Member postings for Steve Withnell

Another combination to watch for is 1/4" and 6mm in brass and copper round bars. The last two suppliers I've used off eBay don't differentiate between the two sizes...When I asked why they had shipped 1/4inch instead of 6mm, it was because they had 1/4inch in stock...

Mystery solved! I thought my account had been hacked when all these PM's started turning up...

Happy New Year!

Steve

The runout on my first lathe was nearly 0.1" and would still make perfectly good parts! Really bad runout will still deliver round parts From a novice point of view (which I will always be at this game), knowing how your machines perform is more important than seeking perfection (which you will never achieve) in them.

Don't buy a collet chuck to make the runout go away - most turned parts are produced in either a 3 or 4 jaw chuck with only a few specialist jobs needing a collet chuck. I have all three - but 75% of jobs are done in the three jaw. 20% are maybe done in the 4-Jaw. A few are done on the face plate. Doesn't leave a lot of jobs that NEED a collet chuck.

I'm definitely with Jim and Hopper on this one.

A more important check might be to see if it is actually turning parallel, rather than taper and work on reducing any taper. This is easy to do - just stick 100mm of 25mm steel bar in the chuck and take a light skim over it's length and see it the start and end diameters are the same. If not - someone in the group who knows the ML10 better than me will advise next steps!

Happy New Year

Steve

My first lesson using a flycutter was that the typical ones sold on eBay don't have anywhere near enough rigidity or mass for anything only the lightest of work. I 'made' one one by bolting 25mm square bar (with a piece of 10mm silver steel as a cutter) to the 250mm face plate on my lathe and used that to face off some large chunks off ally. I don't think the finish would have been as good on the mill.

Regards

Steve

Pretty sure the old Field Marshall was a 12 bore sized cartridge...Dad had one for a short time, think it went for scrap!

Steve

Steve

Get a C3 and start turning! My critieria for my lathe was it had to be the heaviest I could find that would fit on the bench and be new Chinese. Makes perfectly good stuff. Mind you, I don't get tool room jobs from NASA that often

Crazy decision making criteria, but no regrets at all and it's done a quite few jobs now over the ten years I've had it.

Steve

I wouldn't buy a set to be honest. I do have a set and pretty much 95% of the time just use the flat No.2. I don't think I've ever used the rat tail. An exception is the CK branded needle files, I use most of them, though again, the round file doesn't get used much.

Steve

Bit of a tangent - when I was a kid 10 or 11, Grandad asked me if I had a testube I didn't want. I gave him one to make a level - he knocked a hole in the end of the tube and fastened it to a long length of hose pipe. By filling the pipe at one end until water appeared in the test tube he could establish a level over a long distance.

Steve

Years, but I get there in the end...

The very best work I've seen is about infinite patience and the worst was rushed. So long as you are enjoying the process, how long it takes doesn't really matter?

Steve

Oh well, I'd better ditch my '10ths' clock then...

One answer would be "Milling: A Complete Course", by Harold Hall. 10mm end mills would get you started quite nicely.

Steve

Cheers Marcus. I've been asked to make another one of these, so I'll work out the machining as above. I've seen a few single flute cutters around from China, but may stick to a decent slot drill. My mill is flat out at 2,000, so will have to make do at that too!

All done - next step is to see if it performs!. I ended up polishing the sides with the flat of a file, I still had some noticeable ripples in the walls. More practice is probably in order.

My technique is to machine out the cavity a little too deep than skim the top to size, so the bottom of the cavity is parallel to the top of the walls. I could machine a through slot, but I'd still be left with the key issue of getting a nice finish to the side walls and I'd have 16 holes to drill and tap rather than 8 and two lids to make! So all trade offs as ever.

Steve

Edited By Steve Withnell on 27/10/2017 18:58:14

Hi Murray,

I'm using stainless screws through the case into copper rods. It's all about skin effect so the stainless screw is literally a mechnical fixing and irrelevant to performance. The bottom of the copper rods, I chamfer towards the tapped hole so that the edges bite into the aluminium. Instead of conductive grease, I'm using gold leaf as a gasket to ensure a good seal. This is the other reason for needing a nice flat finish to the walls of the case.

