Forum whore
One of my carburetored Gyro's flew over Mt Taranaki a few years ago, I think approx 10,000 feet ( Subaru based engine ).Originally Posted by WilDun
No, this LPG fueling is only for ground based use ( Heat Ranger ), I'm only testing it on my gyro engine because the other two engines weren't ready. Now we have one up and running and the second in a few days I need not bother with LPG on my gyro again, back to petrol and pre mix!
Muddler/Dabbler.
I have now changed the gas jet back to a 1mm and may drill one out to 1.1mm (if I can get a drill) - very small increments on jet size seem to make huge differences, hope to try it out when, or if the weather settles down, perhaps today??
I have MIG tips in 0.6, 0.9, 1.0 and 1.2 sizes, these are very cheap and handy with 6mm threads.
Flettner,
A lot of people make mountains out of molehills but you do the opposite, you make molehills out of mountains!
Yes, I guess I could end up trying an oil fired setup, the only possible drawback for me might be the neighbours, however I haven't really tested them out yet, but I do want to remain onside with them (at least on g'day and friendly wave terms).
I'd say there would be some fumes/smoke with diesel (no unlimited supplies of alcohol like you have!). Also a gravity fed fuel system mightn't be feasible, I haven't got a Hiab or anything like that and I'm not allowed climb up ladders or use a "Gung Ho" attitude anymore! - used to do that and came off second best!
I can see that it is a very simple and effective system though.
I may have missed something somewhere, but does the name "heat ranger" apply to the engine, or some ground vehicle you are developing and is the gyrocopter engine basically the same design? (ie parallel twin with balance shaft).
Hardcore Biker
Willy,
I checked out our small portable furnace unit, see pics, and it has an inlet hole or, as you said, more correctly called a tuyere I think, of ุ90, the burner has an outside of ุ40 and the face of the burner is outside of the inlet face by 30. Seems to work on, and easy to light. Sounds like you are starving yours from air.
In one of the pics you can just see the compressor from a fridge. These make good vacuum pumps and we used this for degassing the melt in the small crucibles we used. Next time Ill put some windows in the bell that goes over the hot crucible to see if there are any bubbles actually coming to the surface of the melt.
Also your crucible holder. To me, I reckon that the handle you use with your right hand should be repositioned to be almost opposite from where it is. Just that you are trying to lift the crucible and its contents with this handle, yet you also have to exert a downward torque on the handle, making for a hard wrist action. My thoughts only though, just trying to look after you, yung fella!
"Success is the ability to go from one failure to another with no loss of enthusiasm.
Muddler/Dabbler.
I agree that it's probably starved of air judging by the orange flame coming out the top but I didn't have the choke fully open at the time and when I did open it fully, the thing tried to imitate a pulse jet ( a bit slower of course, maybe a 3 -5 second cycle).
I can muck around and try different jets, I can allow some air to enter around the the outside of the burner, or I can redesign the whole bloody thing, or .... finally, maybe I'll see reason and go Flettner's way!!
BTW, when you mention "the face" do you mean that the part of the burner that protrudes into the furnace?
So I'll tinker with it for a while and see if I can get it sorted (I see no real reason why I can't).
As for the crucible holder, I had to toss up between that position and the one you are advocating and I chose that one so I could put that ring on the top (only useful for lifting it out of the furnace more easily and is just tacked on for the moment), of course I do have to grip it further down for the actual pouring, it's quite possible that I'll do away with the whole handle altogether of course, (awkward either way) but I'll wait till I get better perspective on it with an actual melt and pour before redesigning it into a mark 2.
If I ever get a melt that is!
Muddler/Dabbler.
As it turned out, I did get a melt! -
This afternoon the weather wasn't bad and I had changed the jet back to 1mm, I decided to drag it all outside and give it a trial run, which looked like it was an improvement, got the gas pressure about right with a nice blue flame.
It looked like it needed more air even with the choke fully open and as I increased gas pressure it started that cycling again which could be stopped with lower gas pressure (but smaller flame) so then I started to fiddle with how far in the burner was set in the "tuyere" (ceramic tube) and as I already had it flush with the furnace end of the tube, I pulled it back out a little, then a little more till it was working very well and I was able to turn up the pressure a little more till it seemed very good.
