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Sep 12, 2019, 09:33 AM
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Twin 90mm EDF to pusher prop jet.


I got the foam F-18 jet kit from a friend that did not want to build it and he thought it was a Star max but was not sure.
The Manuel had very little info other then photos to help you build it. The kit call for two 90mm EDF's. To save on time and weight, I decided to build it as a pusher jet. I did not put any landing gear on it and I was just going to hand launch the jet. all the paint was from Lowe's $2.40 per pant test samples and I brushed it on with Wal-Mart paint brushes.
To my dismay, after completing the build. it dawned on me how big the prop was, 13 X 6. on a Rim Fire .55 with a 6 cell 5000 lipo pack.
I may be Dumb... but I am not Stupid.... I was not going to hand launch that big F-18 with a 13 X 6 spinning right behind my hand....LOL
So I went back to the basement and came up with my dolly to take off from. Goofy looking but dose the job.
The dolly has a 401 gyro to help keep the jet running true down the runway. it disconnects on take off.
I installed 5 E-flight electronic bomb drops. I have to drop all my bombs before landing. I get about 7 to 9 min flights.
The jet is very stable and dose not have any stabilizer unit on it. It is one of the best flying jets I have in my inventory.

Thanks for looking

wayne
Last edited by wayne65; Sep 12, 2019 at 09:42 AM. Reason: spelling
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Sep 12, 2019, 12:50 PM
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Wayne, Great job on the F18. Those pictures for the bomb drops are amazing.
Can you post the flying weight? Also, can you post a few closeup pics of just the dolly?
It looks to be a perfect alternate to hand launching.
Thanks so much.
Stan
Sep 12, 2019, 01:49 PM
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Hi: Stan
Thanks
I will have to take some photos of the Dolly after work.
Had I built the F-18 as an EDF, I would have hand launch the jet but that big Prop
will put the fear of GOD in you, with your hand that close to a spinning Prop......LOL

wayne
Sep 12, 2019, 02:14 PM
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I found some photos of the F-18 :
Please keep in mind. I hand brushed the paint on the hole jet. I would say it is a 10 foot paint job (you have to stand back about 10 feet ) for the jet to look good...LOL
Sep 12, 2019, 02:23 PM
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sorry, copy
Last edited by wayne65; Sep 12, 2019 at 02:24 PM. Reason: copy
Sep 12, 2019, 07:28 PM
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Quote:
Originally Posted by wayne65
I found some photos of the F-18 :
Please keep in mind. I hand brushed the paint on the hole jet. I would say it is a 10 foot paint job (you have to stand back about 10 feet ) for the jet to look good...LOL
Looks good to me. Do you remember Perfect Paint? I painted the fuselage of this Contender with it in 1971 using a brush. It looked like it was spray painted.
A friend painted his full size van with it using a foam brush and that came out like a spray job.
wish it was still around.

Thanks for posting the pictures. Looking forward to see the dolly.
Sep 13, 2019, 05:48 AM
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Hi: Zipman
Yes, I remember Perfect Paint and I also had a Contender in 1975 and 1982. When the Sig Kouger and King Cobra came out, I stopped flying the Contender but the Contender is still a Great plane. Your Contender looks Great and it dose look like it is spray paint.
That's not a bad ideal,,,,, My car can use a paint job.....LOL
I am working on getting the dolly photos off my old cell phone and onto the computer.

wayne
Sep 13, 2019, 07:43 AM
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I slapped the dolly together in about 3hrs. I used some old PVC pipe, wood dial rods, an old Futaba 401 Heli gyro and servo, a shipping tube and some wheels I had in a extra parts box. The dolly went together quick because I stayed up all night thinking how I was going to build it....LOL
after I had it fitted together, I could see the dolly was too flimsy. I grab some wood dial rods and slid then in the PVC pipe. I dropped some CA glue to keep the wood from moving. I just used long dry wall screws to hold the main wheels on. I used a trailing link nose strut and wheel from the extra parts box.
Under the back end of the jet, I glued in two PVC END CAPS (that where bigger then the PVC pipe). On the nose of the dolly, I put a large half cut Shipping Tube.
The under part of the, front of the jet, just sites in the shipping tube. I glued in a pie shape piece of foam to help guide the drop tank up and out of the dolly on take off ( This keeps the trop tank from getting hooked on anything during take off ).
You should see the look on peoples faces when I tell them " this is my retracts, It folds up into the jet on takeoff "......LOL
At one show, I just took off and a guy retrieved my dolly for me. He asked me where to put the dolly. I said put it back on the runway so I could land on it. AND HE DID.... next time I will think before I open my big mouth.

wayne
Sep 13, 2019, 07:46 AM
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Photos
Sep 13, 2019, 07:48 AM
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photos
Sep 13, 2019, 08:05 AM
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The bombs are made of soft foam. This keeps from hurting anyone. The bombs have whistles on them. You can here the bombs falling.
Sounds Cool....
I use the E-Flight bomb release for the bombs. I have the wing tip missiles held on with magnets. It helps, because almost every landing pops off the wing tip missiles. off.

