup you can change speeds, direction etc? I have a couple of leads on some nice older lathes and all this info is starting to come together for me. Hopefully soon I will have a lathe in the shop finally!

Thanks

Jim

[Kim Ford]

Jim; I have an old patterns makers Oliver. It's manual speed range is from 26 rpm to 2200 rpm; 16 different possibilities. Machines were made that did have the range, but it took a transmission and belt changes. The actual transmission on mine is from Lima, and I spoke with an older gentlemen that used to work at Lima and he said the transmission was the same as a Model T. He said if any thing ever breaks just find the rebuild parts dealer and you are in business.

Okay that being said, I did put a VFD on mine anyway, and here is why. I live in dairy country and there are many farms and factories that really need the advantages of a VFD for electric motors and we have a very good supplier in the area. The first thing to realize is that the VFD requires a motor that is inverter rated. What this means is that the insulation on the wire used in the windings can handle the power spikes that a VFD produce without burning up the motor. In today lingo that is called an "Inverter Duty Motor". I had the experts here look at my Lima motor and they said that the insulation was adequate. They also said that if I had a problem to just bring it in and they would re-wind it with the correct wire. My cost about $150.

So, I bought a VFD with full hp rating (full hp at all speeds), had my electrictian put it on and it changes my voltage to 3PH and it works very well. Now, why you want the VFD is not only for the variable speed, but also for the "soft start". With a straight drive motor when you flip the switch you are going that rpm right now, and if your blank or piece is not ready or balanced to go that speed guess what, you are going that speed anyway. The VFD has a soft start process that even if you have it set to start at a higher speed it takes a couple of seconds for it to come up to that speed. In my opinion much safer.

I usually start mine at 0 and just turn the dial, then I can gauge how fast I want it to go. I like it so much, I would not turn without one. My VFD cost about $320 for a unit rated to 5hp and another $100 or so to have the electrician put it on.

My suggestion is if you are looking at this option make sure you talk to a "good" industrial motor supplier in your area and listen to what they tell you, but really any motor that is of industrial quality can be modified to work with a VFD.

This is my experience, hope it helps.

Kim

[Bob Hallowell]

Hey Bob, thanks again for the info, I have been scouring the bay this afternoon and its true you can get some nice 3 phase motors pretty cheap I was surprised. So with your switch setup you can change speeds, direction etc? I have a couple of leads on some nice older lathes and all this info is starting to come together for me. Hopefully soon I will have a lathe in the shop finally!

Thanks

Jim

Jim, if you look at the headstock on my lathe you will see the conduit with the switches top one is fwd\off\rev and the bottom is a potentiometer for speed control. and remember you want to look for an inverter or vecter duty motor with rpm's of 1120 or 1740. If you go this route I can help you hook it up via pm's or phone.

[Frank Kobilsek]

Jim,
Just as this thread has discussed the history of our machines I think the skills of older turners match.

My Dad is 76 and getting into turning for the first tiem since high school. He keeps telling me to use the skew, and honestly I just don't get it. A skew in my hands is dnagerous in a bad way. Dad says 'let me try' and zip zip zip he is forming a nice spindle. Now if I give him a fingernail grind spindle gouge he'll have a low orbit catch in about 30 seconds. THe skills they taught back then went with the machines they had back then.

Frank

[Dennis Peacock]

My Dad is 76 and getting into turning for the first tiem since high school. He keeps telling me to use the skew, and honestly I just don't get it. A skew in my hands is dnagerous in a bad way. Dad says 'let me try' and zip zip zip he is forming a nice spindle. Now if I give him a fingernail grind spindle gouge he'll have a low orbit catch in about 30 seconds. THe skills they taught back then went with the machines they had back then.

Frank

Yes'sir....that's exactly correct. When I was in high school, they NEVER taught anything but spindle turning. If you wanted to use the lathe? Then it will be for spindle turning only. The very first tool they would give you to spindle turn with was a Skew. I launched many pieces that year. :eek: :o :)

[Richard Madison]

Twenty plus years ago the 800 rpm minimum on my single tube Craftsman scared the pootie out of me when trying to rough anything approaching the nominal 12" capacity. I hung a spare 1750 rpm motor on a hinged board directly under the "main" motor. Belt from small pulley on aux. motor to largest pulley on main motor, and "regular" belt from smallest pulley on main motor to the largest spindle pulley, allowing the main motor to function simply as an idler bearing. Installed DPDT switch and duplex outlet to plug in both motors. Since the aux. motor was on a hinged mount, its weight provided belt tension, but only took a moment to lift the mount and remove the belt before using the main motor.

Just a little country engineering, had too much vibration, but functioned remakably well for quite some years and made some pretty nice stuff.

Happily, now have larger modern variable speed lathe. In a way, the variable speed is a boon to the less experienced among us, as we can start slow and speed up as skills and confidence grow.