Member postings for Peter Cook 6

Thanks old mart. I agree that there ought to be something of that sort. But there is no obvious sign on the back end of the spindle of any threads or other attachment points that would allow the bearings to be adjusted.

I've seen the lathes site. The last WJ lathe on page 2 ( the one with orange wood in the background) looks identical to mine, but unless there is something under the brass dust cover between the pulley and front bearing, I can't see anything in those pictures to suggest the sort of adjustment I was expecting.

The two grooves in the front end of the pulley are suggestive. I wonder if there is supposed to be a brass(?) bearing keyed to the slots that the pulley would have pressed against the back face of the front bearing. I was hoping someone had a similar device and would know.

On the NAWCC website there is a brief description of adjusting a Lorch 6mm WW late which says "The pulley has a bearing surface at the front end that should run against the back face of the front bearing. There should be no end play and the spindle should run just a bit stiffish when lightly oiled. I use light machine oil in the holes on top of the headstock bearings."

The box it came in is marked as a Clarkenwell Lathe, and it could well be a Lorch clone with some Wolf Jahn bits ( only the foot and the tool rest are actually marked Wolf Jahn.

I think what I am looking for the detail of the bearing. I will start looking at Lorch.

PS I clamped the front bearing between spacers and twisted. It moved - so I simply aligned the holes and cleaned them out. Hopefully that will be sufficient.

I have a Wolf Jahn 6mm watchmakers lathe. Today in removing a stuck 3 jaw (smart rap with heel of hand on drawbar) instead of the chuck coming out, the spindle did!

Once the chuck was out I removed the spindle to see what state the bearings were in. However that left me with two queries, and I wonder if someone who has one of these can help.

The spindle shows no sign of anything that might be designed to hold it in place in the bearings although there are two loose split brass dust caps on the front bearing.

The pulley does not appear to be designed to bear against the back of the front bearing (at least that is not how it was aligned), and there is no evidence at the back of the headstock of anything which might pull the spindle into the bearings.

Question 1 - am I missing some part that should retain the spindle in the bearings? If not, how is the bearing loading set when reinstalling the spindle in the headstock - and what keeps it in there?

The front bearing appears to have rotated. The oil hole in the bearing is misplaced from the oil hole in the headstock, the rear bearing has the holes lined up.

Question 2 - any suggestions on how the front bearing comes out , or suggestions how I can rotate the bearing in situ to realign the holes.

There are further pictures in my album entitled Wolf Jahn lathe.

Thanks in advance for any help.

Edited By Peter Cook 6 on 08/06/2021 17:24:12

Update. Amazon delivered.

One M10 35mm CSK bolt is perfect.

Thanks again for all the help.

Thanks for all the help as usual - helped provide a solution to the problem and made me think a bit harder!

M10 is a VERY big size for the things I do, and I only had a stock of M10 cap heads. It (should have but) did not occur to me that an M10 CSK would have a head wide enough to cope. So step one is to get a few M10 CSK bolts of the relevant length (Amazon prime is wonderful - arriving today - and cheaper than the petrol to drive to my nearest hardware store).

I would/may copy Paul's idea at some point - once I acquire a M10 Hex bolt, or simply make a thin washer with a centre hole that matches the csk bolt. - Thanks for the idea.

The idea of lifting the table on parallels is not one I had thought of - stored for future reference, however the daylight over the table on my SX1LP is fairly limited as it is, and fixing the drawbar issue will give me future proofing. A ground block is way more complex than I could make with sufficient accuracy.

To answer the queries, the part is one half of a small dog clutch. Overall diameter 12mm.

I had planned to cut the lands out using three cuts. A & B use a 2mm cutter. C is a 1mm cutter. I was planning to do cut A - rotate 90 - repeat four times, then do cut B and rotate four times again. Then rotate 45 degrees and do cut C - probably going straight across, rotate 90 and repeat.

I could do it by holding the part in a Stephenson block in the vice, but given my propensity for error (and scrap production), setting up all the cuts differently seemed somewhat risky. Rotating the block would (probably) loose centre at some point - see above propensity!

I could see how to do cuts A & B it with the table vertical by doing A & B from opposite sides, but I can't do C that way ( I don't think).

