On Tue, 29 Jan 2002, Gunther Schadow wrote: Sadly, I passed up on 100s of replacement pens for these...and the place that had them for $0.05/pkg closed up shop a few months ago. I should have bought them up when I had the chance :/ -Toth

On Tue, 29 Jan 2002, Lawrence Walker wrote: I had a box of the Radio Shack ones, a couple of the printing mechanisms, and one of the Radio Shack pen printers at last years (2000) VCF. I can't find them now, so I think that somebody here must have bought them.

If we're still talking about HP pens, I have a big (about 18x24x10 inches) box of them. If you need them, make me an offer I can't refuse. All are outdated and most are still in sealed packages. Jim Tothwolf wrote:

On Tue, 29 Jan 2002, Roger Merchberger wrote: It's a discontinued item. They closed down the Houston area outlet store based on the little info I can gather. RS' customer relations department didn't have a clue as to what was going on with the Houston outlet store. I need to look at mine I guess. Maybe it isn't a 1520? I thought it needed some kind of wall-wart. -Toth

Wire EDM Tony Duell wrote:

You'd really only make a mold like that if you intended to produce many, due to the expense. And that would be if your mold was at least a three part, with the mold cavity having a through hole, to be capped off on each end by other components of the mold. If you preferred a blind ( not through ) hole cavity, you would probably burn the teeth into it ( after boring out most of the material first ) with a conventional electrode type EDM machine, which might also be a whole lot easier to home brew than a wire type. But then you generally have to machine the electrodes. Easier to do because you would be machining the teeth on it's OD, but machining graphite is a messy, nasty task, and you still need a cutter, though a hand ground fly cutter might do ( milling saw type better ). Other very realistic possibility is ... For an alternate to thread wires, use the shank portion of drill bits. Between all the fractional, wire gage, and letter sizes, there are an awful lot to choose from. You often are able to find something within a thou or so, if not tenths. For info on measuring gears etc, check Machinery's Handbook put out by the Industrial Press. It is the machinist's and mechanical designer's bible. For Tony, having a lathe. If you had a plate, turned circular to indicate it in when you set it up, with the same number of holes as teeth on the gear, drilled in a evenly spaced circular bolt pattern on the face of the plate, bolted to the lathe chuck, and a fixed portion bolted to the bed ( or ways, or headstock, etc. ) with a pin that would locate into the holes in the plate, it could serve as a dividing head for use on the lathe. Then hand grind a slotter type cutting tool to the shape of the valley between the gear teeth, mount it in the tool post, and by moving the carriage up and down the ways, cut that shape into a blank a little shave at a time, dialing the next depth of cut on the cross slide, just like on a slotter ( or shaper ). Tony Duell wrote:

On Thu, 31 Jan 2002, Tony Duell wrote: I'm seriously jealous. OK. I've tried hard to stay out of this thread, but as a silversmith, ex-welder/machinist, and devoted tinkerer, I can no longer sit still. This is not rocket science. Take the thing (the whole assembly) to the local watchmaker. Get N+1 pieces made. Share. Or, with a good indexing head and very basic diamond tools - don't flinch, my set for the flexshaft cost ~$30 - you just do it. Find the OD, and get a rod to suit. Count teeth, guesstimate (tm) the depth and width (ratio) of the teeth. Do basic math. Start cutting trial gears. And, forget casting. In the size gear you're looking at, by the time you remove flash, correct warpage, and polish the casting, you've pretty much machined a gear.... Doc

That's fine and tedious job but you do get results. In old days nearly 120 years ago was done by hand for nearly 500 years on everything before mass production was developed. Tools were hand-made too! With good co-od hand, can make nearly anything. That's how I made few small parts by hand machining, cordless drill, few jeweller's files, small bent-nose pliers. I keep fitting the part in progress to the machine till completed. On wear surfaces, I buff smooth with brass wirebrush on dremel. But if you can find right size and right # of teeth pinion rod, buy it and slice a section and drill hole to size. Oh yeah, can make odd sized drill bits out of right size dia rods even my old jeweller's screwdrivers. Not of what I know of but this term applies, think of squirrel cage made of two discs w/ 7 holes, one for center, six for pins as "teeth". Was popular in clocks including cockoo clocks, classic wind up bed alarm clocks, and old timex bed clocks, late timex ones used junky pot die-cast metal to bind all the pins, axle and gear wheel together - cheap, cheap, cheesy cheap but effective. They hardly wear because the pins are usually loose and allowed to roll when gearing. Make a impression in hard clay and pour 24 hour epoxy or potting plastic in it. Drill CAREFULLY on the exact center when hardened. Regular epoxies doesn't bond to plastic at all that small, about good epoxy's job is with wood. They pop off on plastic and metal. You have to use commerical type epoxies made for chip-making types. That what they does work. Cheers, Wizard

--- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote: I don't think so... the gear in my hand is about 2mm long, slightly less in diameter, and fits on a 6cm long shaft that's less than 1mm in diameter. It resembled the gear that you frequently see on the motor shaft. I suppose I'll have to take some pictures the next time I'm at the farm. Perhaps I've got it turned round in my mind... I'm not looking at the plotter at the moment. I've had that problem with some bolts in automobiles (American and Japanese - the Germans are better at that sort of thing in my experience). Now I can picture it. -ethan __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com

--- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote: Since I don't have mine in front of me, I'll have to say that your explanation sounds logical and you are probably right; I've just remembered things backwards. Makes sense. -ethan __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com

--- "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com> wrote: This is a Commodore plotter for the C-64, VIC-20, etc. It takes paper that resembles cash register tape. It is much smaller than, say, an HP 7475 plotter that takes full sheets of paper. -ethan __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com

--- "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com> wrote: The diameter is slightly smaller than that - (the max height of a 12 point letter is 12/72nd of an inch, or 1/6" or .167") 2mm was an appoximation on my part on behalf of the Europeans reading. The actual size, as I've posted before, is about 0.175" tall, about 0.145" diameter. Exactly. Any glue used would likely clog the bottom of one of the teeth. It's not a flat gear... it's taller than it is across. The idea of a slice of pinion rod is a good one, presuming I can find something with the correct number of teeth and pitch. -ethan __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com