Member postings for Martin Johnson 1

I tried a toroidal "Media light" from home bargains, about 180mm OD on the mill. Quite good, but maybe a bit too large. Cheap though.

Martin

Try machining it before you weigh it in. EN58 can be quite variable ranging from unmachinium to whats all the fuss about. Drilling will probably show up any problems. Sharp drill, slow revs (less than 1/2 mild steel) and keep feeding.

Martin

We have run ASHP for 7years now. Through a program of window replacement, upgrading lofT insulation and the heat pump, we eliminated a £1000 annual LPG bill without increasing the leccy bill. The house has never been warmer. We live near Inverness about 240m ASL.

Yes, get as much radiator surface as possible, this lets you run the HP more efficiently at lower temperature. Run it 24/7 for the same reason. You will need a larger pressurised hot water cylinder and possibly a buffer tank. Run it on economy 7 if you can get that tariff - we were told opposite, but have proved eco 7 is best.

Ours works fine down to -20. Ignore the BS about not working below freezing. There is a region around zero where the defrost load increases and COP drops, but it all works fine.

Why would you want water hot enough to scald yourself? Especially when you pay handsomely for the privilege. Derrrr!

Martin

Thanks for taking the time to post the photo. Everything clear now! Very nice design, well executed.

Martin

I had trouble with valves blowing through on my RR. It was the cross piece that drives the valves being slightly cock eyed and too good a fit in the valve. That made the valves sit cock eyed lifting one end off the port face. Make sure the valve is a free sliding fit on the cross piece and that the valve can sit flat on the face. I hope that is clear. Good luck,

Martin

It was the return part of the "shaft" feature that had me foxed. It looks like quite a reach if you are machining that in steps.

Martin

How did you machine the profile of the clamp base?

Martin

As pointed out by others a DRO cannot perform miracles, but it comes close.

I fitted my well abused 1947 Tom Senior out 15 years ago with a Chinese glass scale 3 axis job. The reason - I had a crankcase casting to machine which cost well over 2 DROs. One slip up with counting turns, scribbling on dials, going past and coming back for the backlash etc would be expensive. I was taught that way, but I wouldn't go back.

I can now delight in picking off pitch circles, cutting radii by numbers, making parts years apart and knowing that all the bolt holes will line up. It saves a lot of time and faffing about.

Martin

Edited By Martin Johnson 1 on 24/09/2023 16:29:11

Paul beat me to it. There was a recent article on the maths of insulating small pipes by Mike Tilby in ME. It proves what Paul describes.

I hope in amongst all this chatter the OP has had a great time steaming Grandad's handiwork.

Martin

Edited By Martin Johnson 1 on 22/09/2023 13:03:57

Paul makes some very balanced points.

My objection is that we are told to treat this boiler like unexploded ordnance. I base my personal risk assessment on historic data. The fact is I cannot recall a total instantaneous failure of a model boiler (I have been jn the game 55 years now, including full size steam excursions). The worst probable outcome is actually a major leak and anybody near gets out of the way. No life changing injuries, no deaths, minor scald possibly.

The one exception would be a device without a safety valve, for which I stated some concern and provided a workable suggestion for finding out and conducting a crude hydraulic test.

Bob, why on earth is lagging the pipes "a must"?

Get real please, gentlemen.

M Johnson

B.Tech (Mech.Eng), Retired C.Eng, F.I. Mech. E

I used the waste strips that separate layers in stacked wood for lagging my Burrell running at 160 psi. No preservative except a lot of stray oil. It was inspected at 10 years, did another 6 and is retired for the time being for other reasons. Full size road engines use common pine next to the boiler.

As an alternative, my latest creation uses flanged up ally crinolines. It would avoid glue issues as noted by others. Soft ally sheet is dead easy to flange, you could even try a bit of spinning.

Martin

This forum would be quite good if it wasn't for the Worshipful Company of H&S Inspectors and Chronic Over Thinkers.

Martin

I am a bit concerned that I cant see a safety valve on the boiler. I am also concerned by the talk of "widow makers".

