GP Aeromaster Kit Build
06-24-2011, 08:01 PM
#26
RE: GP Aeromaster Kit Build
Hi, this is a shot of the stock AM aluminum gear. It and the original wire gear put the wheels much farther back than your set appears to be doing.'
Im sorry for the small pix above but take a close look at how far back the wheels are supposed to be.
MTC YMMV
Tom
Im sorry for the small pix above but take a close look at how far back the wheels are supposed to be.
MTC YMMV
Tom
06-25-2011, 06:04 AM
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RE: GP Aeromaster Kit Build
here is the gp aeromaster i did in the late 90's Mine had the straight short lower wing and the long swept upper with ailerons on only the bottom. The best flying airplane i've had yet. Supertigre .60 for power. When i do it again i'll be putting ailerons on both wings as the only complaint i had is i thiught rool response was slow.Watching you rbuild with interest. Phil
06-25-2011, 06:36 PM
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RE: GP Aeromaster Kit Build
Well, Igot the top of the wing sheeted, using the thick CA method up front and the Titebond II iron-on method on the trailing edge. I think both methods are equally well suited. The substrate would fail before the joint on both, and the thick CA is positionable enough.The CAdoes grab pretty quick, but I think it could be pulled apart if you needed to if you stayed inside 20 seconds or so. The iron-on method is very good, but takes a lot of time waiting an hour for the glue to dry. I will reserve that method for larger, more critical sheeting.
This photo shows the servo bed design for mounting the twin servos in the lower wing. Ichose to move them on out an additional rib from the location where the bell crank is on the plan. I am not sure if was necessary, but I would rather have the aerilon activated closer to the center rather than offset to one side.
Also, note that the servo is rotated slightly to make the pushrod to line up perpendicular to the hinge. Subtle, but with the swept wing and the ribs running straight along the axis of the fuse,rotating the servo keeps the pushrod moving axially only, preventing bending of the control horn on the aerilon.
I don't know if that makes things more clear or muddies the water...
That is not a good angle to explain why I turned the servo slightly. I will get a shot tomorrow from a birds eye view, which will make my point much more clear.
This photo shows the servo bed design for mounting the twin servos in the lower wing. Ichose to move them on out an additional rib from the location where the bell crank is on the plan. I am not sure if was necessary, but I would rather have the aerilon activated closer to the center rather than offset to one side.
Also, note that the servo is rotated slightly to make the pushrod to line up perpendicular to the hinge. Subtle, but with the swept wing and the ribs running straight along the axis of the fuse,rotating the servo keeps the pushrod moving axially only, preventing bending of the control horn on the aerilon.
I don't know if that makes things more clear or muddies the water...
That is not a good angle to explain why I turned the servo slightly. I will get a shot tomorrow from a birds eye view, which will make my point much more clear.
06-27-2011, 06:46 PM
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RE: GP Aeromaster Kit Build
This is the way I think is right to install a servo in a swept wing. Any comments or insight? The control rod is at a right angle to the aerilon hinge line. This is not how it is show on the plans, but I think it is more correct than running the control rod parallel to the ribs.
06-28-2011, 06:35 AM
#32
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RE: GP Aeromaster Kit Build
For AILERONS in a swept wing, you are correct. You want the pushrod at 90-degrees to the hinge line. That makes things go together without any twisting of the aileron horn. Now, if you use a ball link at the control horn and/or servo, then you get rid of the twisting action. In all cases, simplest is best, and a direct pushrod with no angles or bends is always the best way to go.
06-30-2011, 08:00 AM
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RE: GP Aeromaster Kit Build
Well, Iam finished with the bottom wing to the point where I need to separate the aerilons from the wing. The wing is very fat (tall) at the hinge line.
I think the aerilons are a bit ugly as shown on the plans.
I wonder if it will affect flight performance or characteristics if I change the design as follows. I can put thin CA in the partially die cut ribs of the lower wing and cut them any where I want to. I am putting aerilons in the upper wing as well so I have some allowance/opportunity for adesign change.
Does anyone have input on my proposed method?
I think the aerilons are a bit ugly as shown on the plans.
I wonder if it will affect flight performance or characteristics if I change the design as follows. I can put thin CA in the partially die cut ribs of the lower wing and cut them any where I want to. I am putting aerilons in the upper wing as well so I have some allowance/opportunity for adesign change.
Does anyone have input on my proposed method?