Interdigital Digita Filters - I've made a few at 1.3GHz and this is the first I've attempted for 3.4GHz. I thought with less metal to remove it would be easier, but I've also a lot less 'elbow room' with this one. I shall break out some turps! (I've been working with Parafin and Neatcut, but the Neatcut ends up in sticky mess).

Thanks Andrew.

I keep avoiding sending Ketan a wedge for a KX1, which would be ideal for this application The 22mm is not critical because the resonators are tunable. The depth of the case affects the impedance and bandwidth of the filter (etc). The cleaner the finish the better the overall performance.

I've milled a cavity in some Aluminium plate 22mm wide x 56mm long and 15mm deep. The corner radius is 2mm. I need to take a couple of finishing cuts, whats the best technique to get very best finish? Clue - 22mm is a quarter wavelength

I've obviously got a long series 4mm cutter, which is a standard helix carbide type and the only other cutter I have is a 5mm high helix version (which would obviously leave a bit of cleaning up for the corner radius. The depth of the cavity is the critical dimension.

Steve

Absolutely gutted by this very sad loss.

I first came across John probably over ten years on uk.rec.me The group was being plagued by a disruptive troll and had been for some time. John decided enough was enough, posted the troll's real name, full home address and telephone number and signed off the post with a John type challenge. End of troll. How he tracked the guy down I never found out.

I only met John once, at Harrogate quite a few years ago now.

Despite that, his 'fingerprints' are all over my workshop.

My variable speed chinese lathe now has two ratio's - thanks to John
My Stuart Victoria uses bevel gears to drive the governor - parallel depth method, explained freely by John
I have a digital caliper on the bench, with the lower jaw ground away to make an 'odd legs' pair - bodge by John
The liner on my Nemett - my first model - rescued on the final cuts by John explaining sharp HSS, low speed...
Then of course the 'cat's cradle' for holding odd shaped bits in the lathe.
Almost forgot - I use Sharpie Magnum black markers for marking out, rather than engineers marking out fluid.

There will be more - this just the stuff 'at hand' so he is all over my workshop and that's true of so many of us.

John to me was THE stand out guy.

Condolences and deepest sympathy to his family and friends - if we miss him, imagine what it must be like for his loved ones.

Steve

If the 'old iron' has an issue - worn bed, shot headstock bearings - can you diagnose and fix? Chinese PCB pops under warranty you get a new one.

I've got one of those 'horrible' chinese lathes from 10 years back and I have no intent of swapping it out for some 'old iron'. I have considered swapping out for a WM-280, the work that Jason (and others) produce on the WM series is really good, so I don't see the merit in old iron for newcomers at all. When I got into this hobby around 10 years ago, I had the advantage of having some access to a time served turner with 60 years under his belt, half of which spent running his own jobbing shop. His view was to get a chinese machine and that I'd be a muppet to buy a Myford. Did I have to do a bit of 'fettling' yes I did - but I learned a lot about the lathe in the process. I've got the lathe to the point where I can wind valve springs on it (Nemett IC engine) and I have produced the crank for the Whittle V8. So I have no trouble recommending Sieg lathes.

The debate gets confused - it's not about is one lathe better than another, the question is in three parts in my opinion (just like arseholes, everyone has one, but mine has been thoroughly inspected).

1. Will you enjoy using the machine?

2. Will it make the parts you want to make?

3. What's it going to cost to buy and maintain?

In my case, with my old chinese iron, the answer to the first two is yes and to the third, at the time a lot less than a secondhand Myford. Further, a couple of years ago, I pointed an old friend (he is now approaching 80) at Arc's Sieg lathes, he wrote to say he is delighted with the after sales service and the machine, having built a twin cylinder steam engine. Another friend bought some old British iron, and he is struggling to make washers (no joke) on it. It was a fantastic machine once (power feed on both axes, clutch, gearbox, gap bed etc). I wouldn't want that as my first challenge as a newcomer.

In summary, for newcomers to the hobby I'd be looking to either Warco or a Sieg machine from Arc.

From the length of this reply, you can tell it's too bloody cold and damp to go in the shed...

Best regards

Steve