MadModder

No Steve I've no intentions of using that turret - I only got it with a load of spares I bought from a chap in Ireland. It has proved useful as a diagnostic aid though.

When I packed in a couple of weeks ago, the turret disk was stuck mid motion - now it has relaxed into the rearmost (locked) position (presumeable under pressure from that spring), and hydraulically I cannot drive it forward into the fully unlocked position (I'm referring to the front curvic / hirth coupling which is not the one in the pictures above) so I am more convinced that I have a valve issue. First approach is to uncouple the appropriate hydraulic hose but to say that they are hard to get at is an understatement. Somewhere I have a hydraulic piping schematic - hopefully that will let me relax pressure further down the line but it's a bit of a jungle of pipes at the manifold where the valve are.

OK I've been away from this for a couple of weeks to let things soak in in my brain. Sumarising, the tool turret seems mechanically stuck in that the hydraulic cylinders cannot move the central shaft forwards or backwards. Now I call these hydraulic cylinders but actually they are machined cavities in the casting with the central shaft acting as the piston / rod. There is a powerful spring pushing the shaft rearwards aided by one half of the hydraulics with the other side of the double acting 'cylinder' pushing it forwards when a tool change is called for.

So is it a stuck valve maintaining locking pressure, or something internally physically miss-placed?

As an aid to seeing what is going on I dug out my 'spare' turret and rigged it so that I could try moving the shaft with a crowbar against that spring. The whole thing is plonked on the tool disk face with the central shaft pointing upwards and it's too darn heavy for me to shift it so in fact in this experiment the tool disk and central shaft are staying still and I'm raising the rest of the turret upwards by leverage - this direction corresponding to 'forwards' were it mounted in a lathe.

Rear Hirth coupling disengaged (this is the one that applies rotation to the tool disk) - ignore all the detritus on the coupling, this has been sitting open in the workshop for months:

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Rear Hirth coupling engaged by crowbar:

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So it is possible to mechanically move the shaft on the 'spare' turret with the hydraulics disconnected - I could hear the gurgling of the residual oil as I did it !

This gives me confidence to perform the same experiment on the actual turret in the lathe which is the next step I think.

While I was inside the 'spare' turret I think I've found out why the chap couldn't get good tool alignment with it - there's a massive crack in the casting !

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Hi Folks,
Spring is here, meteorologically speaking, and I hope to soon be back to a video every week! There is upcoming field work as well, to get a head start before it all starts to grow like mad! This week I dive into the D type replica engine fitting, and make good progress. I use the two slot method to get the bearing plate adjustable in two planes and also add a slot for chain tensioning, but I stall out when the only milling cutter I have of the right size turns out to be as blunt as my A*se!! Thursday is antique repairs and another wide variety of antique metalwork to fix and fettle ready for the upcoming antique fair season! Thanks for watching and see you all next week!
Phil, in warmer and dryer East Yorkshire!

 :bugeye:That looks fantastic! Now to check it out in the real world to see how well it preforms.
Congrats on a job well done. 

Well after a slight pause of uhhh 5 years I FINALLY completed the ELS for my homemade lathe. For me, where I got hung up was in making the brass plate for a thread table. I was unable to do a good job of that using any type of printer medium as a screen for putting down etching resist. I finally lost patience half a decade ago and simply ran the lathe manually, and continued relying on taps and dies for threading.

This winter's snows and cold here have stopped all my normal casting activity, and put a damper on shop time as well (it's been COLD in there!). Searching for something to do indoors I finally said to myself, finish that ELS threading table plate, test the electronics in place, and finish the damn thing -- you can at least do that indoors!

So out with the printer and various new transparency films, and dry resist film, pieces of scrap test aluminum sheet, a UV blacklight, PC Board etchant, etc and.......nope. I simply could not get a good image of the resist on metal -- there were always bad areas or the exposure was wrong or the contrast wasn't high enough.

I decided finally the problem was probably due to too much of a DIY head on my shoulders. I simply could not get a good enough transparency to expose onto the dry film resist. I had tried every method known to YouTube for this and I could not get their poster's printer results either with an inkjet or laser printer.

I finally thought, what about having it printed at Staples on transparency film? A check online showed this would cost under $2, I could upload the image directly and pick it up in a day. Past experience with the their local printing dept wasn't promising for the other large blueprints I sometimes get, but for two bucks I thought, why not?

Well, the product was perfect. Really solid black. Really clean edges to the admittedly tiny numbers letters I was using. A test run on aluminum showed good masking with the resist film. So I repeated on brass, and all went well! Two bucks. I don't know how much I'd invested over time for special papers inks, toners, etc. to try to get a decent transparency, but it was substantial.

I guess I don't have to DIY everything.

Well sorry to waste space here with the above long-winded chagrin-ology, but the positive side of all this is: I NOW HAVE THREAD CUTTING CAPABILITY WITH MY (mostly) DIY LATHE!!! 

This kinda means my lathe is um, finished....!

(ELS unit and thread table lower left:)

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well, maybe not -- I'm thinking about making a new milling attachment...........