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02-25-2011, 09:15 AM #1
Removing a Rohm chuck on a vintage Lesto drill
I have a severely worn out Rohm keyless on a nice low speed old Lesto hand drill (early 50's?). There's no screw inside the chuck, and the screw on the collar towards the drill body is worn out so much that tightening it is not possible. Holding the drill by the chuck in a drilled out and split wooden block and giving it a counter clock-wise whack resulted in the loosening of the outer sleeve of the chuck. So now the question is: Is it screwed on, or is it a Jacobs taper? Any advice/experience out there?
The drill in question can be seen here:
Truls Erik Johnsen
Johnsen Frameworks | Facebook
02-25-2011, 12:30 PM #2
More than likely screwed, IME taper fittings on pistol drills ate very rare.
Looks like the collar where it goes on the drill is split with an allen screw to lock it on- remove then;-
This is my method.
Grip a TEE (an old chuck key??) in the chuck and rap the end with a hammer in the loosening direction, 2 or 3 raps is usually enough,............ unless you've had some muppet put it on with Loctite
02-25-2011, 12:47 PM #3
If the Rohm chuck is built like an Albrecht, then you can replace the jaw set by simply unscrewing the hood on the front of the chuck. You have the hood loose, so check it out. Albrecht jaws and other parts are easy to buy in the USA, but I have never seen anyone selling Rohm parts. Maybe you can find a source in Europe. If not, try to find a new Rohm chuck of the same model, without regard for the Jacobs taper or thread mount. Then you can transplant the jaws and hood and possibly other parts without needing to get the chuck body off the drill spindle.
02-27-2011, 01:26 PM #4
Thanks for the advice, guys. Got it off tonight. Turned out to be a Jacobs taper. The chuck is most likely a goner, but I will try to take it apart now.
02-28-2011, 01:15 AM #5
Short follow up question on the taper: A quick measurement with a caliper this morning shows that the large end is 12mm, the small end is 11,2mm and the length of the taper is 20mm. As far as I understand, this does not correspond to any of the measurements provided by Wikipedia on Jacobs tapers: Machine taper - Wikipedia, the free encyclopedia
Does anyone recognize this taper?
02-28-2011, 01:33 AM #6
02-28-2011, 05:01 PM #7
JF, you should contact Rohm to see if they can overhaul your chuck. You might be surprised, the Albrecht people here in the US told me that their precision keyless chucks are almost always rebuildable, and I think the Rohms are similar. Good luck, Bill S
08-06-2016, 07:53 AM #8
Lesto drill chuck
I do not know the fitting, which I need to identify to fit another chuck. The shaft appears to be the same as for Truls drill, virtually straight. Anybody have an idea?
08-06-2016, 08:57 AM #9
08-07-2016, 04:07 PM #10
Thanks for pointing this out. There are several B12 chucks on the Bay, so I guess you are right. Should be able to fit one.
08-07-2016, 04:24 PM #11
Just a thought - can anyone comment on the quality of the Chinese keyed chucks? These are on offer at about 6 - 10 uk £. I have a rather tight budget at the moment. There are German types of keyless chuck at around £20, but given these are precision jobs and keyless the price difference is believable, and I have always found keyed chucks adequate. I keep seeing threaded types at car boots, but a B12 would I think not be easy to identify or find.
08-07-2016, 10:04 PM #12
I have some China-made keyed drill chucks, copies of Jacobs ball bearing super chucks. The box has the Golden Goose brand name, but the chuck has a picture of a pelican (pouch under the beak) stamped into the steel. I am using a 1/4 inch size that is extremely accurate and finely finished, nicer than any Jacobs chuck I ever owned.
But I have seen other no-name cheap chucks that were rubbish and disposed of accordingly. Don't know where they were made because I did not buy them new.
I have some very nice-looking Spanish copies of Jacobs chucks, but have not used one. New Jacobs chucks are made in China and are said to be rather dodgy, quality-wise.
I would hesitate to put an expensive new chuck on an old drill motor which would not be worth $10 in the USA. I expect UK prices on old tools are different.
08-08-2016, 04:00 AM #13
They were built in Switzerland, up to a standard not down to a price.
Put a quality chuck on it and you will have a machine that is probably better than anything in the market today at any price.
08-08-2016, 05:12 AM #14
I appreciate the quality of the Lesto. I don't give two hoots what the market price is - the fact is that it is a good drill, and excellent design. People don't always appreciate fine things, but I find myself it a pain when they become very collectable and spend their lives in a display cabinet because they have monetary value.
My problem is I am living on £60 a week at the moment. I don't see the issue in putting an inexpensive chuck on? From what Larry says some Chinese chucks are pretty good. What is a quality chuck? I see prices from £18 to £50 for keyless. Surely a replacement be removed if it wasn't any good, or when I come across something better. At least the drill will be useable. Is fitting a cheap chuck likely to damage the drill?