Weston Magnum R build
#26
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RE: Weston Magnum R build
ORIGINAL: mk1spitfire
Knife edge at 150, sweet
ORIGINAL: john josey
This next comment may cause some concern from some, but i intend to fit a rudder to the magnum in the near future.
I will be installing the servo and control snake during the build, but i will be leaving the rudder off for the first few flights. I just know i will get bored if i dont add another dimention to it ! I know the airframe was designed for out 'n out speed but as far as i know nobody has done this before and nothing ventured nothing gained sort of thing. The first 'hint' of flutter and i wont hesitate to remove it.
For some reason i`m having trouble uploading the pictures from my phone tonight, i`ll keep trying.
This next comment may cause some concern from some, but i intend to fit a rudder to the magnum in the near future.
I will be installing the servo and control snake during the build, but i will be leaving the rudder off for the first few flights. I just know i will get bored if i dont add another dimention to it ! I know the airframe was designed for out 'n out speed but as far as i know nobody has done this before and nothing ventured nothing gained sort of thing. The first 'hint' of flutter and i wont hesitate to remove it.
For some reason i`m having trouble uploading the pictures from my phone tonight, i`ll keep trying.
#27
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RE: Weston Magnum R build
Just a thought - since it already has a split elevator, have you considered moving the vertical fin back an inch or so, and extending the rudder down to the bottom of the fuse? You'd be able to link to it from the side of the fuselage that way too, which to me is less messy than a rudder pushrod on top. The rear of the fuse would want some blending.
MJD
MJD
#28
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RE: Weston Magnum R build
ORIGINAL: MJD
Just a thought - since it already has a split elevator, have you considered moving the vertical fin back an inch or so, and extending the rudder down to the bottom of the fuse? You'd be able to link to it from the side of the fuselage that way too, which to me is less messy than a rudder pushrod on top. The rear of the fuse would want some blending.
MJD
Just a thought - since it already has a split elevator, have you considered moving the vertical fin back an inch or so, and extending the rudder down to the bottom of the fuse? You'd be able to link to it from the side of the fuselage that way too, which to me is less messy than a rudder pushrod on top. The rear of the fuse would want some blending.
MJD
Obviously i`ll keep the gap to a minimum and the linkage will be absolutely slop free, but i still have concerns about flutter. I`m thinking on fitting a longer control horn in an attempt to make it more stable ? Any ideas/suggestions welcolm.
I`ll try again with the pictures.
#29
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RE: Weston Magnum R build
OK got the pictures working.
This one just shows the position of the throttle and rudder servos.
And this one is just the rudder servo and plywood support for the snake. with the servo at that height, there is a full 2mm clearance from the aileron linkage, even with the wing seat getting compressed when tightened i doubt it will be close to 2mm, but i will check just to make sure.
This one just shows the position of the throttle and rudder servos.
And this one is just the rudder servo and plywood support for the snake. with the servo at that height, there is a full 2mm clearance from the aileron linkage, even with the wing seat getting compressed when tightened i doubt it will be close to 2mm, but i will check just to make sure.
#31
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RE: Weston Magnum R build
ORIGINAL: john josey
Obviously i`ll keep the gap to a minimum and the linkage will be absolutely slop free, but i still have concerns about flutter. I`m thinking on fitting a longer control horn in an attempt to make it more stable ? Any ideas/suggestions welcole.
Obviously i`ll keep the gap to a minimum and the linkage will be absolutely slop free, but i still have concerns about flutter. I`m thinking on fitting a longer control horn in an attempt to make it more stable ? Any ideas/suggestions welcole.
Longer horns and servo arms, i.e. attachment points farther from the center of the circle, do indeed reduce the net slop from any clearances or pushrod flexing. So they are a good precaution, but I don't think you need to go nuts i.e. giant scale horns or anything. 7/8" - 1" maybe. I always try to ensure that I have size-on-size fits of the clevis pins to the horn for that reason, i.e. no clearance I can detect but no binding. I am growing very fond of the Sullivan steel horns with the plastic bushing insert.
Don't forget you're not really doing anything more radical than a rudder on a Q500, although you may be wanting more throw. The point being the application is well within the known realm, so your common sense precautions will likely do the trick fine. It's not a 200+ mph aircraft after all, despite Weston's bold claims. Never heard of a radar track over 165 or so yet. Not that ain't fast, it is indeed. But it's achievable without rocket science.
