uuu
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Post by uuu on Nov 12, 2023 8:49:27 GMT
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uuu
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Post by uuu on Nov 5, 2023 14:45:34 GMT
Two cylinder draincocks plus one valvechest = 3. Times three cylinders = 9?
Wilf
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uuu
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Post by uuu on Oct 29, 2023 8:02:19 GMT
Next time, you could try towing it backwards - is there an argument to say that will apply wear to the surfaces more used in forward running on steam?
Wilf
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uuu
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Post by uuu on Oct 23, 2023 7:45:22 GMT
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uuu
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Post by uuu on Oct 20, 2023 13:00:22 GMT
I seemed to get in OK, but a lot of the top and/or bottom of the screen was occupied with fixed information, leaving uncomfortably little working area in the middle.
Wilf
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Post by uuu on Oct 19, 2023 7:24:07 GMT
...I thought the purpose of the rolling road was to put some braking effect on the wheels to show that the locomotive has the ability to travel under it's own steam. This is not fully representative but would show if piston blowby is significant. Brian This is not a feature of the commercial units I bought, nor of the homemade ones I've seen. We've mostly used the rolling road to check things like valve events, function of axle pump, listen for odd knocks etc. To add a bit of load, if needed, we've part-applied the loco brakes. Wilf
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Post by uuu on Oct 18, 2023 16:11:53 GMT
Yes - they pick up a lot more energy from radiation within the firebox than absorbing it from the flue gases in the tubes. So for maximum effect, have them go almost to the back.
That will have some consequences: with higher temperature steam, the o-rings and other degradable components downwind of the flow will need to be rated accordingly. You'd also need to ensure your lubrication is OK - not that you need to use the almost-solid gloop, just be aware.
And shortening them later is easier than stretching them! Not that you'll need to.
Wilf
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Post by uuu on Oct 17, 2023 14:48:04 GMT
If your loco is an 0-4-0, you could make a giant hamster wheel, and resolve all these issues.
Wilf
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Post by uuu on Oct 17, 2023 11:12:36 GMT
I've not noticed this. But I could think of two other reasons that a loco might run less sweetly on rollers, than on the track:
If the coupling rods and bearings have slop in them, the coupled axles might fight a bit, alternately being behind, and in time with the driven axle. Having linked supports, as suggested by SteveW, might help here.
On the track, the inertia of the moving loco will have a smoothing effect, like a flywheel on a stationery engine. With any load you're pulling adding to this. You only have the wheels and rods to damp any unevenness when running propped up.
Wilf
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uuu
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Post by uuu on Oct 16, 2023 18:09:58 GMT
Here's some chuck fitting instructions from Lathes.co.ukWilf
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Post by uuu on Oct 15, 2023 19:17:57 GMT
I like Simply Bearings. They have a full choice, budget and premium, and they deliver free for orders over £5. Wilf
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uuu
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Post by uuu on Oct 15, 2023 8:56:44 GMT
I got mine from CMD: WebsiteThey do all gauges, I suspect with the same bearings. Fabulously overengineered and chunky. Mine are 6203RS, 40x17x12mm (ODxIDxW) Wilf
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Post by uuu on Oct 15, 2023 8:09:05 GMT
Ancient civilisations knew how to make things last. Pottery - that's the stuff. Dig a hole anywhere in the UK and what do you find? Pottery. It's indestructible. There should be international treaties banning it, as it pollutes every square inch of our sacred soil. Plastic - it'll never last - pottery is what you want.
Wilf
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Post by uuu on Oct 14, 2023 16:19:39 GMT
Looks really good.
Wilf
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Post by uuu on Oct 14, 2023 15:24:46 GMT
John and I have finally finished tinkering with the lathe up at the club. It’s an old Warco: its owner had lost patience with it and got a Myford Seven instead.
It’s quite nice to use initially – chunky, and the saddle, cross-slide, top slide and tailstock all move smoothly. The graduations on the handwheels are clear, and in sensible units (unlike some that I’ve seen). So turning on it is pleasant. It had been fitted with a three-phase motor by the original owner, and he just used the speed control on the inverter – he’d given up with changing the belts.
