Member postings for Martin Shaw 1

A number of folk have been exceptionally helpful, and as a thank you , I though I would post some pics of the Mk2 approach.

The first shows the revised set up, thank you John Haine, which works well. The second and third pics are the result of a few passes of a 14mm end mill, it looks a bit rough because it was, certainly somewhat better than the last attempt, but the cutter was putting a lot of vibration into the exercise. I suddenly twigged that the cutter was blunt, I can't recall what I might have used it on, but blunt nonetheless. I was going to use a 16mm cutter, regrettably the brand new, never unwrapped R8 cutter holder wouldn't take a 16mm cutter shank, so it'll have to go back to the supplier for a new one. A new 12mm cutter of course cut properly. The fourth pic shows the final surface finish, which in high enlargement looks rough but in practice isn't. What you see is really the striations of the cutter tips, which polish out on a bit of wet and dry. The cutting was done at 1200rpm, it felt right even if 1500rpm is a better speed, and the feed rate was a bit lower, either way it's all worked out quite well, so my grateful thanks to everyone who has contributed their thoughts, it's appreciated.

Regards

Martin

Thanks for the explanation John, logical and simple. Anyone want a dovetail cutter, v little use? I was going to have a go this afternoon, but after our trip both my wife and I have picked up a nasty lurgy, so enthusiasm for the workshop is low.

Kind Regards

Martin

Jason

Thanks for your thoughts, there is a bit of excess in the X gib but not for the full travel, so it 's probably part of the problem. Can't do much about the tool grinding however you have picked up the other major problem which is bad clamping practice. I have had a look and apart from the visibly obvious there is also a lift of the parallel at the rear because of it's location on the bed. Fortunately there is anough of an edge to realign when I have sorted a better arrangement. Thanks for yours and others help.

Regards

Martin

Following on from Thursday, I had to pop down south to see my Dad, at nearly 94 he is ageing quite rapidly. However here are pics of the set up, as you can see the swarf is, from Jason's description, about right so I think the tooth load is about right, but the close up shows the ridged paterrn in the cutting surface. Having had a couple of days to think about this I'm reasonably happy that it is a too high feed rate with a too slow rpm, but if anyone thinks otherwise I'm happy to be corrected.

Regards

Martin

Unfortunately it will be Saturday before I can post a picture, but I will do so then.

Regards

Martin

Jason

That's very interesting, much better surface finish than I'm getting, so I have to conclude that either my revs or my feed rate are drastically wrong, possibly both. I am getting the swarf you describe so possibly depth of cut is right and I wonder if a high feed rate combined with a slow rev is allowing the cutter to take " bites" from the work with the attendant ridged finish. I'll have another go at it and see where it leads.

Regards

Martin

Jason

The final shape will be nearly square, in a rhombic form, so it doesn't really have narrow sides. I'll post a pic in due course.

My thanks to everyone who has contributed to this thread, it has helped greatly.

Regards

Martin

Andrew

In my naievety I thought it the sensible approach, others have given me an alternative view. You may well be right regarding speed and feed rate, I'm not able to make a judgement, so I made the best possible guess with my limited knowledge, which is why my question is in the beginners section.

As an afterthought my stock is 150mm long which means that a full cut would according to your numbers take 15 seconds, surely much too quick.

Regards

Martin

Edited By Martin Shaw 1 on 06/02/2018 21:52:04

Edited By Martin Shaw 1 on 06/02/2018 21:52:29

Joe

The cutter is brand new from Arc, and whilst it's probably not the best cutter money can buy, it would I hope be more than adequately made. As to run out on the mill, to be honest I haven't measured it, but I've no reason to think it poor, other work I've used it for seems accurate enough for my limited skills, perhaps I should inform myself.

Lofty

Thanks for the link, that may save me some grief.

Regards

Martin

John

That is clever, far too much for my little brain. It's also likely more precise than my way so I'll file in the useful to remember drawer, thanks.

Martin

Joe 20mm dia 8 teeth

Lofty Thanks, does the info above change your view?

Jason A possibility, but I am starting from a piece 1/2" by 1/4". I dont have an angular vice, so the DT cutter is the less expensive of the choices.

Doug In my involvement with lubrication on full size steam locomotives it is now the generally accepted view that "oil grooves" are undesirable, at least in rotating components as they break up the film between surfaces, Of course a gib strip isn't under the same load, but.

KWIL I've no doubt your right however if it ends up as planned the gib strip will be about 8mm between faces so it will be fairly rigid. I am trying out a mod to the Sieg design so that the void between the slides is as completely filled by the gib strip as possible, ideally to the point that the adjisting screws are solely for snugging up. This is to try and get the gib and slide mating surface to stay fully in contact and will hopefully do something about the currently next to useless design. Taper gibs would be better but there's not a lot of meat. I have done Steve Jordan's mod to the saddle and that has improved things beyond belief. If it all works out I'll do it in steel.

