Fixing the electrics in my old German mill Ruhla 250/710

Discussion on all milling machines vertical & horizontal, including but not limited to Bridgeports, Hardinge, South Bend, Clausing, Van Norman, including imports.

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NP317
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by NP317 »

Wow! Congrats!!
Another job well done...nearly.
You ARE Brilliant.
RussN
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Harold_V
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by Harold_V »

Well done. Figured you could do it if I did.
I had the same problem with the power supply for my induction melting system. The seven relays, which were inconsistent and rarely all worked at the same time, are obsolete, so I replaced them with totally different types (one is for DC). Turned out great, and worked the first time.

H
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liveaboard
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by liveaboard »

Thanks guys;
I was starting to think this one might defeat me.

I mostly employ a technique I started using when I worked in an auto repair garage in the late '70s, which my boss dubbed "stumbling across the problem".
I stare at it, poke it, play with it, and hope I notice something. Usually, it works for me.

This time I had to resort to serious thought and staring at the wiring diagrams late into the night.

Today I did some reassembly and made a couple of minor parts. I bought a gear and matching gear rack for the top slide, and cutting it down to fit will be one of the first jobs I'll do on the mill.

And I still have to figure out how to fit it into my container workshop.
I was going to put it against the back wall, but that will limit the length of parts I can work on to 3.5 feet from the cut.
So I'll try to put it on one side, and cut out a hole for the top slide to extend through. I'll have to see if it gets too tight in there.
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by pete »

Major congratulations getting those electrical issues sorted out Mark, not a hope I could have done the same. But top slide? Do you mean the Y axis ram?
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liveaboard
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by liveaboard »

I don't know what the parts are called;
This machine has 2 upper slides;
The top one holds the vertical spindle and / or the outer horizontal bearing for horizontal milling. it can be moved manually but it's not intended to be moved during work, only for setup, then clamped tight. It has a simple rack and pinion. it weighs 145 pounds without the milling head on it.

The middle slide has a fine hand wheel with 0.02mm graduations and can be operated under power as well.
When they're both all the way back, they protrude to the rear of the machine foot quite a long way when your workspace is 8' wide.
fuw 250 710 home 2.jpg
pete
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by pete »

In the conventional sense Mark your mill doesn't have a table Y axis. That's pretty usual on those Deckel type mills. Your upper slide would be much like a Bridgeport type with it's ram that's also not meant to be used while cutting. So I think your right and it sounds like you have the upper Y axis ram slide as a rough location for the part size and then the lower slide does the same job a table Y axis does. Other than having a rotatable turret on the Bridgeports and clones, your mill would be in most cases much more rigid and even more versatile than mine.

You should measure the vertical pitch spacing your tee slotted table bolts to and ask on the PM Deckel, Maho, Aciera, Abene sub forum what the other Euro mills have. My guess is Ruhla very likely copied the same dimensions those other mills have. I'd be quite surprised if they didn't. If so? Then there's a large number of other manufacturers sub tables with rotary tables, universal one and two axis pivoting tables etc that could also be used on yours if you ever come across one at a decent price.
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by Patio »

Wow Mark, that is a heck of a machine! I am a little late to the show, but I sure hope it works out for you. Good on you for going through all the motions and getting things sorted out.
P
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liveaboard
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by liveaboard »

Thanks Patio, I read your posts with awe and admiration!
pete wrote: Thu Jun 03, 2021 4:11 pm My guess is Ruhla very likely copied the same dimensions those other mills have. I'd be quite surprised if they didn't. If so? Then there's a large number of other manufacturers sub tables with rotary tables, universal one and two axis pivoting tables etc that could also be used on yours if you ever come across one at a decent price.
It's hard to say who copied who; the Thiel / Ruhla was developed at the same time as Deckel and others.

I appreciate the thought, but down here where I live machine tools are almost nonexistent and those tables are too heavy for courier services.
Door to door half pallet can be done for around $200, I spent $750 to get my mill brought from Germany.

I thought the Ruhla were all shipped with tilting tables but mine is horizontal only, although it can be shifted left and right along the slots for a few inches.
It weighs 175 lbs.

The electrics have a connection for optional powered rotary table but I've never seen one for sale. I wonder if there is one somewhere? Probably lost under a heap of scrap... I saw some static tables advertised on German ebay.

Almost all the old universal machines I saw for sale were missing everything not bolted on, particularly the outer horizontal shaft bearing holder.
So sad; the missing parts must mean that the machine was separated from its user before sale, either by death or bankruptcy. Mine has that part at least.

I bought a hand crank 8" rotary table from ebay UK before Brexit cut us off.
The seller was a rare person who would post it within the UK, and I had it sent to a trucking company there who brought it to within driving distance of me here.
Just to illustrate the logistics of second hand tool purchasing in rural Portugal.
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by pete »

Yeah I understand your logistics all too well Mark. I'm in the exact same position and have been since I got interested in this. Most of our manufacturing industry is roughly 3,000 miles from where I am. Because of my job at the time I got a deal on the shipping for my mill and paid almost what you did moving it from New Jersery to the west coast. Those shipping costs really hurt and are a royal pita. Given when your mill was built it's a bit unusual they were offering a non mechanical powered rotary table and added the electrical components just for that. I don't recall seeing even a picture of one so far so they must have been fairly rare. Having a one or two axis tilt/swivel table might be more of a handy to have item for most of us. I guess it all depends on what you end up doing with your mill.
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liveaboard
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by liveaboard »

They also had an optional high speed milling head with it's own motor, I don't know what it was for or how fast it spun but the basic machine does 2400 rpm I think.

After reading your post I did look on ebay.de just out of curiosity. There are 2 such tables for sale, around $1,000 each + $350 to ship anywhere in Europe.
I paid $1,500 for the whole machine!
+ tax + shipping.
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by pete »

Yeah the tooling and accessory costs for a mill are always a lot more than what the mill will cost you even buying a new one. Those high speed heads were probably meant for tool & die work Mark. If my memory isn't faulty I think I remember seeing numbers that they ran up to about 4,000-4,500 rpm. There were also a number of specialty heads built for these mills although I don't know about your Ruhla. They made high speed heads with fixed and moveable spindles, slotting heads for cutting internal key ways, and what are generally referred to as a multi axis head that can be rotated in two different directions. That allows you to do single or compound angle machining. My Bridgeport clone can do so, but those Euro heads are far more rigid and mounted better than the light weight Bridgeport knuckle design. Lot's of the later models of Shaublin mills came with that type of head, but I think there drive system and mounting design is much different than what you have. As far as your location in Portugal and especially being in a rural area I can see where finding anything would be tough. About the only country that's a bit closer to you I know of that does have a fair amount of heavy industry and machine tool history would be Spain. My Emco mills X,Y table was built there. Checking for used tool dealers in Spain might be worthwhile? But I've also found that Google translate isn't the greatest for highly technical terms. It works best with a single word, but for full sentences and paragraphs sometimes you have to guess a bit about the answers it's providing. By now you must be getting a bit impatient about getting your mill operational. :-)
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by Bill Shields »

liveaboard wrote: Fri Jun 04, 2021 3:49 pm They also had an optional high speed milling head with it's own motor, I don't know what it was for or how fast it spun but the basic machine does 2400 rpm I think.

After reading your post I did look on ebay.de just out of curiosity. There are 2 such tables for sale, around $1,000 each + $350 to ship anywhere in Europe.
I paid $1,500 for the whole machine!
+ tax + shipping.
plus relays, contactors & sweat...
Too many things going on to bother listing them.
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