But there were one or two bits we wanted to improve. So I re-did the switchgear, putting in a push-button start and stop, and arranging things so it would not restart unexpectedly. I also rewired to separate low and high voltage cables.
We’d not been happy with low speed torque for screwcutting, so we wanted to reinstate the low ranges of the belt drive. Dear me, it’s a horrible system. There’s an intermediate pulley between the motor and spindle – for low speeds a belt in one position runs motor to intermediate, and another with three positions from intermediate to spindle. So you just need to move the top belt to change speed. Which means slacking off the intermediate pulley – with a spanner, around the back of the lathe – so pull it away from the wall first. Ah – but that pulley won’t move up as it’s restrained by the lower belt. So a different spanner needed to loosen off the motor. Lift motor, lift intermediate pulley, change belt, pull intermediate down, adjust tension and tighten, pull motor down, adjust tension and tighten, different spanner. Job done. Repeat when finished to re-instate the previous speed range.
We did a bit of fettling while we were at it – enlarging the hole where the motor poked through, because it didn’t really swing far enough. And bunging up stray holes where swarf could enter the belt casing.
Of course, if you’re screwcutting, you need to arrange the changewheels. Dear me, it’s a horrible system. They’re held on the shaft with circlips – and not the sort with two little holes for pliers – they’re the plain type you lever off, so they go ping and you lose them. The wheels are quite thin, and the whole assembly is in the side cabinet – so not as easy to get at as with an all-around hinge-off cover. Still, my rewiring did clear a bit more space around the wheels so they’re more accessible than they were.
We did wonder why the centring of the chick was so far off. It didn’t take long to realise why. Dear me, it’s a horrible system. Instead of a threaded spindle nose, or a taper mount, there’s what is effectively a permanently mounted chuck backplate forming the end of the spindle. So the back of each chuck is naked, as if to be fitted with a backplate. But, where each backplate register on a normal system would be turned and precision fitted to each chuck, this one is loose. So you mount the chuck, with three horrid little screws, then tap it into truth as best you can.
The lever that engages feed for self-act or screwcutting was stuck. Dear me, it’s not a horrible system. The lever moves a sliding gear on a layshaft in the headstock. It was gummed up with grease, that’s all. Perhaps original transit grease? Not that it’s feasible to disassemble it, without first removing the spindle. So we freed it off well enough, and it works quite smoothly now. On one side the gears engage fully, on the other not really, but enough to get by. There seems to be too much end-float, but we can’t see a way of adjusting it, without a full strip down.
We did get help as we were working from a club member who has a similar machine at home – and is happy with his. But I’m glad it’s not my lathe.
Wilf
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uuu
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Post by uuu on Oct 13, 2023 12:11:46 GMT
Perhaps, once you've got the leadscrew running smoothly, you could tighten the gibs a little, so more force is required to knock it off a set position.
Wilf
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Post by uuu on Oct 9, 2023 14:57:32 GMT
I thought there was a wavy washer between the dial and the ball handle, that provides enough friction to keep the dial in position. Could you add a similar thing under the adjustment nut which, when done up to be completely flat would add tension, without any extra backlash?
Wilf
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Post by uuu on Oct 6, 2023 13:11:24 GMT
33 and 34 gears are useful for adapting an imperial gearbox to do metric threads - a much easier alternative to the fiddly-to-fit conversion set.
Wilf
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Post by uuu on Sept 25, 2023 13:48:06 GMT
I'm sure the late (and latterly much derided) LBSC will have had words of wisdom on the subject of clearances in water gauges, I just can't recall them, other than not to make the clearance hole in the nut so large that the rubber seal squeezed out. I've looked up in "Shop Shed and Road". LBSC's fittings are drilled No.12 for 3/16" glass. So that's a nominal 0.1890" hole for a 0.1875" tube. So hardly any clearance at all. Hmmm. That's for the top fitting. The bottom is described as having a 3/16" hole drilled part way in - so no clearance at all. The clamping nuts "need no special description", so the holes in them are not dimensioned. Wilf
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Post by uuu on Sept 17, 2023 12:04:17 GMT
A PW is a Percy William. He starts off quite thin (say 150 lbs), then gets fatter as he ages (perhaps up to 220 lbs).
Wilf
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