Wayne
Sep 13, 2019, 08:17 AM
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it fly's off paved runway very easy. I have taken off of grass runways, the jet might bounce off the dolly if the runway is a ruff grass field. The Rim-fire .55 has tons of power so I can just punch the throttle and the jet will be air born before it can bounce off the dolly.

wayne
Sep 13, 2019, 09:23 PM
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Quote:
Originally Posted by wayne65
I slapped the dolly together in about 3hrs. I used some old PVC pipe, wood dial rods, an old Futaba 401 Heli gyro and servo, a shipping tube and some wheels I had in a extra parts box. The dolly went together quick because I stayed up all night thinking how I was going to build it....LOL
after I had it fitted together, I could see the dolly was too flimsy. I grab some wood dial rods and slid then in the PVC pipe. I dropped some CA glue to keep the wood from moving. I just used long dry wall screws to hold the main wheels on. I used a trailing link nose strut and wheel from the extra parts box.
Under the back end of the jet, I glued in two PVC END CAPS (that where bigger then the PVC pipe). On the nose of the dolly, I put a large half cut Shipping Tube.
The under part of the, front of the jet, just sites in the shipping tube. I glued in a pie shape piece of foam to help guide the drop tank up and out of the dolly on take off ( This keeps the trop tank from getting hooked on anything during take off ).
You should see the look on peoples faces when I tell them " this is my retracts, It folds up into the jet on takeoff "......LOL
At one show, I just took off and a guy retrieved my dolly for me. He asked me where to put the dolly. I said put it back on the runway so I could land on it. AND HE DID.... next time I will think before I open my big mouth.

wayne
AMAZING Engineering on that dolly. Great work, I looked at all the pictures but need to go back and study them in length. I liked your humor with the retractable dolly comments. Now the bombs are another highlight. They look real in the in flight pictures and got to sound real as well.
Who makes your foam F-18? So it looks like you have the dolly under your control until lift off when the dolly servo connector is pulled out. Is this correct?

Wayne, Thank You for posting all those pictures and the detailed description of the dolly build. I hope to get to use a version of your invention in the near future. I really like the pusher jets and eliminating the retracts. I got interested in this type of jet modeling just as 6mmflyrc was closing their business.
Actually I was on their site ordering what was their last F18 kit and was ready to pay when I got an email it was already sold and there were no more. Bummer.
Luckily thru the RCG classifieds I found there Skyray and F-15 kit so that is what I will be starting with. I see from your blog you have built some beautiful jet models. Keep them coming, its great encouragement seeing others in this hobby being successful and innovative. Thanks for some great ideas. I learn something new every time I come on RCG.
Stan
Sep 16, 2019, 06:46 AM
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Hi: Stan

Thank You for the kind words.
I am not sure what kit it is. The guy I got it from thought is was a Star-Max but not sure. The info that came with it were just some photos to build it and were not much help.
I will tell you this much. I have built a lot of the old Com-Bat Models jets and it is almost the same size as My F-18. All of the Com-bat Models were built around a .45 2cycl. pusher prop Gas motor that is close to an 80mm to 90mm size EDF. It is not hard to convert an EDF to a pusher Prop. If you want to build a nice size pusher prop jet, I would look into just getting a body kit of the jet you like in a 70mm to 90mm size and a .55 size electric motor should have more then enough power to fly it.
Keep in mind that foam jets work better as a grass lander then a wood or fiberglass jet.
You still need to put some fiberglass on the bottom of a foam jet for add protection on landings BUT fiberglass and wood kits do not like grass landings ( the flexing on the landing will cause more cracks and breaks for wood and fiberglass kits).
Everyone should know...Crack is bad.....JUST SAY NO TO Drugs....LOL

Wayne..
Sep 16, 2019, 07:02 AM
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Also, I for got to add: If I had used my brain.....I would have mounted the Gyro or any type of stabilizer in the jet and not on the dolly. DDAAAaaa.
Although my f-18 Fly's like it is on a gyro, not all builds will fly just right. So it is nice to have the added stabilizer on board if needed.
I have thought to make my next build with an electromagnet release on the dolly. Then I can do a lot more grass takeoff's without bouncing off the dolly : JUST MAK SURE you keep it far away from your receiver....LOL
Just keep in mind to put all the added weight on the dolly. This will keep the wing loading WAY down and make for a nice flying Jet.

Wayne


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