wefalck

A Lorch Micro-Mill that never was ...

92 posts in this topic

Love your attention to detail such as 'improving' the large washer! That is a beautiful as well as practical machine you have there.

mtaylor likes this

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Thanks, gentlemen. I like to have beautiful things around me - this includes my machines and tools B)

 

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Managed to squeeze a couple of hours in the workshop in between business travels and entertaining friends, who stayed with us for a week ...

 

The rotating spindles, such as the main spindle and grinding spindles on watchmakers lathes have a knurled sleeve in brass that is meant to prevent dirt from entering the bearings. The one for the grinding spindle used as dividing head was missing. Using an original one as example, a replacement was fashioned from a piece of round brass. After facing a short length of brass it was drilled 5 mm and taken onto a respective arbor for turning the outside to size. A rim was left standing that was given a round knurl. Back on the 3-jaw-chuck, the inside was bored to a tight fit to the body of the milling spindle. The front part was given a concave bevel with a form-tool.

 

MF-118.jpg

 

MF-119.jpg

 

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MF-122.jpg

The various steps in machining a new dust-sleeve

 

MF-123.jpg

Original dust-sleeve (right) and fabricated copy (left)

 

MF-124.jpg

Sleeves in place - an original one on top, the newly made one below

 

To be continued ...

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Wefalck I just love that round knurling tool, My one concern would be the amount of pressure needed to push into the brass with a single roll, you have obviously overcome that issue.

 

I am so tempted to make one though. anything in particular to watch out for?

 

Michael

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The amount of pressure needed obviously depends on the hardness of the material to be knurled. I found that the brass I am using is very easy to knurl. I also knurl brass dry ! Just at the end, to wash out swarf, I gave it a blast of WD40. Knurling is actually a kind of milling operation, meaning the material is not displaced but more or less cut. Some of the material though squeezes to the sides of the knurled rim and needs to be cleaned up with a light cut on the lathe or free-hand with a file.

 

I seem to have been lucky that the hardening of the knurl seems to have worked fine. There is a risk that with my primitve arrangements for this it may crack. I pre-heated it with the hot-air soldering gun and then continued with a blow-torch until it was heated to a cherry-red. The PROXXON-torch I used was a bit on the weak side, a bigger one would have been better. On the other hand, one should avoid to overheat, because this burns the carbon in the steel. Heating on a bit of charcoal can counteract this.

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Now that you have almost completed your prototype, I'll send over my 'Lanco' for you to adapt ;):)  Very nice work Wefalck; that will be a very useful mini-machine and a fine addition to your wonderful workshop.

 

cheers

 

Pat

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OK, first another little item, I have been working on in between travels ...

 

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Several years ago I constructed a micro-vise that was intended to be hold in a collet e.g. in the upright collet-holder on the larger Wolf, Jahn & Co. milling machine. The stem has a 5 mm diameter, which was chosen so that it also fits into the largest regular collet of a 6 mm-lathe.

 

micro-vice-07.jpg

Shop-made micro-vice

 

While the collet thus can be mounted in the dividing head, this may not always be convenient. Therefore, a small holding block was fashioned from a piece of steel.

 

MF-114.jpg

 

MF-115.jpg

 

MF-116.jpg

 

MF-117.jpg

Steps in machining the holder for the micro-vice

 

This holder allows to rotate the vice around the clamping bolt, but also in the mounting hole. With this arrangement and the tilting capability of the vice itself, it can be offered to the milling spindle in any conceivable angle.

 

http://www.maritima-et-mechanika.org/tools/micromill/MF-125.jpg

Parts of  the holder for the micro-vice

 

http://www.maritima-et-mechanika.org/tools/micromill/MF-126.jpg

Holder and micro-vice

 

MF-127.jpg

 

MF-128.jpg

 

MF-129.jpg

Various ways of positioning the micro-vice

 

To be continued ...

mtaylor, Longobard, jud and 6 others like this

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The motor also needs a housing, so that the electrical connections can be adequately installed. I wanted to make the supply cable detachable in order not to have it hangig around, when the mill stored away. Unfortunately, the motor has the somewhat odd outer diameter of 51 mm and it was not so easy to come by a suitable pipe. Finally, I chanced upon a can from a weird drink that pretended to be an alcohol-free Bellini-cocktail. In this way the overly expensive can somewhat amortised. I shortened it to suit with a diamond saw in the hand-held electrical drill. A lid was cut and turned from a piece of 5 mm Plexiglas™. Three fastening holes were pierced with a needle and opened up using cutting broaches in the very thin and flimsy drinks can. The lid was drilled and tapped for M2 screws. A 6 mm hole for a 3.5 mm mono-socket was pre-drilled with a small drill and then reamed to size into the bottom of the can.

