The Workshop Progress thread 2018

With the delivery and installation of the Sieg SC4-510 lathe and the SX2.7 Hi Torque Mill the workshop tooling is mostly complete. I am just tidying up a bit and getting things sorted out so here is a quick tour round

Plumbing done on the Rocking Valve engine:

And, hopefully, a bit of video of the first run:

https://youtu.be/wc0bhx2L9lo

Jim

Edited By Jim Nic on 06/06/2018 17:05:52

Edited By JasonB on 06/06/2018 17:07:21

Looks good, I've not done an engine with a rocking valve but do have one drawn up ready to make.

Thanks for sorting out the link Jason.

The engine was straightforward to make and the valve operation was simple to work out as I could see it through the air inlet. The only puzzle for me was when I came to the first run, it didn't. The air just leaked right through the engine and out of the exhaust. After a bit of head scratching I fixed it by fitting the piston O ring which I had left off for the trial run.

Jim

Nice work Jim, an interesting design.

Yes, agree with Neil. Really nice work, caught my eye this engine, unusual. Well done Jim.

Long, boring ramble about a couple of week's shed time. ->

I've got a job that the plasma cutter function of the welder would be handy for but...

The first time I used the plasma cutter thingy on the welding set the fumes blocked up the filters on the shed's computer cupboard and A/C-heater (lungs, what lungs). Made a better filter for the computer cupboard, but wanted something to get the crud out of the shed's air. My old dust extractor vibrated so much that it had worn through the casing of the motor's run capacitor and blown it up along with some of the motor's wires.

I have some 2hp 3ph flange mount motors that I'd been given, so turned down the shaft of one and put a new keyseat in it, fitted it to the dust extractor where the clapped out 1/2 hp single phase motor had gone and got a VFD for it. It doesn't need 2hp, but I have some ideas for variable speed where a howling gale isn't needed.

Wired it all up and tried it out. Then came across the balance problem that had eaten the original motor. Hmm, it needs balancing...

Made a four wheel, single plane, static balancing rig. Tested it by balancing all my surface grinder wheels and then went on to the dust extractor's fan. Worked out where to TIG weld a washer onto the fan to balance it, then discovered that the little plastic lever that works the TIG welder's torch switch has gone walkies. Came in at that point tonight. I'll mill a replacement out of a bit of ally tomorrow.

Curiously, a grinding wheel that had been giving less than perfect surface finish turned out to have a lousy balance, whereas one that had produced good results appeared to have been close to perfectly balanced.

Balancer with grinding wheel:-

Balancer with fan and balance-weight washer:-

Following the advice of Graham Corry I turned up a new hot tube for the Robinson X-Type with a smaller outside diameter, in this case 7/32" rather than the previous 1/4" from a bit of 303 Stainless and drilled an 1/8" hole up it 2.25" long. Seems to have done the trick as the tube now glows red with just the small burner and does not need additional heating. Can't show a nice finish on it as the heat nucked that up.

Well done that man...

George.

Time for a scale model rock crusher (Blackpool rock??) or chaff cutter. etc.

The workshop gods smiled on me today! I'd just cut off a bit of aluminium stock on the bandsaw and was deburring it in the vice prior to milling a replacement TIG torch switch lever. I was thinking to myself that, once I'd spent a couple of hours making the replacement, that the original was bound to turn up. That's when I looked down by the side of the vice...

Welded 'balance weight' washer on to dust extractor fan and put it all back together again. Ran the VFD up from 0 to a bit over 3000 rpm and there was no significant vibration. .

Time to do some retail therapy and sort out ductwork.

Oh No, the X-type was commonly know as the "chippy" engine as Robinsons supplied a lot to the catering industry, this engine would most likely have been seen driving a chip chopper down the local chippy as shown here

I guess that these days, it'd be run from bio diesel made from the frying oil. Did dripping work as a fuel for a full size hot-tube engine? Expired minds want to know...

Just for all you doubters who think I never make anything - I've been in the workshop, working as fast as Jason all weekend!

I finally finished all the parts for my Crayford focuser, although it still needs come fine tuning and a bit of cosmetic finishing. The scary bit is going to be anodising it.

Hi,

I can see why it's called a 'hot tube' engine, but what doeas the hot tube do, heat water, expand air?

Thanks,

Ian

Think of the hot tube as a spark plug.

The tube fits into a cavity that has a small passage leading to the top of the cylinder, as the gas/air mixture is compressed by the piston it reaches a point where it will ignite, the compression also pushes some of heh gas/air mix up into the hot tube where the red hot tube will iginite it in much the same way that a spark plug does in a modern engine.

Nice Crayford Neil, shame John Wall isn't around to see it.

That looks a fine piece of engineering Neil, congratulations

Alan

That's nice work Neil

Thanks Jason, now I get it.

Very nice Neil, shame it doesn't use steam but hey other than that it looks very well made.