Re: [CAD_CAM_EDM_DRO] Tool up

info.host@... wrote:

> > If you are willing to wait for your own car several years
> > and think about building your own professional shop,
>
> My own car? Why would I want my own car when I can just ask for a lift
> somewhere? Car's are way...... too expensive for people my age compared to
> what they actually do. I could buy a small mill with the insurance for one
> year, and rightly so I think.
>
> I can understand what you're saying because a mill of this fairly humongo
> proportions, when it's sized against a Sherline, could end up being one
> incredible pain should it ever need to go. I think what is drawing me
> towards it is that I'm pretty sure I could buy the actual metal for £350,
> which is about £200 less than a Sherline. Then I add the £200 back on for
> the hiab crane and I have one Sherline in cost. Add either a converter or
> new spindle motor, another £80 -140. Now I'm at £630. I would then have
> roughly £250 to spend on some tools to get started with and something to go
> under the spindle. How accurate are these machines typically when you find
> them?
>
> Please don't think I've ruled out Sherline, Tiag and the others, I most
> definitely haven't.

Well, I would tell you to DO IT! I have a converted Bridgeport, and
I can't imagine doing a lot of things I do on a smaller, or lighter
machine. I still have some rigidity problems (often in fixturing,
not necessarily the machine itself) and run into motion envelope
problems, too. I have an oddball setup, which gives me 30 x 7"
760 x 175 mm. I can get back an inch or two of the Y axis range
I lost when I made the ballscrew retrofit, but it requires taking the
whole machine apart, again, and I haven't had time to let it be down.

If the machine doesn't show a lot of wear, then it probably is fairly
accurate. But, you should know that CNC retrofits on Acme screw
machines don't work out real well. Also, worn Acme screws would be
a major source of error. A DRO or linear encoder would mostly fix that.

Look on eBay for tooling.

Jon