I’d never heard of one before.
Wish I’d seen this before now, cause it seems like something every machine shop needs…
Here’s some propaganda from the manufacturer about some of its fabulousness…
Finally a use for harbor freight taps!
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There was an article awhile back in one of the machining magazines (Home Shop Machinist?) that described building a simple electric discharge machining (EDM). It was pretty basic; 40W light bulb, switches, wiring, and a tupperware container with electrolyte (salt) solution if I remember correctly.
I was considering finding that article because it might be the easier way to machine the key ways for the colchester lathe we are working on.
FYI: RepRap on EDM
I wish I didn’t have to put in a bunch of characters to say that make me guffaw out loud!
I am forced to ask:
Why not just use a keyway broach?
It doesn’t get much simpler than that, to my way of thinking…
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FWIW, that’s actually his current plan. He’s having a quick meeting tonight on it if you’re interested in looking in on it all.
Why not just use a keyway broach?
It doesn’t get much simpler than that, to my way of thinking…
Two problems. The big one with a keyway broach for this purpose is that there are eight indexed key slots in the bore of each change gear.
Number two is a slightly different problem. Until I can get my hands on a change gear to measure, there is a possibility (and from the pictures I have seen of the change gears for this lathe a strong possibility) that the key ways are of a non-standard size.
If the key ways are a standard size broach, that is my intent. I have a way to handle indexing all eight key ways with a standard broach if that will work.
The EDM is only a fall back position if my prefered method (broach) doesn’t work. Actually it is my second to last prefered method with the last being to hand file the key ways… That said, I am still interested in finding the EDM article (or similar) because it looks like a cool method to play with.
I have been following the “making gears” [chat][1] with interest. I was a little confused about how the keyway cut was currently being planned.
Although I do not understand the drive to want the lathe to make threads, I am excited that there is a project which appears to have gained momentum, and will employ a fair number of our “removal equipment” to make something that will make them even more useful.
As for “interested”, i am, but my time is, regrettably, already spoken for.
I did consider volunteering to make the trip to online metals as Mr. Anderson requested, but as I am not clear on what is being picked up, I am afraid my transport* might be inadequate.
*small hatchback, <800lbs payload, chunks of steel tend to add up fast.
[1]: Get together to discuss and work on the colchester lathe replacement gearing
@jast (Andrew) said
Although I do not understand the drive to want the lathe to make
threads, I am excited that there is a project which appears to have
gained momentum, and will employ a fair number of our “removal
equipment” to make something that will make them even more useful.
The main need for threading on the lathe is for those items for which you can’t use a traditional tap or die approach. For instance, if you want to make filter adapters for cameras, microscopes, etc… you need a lathe with threading capability (and metric threading at that). Also if you need a thread pitch you don’t have either a tap or die for, the lathe threading is a good alternative (though a lot more work that tap and die).
You also need threading capability on lathes for a number of things other than screw threads. For instance if your want to create a worm gear, that is done using the threading mechanism. And worm gears, especially, are one of those items where it can be more cost effective to make your own, rather then buy one (if you can).
As to the key way cut method I am currently planning, I was actually thinking of 3D printing a model to demonstrate it for anyone interested! I have been asked several questions about it and my communication skills weren’t up to the task of explaining my intent.
Thanks for considering to pick up the items. Another member has already done so for us, but the items in question wouldn’t have taxed your car or even Stan’s bike (other then distance). Less then 5-10 pounds I would estimate.
My stepfather had some gadget back in the 80’s that he called a “spark eroder”. They used it to get broken bolts out of engine blocks. Looked like a welder. Been a long time since I saw it.
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Metal Disintegrater,I have this diy manual in my library, it’s interesting, but I’d probably try a gouging rod on anything that wasn’t an engine block.
I’m sure you’re aware of RDG on ebay UK that sells (all?) change gears for Colchesters. Curiously there is no 42T…http://www.rdgtools.co.uk/acatalog/Colchester-Bantam-Gears-.html
Good luck and Godspeed.
@FreOn
Yep, We in fact need two change gears at a minimum to have full use of the normal threading table for this lathe, a 36T and a 42T. I have already ordered the 36T gear from RDG. I also emailed them to see if they had or could provide a 42T (and 127T). They said they turn up occasionally, but couldn’t provide a time estimate. Many of the other ‘standard’ gears are available from RDG, so I will probably purchase them as I have a need rather then making them. But most of the tooling will now be here in case someone wants to make a gear instead of buying it for some specific purpose. So making them is the best available option at this point.
After all what good is a machine shop if you can’t occasionally replace some impossible to find part!