Here is a list of all the postings mick H has made in our forums. Click on a thread name to jump to the thread.
|Thread: Boiler certification in a launch|
|Thread: pneumatic fittings|
Thank you Dave. That is the sort of information that I need. I am quite happy about the push fit seal but possible degradation of the body is an obvious concern. I have been told that all metal versions are available which should solve that problem and I hope to discover where I can get them tomorrow. The link that you posted is a really useful one.
Edited By mick H on 05/11/2018 20:19:16
I have managed to establish that these things are not manufactured in UK but I have a couple of contact leads to pursue in the morning.
Thank you for your interest David. The vapour pressure of butane at 25 degC is only about 35psi. The controller is rated at 10 bar so there is a pretty significant safety margin.
I have had a look at the Ebay item you mentioned but that is for a full scale appliance. What I need are gas controls for small scale .....typically 10mm to the foot ....locomotives, traction engines etc. My current build is a launch with a steam/gas propulsion system. Cost is not a problem but because miniature gas controls are not generally available I invariably have to design and make my own. The controllers that I am referring to are far superior in control terms to anything that I have been able to make in the past.
Jason.....yes spot on (and a better photograph than mine). They do offer very good control as you say and seem to be very well made. The body of the controller is nylon. I seem to recall reading somewhere that the reason that some controllers fail is because of the molecular size of the substance that is to be controlled ie the smaller molecules squeeze past, but LPG gases are generally, I believe, heavier than say Helium and I don't think that this would be relevant here.
Edited By mick H on 05/11/2018 16:12:56
Hallo Martin. I take your point but a gas leak from any fitting will be equally not detectable. It will still go bang (under the right conditions) whichever (faulty) fitting I use.
Photo of the flow control on way.
I have used 4mm pneumatic push fittings for loco plumbing for a while now and find them to be cheap, reliable, unobtrusive and easy to connect/disconnect. Typical specs are up to 60 deg.C use and 10 Bar pressure and for use with water, oil and air. There is a really neat little flow controller in the range that I would like to use as a butane gas controller but I cannot find out whether it is suitable for LPG. The suppliers are very cagey about recommending them for this use and I don't blame them for not committing themselves to something not specifically mentioned by the manufacturers. But, I am also aware that things can be used quite safely for purposes not specifically recommended eg if water is OK, what about beer?
My experiments so far have been quite satisfactory but are there any experts out there with a point of view?
|Thread: O ring/piston fit|
I am refurbishing a twin cylinder marine engine with 5/8" pistons fitted with O rings. One of the pistons glides down the bore in an smooth and easy manner. The other piston requires more pressure to push it down. I assume that it is most desirable to have equal resistance in both cylinders for best performance. I thought that I might "measure" the force required to send the "easy" piston down the bore by applying weights. Then I could possibly adjust the O ring groove depth on the second piston until the same amount of weight sends it on its way.
As a master of indecision, I then thought....."perhaps the "easy" piston is too easy and the stiffer piston is correct ?" In other words tighten up the "easy" piston ring.
Just how much force is optimal. Any ideas please.
|Thread: Junior Hacksaw Blades|
I always used Eclipse blades because of their superiority but found that my supplier had sold out and could only offer me another make.....Bahco, made in Germany. It is sad to say and with great regret that I have to admit that the Bahco blades are imho better than the Eclipse by a good margin.
|Thread: D bits|
Thanks Brian. I shall try one out on a vertical boiler I am building.
That O ring check valve looks interesting. Is the O ring mounted on a spring loaded plunger?
|Thread: ME Vertical Boiler & Hand Pump|
Thanks Phil. Thanks also for the Searchable Index- very good.
Was there a previous series on a vertical boiler published in ME some time ago? I seem to remember seeing it in one of my bound volumes. I have started to plough through them but there is so much material I have given up.
|Thread: Moped Restoration -NSU Quickly/Chinese scooter- constant rebuilds|
I had an NSU in the late fifties and hated it. It was so "uncool" but it was needs must at the time. I would love to get my hands on one now though and I think it would now classify as "supercool". So well made and reliable although as I recall I was very prone to punctures as I couldn't afford decent inner tubes. The spark plug needed regular dewhiskering and having dewhiskered on one occasion I loosely screwed the plug into the cylinder head and forgot to tighten it up. Believe it or not the engine started with only about two of the threads engaged....a bit rough, but it started. Amazing. Saw one in the ring at the Carrington Steam Rally this year, going like the clappers with the blue smoke coming out of the exhaust.
|Thread: Self starting small steam engines|
At the risk of boring the forum to death on this subject, I have had some further thoughts overnight (dangerous territory). I intend to make a boiler feed pump which will be actuated by a drop link from the rotary valve at the flywheel end of things. The pump will obviously be a load on the engine especially at the beginning of the delivery stroke. If the links were adjusted appropriately would this provide the necessary "brake" to stop the engine at the required place? Is there a method of calculating this or is it a trial and error exercise? As ever, your thoughts are valued.
What are you intending the engine for Ed?
Thanks Jason / Bazyle, That sounds good. Gauging the depth of the recess will obviously be the subject of trial and error. I was wondering about the inevitable "click, click, click...." as the plunger engages the recess but a plunger with a teflon tip might solve that problem. You never know, this could become an essential add-on for non-selfstarting engines. Thanks for the assistance everybody but any other suggestions still welcome.
I have been playing with it this morning and I have found that I can get 100% self starting on very little air (5-10psi) if I position No.1 cylinder at approximately 45 deg. after tdc. I can find no other position which will give me repeatable results. Perhaps a small cam....such as a round headed rivet....on the flywheel circumference with a light spring loaded plunger playing on the flywheel circumference might encourage it to stop in the required position. Would this be the basis of the idea that Bazyle refers to? Experiments continue.
This is the engine. How would your cam/spring idea work Bazyle?
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