Screaming Demon big block bash
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RE: Screaming Demon big block bash
Some would say that might be the best thing for it. Especially if I open the windows first.
If I wait too long I will be running indoors. It was bitter cold and dismal grey yesterday, with fine mist blowing almost parallel to the ground. A bit like where you live 200 days of the year..
MJD
p.s. where "south" in UK are you? My dad's folks were from Dorset, and the name comes from that area too. My folks met in London, she was a WAAF on radar, my dad was in radar at bomber HQ.
If I wait too long I will be running indoors. It was bitter cold and dismal grey yesterday, with fine mist blowing almost parallel to the ground. A bit like where you live 200 days of the year..
MJD
p.s. where "south" in UK are you? My dad's folks were from Dorset, and the name comes from that area too. My folks met in London, she was a WAAF on radar, my dad was in radar at bomber HQ.
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RE: Screaming Demon big block bash
Nice to see you underestamated
A bit like where you live 200 days of the year..
Know that area very well, I believe swanage was an experimental radar testing area. Churchill came there i'm told
A bit like where you live 200 days of the year..
Know that area very well, I believe swanage was an experimental radar testing area. Churchill came there i'm told
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RE: Screaming Demon big block bash
Speaking of radar and southern England, my siblings and I found out only months ago that my dad, who always waved off what he did as installing and fixing radar somewhere around London, was stationed at RAF bomber HQ for his whole term of service and was a squadron leader with Pathfinders. He also led a delegation that traveled to MIT to debrief the US on radar technology. Might have mentioned all this interesting stuff when he was alive. Radar was his area of expertise. So we have some research to do! Live and learn. With my mixed German and British heritiage, I have these two personalities that constantly hurl insults at each other. But I am very fond of German V weapons, Spitfires, pulsejets, and small quirky diesel engines.
MJD
MJD
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RE: Screaming Demon big block bash
This is getting ridiculous!
This is the 10% smaller bench running prop made from the other 8.25x10 I had. No way am I making it any smaller.. [:-]
Mixed up a gallon of fuel I have dubbed "OPS brew", meaning this is what I'm using and sticking to until I have reason not to - 12.8% castor, 7.2% syn, 5% nitromethane, 75% methanol. That's what you get when you mix FAI fuel and 10% syn/cas sport fuel 50/50, then add castor to bring total oil to 20%. Seemed a sensible mixture and easy to replicate via a trip to one of two LHS's. And I have one head shim installed for now.
The pipe is set at 12" plug to high point to start, and it will likely end up towards 11" by the time I'm done. I have set the pipe up clamped to a piece of u-channel, actually shelf bracket track, you know the stuff. So it is easily loosened, moved, and re-anchored as I trim the header. I wrapped the part where the clamp is with a few turns of that clingy silicone repair tape.
The plan is to meet up at my buddy's garage around 8pm and set up the stand, and a camera/tripod to record the festivities. We're having an OPS party.. grunt grunt, who let the geeks out. So hopefully something will occur that I am not ashamed to post. I suspect it will run very fast and scare us. [>:] Yes I will warm the head, start it, pin it, and get it staged into a rich 2c right away. One minute runs, cool, repeat..
Whee.
MJD
This is the 10% smaller bench running prop made from the other 8.25x10 I had. No way am I making it any smaller.. [:-]
Mixed up a gallon of fuel I have dubbed "OPS brew", meaning this is what I'm using and sticking to until I have reason not to - 12.8% castor, 7.2% syn, 5% nitromethane, 75% methanol. That's what you get when you mix FAI fuel and 10% syn/cas sport fuel 50/50, then add castor to bring total oil to 20%. Seemed a sensible mixture and easy to replicate via a trip to one of two LHS's. And I have one head shim installed for now.
The pipe is set at 12" plug to high point to start, and it will likely end up towards 11" by the time I'm done. I have set the pipe up clamped to a piece of u-channel, actually shelf bracket track, you know the stuff. So it is easily loosened, moved, and re-anchored as I trim the header. I wrapped the part where the clamp is with a few turns of that clingy silicone repair tape.
