Member postings for andrew lyner

Wow - more fab information there!

I have read about the questionable finish on the gibs and, bearing in mind I want to do things one at a time, rather than a major rebury, that's something I can go for soon. Those diamond laps sound useful. When I last look at them (on a stand at a past Boat Show) they seemed quite expensive but, if there is a cheaper source, I could go for some of those. I just acquired a 7mm spanner for gib adjustment and that saves a lot of bad language with a small adjustable.

I like the idea of a clutch on the banjo. As Wayco have gone to the trouble of giving me a wheel on the lead screw, I may as well make use of it and it's only 'half useful' at the moment. That banjo adjustment is a pain and I may take a ring spanner and going it down to fit in that limited space. No excessive torque required.

I looked at images of a Derlin style anti backlash nut. Looks clever and a mod could be possible but it could affect the range of movement without some more effort.

Thanks for all those useful opinions.

The reason for my concern is that I am chasing the dreaded chatter. The cross slide movement is just one thing that could be contributing. The way I'm grinding the tools could be having an effect perhaps; I have minimal length of tool projecting and I make sure the (original) tool post is tightened well down.

One thing that I find annoying is the way that, when I take of the drive to the feed and the machine is doing no work, I have to pull the cross slide away pdq and backlash delays that. The top slide is far better behaved, I find with a light feel to the feed screw and no noticeable backlash.

On the subject of adjustments, I would also like to know the best way of adjusting the change gears when I go back to the 20/80-20/80 setup. The gears seem to chummer a lot and, when in neutral, I can't always turn the lead screw end wheel backwards cos the gears seem to 'bunch up'. Adjustment is a bit of a pig, with that nut in behind the gears that sets the position of the intermediate pair being hard to get to and allows about 15 degrees of spanner movement. The gears are steel, unlike the majority which seem to use plastic. Could they just be pool made?

I have just bought a dial indicator and I actually measured the backlash on my Warco Super Mini Lathe. It seems to be around 0.2mm and you can 'just' see it move and hear a small clunk at each end.

I have been fooling around with those three screws on the slide and I understand, from several on line sources, that you can minimise the backlash by 'tilting' the nut on the lead screw with the outer two and they rock the nut about the smaller middle screw. I have tried various combinations and, at times, the slop is just over 0.1mm and can be very much worse, too. How is the system supposed to operate?

I'd love to learn of a nice iterative and convergent procedure to improve the slop. It's a very popular topic with lathe owners but perhaps a member here could help me to get a proper answer.

Cheers
Andrew

Thanks.

This is all good stuff; The forum is so interesting for me; I need all this info.

I shall have to take it one thing at a time or I will be spending too much too soon! You will all appreciate that problem, I'm sure.

Oh yesssss. Of course. I never though of that. Save several more mm of boring time.

I'm not holding the bar in a drill chuck. The drill size seems to be what limits the size of the initial hole (at least I though it did. But perhaps that's nonsense and it isn't necessary to have a pilot hole. That could explain a lot!

I have a mini lathe with a drill chuck that will hold a 13mm max drill. I want to buy a boring bar that is as robust as possible. If I get a 10mm bar, what size of insert can I use, to ensure clearance at the start of the cutting? I want to avoid needing to do the job in steps - using a smaller bare to start with.

The spec of these tools is a bit bewildering - with a whole list of numbers and letters, describing them. My data book gives a sort of translation but I would appreciate some direct advice.

I will be working with aluminium so am I right in assuming that the right tip would be essential? (Dumb question. probably) From what I can see, the way that the dimensions of the cutter are described with those letters, sort of makes sense, with a high clearance angle for aluminium. I guess that it will all come clear with experience.

I live in Essex / London borders and I have not traced a suitable source from some time spent on Google. When I lived in Brighton, things were very different. Random Stainless bits for my boat could sometimes be had at scrap prices. Any info would be very welcome.

I did consider that but the filter holder is very thin and I doubted that I could finish of the mangled face. Turned out fine though, as it happened. I can't help thinking that a different parting tool holder would help - or even a design that could fit the Warco post.

An alternative could have been to use tubing, rather than bar. I really need a cupboard full of off-cuts; I haven't located a suitable scrap metal merchant near my new home. There was a brilliant place in Brighton that would sell useful stuff at really good prices. eBay is not a cheap source of bits and bobs,

Thanks for yet another useful set of comments, chaps. I think I may well go for the Warco low cost post.

Incidentally, I just found a limitation to my new Mini when trying to part off a 50mm aluminium bar. I managed it by lengthening the parting blade a bit at a time. There was some chatter and some clogging / stalling but I managed to tame it by adjusting side clearances and position and frequent clearing of swarf. I was on tenterhooks as the cut got deeper and deeper but the work fell off with a satisfying plop.

This was with the standard four position tool post. I guess you will all say that it's not a good thing to try and I'd agree but I needed a 47mm 0.75mm male thread for an optical filter so I couldn't think of any other way round it.

"and of course the fact that tool changing isn't tool free."

Ah yes. Pictures of other posts show a lever. That could be an advantage.

I have recently started using my new super mini lathe and I am pretty impressed with it on the whole. The tool post is not too convenient to use and I have been considering getting a Quick Change version. Warco offer a low cost QC post and I was wondering how it is likely to compare with the other one or two that seem to be available at similar cost.

Does anyone have experience of the Warco post, compared with others?

Thanks so much guys. That was just the info I needed. I can do arithmetic with the best of them but 'you never know' about what goes on inside. I tried counting the gear teeth in the box but I went into Ratio Overdrive. The numbers in the Table gave me a strong message and you confirmed it.

@Alan Vos I appreciated the caveat about the actual choice of wheels and the fact that some combinations may not fit

"Pitch tables cover the most common/popular options. 0.75, while easy to achive, is less common (M4.5 or fine)." This an odd requirement for a thread on a 2" telescope filter barrel.

I was looking for a suitable handbook so I may go for that recommendation.

Cheers

Hi

I just bought a Warco Super Mini Lathe and I am pretty pleased with it - it looks and works a lot like its big brothers. I am sure that its inadequacies can be pointed out by experienced machinists but it is what it is.

My question is about thread cutting. I need a 0.75mm pitch but the table on the gear cover doesn't include it as an option. I have a good selection of gears supplied and I was working out how to use what I have to modify the threads shown on the table.

Can it be this easy? A 1.5mm thread uses A40 B60 C60 D40 and that seems to imply the lead screw is 1.5mm pitch (?). To get a 0.75mm thread, it looks like I could replace C with a 30 wheel. From the diagram it seems that B and C are keyed together or a single wheel can be used on that shaft.

Any comments welcome.

Cheers