started this project a while ago and have been slowly plodding through it.
I need to make/obtain change gears for my denford lathe, these don't often/ever come up in the usual places and rather then buy and modify new gear I thought id make my own
first issue with this is no dividing head/indexer
being the cheap person I am I didn't fancy paying out for a proper DH and although a spindexer would do the job I thought id have a bash at making one myself
original plans were for a copy of L.H. Sparey's VDH but I thought I would add a worm gear so it could also be used for milling rounds
so I melted down a few alloy wheels from my 4x4 into manageable chunks and then built a quick furnace (ty VT for testing POP refractory)
made a quick and dirty green sand mold, (more of and open mold but with a sand lid)
ended up with something looking vaguely like what I wanted, I didn't quite melt enough ally to fill the casting but never mind
after it cooled I cleaned it up and quickly realised that all the sand inclusions would quickly destroy my cutters, so I knocked up a quick and dirty flycutter using a few bits of scrap
with things clamped as best I could I proceeded to try and square things up
as you can see the ally is not a good casting, lots of sand inclusions and gas porosity, I suspect I got things too hot. but its my first attempt so im happy enough with it.
then came the problem of boring it out, iv not got the tooling for the mill and it wouldn't fit on my lathe ( too big to swing and no boring table)
I then realised that if I made the base narrower it might just fit in the lathe chuck
cleared the saddle by 1mm
I was a bit unsure if it would actually stay on as only 2 jaws are actually gripping but it went well and was soon bored to 25mm
a test fit with a bit of 25mm bar showed id made it a bit loose, but its useable
I turned the shaft up with one end at 7/16th ( bore of my change gears) and the other at 16mm. also made and fitted a lock from a bit of brass bar (sorry no pics)
im now onto making a worm gear to fit on the back end. so far iv made a 76T, 66T, 44T and 35T
also
when I realised how poor the casting was I tried again and came up with this one
this one was squared up just on the lathe and then a quick skim around the top on the mill. im now letting it age on a shelf for when this first one goes horribly wrong.
