Member postings for Tony Payn

Wow, that's a big heavy lathe. Looks like it comes with a stand which no doubt sets the machine at comfortable height if the stand is placed on the floor. I think the idea of pouring concrete over the floor (with a plastic membrane to allow removal of the concrete in future) is good, but the weight of the lathe may well crack it unless it is pretty substantial in itself. Making it too thick though might raise it up too high.

I was inspired by some web articles about lathes made from concrete during World War II. I wonder if there would be a benefit in making some sort of reinforced concrete plinth, similar to how concrete floors for buildings are reinforced with steel 'rebar'. Something along the lines of making a box mould, laying in the rebar (they usually bend the ends to stop the rebar pulling through the concrete), placing in position over the plastic membrane and pouring in the concrete. Perhaps a depth of 5 inches or so? With some rebar in the lower half and also some in the top half.

The benefit would be to spread the load of the lathe evenly to the floor over the entire surface area of the plinth. Machine mounts will put the loading at specific points which may do untoward things to your flagstones, and depending on how they were installed, might they move under point pressure?

Might be worth looking in machine mart for some chain hoists or similar to help you move it. Some of the engine hoists might be useful too, but not sure of their maximum weight capacity.

Wow, a lot of replies to my post and thank you all for your comments.

I entirely agree with John Alexander Stewart about the benefits of paper copies. I am just this way with books - no Kindles or such for me. I would be with magazines too except they need somewhere to store them, my other half is none too keen on me collecting more stuff to dust!

I tried my old desktop again this evening and the problem is that when the offline reader loads, no magazine covers are shown but instead, an exception is thrown which brings up a box asking me if I want to debug the application (= offline reader). When I decline this, it closes the application.

However, some good news is that on my new laptop (Windows 8.1), the offline reader now works! One of the enormous number of updates Windows did the other day must have done something to make it work.

So I'll monitor the situation over the next few days and then make a decision on re-subscribing. In the meantime I am a relatively happy bunny once again - I can at least read the ones I paid for.

I've subscribed to the digital edition of MEW for one year now, but will not be renewing. At the end of that year, I have nothing to show for it.

Most of my year's subscription were downloaded to 'keep' on my old PC running Windows XP. Due to expiry of support for that by Microsoft, that is no longer connected to the internet for security. However, I can no longer read my downloaded magazines, as internet access seems to be required to validate whether I am entitled to read the downloaded magazines or not, and as this fails, I can no longer read them.

I bought a new laptop (not just for MEW) but as it runs Windows 8.1, and the offline reader seems incompatible, I can't see anything I've downloaded onto that computer either.

An email to PocketMags explaining these problems has received no reply.

I could continue subscribing and looking at the archive, but I have not received what I was promised and am reluctant to soldier on with what is in effect 'half a subscription'.

Shame, I was enjoying the magazine.

Hello Rik

That's a neat way to rescue a condemned grinder and is an improvement that ought to come as standard.

Thanks for sharing it!

Tony

The thread rolling machine for spokes look interesting in the photos posted by John (Bogstandard2). They don't look too difficult to make either. How do they work and what would be needed to make one? I guess the three 'prongs' have hardened threads on them - are they geared together?

A friend of mine has an Ariel Colt on which one wheel has over-long spokes, which consequently exit the hub almost tangentially to use up the spoke length before reaching the rim. He'll need to shorten the spokes and put new threads on the ends to correct it, that's why the spoke threading machine looks interesting.

I guess the principle could be applied to other things as well. Sorry it's a bit off-topic, not much about models, but could be a good solution for this problem.

Thanks

Tony

Hello Nick

You ask if I'm sure the bed is twisted. The truthful answer is "no". What I am doing though is attempting to set up the lathe for turning parallel, as described by Harold Hall in his book "Lathework - a complete course". In the book, and in numerous YouTube videos and other on-line sources, methods are described whereby a check is made that the tool cuts the same diameter when it is both near the headstock and when moved via the carriage to near the tailstock end (no tailstock used). The suggested cause of inconsistency here is that the lathe bed may not be aligned for best result, and that by putting deliberate movements onto the lathe bed, the ability to turn parallel can be adjusted. None of that means, I suppose, that the bed is actually twisted - the headstock could perhaps be a bit out of line and I might be effecting a compensation for that.

What I do know is that the mean value of the DTI moves as the carriage moves, and I'd like to eliminate this, if I am to complete the project in the book.