Thanks again for the help and ideas. Just waiting for Amazon now.

Edited By Peter Cook 6 on 30/05/2021 12:22:02

Edited By Peter Cook 6 on 30/05/2021 12:26:46

I have a small rotary table with an MT2 hole in the centre. I want to put my MT2 ER25 Collet chuck in to machine some concentric lands at 90 degree spacings on a small (12mm diameter) part.

The problem is that the bottom of the central tube is only about 3.5 mm above the base of the table itself - so not enough room for an M10 bolt and washer to act as a drawbar. It's not a problem with the table set vertical, but horizontally it's a bit of a problem.

I am planning to make up a special which is thin enough on the bottom to fit, and with holes for a pin wrench to do it up.

However, given that the real grip on a morse tape is provided by the taper itself once engaged, could I get away with installing the collet holder. Use a standard M10 bolt and washer to pull the taper up fairly tight, then remove the bolt before mounting the table horizontally?

Or is that pushing my luck!

Or alternatively, am I missing something.

Edited By Peter Cook 6 on 29/05/2021 19:11:30

According to the ARC website there are 3 depending on the taper.

"Drawbars for the SIEG SX3 mill.

Choice of M12 or 3/8” Whit thread for MT3 spindles or 7/16" UNF thread for R8 spindles."

You will only ever use 10% of the junk you accumulate. Trouble is

a) you don't know which 10% you are going to use until you need it!

b) The stuff you need now is always in the stuff you disposed of last week to make space!

Just a thought - assuming you have tried a new battery. Have you tried stripping and cleaning the read head. The zero function (on all the ones I have opened up) relies on a small piece of metal shorting across a grid of fine traces on the PCB.

If you have got a small ( the traces are about 0.2mm apart if that) piece of metal swarf inside the read head, it might intermittently short out the traces and zero the calliper.

Out of interest the last time this topic came up I decided to "invest" in a set of 500-196-30 150mm callipers(@34.99)

As expected what arrived were a clearly fake set (I have some genuine 500-196-30's for comparison) and they were marked 500-196-20 on the back and on the box, which made the protest easier. I objected on Ebay and requested a return at their expense - the goods were clearly not as advertised.

I got a full refund - no questions asked from the seller - and said they were fake in the feedback.

At £34.99 they were barely acceptable, At £20 they would have been a good buy. For free and knowing that the counterfeiters lost out on the money and the goods - they work just fine!!

I have now learned there is a difference between machining EN1A & EN3B steel!

I want a 1.5mm wide slot, 6mm long 3mm deep in the end of a 12mm bar with a 6mm hole through. It's to insert a key to make a D hole so that the flat on an electric motor shaft will drive the rod. Eventually it will be a dog clutch.

Made the piece from a very short length of EN1A steel I had lying about. Very pleased, made the slot first attempt with no trouble.

Then I messed up the other end, and had to start again. The only 12mm I had was EN3B.

Three (admittedly cheap) 1.5mm carbide milling cutters later I had the new slot. The first broke (my fault) because I took too big a cut (1mm depth), The second grabbed where the slot breaks through into the central bore. The third just broke!!

EN3B does not machine as well as EN1A, at least at my skill level!! Now I know that.

Calum. Just an off the wall idea.

Could you run steel cables through the holes for the lifting poles ( or through poles fitted in the holes to give the lathe a bit of protection) and hoist it that way.

Side on lift gets you to the door with the lathe pointing the right way for entry. Beg/borrow/rent something like an engine crane and lift from the end to slip it through the door. The lifting cables should not add too much width for that bit.

Winding gets to be a habit if you have clocks. I have 40+. 12 are 30 hour, most of the rest are 8 day with a few longer duration (one is year going).

Personally, unless the 30 hour clocks were VERY accurate, the irritation of them being wrong would far outweigh the hassle of winding. 30 hours get wound and put right every night on the way to bed. 8 day clocks get added to the winding and correcting schedule on Saturday nights.

It's just a routine!

I remember working on pneumatic 3 term (PID) controllers in a glass factory in the early 1970's. They were used on electrically heated furnaces (and others) as they were more immune to the electrical noise such furnaces and their downstream conveyors produced.