07-02-2011, 07:06 AM
#35
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RE: GP Aeromaster Kit Build
The top rib profile above is upside down...The ailerons are top hinged. Personally, I would stay with that configuration, works great!
-Johnny-
-Johnny-
07-02-2011, 09:32 AM
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RE: GP Aeromaster Kit Build
Johnny, Iwas proceedingwith the top hinged aerilons since that is what the designer intended and I did not have enough experience to change them. Like you said, Ihad them upside down, and being top hinged the gap is on the bottom and unless you are laying on the ground looking up, the large gap is not visible. Note that I shortened the aerilons by one rib and moved the servo out a rib, respectively. I think they are going to be plenty longenough going with aerilons on both wings, and this will also strengthen the wing center/where attached to the fuse.
Well, it took a little contemplation and trepidation to cut the aerilons out of a wing that you just spent a week of evenings building, but Itook the knife and saw to it eventually:
Well, it took a little contemplation and trepidation to cut the aerilons out of a wing that you just spent a week of evenings building, but Itook the knife and saw to it eventually:
07-02-2011, 09:42 AM
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RE: GP Aeromaster Kit Build
The next step is to fair the front edge of the aerilon so a 1/8" cap strip can be glued on. It is best to use a sanding block so that the front of the aerilon stays flat and straight to better accept the cap and line up with the wing closely.
07-02-2011, 09:45 AM
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RE: GP Aeromaster Kit Build
After gluing 1/4" hinge support blocks in place and attaching the front cap, I did my 120 grit sanding of the first aerilon before transferring back the hinge location markers to the newly semi-finished side.
And then back to the second aerilon:
And then back to the second aerilon:
07-02-2011, 09:56 AM
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RE: GP Aeromaster Kit Build
It is necessary to carefully cut the sheeting and ribs even with the back of the rear spars. Carefully slit the sheeting with a hobby knife since it is with the grain and saw the ribs since they are across the grain. Then sand and fair flat and straight to accept the 1/8" cap:
Before:
After:
Before:
After:
07-02-2011, 10:04 AM
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RE: GP Aeromaster Kit Build
I may go out of order on the next wing and build the wingtips before cutting out the aerilons. This area is very fragile, although I have not broken one yet (edit: I take that back; I broke one while putting in the shear web behind the main spars 
):
):
07-18-2011, 07:04 PM
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RE: GP Aeromaster Kit Build
Hey Brian,
Yep, a little. I finished the lower wing (wingtips, aerilon hinging, etc.). I have been meaning to post pics with a little write-up; we took a vacation, I was researching used pickup trucks, etc. Busy, busy.
I will get to this tomorrow - it keeps me motivated and I need to get started on/finished with the second wing. I have a couple of other projects following this one that I really want to get to.
I saw a giant GP Aeromaster Kit (1.8) for sale in the classifieds today. I asked the seller to provide the specs to me, I am really interested in that kit...
Thanks for the motivation!
Yep, a little. I finished the lower wing (wingtips, aerilon hinging, etc.). I have been meaning to post pics with a little write-up; we took a vacation, I was researching used pickup trucks, etc. Busy, busy.
I will get to this tomorrow - it keeps me motivated and I need to get started on/finished with the second wing. I have a couple of other projects following this one that I really want to get to.
I saw a giant GP Aeromaster Kit (1.8) for sale in the classifieds today. I asked the seller to provide the specs to me, I am really interested in that kit...
Thanks for the motivation!
07-18-2011, 08:58 PM
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RE: GP Aeromaster Kit Build
This is an old pretty much trashed Aeromster that I picked up in a trade that also included an unstarted kit of the same plane. The unbuilt kit, unfortunately, included plans for a Lou Andrews Aeromaster Too in place of plans for the GP kit. Since I had no plans for the GP kit, I did not know what the cowl on the original looked like (the trashed plane had no cowl with it). So, one afternoon, I cobbled together the cowl you see here. I have since acquired plans for the GP kit (thank you Gray Beard) and may build the round cowl as shown in your pics some day when I have nothing better to do.
This one has ailerons only on the bottom wing. When I build the kit, I will put ailerons on both wings. It has an OS .61 FSR inverted in it that runs well, but I will probably never fly this turkey. It had a lot of damage that I repaired before I recovered it, but I'm not sure I would want to trust it in the air with a good engine and 2.4 radio gear that I would not like to lose. One of the reasons I wanted to do this repair/recover job is that I wanted to experiment with Koverall for the first time. That is what is on the plane you see here; Koverall painted with household latex paint that I bought at Lowes. I sprayed it through a cheap HVLP gun at about 40 psi. That was also my first attempt with an HLVP gun and I think it turned out OK for a first attempt.