MJD
#32
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RE: Weston Magnum R build
Thanks for the positive comments guys. I`m just in from spending most of the day working on the rudder and fitting the aileron servo, and after reading your comments thats pretty much what i`ve done including the 1" horn, spooky or what ?
I fly jets, so i`m no stranger to fast aeroplanes, but this is new territory for me with a prop model.
I`ll post some pictures of the progress so far.
cheers
john
I fly jets, so i`m no stranger to fast aeroplanes, but this is new territory for me with a prop model.
I`ll post some pictures of the progress so far.
cheers
john
#33
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Thread Starter
RE: Weston Magnum R build
I was intending using 1/4" sheet balsa, but i diden`t have any and i couldn`t be bothered with the 30 mile round trip to go and get some. so i decided to use 1/2 sheet that i had lying around, which turned out to be the better choice. covered the fin and fus with masking tape so as not to scratch the covering when trying to sand it to shape.
#34
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Thread Starter
RE: Weston Magnum R build
I made up a couple of thin ply 'tangs' in an attemp to hold the rudder ridged to the fin and fus while i attempted to sand it to shape, which i must say worked suprisingly well.
For some reason i`m only able to add one image per post before it times out on me, it was ok before so maybe it`s something i`ve done.
For some reason i`m only able to add one image per post before it times out on me, it was ok before so maybe it`s something i`ve done.
#36
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Thread Starter
RE: Weston Magnum R build
I`m really pleased with the way it`s turned out, although the bottom doesn`t look quite right even though it does follow the contour of the fus.
i have decided to cut the bottom to a different angle as shown in the next picture with the blue pen line.
i have decided to cut the bottom to a different angle as shown in the next picture with the blue pen line.
#38
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Thread Starter
RE: Weston Magnum R build
I diden`t like the supplied aileron liteply mount so i made my own from 3mm birch ply and resessed them to drop the servo, and give an extra bit of clearance with the rudder servo (it diden`t really need it) just another precaution.
#39
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Thread Starter
RE: Weston Magnum R build
Aileron servo in it`s final resting place. I decided to balsaloc the covering that i had cut away to insert the plywood mounts and iron it back in place just to tidy things up.
#40
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RE: Weston Magnum R build
And the final one for today. All hooked up ready to go. At the moment the ATV`s are at 85% to get the recommended 8mm travel, so i might raise the connectors on the threaded part of the torque rods to get the ATV`s closer to 100%. although a slight loss in resolution is the least of my worries i would think (wheres the scared smiley)
I`m gonna have to go to the model shop tomorro to see if i can get covering for the rudder to match the rest of the model.
I`m gonna have to go to the model shop tomorro to see if i can get covering for the rudder to match the rest of the model.
#42
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Thread Starter
RE: Weston Magnum R build
ORIGINAL: mk1spitfire
looking good,you guna use c/a hinges to put rudder in?
looking good,you guna use c/a hinges to put rudder in?
After giving it a bit of thought i decided to have two of each, maybe overkill, but not worth taking any chances with. I`ll post a few more pics shortly.
john
#44
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Thread Starter
RE: Weston Magnum R build
Managed to pick up some iron on film that is a pretty close match colour wise, which was lucky.
As a last resort i had a can of Tamiya spray paint which i know is a almost perfect colour match (TS 47 chrome yellow) but it would have meant glassing the rudder and then having to fuel proof it ! and i just couldn`t be bothered truth be told.
As a last resort i had a can of Tamiya spray paint which i know is a almost perfect colour match (TS 47 chrome yellow) but it would have meant glassing the rudder and then having to fuel proof it ! and i just couldn`t be bothered truth be told.
#46
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Thread Starter
RE: Weston Magnum R build
I was a bit concerned that it might look out of place hanging off the back of the fin, but i have to say i think it blends in quite well. The fin /rudder kind of reminds me of the 1980`s Hanno prettner supra fly type of thing ?
#48
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RE: Weston Magnum R build
ORIGINAL: smoknrv4
Looks awesome! Nice job, keep it up John.
Looks awesome! Nice job, keep it up John.
Again thanks for the kind words, sametoo the others that have given sound advice and positive comments, especially MJD for taking the time to explain his advice in detail, it really is appreciated.
cheers
john
#50
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Thread Starter
RE: Weston Magnum R build
ORIGINAL: Mike06659
I bet an electric conversion in this airframe would put it in the 200 mph range. Food for thought
I bet an electric conversion in this airframe would put it in the 200 mph range. Food for thought