Learjet .40 Build
12-10-2008, 06:34 PM
#51
RE: Learjet .40 Build
Wings are ready to be joined but I need to get some 30 min epoxy so I went back to work on the fuse.
Spent the last two evenings on the fuselage sheeting. I ran out of CyA so I need to go to the hobby shop tomorrow.
Spent the last two evenings on the fuselage sheeting. I ran out of CyA so I need to go to the hobby shop tomorrow.
12-10-2008, 08:23 PM
#52
RE: Learjet .40 Build
Your Learjet is looking great Chris!!!
As for the spinner, I think they use some of the ones that the pylon racers use. Look under "Pylon Spinner". That might help.
Scott
As for the spinner, I think they use some of the ones that the pylon racers use. Look under "Pylon Spinner". That might help.
Scott
12-12-2008, 01:28 AM
#53
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RE: Learjet .40 Build
Hey Chris, when you join your wings let me know what the dihedral looks like. I set mine according to the included gauge and it looked like a v when put together, the plans show the dihedral detail, and it calls for 1.25" from bottom of the wingtip to the building surface. Well with the factory dihedral gauge it set it to 3" from bottom of tip to surface. [sm=confused.gif] I ended up making my own setup to get the proper angle. I know this is an old kit but someone must have been passing the peace pipe when they did the engineering of this kit, especially the instruction manual, alot of mistakes in it, and v.1.1 is supposed to have all the proper instructions, I have both v.1 and v.1.1. Check to see what version manual you have.
12-12-2008, 04:18 AM
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RE: Learjet .40 Build
ORIGINAL: hawkpilot
Hey Chris, when you join your wings let me know what the dihedral looks like. I set mine according to the included gauge and it looked like a v when put together, the plans show the dihedral detail, and it calls for 1.25" from bottom of the wingtip to the building surface. Well with the factory dihedral gauge it set it to 3" from bottom of tip to surface. [sm=confused.gif] I ended up making my own setup to get the proper angle. I know this is an old kit but someone must have been passing the peace pipe when they did the engineering of this kit, especially the instruction manual, alot of mistakes in it, and v.1.1 is supposed to have all the proper instructions, I have both v.1 and v.1.1. Check to see what version manual you have.
Hey Chris, when you join your wings let me know what the dihedral looks like. I set mine according to the included gauge and it looked like a v when put together, the plans show the dihedral detail, and it calls for 1.25" from bottom of the wingtip to the building surface. Well with the factory dihedral gauge it set it to 3" from bottom of tip to surface. [sm=confused.gif] I ended up making my own setup to get the proper angle. I know this is an old kit but someone must have been passing the peace pipe when they did the engineering of this kit, especially the instruction manual, alot of mistakes in it, and v.1.1 is supposed to have all the proper instructions, I have both v.1 and v.1.1. Check to see what version manual you have.
12-12-2008, 09:40 AM
#55
RE: Learjet .40 Build
I'll look and see what manual I have when I get home tonight. I have also noticed several mistakes in mine. The dihedral when dry fit looks to be pretty close to the 1.25" the plans call for but I have not measured it. I'll clamp it and measure it and let you know.
Did yours fit well at the front of the wing where you then glue the mounting block to the front center section of the wing? Mine does not seem to have much wood to glue the block to and I'm worried about its strength. The fiberglassing of this area I guess should make it strong enough, just curious hows yours came out? Do you have any pictures of it?. Seems the only things to glue the block to are the leading edges and the two center #1 ribs. Doesnt seem like much to hold it.
Did yours fit well at the front of the wing where you then glue the mounting block to the front center section of the wing? Mine does not seem to have much wood to glue the block to and I'm worried about its strength. The fiberglassing of this area I guess should make it strong enough, just curious hows yours came out? Do you have any pictures of it?. Seems the only things to glue the block to are the leading edges and the two center #1 ribs. Doesnt seem like much to hold it.
12-12-2008, 10:09 AM
#56
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RE: Learjet .40 Build
I had the same thought about the block, so I added some of the leftover 3/4 balsa stick behind it with a generous amount of thick ca. I questioned the strength alot. There is only the 2 w1 ribs and mine did not even make it to the le so the only thing that would have held it is the sheeting, ribs and the pins. After the mental image of the wing flying off in a loop I made the decision to fix it. I dont have a pic yet but will take one after I install the fiberglass.
12-12-2008, 01:37 PM
#57
RE: Learjet .40 Build
Glad I am not the only one questioning that. I am sure fiberglassing the block around the top to bottom will make it strong enough but I think I will reinforce it quite a bit with that leftover 3/4 stock connecting W-1 to W-2 top and bottom and maybe even on the sides to square in W-1 and W-2. Ill take pictures of what i end up doing.
I'll also let you know what my dihedral actually ends up being.
I'll also let you know what my dihedral actually ends up being.
12-12-2008, 02:24 PM
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RE: Learjet .40 Build
Chris, here are a few pics of the le, I had already glued the block on and did not getto take a pic of the reinforcement that I did.
12-12-2008, 05:49 PM
#61
RE: Learjet .40 Build
Just measured my dihedral. Looks like I have about 1.4" inches per side. Measured from from table to bottom of the LE at the tip while the wing was level.
