Engine mounting?
#1
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From: Calgary,
AB, CANADA
I am ready to mount my Moki 1.8 on my Hanger 9 Edge 540.
Thats the good news, the bad news is that I dont have a clue how to do it properly.(only the second plane I have ever built)
My Sig 300xs had a center referance point and some instruction on how to go about it, the Hanger 9 manual has neither. In fact the hole in the fire wall is offset.
I suppose I could hold it nose up and kind of position the engine inside the cowl but, I am thinking there must be a more scientific way of accomplishing this task.
So, at the risk of sounding like a complete dolt, that is my request for help.
Thanx in advance.
Lean540
Thats the good news, the bad news is that I dont have a clue how to do it properly.(only the second plane I have ever built)
My Sig 300xs had a center referance point and some instruction on how to go about it, the Hanger 9 manual has neither. In fact the hole in the fire wall is offset.
I suppose I could hold it nose up and kind of position the engine inside the cowl but, I am thinking there must be a more scientific way of accomplishing this task.
So, at the risk of sounding like a complete dolt, that is my request for help.
Thanx in advance.
Lean540
#4
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From: Crete,
IL
You pretty much answered your own question. Stand the fuse up and get the motor positioned so the spinner is centered on the cowl. If you have to cut the cowl to clear the head, that will have to be done first.
#5
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From: Los Angeles,
CA
Originally posted by RC Outlaw
What in the HE$$ are you going to do with it when you find out how to mount the motor to it????????????????????????
What in the HE$$ are you going to do with it when you find out how to mount the motor to it????????????????????????
Also, I have nailed the wing on with 9 inch nails. Will that be enough?
Thanks
-DC
#6
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From: Calgary,
AB, CANADA
Ok, I think I have learned a lesson here on this one.
Next time I will try to word the question a little differently to try to avoid the "wrong type" of responder to the request for help.
The flying part I picked up very quickly and naturally, or so I have been told.
This was not my problem.
I have only personally mounted one engine to date and there was adequate instruction in that case.
Unfortunately I live in a very isolated part of Northern Alberta and do not have any local "connections" for advice.
Thank you "Stickjammer" for the info.
If anyone else has any they feel may be useful to me that would be much appreciated.
Thanks again.
Lean540
Next time I will try to word the question a little differently to try to avoid the "wrong type" of responder to the request for help.
The flying part I picked up very quickly and naturally, or so I have been told.
This was not my problem.
I have only personally mounted one engine to date and there was adequate instruction in that case.
Unfortunately I live in a very isolated part of Northern Alberta and do not have any local "connections" for advice.
Thank you "Stickjammer" for the info.
If anyone else has any they feel may be useful to me that would be much appreciated.
Thanks again.
Lean540
#7
You just have to make sure you have the engine on the correct thrust line. Your plans should show where that is.
Don't you hate it when some people have nothing useful to contribute? Gates are down, lights are flashing but the train ain't coming.
Don't you hate it when some people have nothing useful to contribute? Gates are down, lights are flashing but the train ain't coming.
#9
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From: New London,
OH
place the cowl on the fuselage where you want it, don't fasten it to the plane yet. take a measurment from the firewall to the outside of the cowl through the hole where the crankshaft sticks out. add whatever gap you want for spinner clearance. mount the spinner backplate to the engine. set the engine in the engine mount and measure the same distance from the firewall to the spinner backplate and mark and mount the engine. this will be close and you can make final adjustments before you permanently attach the cowling. i hope this helps and good luck flying your edge. I have had students that are ready for this type aircraft as their second plane too! I think the others are just jealous!
#10
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From: Calgary,
AB, CANADA
What a great thing this forum is!!!
Not only can you get help with almost anything related to RC from complete strangers from all over the world but, they will in the process of helping you, defend you as well.
Thanx to all of you, I plan to stick aroung in the hobby, and the forum, and return every good deed that has been bestowed upon me.
I realize that once one has learned a skill that it is sometime's hard to understand how another cannot.
How's that for optimism?
Lean540
Not only can you get help with almost anything related to RC from complete strangers from all over the world but, they will in the process of helping you, defend you as well.
Thanx to all of you, I plan to stick aroung in the hobby, and the forum, and return every good deed that has been bestowed upon me.
I realize that once one has learned a skill that it is sometime's hard to understand how another cannot.
How's that for optimism?
Lean540
#11
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From: Los Angeles,
CA
Originally posted by Lean540
What a great thing this forum is!!!
Not only can you get help with almost anything related to RC from complete strangers from all over the world but, they will in the process of helping you, defend you as well.
Thanx to all of you, I plan to stick aroung in the hobby, and the forum, and return every good deed that has been bestowed upon me.
I realize that once one has learned a skill that it is sometime's hard to understand how another cannot.
How's that for optimism?
Lean540
What a great thing this forum is!!!
Not only can you get help with almost anything related to RC from complete strangers from all over the world but, they will in the process of helping you, defend you as well.
Thanx to all of you, I plan to stick aroung in the hobby, and the forum, and return every good deed that has been bestowed upon me.
I realize that once one has learned a skill that it is sometime's hard to understand how another cannot.
How's that for optimism?
Lean540
I apologize for my little joke before. I just couldn't resist it!
<returns to a slightly more serious mode>
David C.
#12
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From: Spring Hill,
FL
I got lost in all the strange posts so far, so this may have been stated. The reason the engine is off center is most probably because there is offset in the engine mounting (right/down thrust). If this is so then the engine doesn't get mounted directly on the center and thrust lines. It gets moved over slightly so that the back of the propeller is center on the center and thrust lines. If that doesn't make sense, please say so and I'll try to explain it in English.
#13
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From: Spring Hill,
FL
Originally posted by David Cutler
While we are about it, I've just finished my scratch built $10,000 scale B52 model bomber with 4 turbine jets, and wonder if you could tell me what those funning stick things that protrude out of the front of my transmitter are for? I've tried wiggling them around, and all it does is makes a funny buzzing sound somewheree in the model, while the back edge of the wings and tail flap up and down a bit.
Also, I have nailed the wing on with 9 inch nails. Will that be enough?
Thanks
-DC
While we are about it, I've just finished my scratch built $10,000 scale B52 model bomber with 4 turbine jets, and wonder if you could tell me what those funning stick things that protrude out of the front of my transmitter are for? I've tried wiggling them around, and all it does is makes a funny buzzing sound somewheree in the model, while the back edge of the wings and tail flap up and down a bit.
Also, I have nailed the wing on with 9 inch nails. Will that be enough?
Thanks
-DC

