Gallery, Projects and General > Project Logs

Electronic Leadscrew for the New Lathe

<< < (2/32) > >>

SwarfnStuff:
I subscribe to the KISS principle wherever possible.  If I were to go ELS I think Bertie's idea would be my choice so I would like more info from Bertie, AKA explain a bit more please B. This is one of those good to have mods in my one day do list. 

PekkaNF:
Damn you VT :lol:

Few years back I did some armchair engineering and went trough the whole google over and found arguments/flames/missing the point and you name. It came pretty obvious that: Whole lot is pretty simple at first sight, but you need to make and informed decision on following approaches:
* KISS = limited, but least you have some chance in success. When it is comes mostly programmable project there is a great temptation to add way too many conflicting features. Deside what you want and stick to it. I went other way and didn't complete it.
* Do you want only to eliminate change gears, or also with spindle start/stop? How about automatic threading with multipass? Do you have temptation to make taper and taper threads....see where I'm getting?
* Mechanical or system inaccuracies - acme screw, backlash, lightweight? Or ballscrew and great stiffness.
* Brute force or a lot of fiddling, esitmation and cheesy math. Like this spindle speed caculation: Do you have enough spindle gear inertia and stiff (AC drive or constant rpm servo) to keep the spindle near constant velocity and can get by with one pulse per revolution. Or do you have lightweigh mechanics and fluctuating DC-drive and really need all the pulses you can get and processor to cope with vartying spindle speed and beeffy servodrive to keep up the feed with this fluctuation. Like shooting moving target that chances it's speed all the time?

The big question that dawned to me is: If you lathe and gear is big enough to make electronics and calculus simple it is likely to have threading feeds. If your lathe does not have it you have to make it CNC way and then this ecological niece is not that big.

Anyway, I don't see any fundamental reason it would not work simple if carefully designed. Therefore I'm tooling up slowly to make one of my lathe "ready" for some sort of ELS.

Pretty sure my ramblings will not add much, but here is one eager watcher.

Pekka

JHovel:
What's wrong eith the ELS here http://autoartisans.com/ELS/
What made you say "they don't seem to work very well"?
I've built it and converted my lathe. Not only is it dead easy, but it also has a port to connect to a CNC controller if you want to go that way for some jobs. And you can continue to ue the lathe manually.
When threading, it does not reverse the spindle. It retracts the tool and reverses it quickly back to the starting point, feeds it back in with a setable increment and runs down the thread again. It moves the tool along the flank of the thread so it cuts only on one side - the 'proper' way.
I lave the fact that it has its own look-up tables for just about all standard threads, can do taper threads, turn standard tapers  and can broach without the spindle running.
What more do you need?
Joe

John Rudd:
Full kit available here....

http://medw.co.uk/wiki/index.php?page=ELS+Price+List

John Stevenson:
Been thru this and touched on most of what has been mentioned here.
Got the tee shirt, been sick all over it and it's now a shop rag.

Unfortunately got to go out today so wont be able to post until later tonight but there are answers.

Navigation

[0] Message Index

[#] Next page

[*] Previous page