This one has ailerons only on the bottom wing. When I build the kit, I will put ailerons on both wings. It has an OS .61 FSR inverted in it that runs well, but I will probably never fly this turkey. It had a lot of damage that I repaired before I recovered it, but I'm not sure I would want to trust it in the air with a good engine and 2.4 radio gear that I would not like to lose. One of the reasons I wanted to do this repair/recover job is that I wanted to experiment with Koverall for the first time. That is what is on the plane you see here; Koverall painted with household latex paint that I bought at Lowes. I sprayed it through a cheap HVLP gun at about 40 psi. That was also my first attempt with an HLVP gun and I think it turned out OK for a first attempt.
07-20-2011, 02:52 PM
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RE: GP Aeromaster Kit Build
Well, as Isaid above in the text, I finished the bottom wing a week or so ago.
Here is one of the typical wingtip details. There is not too much to doing these other than trying to make sure the 1/8" balsa wingtip itself gets glued onto the outer rib at a 90 deg angle. After that, it is cutting some 1/4" stock at angles, sanding them to fit, and then sheeting. This example tip is only shaped with 80 grit; Inormally wait until right before covering to go over the model with 120/180:
I did encounter this one problem wingtip that when Iput on sheeting it dimpled in.That is certainly one of the drawbacks to CA, you only get one chance. Idon't know if Iam going to fill it or rip it off:
Here is one of the typical wingtip details. There is not too much to doing these other than trying to make sure the 1/8" balsa wingtip itself gets glued onto the outer rib at a 90 deg angle. After that, it is cutting some 1/4" stock at angles, sanding them to fit, and then sheeting. This example tip is only shaped with 80 grit; Inormally wait until right before covering to go over the model with 120/180:
I did encounter this one problem wingtip that when Iput on sheeting it dimpled in.That is certainly one of the drawbacks to CA, you only get one chance. Idon't know if Iam going to fill it or rip it off:
07-20-2011, 02:58 PM
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RE: GP Aeromaster Kit Build
I finished my GP Aeromaster about 2 months ago and have had it in the air maybe 10 times. It is my first bipe. I am an ok pilot but nothing like some of the guys at my field. Especially Greg. He helped me re-learn to fly and has maidened 3 of my models. he can make my Aeromaster dance in the sky whereas I find it very difficult. His takeoffs and landings are spot on. I hit the high grass once and on the last landing hit kinda hard and the wire gear popped the left main and I cartwheeled. Fortunatly....no damage at all. Its a pretty bird, espcially in the air. I hope I can get ALOT better at flying before I really hurt this thing.
07-20-2011, 02:58 PM
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RE: GP Aeromaster Kit Build
Standard servos barely fit in these wings. The plywood bed is really close to the rib profile(s) it is mounted between. When the covering is shrunk on the top side of the wing it is going to come dangerously close to touching the bottom of the servo bed (this pictureis the under side of the lower wing, Iam talking about the top or the wingor other side of this servo bed detail). This reminds me that Ineed to sheet over the servoarm,looks like Ikind of forgot thatdetail. The aerilon does not look as bad as the cross section on the plans makes it look.
07-20-2011, 03:16 PM
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RE: GP Aeromaster Kit Build
Anyway, here is a shot of the completed lower wing. Off to the left, see the US40 wings Irecently acquired in a partially completed kit deal 
. I said Iwas not going to start another project until this one was done, but acquisitions don't count!
. I said Iwas not going to start another project until this one was done, but acquisitions don't count!
07-20-2011, 05:15 PM
#50
RE: GP Aeromaster Kit Build
Rick-
You might want to look at that servo install again. The push rod angle to the aileron is wrong...
I think what happened is you expected the ribs to be angled against the the wing as illustrated in your drawing, and they aren't. Keep the servo parallel with the ribs for a 90 degree connection.
Brian
p.s. I just noticed it... my apologies for not catching it quicker.
You might want to look at that servo install again. The push rod angle to the aileron is wrong...
I think what happened is you expected the ribs to be angled against the the wing as illustrated in your drawing, and they aren't. Keep the servo parallel with the ribs for a 90 degree connection.
Brian
p.s. I just noticed it... my apologies for not catching it quicker.