But to answer your question, you'll notice that those two sticks are removable. They get mounted in the cockpit (one for pilot, one for co-pilot). You are using R/C pilots, correct?
Then you program the receiver to command the pilot and they move the sticks and fly the plane while you sit back, have a smoke and a beer and talk to your buddies.
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From: Los Angeles,
CA
Originally posted by CafeenMan
Sounds like you got a great deal on your turbines. Let's see, 4 turbines @ $3,000 ea. + model + hardware, + finishing materials all for only $10K. Where do you shop, out of curiousity?
But to answer your question, you'll notice that those two sticks are removable. They get mounted in the cockpit (one for pilot, one for co-pilot). You are using R/C pilots, correct?
Then you program the receiver to command the pilot and they move the sticks and fly the plane while you sit back, have a smoke and a beer and talk to your buddies.
Sounds like you got a great deal on your turbines. Let's see, 4 turbines @ $3,000 ea. + model + hardware, + finishing materials all for only $10K. Where do you shop, out of curiousity?

But to answer your question, you'll notice that those two sticks are removable. They get mounted in the cockpit (one for pilot, one for co-pilot). You are using R/C pilots, correct?
Then you program the receiver to command the pilot and they move the sticks and fly the plane while you sit back, have a smoke and a beer and talk to your buddies.
I used to use the cat to fly my 40% 300S until I got a nasty disease from the scratches I got while trying to nail her inside the cockpit.
-DC
#17
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From: Halifax, NS, CANADA
A (Robart?) incident meter is a bubble level that is also graduated in degrees and specifically designed for model making. Remember, the firewall will dictate what the (accidental or intentional) thrust line is. In other words, if your firewall is installed with unintentional offset (crooked, eh?) then the aircraft will be diffcult to control (watch the takeoffs). Hopefully I have not completely confused you. Harry Higgly makes a good book on this and well worth reading. (RCM Magazine). To sum up, square (level) the firewall, jig the model on this and set the wing incidence.
#18
Senior Member
Is some right thrust built into the firewall, or are there instructions regarding right thrust? If not built into the firewall, then some washers under the left side of the mount will establish the thrust line.
You have to mount the engine with a slight left offset so that the propeller/spinner will end up centered where it exits the cowl (i.e. the fuse center line)
If the right thrust is built into the firewall, and if the distance from the back of the engine mount to the propeller is "x", and the thrust angle is "theta", then the left offset along the firewall that will center the propeller is: y = x*TAN(theta).
If the firewall is perpendicular to the fuselage and you'll and washers to establish the right thrust, then my geometry shows the offset to be y = x*TAN(theta)/COS(theta).
In both cases, since we're talking about small angles,
y = SIN(theta) is an adequate approximation.
Since none of the construction is very precise, the last is fine in all cases.
I gather you've got a scientific calculator or some old sin tables lying around?
Scientific enough? It's high school geometry
You have to mount the engine with a slight left offset so that the propeller/spinner will end up centered where it exits the cowl (i.e. the fuse center line)
If the right thrust is built into the firewall, and if the distance from the back of the engine mount to the propeller is "x", and the thrust angle is "theta", then the left offset along the firewall that will center the propeller is: y = x*TAN(theta).
If the firewall is perpendicular to the fuselage and you'll and washers to establish the right thrust, then my geometry shows the offset to be y = x*TAN(theta)/COS(theta).
In both cases, since we're talking about small angles,
y = SIN(theta) is an adequate approximation.
Since none of the construction is very precise, the last is fine in all cases.
I gather you've got a scientific calculator or some old sin tables lying around?

Scientific enough? It's high school geometry