At first I thought that it was because there was more air getting in past the burner tube but eventually I came to the conclusion that it was caused by the flare effect when the end of the burner tube was recessed to the correct depth into the ceramic tube.
I had a bit of an old bread & butter plate positioned on the wall of the furnace to prevent it being destroyed by the hot flame and that was almost white hot in less than 5 mins, so I thought I might try the crucible which was red hot in 5 minutes or so, then of course, it was "what the hell, let's try some ally as well", which I did and in about 20 mins total, voila! molten aluminium!!
Tried out my tongs which worked fine, poured it into some greensand and I had done my first successful pour! - just a blob in the sand really (no smoke at all). - think I'll cut down that inner handle with the ring to just a stump and that should be enough to give me a grip to turn it when pouring.
I now see that maybe holding the main handle underneath (with right hand) and swivelling my wrist "axially" that there would be better weight bearing and much more travel available from my wrist when pouring - good point Ken!
I do feel that I could possibly let everything just swivel in my right hand and use the left hand for turning - we'll see.
The burner theory here isn't really important right now, (if anyone has a theory I would be willing to listen though) - but it has all worked well for the moment and I'm happy!
Must say I didn't like the quality of the ally though, quite a coarse grain when broken, might've been high silicon, I dunno, but it doesn't really matter for this purpose.
Next melt, I'll try a pattern and mould, - should sleep well tonight though!
Thanks all you guys for your input.
L-Plate Rider
Good to hear it is working ok for you now, the next fun part is making some parts. My biggest problem is finding a reliable parting compound for green sand, have had no luck with talcum powder it works more like glue! the best results have been with graphite, but I don't want to use that with aluminium, it is a no no even to mark aircraft ally with a pencil, aparently causes electrolysis. I can see why Flettner uses sodium silicate bonded sand. Got a bunch of patterns ready to do a pour in the very near future.
regards Mike T.
Forum whore
You will post pictures for us?
Forum whore
Pictures of your steambike would be pretty interesting too, maybe Flettner could make a steam gyro
My neighbours diary says I have boundary issues
Muddler/Dabbler.
Mike, - Being a bit green around the gills and ignorant of the "proper" ways of doing things, I tend to try anything, so for one of my practice moulds I tried using gladwrap instead of parting powder! - and (to me) it seemed to work quite well, its just that you need to slit it where the holes go.
PS I'm only talking about seperating the two halves of the the flask with the sand in place - guess you're discussing taking the patterns from the sand.
Muddler/Dabbler.
KEN,
Tried the suggestion you made about handle positioning and it's good! - I had to move it out slightly to clear the furnace casing but that wasn't a problem!
Thanks for the tip.
Forum whore
Wow, imagine that! https://youtu.be/-fo7SmNuUU4
Anorak
Amazing stuff 4 valves per cylinder as well.
Shame so many surplus units were blown to bits in offshore racing in the states up until the 70's
Most of the modern metals and treatments were developed by RR.
Even the Yanks had to cede that it was better than anything they had which is why the last of the Mustangs were Merlin powered.
Kinky is using a feather. Perverted is using the whole chicken
Bucket Racer/Crasher
It's worth having a close look at the heads on the Merlin. The Mitsi 1800 engine in my old Libero had a similar valve actuation mechanism with a central camshaft acting on rockers that operated a pair of valves on each side, all rollers of course. Very very sweet engineering. Those crankshafts were lovely engineering as well, the whole engine was actually.
Hardcore Biker
I'm gunna get a pipe. Must say though, it was a pretty impressive effort.
"Success is the ability to go from one failure to another with no loss of enthusiasm.
Low personal B.M.E.P.
The Merlin only became a practical proposition once Packard had redrawn it for production. And once they'd set up for proper production methods. RR basically hand built each one with hours of hand fitting to achieve correct clearances because they couldn't make a run of parts even close to the same...
The best Merlin story is from the young uni grad who RR brought in to look at the blower airflow. He boosted it from around 1200HP to over 2000 in the final versions. Gets my vote for tuner of that decade. Later designed most of their jet engines too. Wrote autobiography "Not much of an engineer", can't remember his name.
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