I had the opposite. I bought a metric Tom Senior mill and being an old fart who can only work in Imperial. I fitted a three axis dro system to work in imperial. Since then I have never looked at the metric dials on the mill.

All my machines are Imperial Chris – but I move between Metric & Imperial (Decimal) measurements without really thinking too much about it these days – mental approximations help. 1mm is about 40 thou – 4 thou about 0.1mm – 10 inches is 254mm…etc

But if you are fitting a DRO – then it will do the conversions for you. If the mill is in great shape and the price is also good – then go for it. Much better to have a really good Imperial machine than a crappy Metric one….you will soon get used working with it…

Regards,

IamT

I wouldn't even hesitate – fit a DRO and be done with it. I've got a 2-axis DRO on my (metric) Bridgeport and it's the single most useful accessory I've ever bought. No need to change anything on the mill, just use the DRO. I have a mix of imperial and metric machine tools and, like Ian, it's not a problem working in both systems.

I didn't fit, and don't miss, a third DRO scale on the knee of my Bridgeport. A DRO has other advantageous features, like bolt hole patterns. Great for bolt holes (!) and also for roughing out large holes. Just do some simple calculations so that you drill a series of holes where each hole overlaps by a few thou, drill the holes and then knock the centre out. Like this:

Andrew

I have a metric Tom Senior Vertical Light with X & Y DRO's and bought a three axis DRO display so that I could easily upgrade with a Z axis at a later date.

It was a fair chunk of money but really was money well spent – and I never look at the manual controls! You can buy this kit cheaply on Ebay etc but I found Machine DRO (right) to be really helpful and I managed to buy the kit during a Black Friday promotion.

Regards, Nick.