....is that he has demonstrated on his stand, just how simple a wheel-cutting engine can be when using a stepper-controlled worm; (although if pinion cutting were to be contemplated as well, then a mechanical brake would also be needed.)
Well done, Mr.Jeffrey! (Seriously)
Incidentally, in this sort of application, where speed of stepping is irrelevant, and it is neither here nor there whether it takes 1/10 second or 5 seconds to move to the next tooth position, then control from a PC is perfectly possible.
All you'd then need is some stepper drivers driven by the parallel port, and a little bit of VB software, available to most as the macro language of Word, Excel, etc.
No need to go to the expense of buying a Quotient Mistress!
Actually, if you had examined the dividing head more closely, you would have spotted that there is already a mechanical brake fitted between the worm wheel and the rear bearing, operating on the rear end of the spindle. Manually operated, but functional nonetheless if you really need to use it. The full design can be seen on my website (which you won't of course find until you learn to spell my name correctly).
However, its primary purpose is to lock the spindle in situations where backlash is an issue; as John S has pointed out, a 72:1 worm drive, coupled with holding current on the stepper motor, already does a very sound job of preventing cutting forces from back-driving the worm. Hence, the only reason to use the lock is to lose the (usually very small) amount of movement resulting from backlash between the worm & wheel.
The far more significant thing that would be needed for pinion cutting would be some kind of tailstock support for the dividing head, given that pinions are generally made from varieties of steel (such as silver steel) that are thin relative to their length and not terribly free cutting, and over all, you would probably find that the setup I used wouldn't be rigid enough to cut a pinion. However, you might well put something together that would cut pinions successfully if you started from a more rigid X-Y table (a cannibalized Eastern-origin cross-vice, for example).
Thank you (seriously) for those few kind words.
Actually, I should also thank you (serionsly also) for providing me with so much free publicity. I did not believe the old addage that "there's no such thing as bad publicity" until now. I am happy to report that the show was DivisionMaster's most successful week of (cynical) trading to date, exceeding the sales at the 2002 show by a very large margin indeed; the rude personal comments made by yourself brought dozens of people to our stand that otherwise might not have bothered to visit, and in no small way contributed to our sales.
Many newsgroup members that I had never spoken to before went out of their way to introduce themselves to me and to make encouraging comments about our company and its products, and to make sympathetic and disparaging comments about a certain disruptive member of the newsgroup; my thanks to them for their friendship and support!
It is just unfortunate that Mr Bean didn't feel able (for whatever reason) to introduce himself to me; I would have welcomed the opportunity to thank him personally.
I followed your lead. You didn't introduce yourself, but went straight into a discussion about pricing. Clearly you were more interested in my money than in me.
It is just unfortunate that you didn't feel able (for whatever reason) to introduce yourself to me;
If true, then that would just go to show how many people there are out there with more money than sense. Any cynical (your word, as below) trader would be expected to take advantage of such gullible people.
As to "rude personal comments", I did no more than to follow the example set by you when you acted in common cause with Mr.Stevenson after I had made genuine contributions to the discussions about stepper motors. What goes around comes around? That you choose to make a very public association with such an infantile, aggressive and latterly violence-threatening individual says more about you than your silly boast below.
Violence- threatening ??? Threatening?? That wasn't a threat, it was a promise. I waited all dinnertime for you on Wednesday. Many people came up and asked if you had shown up. For some reason most had video camera's ?
Not a silly boast below at all. Tony's sales were well in excess of your three months unemployment. And because Tony's sales have increased, so have mine as I make the Vertex couplings and drive parts for the divisionmaster. So I also must take this opportunity to thank you as well
Anyway how are we getting on with this VB application that you are writing? Don't forget as we, the general public, are paying your unemployment benefit, anything you wish to publish will be in the public domain and we wish to take his chance to thank you for your tireless work on out behalf.
On the contrary - I did indeed introduce myself. At all times that I was on the stand, I was wearing a very clearly printed name-badge identifying both myself and my company. You, on the other hand, were doing your usual trick of hiding behind your cloak of anonymity.
There was no occasion during the entire Donnington show where I "went straight into a discussion about pricing" without first being prompted to do so by the people I was talking to.
And for the record, I have no interest whatsoever in your money, and unless you manage to buy from me without identifying yourself, you will never be a customer of mine.
Keep it up, Mr Bean. The more comments you post on this subject, the more free advertising I get.
The penny has just dropped, or in our case Tony the five quid.
The Twonk can't read. He's either blind, dyslectic, or he been doing what his mam said would happen if he played with it too much.
This has got to be the obvious answer otherwise how can you explain the fact he couldn't read your name, can't read any technical literature that says Bridgeport, Heidenhain, Fadal and Fanuc are all using PC based controls to operate motors. Not just old fashioned steppers but servo's with encoder feed back.
You know what an encoder is Mr H. A. S. Been don't you ?? It sends pulses out so it can tell where it is in relation to a programmed move. A bit like your brain path between hand and mouth but in your case channel A,A' is lacking a few pulses.
Just in case you do have trouble reading this here's the above message in braille
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