There is considerable run-out which is also greater at the tail stock end than at the head end. That's why I'm going off the mean value for assessment of parallelism. Once I've got the bed sorted, I'll see if I can reduce the run-out. I have a 4 jaw independent chuck with which I can pretty well eliminate run-out, but the DTI reading still changes as the carriage moves along.

The bar came from a printer, it used to have a rubber sleeve over it as a support for the paper when the impacting through the ribbon. It's not a special test bar but is beautifully straight, smooth and parallel according to my micrometer. I was glad to get this useful bar out of the printer, which was being scrapped.

Tony

Many thanks to you all for your replies and thoughts, all very much appreciated.

The stand is quite flimsy and what I think is happening is that the lathe, being heavy cast iron construction, pulls the stand to conform to the shape that the underside of the lathe has. The amount of twist in the bed is quite small and this is noted with a bar held in the chuck at headstock but not supported at tail end, just making DTI measurements along the bed.

To eliminate the small amount of twist in the bed (only a few thousandths - I forget the exact amount), I've put shims between the lathe and the stand. What seems to be happening is that this bends the stand a lot more than it bends the lathe. The net result is that one corner of the stand lifts off the floor, making the whole think rock when given a push.

Even though the twist reads only a few thou, it needs a stonking great shim (2 mm) to eliminate it, again I think this is because the stand hasn't got the strength to fight against the lathe stiffness, so the lathe more or less stays where it wants and twists the stand, unless the shim is big enough to put some real stress into the stand.

What I think is needed is a way to prevent the stand from lifting one corner (preferably preventing it lifting any corners at all), which is why I thought of bolting it to the floor or weighing it down. Then, when shimmed, the lathe will have to twist itself or twist the stand together with the garage floor as well, which is considerably heavier and not very flexible at all.

I don't really want to move the lathe off the stand as it weighs so much, otherwise reinforcing the stand could be a possibility.

I think I'll have a go at bolting the stand to the floor and see if this improves things. I'll post the results when done.

Tony

Hi,

I have a Clarke CL500 lathe which sits on the stand (also provided by Clarke and the right one for this model) on a concrete floor. I've been trying to eliminate twist in the bed by shimming up one corner of the lathe. The stand is made from sheet steel with welded and bolted construction.

my problem is that when the corner of the lathe is shimmed up, the stand rocks on the concrete floor. The stand sits pretty flat, without rocking, when there are no shims used, but then there is a slight twist in the bed.

Should I bolt the stand to the concrete floor? Has anyone any recommendations of the best way to tackle this? I had thought of adding weights to the stand, might this be enough?

i think the twist is quite small but as the corner of the stand lifts, it needs a big shim to affect the lathe bed by a small amount.

the lathe is firmly bolted to the stand, and I have slackened/re-tightened all of the bolts in the stand itself.

thanks!

Tony

Russell, regarding routing PCBs and CAD, I think you will probably need to do some processing on the output file from just about any CAD package. There's a company producing dedicated PCB routing tools (LPKF at www.kpkf.com) and we bought one of those machines at work. Very good is was too. I remember that the PCB file in gerber format had first to be translated by the software provided with the machine. This worked out tool paths to remove copper in the most efficient way, using large tools for big areas and small tools for fine pitch parts. It calculated how far it needed to be from the track according to tool width etc. Perhaps your setup does the same. The motor in that machine span at some ridiculous speed - I think it was something like 26,000 rpm which was necessary to get a decent cut. And the cutters wore out quite quickly, due more to the glass in the laminate than to the copper.

As for the comments on free software made by several, I quite agree. I was one of the first to sign up for Alibre. When they launched, it was called something else (X-CAD, I think) and if you we're one of the first 10,000 to register, you got some enhancements in the free package. It came with a promise of 'for life', if I remember correctly. Then they cut it down to almost useless unless you pay for the hobby version. I don't use it anymore.

The 3D software offered by RS Components looks very capable and comprehensive. I've only tried it for a few hours but so far I'd say it's as featured as Alibre. It could well be based on Sketchup but is definitely an engineering package. One of the reasons I'm prepared to invest time in it, is because RS are behind it. Their goal is to provide software free and I don't imagine they would suddenly change that policy, in the same way that Alibre did.

The commercial version at www.spaceclaim.com is probably a bit more capable than the free one but if it is like the PCB package, new features should be added fairly regularly.

RS Components are providing a free 3D CAD suite based on SpaceClaim professional software. www.designspark.com

Thet also have a free PCB design package too, based on EasyPC.