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        Build Log F18 with Microjet V3

#1 Lt599 Aug 09, 2012 04:04 PM

F18 with Microjet V3
 
8 Attachment(s)
Well I finished my delta build over in the EDF forum and decided I would try my hand at a park jet pusher. I chose the F18 from Schumate because from what I have read it is very popular and a great flying model. I also chose the F18 because I have been planning a twin 70mm EDF model and I have seen a number of scaled up builds from these plans. There will be some firsts for me. This will be the first build that I have used printed plans, my other builds have either been my own design or from 3 views. This will be the first build that I have done using FFF as the primary construction material. Up until a couple of months ago I had never seen FFF only read about it. FFF is not readily available up here in the pacific north west. I travelled across the country a couple of months ago and on my way though louisiana I picked up 5 bundles....my wife thinks Im crazy:) I took a piece to my LHS yesterday and we compared it to depron, the guys their thought it was great material, they had never seen it before in person either. So here goes.

F18 plans by Steve Shumate at 100%
Grayson Microjet V3
20 amp ESC
2100 3s 20c
6x4 APC prop.
Corona 929MG x3
Orange RX 6 with satellite

I intend to follow the plans with a couple of exceptions. The plans I have are for the F18/A. I changed the strakes and intakes to a Super Hornet. I plan on useing balsa on the LE's and on the hinge lines. I will use Robart pin hinges instead of tape(I dont care for tape hinges) I am going to skip the rudders, but I will program flaps on my Dx7.I am using Dow XPS laminated for the nose and canopy. Well these are my plans so far, subject to change as I go:D

#2 jeffsch Aug 18, 2012 10:15 AM

Looks like a great start!

#3 Waltjg Aug 18, 2012 03:32 PM

Lt,looks great !! This is a great fun plane! W

#4 Lt599 Aug 18, 2012 06:04 PM

I think it will be fun. I have one of the guys in my flight club that wants me to build him the T38, so this is good practice. I sure like working with the FFF. Walt I look forward to your next build, really to bad about V1:( Isnt it funny that we are always looking for foam that we cant find locally. I think the Micro jet should push this F18, but I have never used one so if anybody has any input please let me know. I have 1600 and 2100 mah batts. Id like to use the 2100's but I do not want it to be to heavy.

#5 Waltjg Aug 18, 2012 08:31 PM

Greg, I would try the 1600ma battery first, what C rating is it? Also I would go with the 6x4 APC prop, if you have a watt meter, use that and see what kind ofe numbers you are getting with this set up.. It will fly better with the smaller battery, then you can always work up to the larger heavier battery. W

#6 Lt599 Aug 20, 2012 01:17 AM

9 Attachment(s)
Well I got a little done, got side tracked building an air boat for my son and dusting off my 20+ year old Graupner hydro, had to spend some time at the lake during the hot days.:) Walt, I ran it on a 3s 1600 20c with a partial charge ( I just recieved the batt. and did not charge it) At WOT it settled in at 146 watts at 15 amps. with a 6x4 APC. Here are some picks.

#7 Waltjg Aug 20, 2012 07:58 AM

Greg, start out with the smaller battery... Also, the control arm on the cf rod for your elevators, if you can, drill a very tiny hole through it and insert a piece of wire for a pin,, these sometimes will come loose from the cf rod, usually resulting in something very bad happening very quickly!:eek: on the esc, I have been cutting a hole to fit in the bottom of the fuse and mounting them there so that they get plenty of cooling. Looks great so far, this is a very cool plane!! W:D

#8 jeffsch Aug 20, 2012 10:07 AM

Lt599, nice work. The foam wire keepers for the motor and servo wires is a nice touch. (Thanks for posting detailed pictures; they show clever bits of workmanship!)

#9 Lt599 Aug 20, 2012 01:00 PM

Quote:

Originally Posted by Waltjg (Post 22496823)
Greg, start out with the smaller battery... Also, the control arm on the cf rod for your elevators, if you can, drill a very tiny hole through it and insert a piece of wire for a pin,, these sometimes will come loose from the cf rod, usually resulting in something very bad happening very quickly!:eek: on the esc, I have been cutting a hole to fit in the bottom of the fuse and mounting them there so that they get plenty of cooling. Looks great so far, this is a very cool plane!! W:D

Walt, I CAed the CF rod into the nylon clevis's do you still think a pin is in order? I CAed the servo arm and stops onto the CF pivot rod for the flying stab also:eek: I did use some epoxy too, made me feel better:) But seriously I do not want a weak point, plus once the fuse top is glued on I would have to cut to get to it. Any info is good,thanks, Greg

#10 Lt599 Aug 20, 2012 05:31 PM

Update: Walt I decided to go with just music wire with Z bends for the flying stab control..no worries then. I ran into a set back! I assembled the wing, epoxied in the CF spar, glued balsa on the LE and the hinge lines,was getting ready to hinge the ailerons when I realized something. Some how when I printed the plans and put them together my wing ended up being 1 1/4" longer on one side of the center line!!!:eek: I have no idea how I missed that! No way I can fix it the wing would be to narrow.:mad: That really :censored: sucks. Now I have to build a new wing. At least I have enough material on hand :)

#11 Waltjg Aug 20, 2012 05:47 PM

Greg, can you glue some on the otherside to extend it?? Remember your working with foam, and you can do anything!! W

#12 Lt599 Aug 20, 2012 07:40 PM

Walt, thought about it but I would have had to extend the balsa edges also. I have a new wing cut and the CF rod is epoxied and drying. I have just enough balsa left to re edge the new wing. If I screw up it will be off to the hobby shop tomorrow:) Right now im deciding between CA hinges or the Robart pins. I have both, we'll see. Are you building anything right now or waiting for foam? Greg

#13 Lt599 Aug 21, 2012 02:14 AM

14 Attachment(s)
Despite my set back earlier with the wing I managed to make some progress today. Since I changed the intakes and the strakes to make it resemble the Super Hornet I went ahead and added 1/2" to span and chord when I built the new wing.

#14 Waltjg Aug 21, 2012 06:59 AM

Hi Greg, comming along really great there! I'm fiddling with some ideas but not really into a build yet, there are a lot of them I want to build though including another hornet! I love that plane, it looks so cool in the air.. I've got some of the pin hinges also but always end up using the ca hinges cause that is what I'm used to, I need to use them I'm sure they work better than the ca hinges... You did the right thing by redoing the wing, don't worry about a mistake, I make them all the time and have to fix or redo stuff, I think that is just the nature of building these especially if your scratching one out like I did the Mig. RIP.. I'll try another one of those when I get up north to get some thick foam, but there are others to build now! W :D

#15 Lt599 Aug 21, 2012 12:44 PM

I went with the Robarts after trying to cut hinge slots in one of the airlerons. I came through the skin three times, I tried using my slot tool and also the exacto. I think it is because the wing and balsa strip is so thin with a single sheet, or I was trying to go to fast:) I wanted to try the CA hinges, my thought was with them I could get away with 3 per aileron and would not have to mess with the vaseline.The small pins are kind of a :censored: to install and get straight so they dont bind and to get enough glue in the hole without glueing the hinge pivot. The big ones are much easier to work with.


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