Lather light show !

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Jaxian
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Joined: Fri Mar 15, 2013 1:38 am

Lather light show !

Post by Jaxian »

Sorry about the horrible pun. Just thought it was an interesting photo.
Flux capacitor 001.jpg
This is a pic of the tubes on my 1959 WIAD equipped Monarch 10EE. The small ones are timers and switches (and other things I don't know), the two large ones are the thyratrons. They apparently convert AC to DC. They also are load compensating. If you load down the spindle the purple light between the two discs gets brighter as it adds more power so the rpm never changes regardless of load.

The machine is interesting. Plugs into single phase AC but the motor is 3 phase DC (apparently much better for motor control). It is filled with transformers, tubes and tons of electrical stuff. Field weakening braking and fast reversing. As there are no gears involved there is nothing to grind. Very odd being able to vary the rpm from 40 to 4000 by just turning a knob, it's like a VFD but 30 years early.

No gears touch the spindle, just a flat belt to ensure a good surface finish. I thought this sounded like a lot of work for nothing but have to admit, this was my first cut. Didn't play with the speeds and feeds, just went deep enough to clean up the existing cut from my other lathe. I think like .025. I have to admit, for not having any experience or time into getting to know the machine I was impressed with the surface finish. Or I just got lucky. Been very busy trying to get another new machine up and running so have not take another cut in the month or two I have had it now. Can't wait to start using it.

The cut:
First cuts 10EE small.jpg
The distraction keeping me from messing with the new/old Monarch. More on it another time. Taking homeshop to a whole new level.
New CNC mill small .jpg
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SteveHGraham
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Re: Lather light show !

Post by SteveHGraham »

I remember reading up on those tubes a while back. Aren't they around $1700 each, new? I'm used to paying 10-40 dollars per tube for guitar amps, but then the amperage is a little lower. You need a serious tube to get real wattage. The bigger tubes below the thyratrons look like KT88's, two of which would only give you about 35 watts in a guitar amp.
Every hard-fried egg began life sunny-side up.
Jaxian
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Re: Lather light show !

Post by Jaxian »

You are spot on Steve, all the smaller ones, I think there are like 7 or so all are in the $100 area so not bad at all. I got the number off the thyratrons and new they run from $1600 to $2000 each.

Which brings up the dilemma. There is a guy who makes a really nice solid state unit that replaces the functionality of the tubes while leaving all the controls and stuff intact. This keeps it from looking hacked like a VFD conversion. That solid state unit is only like $1150. So, if (when) a thyratron goes dead, do I buy a new one or spend only a little more than half and replace the whole tube functionality with a rock solid item. Not sure it works as good as tubes, then again mine seems to be working VERY well based on all the threads of people complaining about tuning them and trying to get them to run right.

My plan is just to get rich between now and then so that I can just by the tubes without feeling the pain. (this has been my plan for many decades at this point and it has yet to pan out but I figure it must work at some point right)
spro
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Re: Lather light show !

Post by spro »

Who'd a thought those thyratrons would become so expensive? There is probably a list of #s and cross reference to similar tubes and they may need tuning. It works so well now, that surface is like a mirror. It is also very clean in there and the electronics probably suspended against most any vibration. I still think there are some of those tubes in cardboard boxes stuffed away in closets or attics. No one would know if they were valuable unless the #s were more widely known.
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SteveHGraham
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Re: Lather light show !

Post by SteveHGraham »

I don't know how things work with high-powered systems like that, but with little stuff, solid state is sturdier and longer-lasting than tubes. I suppose it depends on how much the tubes are being stressed, though. In a guitar amp, you can wear tubes out in a few months, but they last nearly forever in a Hammond organ.

If you go with tubes and need to replace the little ones, you shouldn't ignore new old stock on Ebay, plus audio sites like Tube Depot. You might get a better deal.
Every hard-fried egg began life sunny-side up.
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Harold_V
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Re: Lather light show !

Post by Harold_V »

Jaxian wrote: So, if (when) a thyratron goes dead, do I buy a new one or spend only a little more than half and replace the whole tube functionality with a rock solid item. Not sure it works as good as tubes,
I've related my experience before, but it may interest you to hear what I witnessed.
I started in the shop in August, 1957. Not too long afterwards I was assigned to an EE that was purchased new, a 1956 model. I remained with that job for 7½ years and can recall the EE being down two times, each time for replacement of one of the thyratrons.

The only question I'd have, given your lathe was mine, is if the conversion you spoke of was capable of duplicating the performance of the old electronic system. It was a revolutionary design, providing torque at ridiculously low speeds of the motor. It would not be desirable to lose that------so ascertain that you wouldn't before making the decision.

Do keep in mind, the lathe I ran was in a production facility, operated 16 hours daily. If you use yours intermittently, it may or may not have issues with tubes. Hard to say.

I envy you your machine. I've operated a lot of engine lathes in my many years in the shop, but none come close to the feel and ability of an EE.

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.
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