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

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

Post by liveaboard »

It's purely academic; I have no budget for tables or heads, and no need either.
In case a need should arise in future, I'll deal with it then.

I like ebay auctions because every now and then, I got a really great deal on something when no one else bid seriously; but considering the time spent, it's been as much about entertainment as anything else.

I bought a lot of things from the UK that way, because there was cheap transport available for items that could still be posted within the UK.
Spain and Portugal have a different culture for used things; In 12 years here, I've rarely found a bargain.
Postage rates even from Spain take the fun out of small purchases, although some retailers there ship to Portugal without extra cost.

I'm amazed at the prices people expect for used anything. I used to make reasonable offers but I gave up the habit because it didn't ever work.
I drove for miles and miles, only to view worn out scrap that the seller asked 80% of retail for.

I did buy several quality hand tools at a flea market once, during the depths of the 2008 crisis.
Considering the number of times I drove to and from that market, 30 miles each way, there was no profit in that either. It was just for the excitement of the chase.

Right now I need an ER40 collet chuck and 14mm cutters for my boring head. There are EU ebay sellers with reasonable prices, not as cheap as the UK though.
That will hopefully be the end of milling machine expenditure for a while.
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liveaboard
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by liveaboard »

moved the machine to the shop today; here are some pics.

After clearing out a few hundred kilos of metal that was stored in the back of the container, I brought the mill over from the garage with the tractor.
ready to lift.jpg
After setting it on a couple of lengths of wood so I could retract the forks, I lifted it with ropes to take the wood out. The extra distance from the loader pivot meant it was barely able to lift, even with the table and spindle removed.
lifting off the wood blocks.jpg
Next I pushed it into the container with a hardwood plank; But it went slightly off course to the right. I was worried this might happen and actually had no plan for it.
first push.jpg
It didn't take long to think of a solution. This worked well.
diagonal pull.jpg
I needed a longer piece of wood for the last push, this 2x4 was the only thing I had long enough.
pushing with 2x4.jpg
My workbench needed a pull to make room at the rear.
pulling workbench.jpg
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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 had it in the center, but decided to shift it left as all the controls are on the right.
You can see my ancient jack on the floor.
pushing left.jpg
Next I brought the table over and mounted it. 175 lbs.
fitting the table.jpg
I checked the table and it seems flat, but as it moves there is considerable error; more than 0.10 mm
I'm not sure what to do about it, maybe tightening the gibs will help; when I figure out how.
table error2.jpg
Degreased and cleaned out the mounting, regreased and mounted the spindle head. I need to make a 10mm locating pin to get it vertical quickly.
It's not too heavy to lift by hand, but it would not be fun to get it on the machine without tackle.
mounting spindle head.jpg
While I was moving my drillpress around, I took the opportunity to weigh it. Exactly what I thought, 350kg, 770 lbs. The column is 120mm, nearly 5" solid.
weighing drillpress.jpg
And everything back inside.
container shop 2.jpg
Tomorrow is 2nd vaccine, and car parts should arrive so I can fix it up to get it through inspection, so I won't have time for the mill until mid or end of the week.
Russ Hanscom
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Location: Farmington, NM

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

Post by Russ Hanscom »

A lot of progress and some creative solutions.

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

Post by Poloris »

You are not alone.
I brought this 2 months ago.
I have not run it as I don't have 3 phase power yet, but it was fully functional and used until recently.
I too would like to find a manual.
Mark
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Mill5.jpg
Ruhla 33.jpg
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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 have a manual; it's a pretty bad copy of the German one, I got it from a German machinist group. I've translated most of it so I have an English version too.
I also have the electrical manual, relay layout chart, and wiring diagrams. They're a bit hard to follow but I did use them to figure out and solve some problems.

Where are you?
Poloris
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by Poloris »

Perth, Western Australia.
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liveaboard
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by liveaboard »

Wow, your machine has traveled a long way.
I'll make a file with the info and send you a link so you can download it.
Poloris
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by Poloris »

Thank you that will be a huge help. I have downloaded a Russian manual, but all I can do is look at the diagrams.
Your explanation of the spindle speed selection clears up a bit of the mystery.
Mark
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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've sent you a PM
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by liveaboard »

More updating on the electric board; one of the ancient fuses on the feed motor failed.
Funny things happen when a fuse of a 3-phase machine blows... in this case, my whole house went dark as the main breaker tripped.
This type of fuse is common in Germany and the Netherlands, but do not exist here in Portugal.
I took it to the electric supply shop and put it on the counter.
"What's THAT?" the salesman asked, and I knew it was never here.

I decided to cut out most of the fuses and put in a 4 pole breaker. While I was at it, I put in a protection relay for the coolant pump motor because I had one. The original was removed before I bought the machine.
Ruhla 250-710 fuse replaced by breaker.jpg
The breaker supplies the feed, pump, and spindle motors. I left the fuses that would supply the optional Ruhla high speed spindle just in case one of those should ever become attached to this mill, a highly unlikely event. Those fuses are after the direction knob, so they need to be separate.
I also left the small 6A fuses for the stepdown transformers, they're supplied by the new breaker.


And; 6 months after they went missing, the siemens relays I ordered for it turned up.
new relays arrived late.jpg
SERHII
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Re: Fixing the electrics in my old German mill Ruhla 250/710

Post by SERHII »

Hello to all the owners of this milling machine Ruhla 250/710!
The same problem arose - no electrical circuits. Who reported that they downloaded the instruction in Russian.
You can send a link or instructions. Thanks to all!
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