The plan is to meet up at my buddy's garage around 8pm and set up the stand, and a camera/tripod to record the festivities. We're having an OPS party.. grunt grunt, who let the geeks out. So hopefully something will occur that I am not ashamed to post. I suspect it will run very fast and scare us. [>:] Yes I will warm the head, start it, pin it, and get it staged into a rich 2c right away. One minute runs, cool, repeat..
Whee.
MJD
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RE: Screaming Demon big block bash
Installed servos, radio gear and got a pipe. Next up will be making some sort of cowling/hatch (does anyone have ideas on the best way to do that) and making the wingtips.
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RE: Screaming Demon big block bash
ORIGINAL: RVman
Installed servos, radio gear and got a pipe. Next up will be making some sort of cowling/hatch (does anyone have ideas on the best way to do that) and making the wingtips.
Installed servos, radio gear and got a pipe. Next up will be making some sort of cowling/hatch (does anyone have ideas on the best way to do that) and making the wingtips.
This does not constitute a complete answer I know. But my point is that I should have started using 1/64" ply earlier. CP was also working on me recently to do something with it, he's already seen the light.
As to "how to", what's wrong with the instructions? [&o]
MJD
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RE: Screaming Demon big block bash
The guys who used to build planes with plywood siding steamed the panels and then they could be forced into compound curves. I bought a 2 foot by 4 foot sheet of 1/64" plywood a few years ago...don't remember the exact price except it was North of $40 [IIRC].
Each ply is 1/194", not counting the glue?
Each ply is 1/194", not counting the glue?
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RE: Screaming Demon big block bash
1/192"? I think the outside plies are thinner actually, it gets sanded to final dimensions.
It's cool stuff isn't it? I have a collection of indoor contest grade wood including some .006" and .008" sheet. I like just fondling it and imagining if my fingers were smaller or I was patient. Pennyplanes were pushing it for me, at 7-8 hours build time.
MJD
It's cool stuff isn't it? I have a collection of indoor contest grade wood including some .006" and .008" sheet. I like just fondling it and imagining if my fingers were smaller or I was patient. Pennyplanes were pushing it for me, at 7-8 hours build time.
MJD
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RE: Screaming Demon big block bash
Finished up a cowling and hatch that seems like it should work alright. Just needs some filler here and there. Do the cooling openings look sufficient?
It was snowing here this morning [X(].
It was snowing here this morning [X(].
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RE: Screaming Demon big block bash
ORIGINAL: RVman
Do the cooling openings look sufficient?
Do the cooling openings look sufficient?
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RE: Screaming Demon big block bash
Thanks Mike, also the header & coupler will take up some of that space. I haven't got the header yet but I'll keep the 1:1.5 ratio in mind. It will be easy to add a few blocks of balsa to the inside to make it smaller if needed.
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RE: Screaming Demon big block bash
Do the cooling openings look sufficient?
The pictures show a cowl from an F3D Pylon Racer. There is a shroud that is a tight fit on the upper engine. This shroud forces the ducted incoming air through the fins and around to the rear outlet. There is about 1/8"learance betwwn the pipe and the inner wall of the cowl. Again this forces the cooling air where it is needed. Without this type of ducting and shroud the incoming air will have little effect. Another advantage of this controlled cooling is that a constant engine temperature can be established.
There is nothing new or revolutionary here. Control Line team racers and Speed flyers have used this for years. The VW bug used it in the thirties. Take look at some pictures of WW1 aircraft engines of ninety years ago.
Ed S
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RE: Screaming Demon big block bash
Tom,
Maybe extend it back and taper it down. The trailing edge shape is important when it comes to drag.
http://www.grc.nasa.gov/WWW/K-12/airplane/shaped.html
It looks like it will be fast no matter what you do.
Maybe extend it back and taper it down. The trailing edge shape is important when it comes to drag.
http://www.grc.nasa.gov/WWW/K-12/airplane/shaped.html
It looks like it will be fast no matter what you do.
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RE: Screaming Demon big block bash
Ed, the gaps around the cylinder are all about 1/8" so that should be ok. I will try to make up something better for the header. Thank you for the info,