Thread: Fitting a DRO to a Myford ML7R

Got a reply from xiao1207:
"Yes, we supply KA500-170 1um scale. For a 2-axis lathe kit, with one KA500-170 1um scale on cross slide and one KA300-520mm 5um scale on longitudinal axis, effective travel, price is 475 AUD, including door to door air shipping to your workshop in Australia."

This is the sort of service these guys give, quick replies and nothing is to much trouble. A lot different to dealing with Aus companies where they make you feel like it's coming out of their pocket and are not real interested, and most never return emails or phone calls.

Some of them will or can supply a aluminium backplate for the cross slide to make fitting a bit easier as well. It looks like the cross slide scale fitted in your link has one, so just make sure you get it with your order. With your other scale only being 520mm travel he might be able to supply on for that as well. I doubt they will add very much to your order.

Dave

Righto, will get back to xiao1207 on that. Thanks for heads up, I wouldn't have thought to ask.

No that seller does not have the kind of mounting plates seen in that MEW article by the Allendale guys. I've had a good look at it, it requires I mill some aluminium bigger than I can get at the local Ullrich Aluminium. So I guess its off to Bohler Uddeholm in Sydney. I wonder how they deal with little guys like me -- other guy at the counter is ordering enough material to build a new harbour ferry terminal ("err no better make that 40 tonnes of the 100x300, and 80 tonnes of the 400"), and I go up asking for 2m of 50x25mm bar.

It's usually only about 8mm thick by whatever height the scale is. They can be mounted without it, I would just wait until you get the scales to have a look at where it will go.


Dave

Yes I agree with that. I'll get the dro and sort out the mounting later. It comes down to milling a couple of Alu bar sections, not a big deal. So then, what with the DRO and with the VFD that's already on, this tricked-up ML7-R might even get on the cover of Street Lathes.

Originally Posted by Gunnaduit

Yes I agree with that. I'll get the dro and sort out the mounting later. It comes down to milling a couple of Alu bar sections, not a big deal. So then, what with the DRO and with the VFD that's already on, this tricked-up ML7-R might even get on the cover of Street Lathes.

Just make sure you get a grade aluminium that machines easy and is not gummy. All the back plates I have seen, have a small lip sticking out along the bottom for the scale to locate onto. This way you set up the back plate with a dial indicator, then the scale can just be rested on this lip and bolted in place without having to align it as well.
On the cross slide on mine I just used a piece of 6mm flat bar as a back plate which has worked fine.
It is best to keep the width down of the back plate because anything added to the right side of the cross slide will limit how close the tail stock can come to it. It also limits you on the amount the saddle can travel toward the tail stock when turning between centres.
I added way wipers to my 12 x 36 Chinese lathe, and used one of those holes to put an extended screw in with a rubber cap to stop the scale getting damaged from the tailstock. (pictured below) The rubber capped bolt contacts the saddle before the tailstock hits the scales by about 3mm.




I cut the scale cover off along the top corner so it was just an angle and screwed it to the 6mm flat bar with 3 x M3 counter sunk screws along the top, and made up a end cap to suit and attached it with 3 x M3 as well.

The side of the scale cover needed trimming as it was to high to fit. I added a small cover over the reader head that goes up under the main cover so it was fully protected. You can just see the cable exiting out of the bottom in the picture below and it runs under to the left side and out to the back of the saddle. This was the easiest and neatest way on my lathe to get it over there. You can also see the spot on the left of the reader head with no paint where the rubber capped bolt on the tail stock hits onto the carriage.


The aluminium tube at the top of this picture is where the scale cable runs out over the back of the carriage.

Dave

Ah, a CQ6230A ... I know it well (bloody ought to after completely disassembling mine, fettling, sandblasting, deswarfing all threaded holes, reassembling, repainting etc. And that was on a virtually new machine. Or rather, a set of castings that had been painted and assembled for transport from the factory). Actually came up pretty well. But I fell in love with the retro-styling of the Myford, plus it's a lot quieter and big enough for my needs - though I've still got The Hulk as well.

Anyhow, as you say "anything added to the right side of the cross slide will limit how close the tail stock can come to it. It also limits you on the amount the saddle can travel toward the tail stock when turning between centres"
Yes I'm very aware of that and it does make me a bit uneasy about the retrofit. There's a fellow in Coventry UK who milled a mounting frame that juts out the back of his cross-slide, so that the whole cross-slide scale is back out of the way. Looks ungainly but gets over this problem.

I have had this one for around 7 years and have had no problems with it. From what I have heard recently off a manager selling them, there are different grades.

I have seen a few with the scale out over the back, and like you I am not real fussed on them, as they would be easily broken hanging out there.

If you worried about the 30mm or so room it will take up, you can use a MT2 to MT2 or MT3 to MT3 (depending on your machine) extension in the tail stock which will give you a lot more room.

I find having the DRO far out ways the little loss of tail stock travel.

Dave

Originally Posted by Dave J

I find having the DRO far out ways the little loss of tail stock travel.
Dave

Yes right. That's going to be the fun of DRO. Its all about trade-offs.

CQ6230A - I was being a bit unkind, as what was redeeming about it was that they did get the principle machined surfaces right. Just the overall finish that was blech (mine was from H&F, in 2001). Never liked the geared head though. Noisy, and difficult to get the gear changers on the right alignment. But a big solid machine.

After looking at the H&F's lathes that is why I bought the one from Gasweld for the same price. The fit and finish is far better and I have found it to be accurate strait out of the box with nothing needed to be done. There was no sand anywhere and from what I have taken apart, no problems so far. It was a good step up from the Hercus I had before. As for gear noise I can't say mine is that bad and to change gears I just rock the chuck and don't use the inching button. I would rather shift a lever than change a belt.

I am not sure if you seen it, but we where only talking about comparing these 2 machines a few weeks ago and after looking at both, Darren also thought they where better finished lathe as well.
https://www.woodworkforums.com/f65/cq...-lathe-132768/

I picked up 2 H&F's steadies and a 4 jaw chuck all new/second hand locally and putting them side by side with the Gasweld ones I could easily tell the difference. I was also thinking about a CL38 lathe but after looking at it in person, I think I will do like RC and get it through someone else.

Dave

LOL, yes, I think if I'd been back there at that time, I'd have gone with the Gasweld one too. Its good we've got this forum to share these reviews so others have a better chance. I have got a few machines from H&F (pedestal drill, X3 mill, rotary table, Kurt-style vice) but never any fine tooling or cutters. Its just that in this small town of Canberra, the local industrial supplier M&G are an H&F agent.
Your plan on a CL38 is certainly going big! If I was back in the market I'd get a "machtech Turner 280 x 700", not because it's a classic (or big) but because Promica make a reasonably priced cnc kit for it.
Well I am sucking in breath right now before slapping down my cash on the Sino DRO kit with the 1um slimline crosslide scale. Procrastinating before spending up big is a survival mechanism that sometimes works.