|Nigel Graham 2||22/06/2022 23:50:19|
|2287 forum posts|
Why the You-tube video cited below appeared as it did on a forum dedicated to caving not engineering, when it has nowt to do with caving and all to do with engineering, I have no idea; but this is the link I was sent by a friend who found it there..... I don't how to cite the video directly.
With its huge flywheel (which looks like the business-end of an old chaff-cutter) and its spidery motion-work everywhere, it evokes Blenkinsop and Trevithik. I can't work out though if the reverser works through the valve-gear or the transmission.
I like the built-up wheels. I thought they were ex-quarry tramway items until the builder's remark about them, and a close-up that shows the welds.
I hope he's joking when he appears to suggest if the air-bottle, noticeably lacking a pressure-regulator, can be charged to 3000psi, then....
|Jon Lawes||23/06/2022 05:05:05|
995 forum posts
Could it be this one? The forum is blocked on my computer.
Edited By Jon Lawes on 23/06/2022 05:05:18
|Speedy Builder5||23/06/2022 06:33:37|
|2653 forum posts|
Could be this guy ?
23070 forum posts
Reverser must be through the transmission as the flywheel keeps turning in the same direction. Looks like it tightens one of two belts depending if you push or pull the lever.
Edited By JasonB on 23/06/2022 07:00:34
|589 forum posts|
Reversing seems to be by tensioning either a straight or twisted belt onto a ?countershaft..
Jason beat me to it, JB delete the spare one if you like.. and the one with the redundant comments on reversing
Edited By DiogenesII on 23/06/2022 07:04:26
Edited By DiogenesII on 23/06/2022 07:07:03
|David Jupp||23/06/2022 07:50:37|
|838 forum posts|
Nigel, 3000 psi sounds reasonable for an air bottle, 207 bar. Some diving air bottles are rated for 300 bar.
23070 forum posts
It's not the bottle, it's some of those welds on the inlets to the cylinders that may see the full 3000psi with no regulator. I know the limits of my welding. That's if the perished hoses don't let go first.
Edited By JasonB on 23/06/2022 08:14:13
|David Jupp||23/06/2022 09:25:01|
|838 forum posts|
Yeah - or the lack of clips on some of the hose attachments. I think I spotted 2MPa on the hose (20bar) - which would have been its rating before it perished.
|Mark Rand||23/06/2022 10:22:50|
|1314 forum posts|
While we're nitpicking, It would have been so much simpler and more elegant to have made slip eccentrics as used on some gauge 0 locos than the belt reverser.
|Mr C||23/06/2022 21:54:57|
|7 forum posts|
He has no idea about how railways work and seems to like to reinvent the wheel rather than looking at what is out there. He has a clever way of making wheels but the flanges look like a bigger version of course scale 0 Gauge flanges. He measures the gauge from the tread rather than back to back. Some of his other contraptions are a H&S nightmare as well. His wood chopper is just plain scary as to his flash steam boiler using butane gas cylinders as floats, he was surprised when it exploded.
Some of the vidoes on his other channel about his small holding and animals are nice and he does live somewhere near Bantry Bay, lucky man.
|Nigel Graham 2||24/06/2022 00:09:52|
|2287 forum posts|
I wouldn't be quite that dismissive.
His rails are badly-proportioned but the point-blade briefly shown appears correctly to be ribbed for stiffness. There is of course nothing wrong with bar rail, but his rails are disproportionally tall and narrow.
Also the loading-ramp angles should be web-down to give a decent load bearing area and better load-bearing - but I have seen the same mistake in photos of some club tracks' steaming-bays.
My comment about working pressure was not whether the cylinder would take 3000psi but whether the machinery would, especially with no pressure-regulator.
Regarding wheel dimensions and flange appearance, they hardly matter. It works on his railway, of whatever gauge he's made it, and there is nothing in the video to suggest he's planning to run his loco and rolling-stock anywhere else.
Although the locomotive is mechanically more Heath-Robinson and Emmett than Churchward and Stanier, and more complicated than necessary, the steel-fabricating looks good. Certainly far better welding than I can manage!
|Peter Krogh||24/06/2022 03:34:22|
223 forum posts
I really like to see someone cut loose and just build right out of their brain. Outstanding fellow! Just do it....
6694 forum posts
She'd be a low flyer at 3,000psi! Luckily, he says he is only charging it with his normal 100psi workshop compressor. Quite intrigued by the axles made from square pipe. Reinventing the wheel ?
|noel shelley||24/06/2022 10:15:04|
|1445 forum posts|
A truely marvellous machine ! Cross coupled with a single closed centre spool valve and double acting cylinders would have doubled the power ( for the pedants - almost !), but the lack of adhesion may be a problem. That some of the welding is not of the highest quality doesn't matter - IT WORKS ! 10 out of 10 ! Noel
|Nicholas Farr||24/06/2022 11:53:45|
3421 forum posts
Hi, apart from anything else, the one thing I would really have a concern about, is that hose that runs from one end to the other with the supply coming from the cylinder connected to it. This is just hanging in mid air and if by some misfortune, any of the connecting points blew apart or the hose snapped off, you would have a hose flying about like an uncontrollable whip, even at 30 psi, let alone 100 psi, which could cause severe injury or even be fatal if the end should hit anyone and more especially if it had part of a fitting on the end of it. One of the most important safety aspects that was stated in my pneumatic courses that I did, was that flexible hoses and pipelines should be adequately secured to framework or on properly designed trays, in the event of them coming apart and releasing compressed air. It's bad enough even when a short length is whipping about under pressure.
23070 forum posts
Noel, how do you make it double acting?
To me the connections are at one end of the cylinder so piston only sees air pressure on one side.
Can't see your single valve either as there are two valves per cylinder one is the inlet that feeds to one end extending the ram and the other the exhaust that allows the air out of the same end of the cylinder as the ram is pushed back by the opposing cylinder x 2 for the other cylinder
And Cross coupled usually has two cranks at opposite ends of a crankshaft, this is more of a horizontally opposed layout.
Edited By JasonB on 24/06/2022 12:07:33
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