But leaks were a constant problem!!

There is no rule about how firms present their prices to the customer. They will ususally chose to present pricing in the way which they belive will maximise conversion from enquiries.

But if they are not accounting for their postage costs in their VAT returns and they get investigated, then they will be stuck with a bill (or worse) from the VAT man.

Edited By Peter Cook 6 on 12/05/2021 14:28:49

From Do you have to pay VAT on postage? – Sound Accounting Services

When you buy postage stamps or pay for standard postage for your franking machine, you’ll pay no VAT because “universal postage services” provided by the Post Office are exempt.

However

When you supply goods by post it counts as a single composite supply for VAT purposes. That means the postage is part of the total cost of the goods and so the VAT rate applicable includes the postage.

So charging VAT on the postage is correct. It gets more complex with zero rated goods and supplies to non UK customers.

That is the base plan. I do have a spare set of soft jaws which I plan to keep for use as "soft jaws", and will probably one day (when my round tuit arrives) make a set of steel jaws. This was the first step to machine a set of jaws like a conventional chuck. Hence the question.

The comments have raised another "interesting" thought. Some time ago I came across a thread on 3D printed soft vice jaws. 3D Printed CNC soft jaws for work holding | Model Engineer (model-engineer.co.uk). I wonder if ...

Thanks for all the input. Always enlightening.

Thanks for the inputs - something to think through.

The core problem is that the Taig 3 jaw doesn't come with "normal" jaws. It only has aluminium replaceable jaw faces. which can be reversed on the steel bases.

As it stands the maximum diameter it holds is about 40mm. I don't use it often as most work I do fits in the ER Collets that the headstock holds. Occasionally I would like to hold something a bit bigger. I do have a four jaw independent with steel stepped jaws that I use when required, but was thinking about modifying the existing jaws to in effect give me a quick "normal" 3 jaw.

I have considered a Sherline 3 jaw, but Mill Hill don't stock the ER thread (1042) version, and when you factor in shipping costs the cost delivered to the UK is horrendous. Dean Williams has made steel tops for the Taig 3 jaw, and that is probably the final route I will take. Looking harder both the Sherline and Dean's version have convex faces - so If I go that route, that is the way I will go.

Thanks again for the inputs.

My 3 jaw chuck (Taig) has reversible machinable aluminium jaws. So far I have only trued up the centres, however I now need to machine some steps in the jaws to get hold of larger items.

I seem to have three options.

One is to bore them from the inside, which produces concave inner faces If I clamp the centre down on something fairly large before cutting, the concave faces will be fairly shallow. This is how they are trued in the first place.

Reverse them and machine from the outside to produce convex faces on the steps.

Or try and mount them in the mill (either as a set, or mount the vice on the rotary table?) and cut flat faces on the steps.

I don't think I could get all three located accurately enough on the mill to get the precision needed. I am inclined to go for reversing the jaws and producing convex faces as that seems likely to give me more consistent contact surfaces (theoretically tangential) at different openings, but I thought I would ask first.

Beautiful car Peter. Very Envious. I had a later one (as a company lease car) in 1990-93. It replaced a succession of 944's and was itself replaced with a 968(?). When I left the company they wanted silly money for the 968 - so unfortunately it went back to the leasing firm.

Edited By Peter Cook 6 on 10/05/2021 14:28:35

Thanks folks, useful as usual - I will probably splash out another £10 on one of the suggestions and see what I get.

Dave - I suspect that the battery life issue is the reason that many cheap ones now don't retain zero - and in reality few people who buy cheap callipers care about zero retention. They do care that the ones that arrive when purchased work, and the ones that retain zero may very well go flat in storage/transit.

Bernard - the one I have successfully butchered was definitely not that hard. Cut the jaws off with a hacksaw no problem.

Ady1 interestingly the pictures on the one you link to show a 0.01mm resolution, but the writeup only claims 0.1 resolution - more sharp practice on E-bay?

MC - perhaps when it stops being a project and turns back into a lathe again I might do so. Long way to go however.

Gary - I had that problem with my now butchered calliper - it kept resetting to 5.04mm at zero. A new battery fixed it. 

Edited By Peter Cook 6 on 09/05/2021 12:13:14