 

MF-130.jpg

 

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MF-132.jpg

The motor housing before painting

 

To be continued ...

aviaamator, BANYAN, cog and 5 others like this

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Well, we prefer the original Bellini, though we were not impressed by the one served in Harry's bar (in the Cipriani hotel in Venice), where it was invented - they seem to be rather nose up in the air there and the setting is not really nice and comfy, more something for serious drinkers, such as Hemingway, who don't want to be distracted by the scenery ... our prefered spot for a Bellini (and some excellent food) is the terrace of the Gritti.

druxey, mtaylor and donrobinson like this

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A very exciting journey through the eyes of an accomplished machinist and tool maker. Although most of us will never achieve this extreme level of tool making, it is an amazing example of work that can't be ignored. What a group of artisans who add new meaning to "We can build nearly anything from very little."

Edited by Dupree Allen
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Thanks for the kind words. Well, actually most of the really serious machining (namely the guides for the slides) was done decades ago by the Lorch-guys in Frankfurt/Germany. That really cannot be done with 'nothing', but requires a bigger and sturdier milling machine than I have. The quality of their workmanship is difficult to find these days. I also wished I could work with cast parts, rather than having to fabricate them.

 

About the scale: sorry, I am so familiar with the size of these machines, that did not think of adding a scale. The overall height of it is 35 cm or 14". for those across the water.

 

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One of the most important aspects of the machine is the flexiblity in holding even tiny work-pieces. The dividing head offers a wide variety of work-holding options using the spindle-tools from the 6 mm-lathe, such as 3- and 6-jaw-scroll-chucks, independent 4-jaw-chucks, ring- and step-chucks, face-plates, as well as the whole range of collets from 0.3 mm to 14 mm diameter.

 

MF-137.jpg

3-jaw chuck

 

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Step-chuck

 

MF-139.jpg

Ring-chuck

 

MF-140.jpg

Independent 4-jaw-chuck

 

MF-141.jpg

A very old face-plate (I have newer model too, but this is not refurbished yet)

 

The dividing head can be positioned at any angle between vertical and horizontal. Direct dividing is provided for by a drum with three rows of 8, 10, and 12 indents respectively. This allows the milling of prisms or pyramids with 2, 3, 4, 5, 6, 8, 10, or 12 sides. A worm-wheel of 40 teeth that is driven by worm on the axis of which is mounted a dividing plate with 90 teeth provides for indirect division of up to 3600. While such divisions are unlikely to occur in practice, the fine angular movement is useful for shape-milling against a schedule table. When the indent is disengaged the worm-drive can be used for round-milling.

 

MF-143.jpg

Dividing head in horizontal position

 

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Dividing head set at an angle

 

TK-17.JPG

Worm and dividing plate for indirect dividing

 

Collets for work-holding are particularly useful, as a wide variety of small parts can actually by milled from round material of various diameters and then sawn-off from the stem held in the collet. The collets, a holder for standard 6 mm end-mills, arbors for slitting saws, as well as a small boring-head are stored in a fitted antique box.

 

MF-142.jpg

Antique collet box adapted to the use with the micro-mill

 

To be continued ...

Edited by wefalck

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Aghh! Now you have done it - I am very jealous of that fabulous set-up :)  Some great flexibility of function you have created in that machine Wefalck.  Any left-over bits I could you use with my Lanco?  (Sorry being a bit cheeky there).  Seriuosly, a really useful set up for small part machining.

 

cheers

 

Pat

Edited by BANYAN
donrobinson, cog and mtaylor like this

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Hope everyone arrived well in the New Year !

 

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Here a few additional pictures of the machine with the attachment for indirect dividing mounted. It also shows the over-arm (or rather under-arm) to support longer and slender parts. Both were already fabricated some 15 years ago for the use on my lathe.

The first picture also show a micrometer depth-stop for the vertical slide, which was made some 20 years for use on the small 6 mm-watchmakers lathe.

 

MF-145.jpg

 

MF-146.jpg

 

MF-147.jpg

 

MF-148.jpg

 

MF-149.jpg

 

MF-150.jpg

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