Thanks for all the help

Regards

Martin

Thanks, it's a brand new cutter so that shouldn't be the issue, I'll try a light climb pass at a higher rev and see what the result is. I'm going to lap the finish anyway but obviously don't want to spend ages polishing off the cutting marks.

Regards

Martin

Hi folks

I'm manufacturing new gib strips for the lathe slides and I'm using a 60deg HSS cutter on CZ121 brass. The cutter is at 500rpm and the feed rate is I guess about 60mm/min, but the finish is distinctly ridged. I'm obviously getting something wrong, but would anyone care to suggest what.

Regards

Martin

Matt

This is a Sieg lathe made in China, the tool post stud is definitely not imperial. I have a similar machine and when I put a QCTP on mine it came with a suitable sized stud to replace the original, and works fine. I would check the thread in the topslide for damage and if necessary run a tap through. Of course if you bought the lathe secondhand a previous owner might have done something weird.

Regards

Martin

Edited By Martin Shaw 1 on 02/02/2018 21:44:22

Happens on my SX2P mill occasionally which is of course exactly the same electronics. I find that isolating the supply usually cures it.

Martin

Ketan

I'd be quite interested to know how you can patent the use of a gas strut to support a more or less vertically moving load. On that principal every car maker in the world is infringing a Taiwanese machine tool manufacturers patent, or paying them a royalty, which I really don't believe. I suspect this comes down to commercial clout rather than patents, notwithstanding that despite the tens of thousands of torsion spring supported milling heads it really is a pretty rubbish way to do it, which is why I and just about the rest of the world do an after market gas strut mod. If the "patent rights" have lapsed, why on earth hasn't the design been changed to something rather better. I suspect I know the reason.

Kind Regards

Martin

Andrew

I would endorse the posts from Howard and Ketan, and whilst acknowledging that Ketan wants to make a sale, there is nothing in his post that is misleading. I have found that the issue only really occurs when the head is at the top of the column and I overcome that by keeping the head locking screw partially tightened. Once you have a feel of it, it becomes second nature and it hasn't caused me a problem. As Howard T comments a worthwhile machine for the price, with all the benefits you have already identified. Be prepared to do a bit of work on getting the X Y and Z gibs adjusted, the factory setting can be a bit variable, other than that I am completely satisfied, apart from the proverbial " a bigger machine would be nice", which is nothing to do with the SX2.

Regards

Martin

Andrew

I bought an SX2P last spring and I haven't had any issues with it. I presume your referring to rack and pinion arrangement that raises the head up the column, I would agree with you that it isn't ideal, but I haven't found it to be a problem in use. I do plan however to do a gas strut mod in due course. In my opinion the brushless motor and R8 spindle taper are major benefits, the other one is of course the fixed column, once it's checked for verticality, you'll not need to bother with it again. The tilting column on the WM14, or indeed any mill is a source of potential error you can do without. It's also very quiet in operation, often the loudest noise is the cutter against the work piece. I would seriously suggest you look at the SX2P again.

From an impartial point of view I have bought items mainly from Arc, but also odd bits from Warco, but not a machine, so I can't comment on their service though I have no reason to doubt it, I can say the service I've had from Arc has been superb.

Regards

Martin

Neil

Yes of course the steel itself wouldn't cost that, the sum of £20 includes studs, washers, nyloc nuts, the piece of steel itself, and a replacement 12mm cutter. As it is I probably don't need a new cutter so take £7 off. If I had been prepared to purchase full lengths I would have got them at an exact or nearly so size, but I would have ended up with 5m of steel bar lying around which I may or may not use. As it is I have got what I wanted for the minmum cash layout, albeit at a trade off of time, and no surplus material. If I had thought better to hacksaw the majority off and make a few passes on the mill to finish it would have been quicker, I'll know better next time. Thanks for everyones input, its been useful.

Regards

Martin

Edited By Martin Shaw 1 on 08/01/2018 14:39:35

Interesting, several answers all with valid bits in. The reason I'm asking is that I'm doing Steve Jordan's mod on the lathe saddle so I phoned a local steel stockholder as to whether they had any bar ends 6 by 20 and 5 by 30. As it was the best they could do was 400mm of 6 by 30, for a very small sum. The only critical dimension is the 6 one so I decided to mill the 30 down to 18. Like silly old duffer I'm far too lazy to want to hacksaw it and whilst I could of got the jig saw out but didn't think of it. The biggest cutter I have is a 12mm 4 flute so I just persevered, it took forever, the mill is not rigid enough to take hacking great lumps off in one go.There is no sign distortion by unbalanced stresses but then I wasn't going hard

Anyway it's ended upwhere I wanted it and whilst I acknowledge that cutter usage was far greater than it might otherwise have been it was only a cheapo, so all in all even If I have to replace the cutter the whole job will cost less than £20.

Thanks for all the thoughts, I would do it differently next time.

Regards

Martin

Edited By Martin Shaw 1 on 07/01/2018 18:38:08