Member postings for Tony Jeffree

Bollocks.

Regards,

Tony

Thanks John - I guess I will have to take a look once I'm done moving the workshop

Regards,

Tony

With LinuxCNC, are you stuck with using the parallel port for I/O, or are there other options? I.e., is it possible to use it with a laptop/USB ports etc? There seem to be a fair number of non-parallel port options developing on MACH, if you are stuck with using a desktop/tower PC that would be a limitation.

Regards,

Tony

People have been shot for jokes way better than that one

Peter -

Spot on.

Regards,

Tony

I was interested, but somewhat bemused, to read the articles by John Pace on his Warco lathe conversion. The bemusement arises from the fact that he has introduced mechanical metric to Imperial conversion via the use of a 127-tooth wheel into the drive train in order to make the resolution per stepper motor step a convenient number in Imperial units. This seems to be necessitated by the fact that he is using Compucut software that appears to be limited to operating only in one set of units. This seems to be an awful lot of fuss and bother, especially as CNC controls that can understand G-code (for example, Mach 3, Desk CNC...) would be able to handle the conversion in software.

Am I missing something here?

Regards,

Tony

I'd forgotten about the scales - just re-read the article!

Regards,

Tony

Norman -

I wouldn't dream of putting a car in a garage - they get soft if you do that.

Thanks - yes, Manchester is certainly "Up North" for most people, but I am moving about 400 miles further North

Stephen -

I am keeping my CNC'd ML-7, my Taig (Peatol) lathe, and my Taig CNC mill. The fact that the latter two have interchangeable headstocks, chucks, backplates, etc. makes that combination particularly versatile.

I like the Cowells a lot; it is a fine little lathe, and it was a lot of fun restoring it. However, I didn't feel that I could justify keeping two lathes with essentially the same capacity/capability (actually the Taig has a bigger capacity). The problem is that at least in the short term my workshop will be smaller than my current one, so something had to give. The room I will be using is in a loft space above a garage, and the pitched roof means that bench space will be at a premium. Long term, once we have made the move and I have figured out how much space I have, who knows.

I did seriously consider selling the Myford instead, but having got the CNC side of that sorted to my satisfaction, that was too much of a stretch.

Cheap at twice the price

A tenner to put it on a pallet...but you didn't ask what I would charge for the pallet

Weighing scale??

We are hoping to move around the end of the year, depending on how quickly the build goes (and how quickly the house sells!)

I have just listed my Cowells ME lathe on Ebay as I am downsizing my workshop in preparation for a move Up North:

**LINK**

The renovation of this lathe was the subject of a series of MEW articles over the last year or so.

I have just listed my CNC mill on Ebay as I am downsizing my workshop in preparation for a move Up North:

**LINK**

This was the subject of a MEW article some while ago.

Harold -

Clockmaking was actually the reason I got into CNC in the first place - and hopefully at some point will again become one of the reasons that I still use CNC (been too busy playing with the machines to have any time to make the clocks), so your comments are interesting.

To me, there is no particular virtue in doing repetetive tasks, such as cutting gear teeth, crossing out wheels, cutting clock frames, by hand; it is simply tedious work that is getting in the way of the parts of the job that give me real satisfaction - the final finishing/polishing and getting the clock to run. If I can find ways of making the tedious bits go away, then all well and good; you also get the benefit of actually being able to cut wheels that have an integral number of teeth, and the right tooth count, if you go the CNC route, which is a considerable attraction to me - if I never use a manual dividing head again, it will be far too soon.

The finish you get with CNC is, in any case, a long way from the kind of finish that you would like to see on a clock - so there is plenty of scope for satisfaction gained by the use of elbow-grease to get a crisp, poliched finish that you can see your face in, there if that is what floats your boat.

CNC is just another workshop tool as far as I am concerned; I use it when the use is convenient and appropriate, and I use manual methods when they are appropriate/convenient. I have a major confession to make on that front - my CNC converted ML7 spends much more of its time doing manual operations than CNC; however, the CNC facility is there for when it is needed (cutting threads and tapers; repetition work such as matching clock pillars would be a good clockmaking use too).

Regards,

Tony

Posted by jason udall on 08/08/2013 11:34:32:
"( Why? " posts John...
++++ SYNTAX ERROR MISMATCHED PARENTHESES ++++
..

His parents were obviously well matched or he wouldn't be here. And what are "heses" anyway?

Regards,

Tony

I'd be a tad concerned if my building was travelling at anywhere near 1,800mm/min

Regards,

Tony

Good question. No very good reason, except that some CNC mills might be a bit pedestrian speed-wise - with a machine that essentially has no cutting forces to deal with and where the head is very light, you would choose rather higher speeds for the axis movements than you would be used to on a CNC mill. Starting from a CNC router table would make perfect sense though - swap out the router for an extruder head, put a heated platter on the bed, and off you go. Funnily enough, I was chatting with John S just this morning and he was suggesting exactly that kind of approach...

Regards,

Tony

I bought a used one on Ebay, complete with the (VHS!) video, and never managed to persuade it to cut a decent point on a drill. After occupying space on my bench for way too long, I sold it on Ebay. Obviously, starting with a new one might be a more rewarding experience, but it isn't an experiment that I would repeat any time soon.

Regards,

Tony

Michael -

No particular reason in principle why you shouldn't use wax in a 3D printer. Sure, the feed mechanism would be different, but there are ways to fix that - for example, use a stick of wax and feed it into the nozzle in the same way that a glue gun feeds its glue stick, or force the wax down a tube using a plunger on a feedscrew. A hopper full of granules and an Archimedes screw feed would be a possibility - that is essentially how the plastic extruders that make the filament work. The challenges would be around accurately controlling the feed rate and the nozzle temperature; might also take some experimentation to get the right wax mix so that it stays put after extrusion but also properly adheres to the layer below.

I know that somehow it has become ingrained in the collective conciousness that ballscrews = zero backlash, but that is just not the case. Any screw system can be made zero backlash with suitable anti-backlash treatments - double nuts, preloaded nuts, etc. etc., but you don't get it for free, even with ballscrews.

Ballscrews come in a wide variety of grades and accuracies, just like conventional screws; for example, the mechanism used for raising and lowering hospital beds often uses ballscrews, but these are installed because they are more efficient than conventional screws, not (for obvious reasons) because high accuracy or zero backlash is needed, and you certainly don't get either with that grade of screw.

The two primary advantages of ballscrews over conventional screws of equivalent accuracy are high efficiency and low wear rate. If you want low backlash as well, then, just as you do with conventional screws, you pay a premium.

With lathe use, for most purposes you don't actually need zero backlash anyway - on the cross-slide, if you are turning the outside of a part, and you are actually cutting metal, then there is always a component of the force on the tool that is pushing the tool away from the work in the direction of the cross-slide feedscrew, so any backlash is always taken up in that direction. The only problem you get is if you change from cutting on the LHS of the tool to cutting on the RHS, as would happen (for example) in machining a complex profile like a chess piece. In that case, as you change flanks, any backlash taken up in the leadscrew would reverse direction also. However, if what you are doing doesn't involve such a change of cutting flank, then you can cope with backlash in the leadscrew with little problem.

My ML& CNC conversion uses the standard screws both for the cross-slide and the leadscrew - I have not had any problems from that source so far.

Regards,

Tony

Edited By Tony Jeffree on 22/07/2013 17:15:55