12-14-2008, 08:35 PM
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RE: Learjet .40 Build
a little more progress from the weekend. I did not get alot built, it was a nice weekend so I had to get some flight time in and try out my new tx (10c). The fuse is interesting! I wet the sides from f2 forward as per instructions, let it sit clamped all day while flying hoping that it would dry in pretty much that position and make it easier to epoxy in, when I removed the clamps it sprang back to the same position as before. The water did not seem to make it anymore flexible either.
12-14-2008, 11:14 PM
#66
RE: Learjet .40 Build
HawkPilot,
Looking good. I wish it was warm enough to do some r/c flying here in Indiana. It hit 40ish but was WINDY.
I did NOT wet from F2 forward when I assembled mine. I just applied epoxy and clamped it, there was plenty of flex and it did not crack. When you apply the sheeting to the fuse sides you will have to use the wetting process or the sheets will crack. I used boiling hot water applied with a sponge and it worked great. I think the secret is to use HOT water.
I did almost nothing this weekend on mine. I did some sanding as well as some trial fitting of the wood block for the wing mount and its about ready to glue in place. I spent some time doing some winter maintenance on my other models. I am out of town most of this week as well so I wont get back to it until late in the week.
Looking good. I wish it was warm enough to do some r/c flying here in Indiana. It hit 40ish but was WINDY.
I did NOT wet from F2 forward when I assembled mine. I just applied epoxy and clamped it, there was plenty of flex and it did not crack. When you apply the sheeting to the fuse sides you will have to use the wetting process or the sheets will crack. I used boiling hot water applied with a sponge and it worked great. I think the secret is to use HOT water.
I did almost nothing this weekend on mine. I did some sanding as well as some trial fitting of the wood block for the wing mount and its about ready to glue in place. I spent some time doing some winter maintenance on my other models. I am out of town most of this week as well so I wont get back to it until late in the week.
12-15-2008, 11:24 AM
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RE: Learjet .40 Build
nice build, i wonder if anyone has fitted it with ducted fans.... that would be interesting to fly/see. if i get the LJ i might try to add some
12-15-2008, 12:48 PM
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RE: Learjet .40 Build
most 70mm E that i saw gave about 4lb/s[*2=8lb/s] on the highest RPM i dont think it should be a problem, but maybe control will be difficult due to the engine positioning im guessing the whole plane is about 5lbs [i dont know exactly but i think most .40's are like that ... >.>] i think the weight was around 1.48 lb
it might not be good enough cause the plane might end around 6-7lbs but then again there is a jet forum on here.... ill just keep watching this build [BTW GL with the EDF LJ]
it might not be good enough cause the plane might end around 6-7lbs but then again there is a jet forum on here.... ill just keep watching this build [BTW GL with the EDF LJ]
12-15-2008, 07:32 PM
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RE: Learjet .40 Build
ORIGINAL: hawkpilot
a little more progress from the weekend. I did not get alot built, it was a nice weekend so I had to get some flight time in and try out my new tx (10c). The fuse is interesting! I wet the sides from f2 forward as per instructions, let it sit clamped all day while flying hoping that it would dry in pretty much that position and make it easier to epoxy in, when I removed the clamps it sprang back to the same position as before. The water did not seem to make it anymore flexible either.
a little more progress from the weekend. I did not get alot built, it was a nice weekend so I had to get some flight time in and try out my new tx (10c). The fuse is interesting! I wet the sides from f2 forward as per instructions, let it sit clamped all day while flying hoping that it would dry in pretty much that position and make it easier to epoxy in, when I removed the clamps it sprang back to the same position as before. The water did not seem to make it anymore flexible either.
chopper
12-15-2008, 09:20 PM
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RE: Learjet .40 Build
Chopper, I forgot I had read an article also about an additive...I think it was alchohol but im not sure. Somewhere I saved the link to the article. (was not the AMA article) I would like to know what you find.
12-15-2008, 09:23 PM
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RE: Learjet .40 Build
I have the for and aft top fuse sheeting on, firewall in. The firewall popped loose on the right side so I re-epoxied it with 6 min epoxy and also epoxied the tri stock reinforcement for added strength. Will post more pics later.
12-16-2008, 09:28 AM
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RE: Learjet .40 Build
ORIGINAL: hawkpilot
Chopper, I forgot I had read an article also about an additive...I think it was alchohol but im not sure. Somewhere I saved the link to the article. (was not the AMA article) I would like to know what you find.
Chopper, I forgot I had read an article also about an additive...I think it was alchohol but im not sure. Somewhere I saved the link to the article. (was not the AMA article) I would like to know what you find.
I found the article. It was in Model Aviation's November's issue. They soaked the balsa sheet with 1/2 cup of ammonia in enough warm water for several hours or overnight. Hope this helps. Good luck.
chopper
12-16-2008, 09:33 AM
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RE: Learjet .40 Build
ORIGINAL: chopper man
Hawkpilot
I found the article. It was in Model Aviation's November's issue. They soaked the balsa sheet with 1/2 cup of ammonia in enough warm water for several hours or overnight. Hope this helps. Good luck.
chopper
ORIGINAL: hawkpilot
Chopper, I forgot I had read an article also about an additive...I think it was alchohol but im not sure. Somewhere I saved the link to the article. (was not the AMA article) I would like to know what you find.
Chopper, I forgot I had read an article also about an additive...I think it was alchohol but im not sure. Somewhere I saved the link to the article. (was not the AMA article) I would like to know what you find.
I found the article. It was in Model Aviation's November's issue. They soaked the balsa sheet with 1/2 cup of ammonia in enough warm water for several hours or overnight. Hope this helps. Good luck.
chopper