Thrust, questions, engine mounting.....
- Thread starter orthobird
- Start date
you can see, i used the SWB mount as a template, and i aligned everything up, using the SWB mount. with the cowl on, it looks like the motor is sitting lower than it should be?? or is it the cowl??
ok, my question, disregards everything else i have said.
this airplane flies awesome as is, and it does well for IMAC.
I did have to add a little down thrust.
Ok, here is my question, if i move the motor, so that it lines up with the cowl, will this affect the flight characteristics of the airplane?
Meaning, if the motor is not positioned on the firewall cross lines, as recommended by the manufacturer, will the airplane not fly as well as if it were on the lines?
ok, my question, disregards everything else i have said.
this airplane flies awesome as is, and it does well for IMAC.
I did have to add a little down thrust.
Ok, here is my question, if i move the motor, so that it lines up with the cowl, will this affect the flight characteristics of the airplane?
Meaning, if the motor is not positioned on the firewall cross lines, as recommended by the manufacturer, will the airplane not fly as well as if it were on the lines?
stangflyer
I like 'em "BIG"!
I'm just tossing this out there "ortho". So don't shoot me. I see that your vertical alignment is right on the money. But don't see anything for horizontal. (Maybe just too faint to see???) Which of course will account for the positioning of the cowl to the motor. Question? Does the cowl fit the rest of the fuse nicely? As in, straight and true? With the exact horizontal plane going straight through the fuse, where is it in association with the horizontal alignment of the motor? My guess...and it is only a guess. If the motor is not true with the horizontal line through the fuse, you may find by aligning it so that it is, the plane may even fly better than it does now. Find your fuse incidence and adjust your motor accordingly. That is what I would do. Again, just a thought I am tossing out there.
IMAC FANATIC
40% happier than most folks.
Was it aligned before the down thrust? 1 or even .5° can make the difference.
Thrust and datum lines arent really adjustable to an airframe I believe, im no engineer, what I know about those things I read from the incidence meters manuals and glo kit plans but we have the benefit of mixes to correct all the habits that might show up.
im thinking a few mm wont make a big difference in overall flight that cant be corrected.
Id really like to know the technical answer though, rc specific not full scale wise. Interesting subject.
Thrust and datum lines arent really adjustable to an airframe I believe, im no engineer, what I know about those things I read from the incidence meters manuals and glo kit plans but we have the benefit of mixes to correct all the habits that might show up.
im thinking a few mm wont make a big difference in overall flight that cant be corrected.
Id really like to know the technical answer though, rc specific not full scale wise. Interesting subject.
49dimes
Damn I'm hungry
I really do not think flight performance will be greatly affected by "lifting the engine" a few mm say 6-8 so your spinner top matches the cowl. That is pretty little. Just be sure to keep your right and down thrust as you have it now. I have heard a few guys complain about how far off the "alignment" was on some edges and extras. Reports I heard that raising it to "please" posed no issues.
bbrown2828
150cc
hello, please look at the picture again with the SWB template., you will notice several things,
1. the swab mount has remade lines on it, to match up with the lines on the motor mount. look at it carefully. they are there.
2. pay attention to the sides of the firewall. you will see that on the right side and left side, there are three screws with washers. ok, now look at the 2md screw down, or should i say, the middle screw in the vertical row. now pay attention to the washer. if you see the washer, there is a line by the top of the washer. this is the horizontal line. now follow this line across to the template, and you will see it matches up. I know, it is difficult to see, but it is there.
hello Brian, before i added that one washer on the top two bolts, it was off like that as well.
Bunky.F.Knuckle
150cc
That is one reason why I don' use those mounting templates. I drilled the first one, and it was off 3/8" to the cowl.
Best thing to do is to hang the airplane from the wing tube between 2 ladders, place the engine on the firewall, place the cowl on, then use the spinner backplate to align the engine to the cowl. But make sure that you have the cowl fastened to the airplane, somehow. Tape i don't think will cut it. Will still allow the cowl to move.
Best thing to do is to hang the airplane from the wing tube between 2 ladders, place the engine on the firewall, place the cowl on, then use the spinner backplate to align the engine to the cowl. But make sure that you have the cowl fastened to the airplane, somehow. Tape i don't think will cut it. Will still allow the cowl to move.
thank you Bunky! i am actually asking this question not for myself, but for a friend of mine who is setting up his 120 LX, and we do not want the same thing that happened to me to happen to him.
We will do what Bunky has described. it will be interesting to see if his cowl and DA 170 line up with the lines, or if we have to drill the holes in a different alignment. I appreciate everyone's input. I believe the consensus is that it does not affect the flight characteristics if it is off by 1/4" or so.
We will do what Bunky has described. it will be interesting to see if his cowl and DA 170 line up with the lines, or if we have to drill the holes in a different alignment. I appreciate everyone's input. I believe the consensus is that it does not affect the flight characteristics if it is off by 1/4" or so.