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Within our club, First Arkansas Soaring Team (F.A.S.T.) there are several of us who are interested in Aerotow. We have had some success with monthly Aerotow events and purchased this model for an Aerotow trainer. I thought I would document the build here so everyone can get an idea of the quality of these super cheap models. Stay tuned and I'll be updating this daily.
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Within our club, First Arkansas Soaring Team (F.A.S.T.) there are several of us who are interested in Aerotow. We have had some success with monthly Aerotow events and purchased this model for an Aerotow trainer. I thought I would document the build here so everyone can get an idea of the quality of these super cheap models. Stay tuned and I'll be updating this daily. -
Here are some photos just to let you see the overall quality, or lack thereof. There seems to be no concept of true or accurate. It would actually be better if they wouldn't do anything. At least you wouldn't have to undo anything, you could just do right the first time.
I'll start with the main wheel in the next post.
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The first thing I did was use a Dremel to cut out the main wheel. The one on the right is the original the other is a 3" wheel I will use.
Laid out the new opening. Note the crooked former inside.
After removing two layers of plywood to widen the hole I epoxied in some hardwood supports.
Then I milled some slots and epoxied in the wheel.
Much better.
Moving on to the tailwheel.
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Obviously the same guy drilled these holes that mounted the main wheel. I think it was Won Hung Lo's brother...Tu Duh Lef. BTW the original wheel was pretty cheesy. This is one I had, very light weight foam wheel.
Epoxied in some doublers and keepers for the rudder controls.
Used a little dab of epoxy to secure the axel to the fuselage.
Next is the rudder.Last edited by ingrahal; 06-03-2016, 04:28 AM.Comment
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I found pencil or pen hard to remove from the finish so I covered the tailpost with masking tape and marked the center line.
I cut the slots and glued the rudder on using CA hinges.
The rudder is designed to be pull-pull controlled but the solid steel rods that came with the kit would not work. I couldn't even force them through the bends in the tubing. Luckily I had some pull-pull cable and that worked nicely.
Next will be the elevator.
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You 'could' leave the wheel alone and just make sure you land in the correct crosswind!
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Like everything else on this model the horizontal stabilizer was crooked. A 1/64" shim on one side took care of it.
Ok so this entire project is an exercise in cheap. That includes the servos we ordered from LemonRx.
I mounted the elevator servo the traditional way, on the hatch cover.
I used a ball link connector for the linkage to make it easy to remove. Had to go to the innermost hole on the horn to get the recommended throw of 20 mm.
Moving on to the electronics and canopy.
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Not for the faint of heart ,but for a few hundred bucks for this kit and some patience can possibly build up to a semi-decent kitComment
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I agree, the airframe can be made airworthy with some patience. I'm more concerned about the cheap electronics, not sure how reliable they will be. Especially in a sailplane where the range will be tested. Here is a list of our costs:
Airframe = $230
Wheels = $10
Rudder cables = $10
Servos = $52
Rx = $25
Batteries = $25
Servo extensions = $10
Canopy = $ 62 (should have been included in kit)
Misc. = $10
Total = $434Last edited by ingrahal; 06-08-2016, 04:17 AM.
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I checked the canopy fit and found that the fuselage was too wide. This area of the fuselage was very weak and poorly assembled. I removed the front former and radio tray. Then pulled the sides of the fuselage together with some strapping tape. I epoxied the former and tray back in and added some plywood cross pieces for structure and mounting the radio gear.
I added this piece to mount the batteries on.
I have some of these Multiplex tow releases on order, but as usual I was too impatient to wait on them to arrive so I headed over to my sons shop and made one on his lathe. I chose brass for the added weight.
I'll move on to the wings next, then final assembly and balance.
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If anyone needs parts- you can go direct to the manufactures direct website: www.hobby88.com
Last i new, they only ship an express method that while a bit pricey, gets items(packed very well) to the USA in 7-10 days.
Here's a price list(1-2yrs old) with item #'sComment
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Thanks Tom, we ordered our canopy from HobbyWin.com and got it in about 2 weeks. $62 shipped. They have other parts too.
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Hi Art.
Wonderful thread and I commend you for taking the time and doing it right. Very detailed and well thought out solutions.
My only disagreement with the thought process is the radio gear. Why put all this effort into a project and put in cheap servos? One good elevator servo and two good aileron servos could save this entire project from possible disaster? If there was anyplace I would spend money its on the servos. Without them you're picking up pieces. Just my two cents.
I'm positive your setup is excellent and hope everything is perfect for you.
Len Buffinton
Team Horizon HobbyComment
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Well of course you're right. I guess my thinking was that this was a test of the cheap radio gear as well as the airframe. Besides the critical servos you mentioned I'm concerned about the range and reliability of the Rx. In this case it's an OrangeRx receiver with a LemonRx satellite. Some of us are getting together for lunch tomorrow and will be discussing this project. Thanks for your input I really appreciate it.
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Hi Art,
We just put together one of these a couple weeks ago so I thought I'd let you know what we put in ours. A club member bought the plane over a year ago but didn't even open the box. He said if we wanted to assemble it then we could have it. As mentioned it is a cheap model so we didn't want to spend too much on it either. There is another thread on RCG for this plane that is over 120 pages. I did read through all of that before we started.
I am not a builder so can't take credit for much of this assembly. My friend Pete did the work.
So here's our setup.
We did not replace the main wheel. It was in pretty solid so we left it.
We put Hitec HS-81 servos in the wing (ailerons and flaps).
The elevator has a Hitec HS-82MG.
The rudder has a Hitec HS-422. It is a pull-pull with wire not the rods that came with the kit.
The tow release is from Esprit which is a TopModel part number top05013 and is operated by a Hitec HS-225MG.
My towing partner had a Spektrum AR7010 receiver so we used that.
The battery is a 5 cell NiMH 2000 mAh (I had 2 of those already so didn't have to buy one).
The flaps were cut off, turned over and re-hinged (as recommended in the other thread).
We left the ailerons alone. They don't go down as far as they go up because of the hinge but that just gave us some built in differential.
The tail wheel was not straight so Pete shimmed it straight. The ballast is some lead shot in a pouch that is held in place with industrial strength Velcro. This way we can adjust how much is in it to fine tune the CG.
We started with the CG at 62 mm but it was pretty nose heavy, ran out of elevator trim. We moved the battery back a bit and she flew better but I think we went too far aft. She was kind of sensitive on the elevator the last couple flights. I don't where that CG ended up. We have it now at 63 mm and adjusted the control rod length for the elevator so the trim can be centered again on the transmitter.
We hope to fly her again on Friday to continue finding the CG we are happy with.
I hope this helps.
DanComment
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