Proposed course of action:

Fill boiler & tank with water. Use the handpump to pressurise the boiler. Bleed any air out through the whistle, then pump up to 100 psi on the gauge. If there is a safety valve, you will know from the water coming out when under pressure. Ideally you would then remove the safety valve, put in a blank plug and pressurise to 120 psi, hold it there for 10 mins and check there are no problems.

You would then be safe to steam it up at pressure up to 60 psi. If there is no safety valve, do not steam it.

Better still, find a friendly club and join it. Let us know where you are and I am sure you will make contact with someone on here.

Martin

I dont quite understand how the diameter of your test bars vary with position in a similar pattern, which would have me checking everything about my method.

That aside, your conclusion about a banana shaped bed looks correct. The next step would be to blue up the saddle and see what emerges on the bed and vice versa. It could be something as stupid as a dent in bed or saddle.

Good luck,

Martin

There is a Kerry owners group on IO groups. You would be welcome.

Martin

A confirmed 4 way toolpost diehard.

Riddles put a lot of effort into making controls easy to handle on the Standards. Whether the art had been christened "Ergonomics" by then, I don't know.

Martin

Glad to be of service, Ian. I have not yet tried restricting the exhaust, but I read that you can explore really slow running with it. Thats a bit tricky to arrange a control in the cab!

Martin

Ian,

I have built my variation on the Southworth and run it this season on my steam lorry at 160 psi. A few bits of experience I have gleaned:

• Include a bypass in the pump delivery line. That way you can get it warmed up on "no load". Makes life a lot easier.
• Mine is run on highly superheated steam (300 C+), so relies totally on the mechanical lubrictor. I had to adjust the Ewins element on this up to max delivery and put a fan tail spray on the oil delivery. Initially, the internals were dry after a run (too little oil), and what oil there was all seemed to disappear out of the valve rod gland - hence the need to "spray" the oil in.
• I have included 3 auto drain cocks (1 on a longish feed line, 1 on each end of cylinder). The free ball in a chamber type that are quite popular on smaller loco cylinders. I am not convinced they do much but they do no harm either. Incidentally, they don't really need drain cocks. They will run quite happily on pressurised water, which is what they do to get rid of condensate - they can only do this slowly though. The water will end up in your hot well, not the bilge.
• I always run the pump on air after a steam run, as my cylinder block is cast iron (as were Weir's). This blows out the condensate and gets plenty of oil in.
• Being cast iron, the shuttle valve still has a tendency to stick, so I have put two little plugs on the caps at each end. Remove the plugs, poke in two small screwdrivers and waggle the shuttle about a bit, replace plugs, open to steam and away you go.

The pump will run very evenly on air against no load (just like KA's example). On steam, even when warmed up it takes a few strokes to get into it's stride when you open the steam valve, but once properly warmed through is OK, but never as even as on air. I think this problem is likely to be more marked for you as a boat is unlikely to be running the superheat that I have.

An ex engineer on the Waverley tells me that they can be temperamental in full size. He recommends opening the steam supply valve when you light the fire and just let the pump warm up with the boiler, you will soon know when the pump is running from the "clonk - clonk". I have tried this approach and it certainly has some merit.

My modifications to the design were driven by two thoughts:

• As drawn it is a symphony of leaks conducted by 6BA bolts. It needs to be far more rugged to be a reliable boiler feed on boats (or steam lorries). If you think I am fishing for 6BA bolts in a filthy bilge or roadside verge - think again!
• As drawn it is not a Weir. The Weir was distingushed by the horizontal shuttle that incorporated a piston valve and distinct absence of extra ports and drillings.
• A bronze cylinder, piston and shuttle is not going to take kindly to highly superheated steam.

You can see more detail about the pump on my Flickr pages of the steam lorry build here:

**LINK**

The Weir pump album is 2 row 3rd from left.

Hope that helps, PM me to compare notes if you wish.

Martin

I do not understand how this thread relates to the OP. That aside, there was such a device in (I think), CR Macintosh Hillhouse at Helensburgh. That seemed to run forever powered by the breeze. As long as you could time the impulse an electromagnet would provide the energy to sustain operation.

Fascinating things to watch. Are there published designs around?

Martin

Beware the pipe bender on 10 mm or 3/8 pipe. The bending radius is very tight and you are likely to get crinkling.

Martin