Advice on ARF build.
#1
Hey guys. I am building a hanger 9 pulse 60 xt. I have everything unpacked and have went threw the instructions one time. Everything looks pretty straight forward and the quality of the kit is very impressive. I just need to run a heat gun over the covering. I will be putting a Saito 91 in it. Does any one have any tips or suggestions on how to build and how to setup for flight? I have never assembled an ARF of this type before, and I fly from a rough grass runway. Any info is appreciated. Thanks guys.
#4
Member
MPW,
It has been my experience that all ARF’s suffer from the same shortcomings. They do not adequately glue the high stress points such as the firewall and gear and they do not fuel proof the engine and tank area.
My suggestions are to reinforce the firewall by adding ¼” triangle stock. Sometimes there may already be some reinforcement there but you should check that it is not just held in place by hot melt glue instead of being adequately glued. I once had a H9 J3 that I could pick out the triangle stock with my fingernail. It looked good at first glance but was completely worthless as reinforcement.
The next high stress area is the landing gear. I have seen many ARF’s that will shed the gear during a normal landing on moderately rough grass. Some members of my club suggest that the lightweight gear acts as a mechanical fuse and will break away easily there by saving more extensive damage to the rest of the airframe. They make a good point, but the gear should at least be able to withstand a bounce or two without parting company.
I don’t know of any company that fuel proofs the engine compartment and tank area. You should have to take care of that little chore as well.
I like to add a few more hinges to the control surfaces in addition to what is supplied with the kit and keep the gaps as small as possible. High speed flutter can either tear off the control surface or jerk the gears out of your servos.
Double check the reinforcement around the fin and stab as well as the wing hold downs. Sometimes these can use a little touch up.
Then go fly and have fun, secure in the knowledge that it should not come apart right in the middle of some elegantly preformed maneuver.
It has been my experience that all ARF’s suffer from the same shortcomings. They do not adequately glue the high stress points such as the firewall and gear and they do not fuel proof the engine and tank area.
My suggestions are to reinforce the firewall by adding ¼” triangle stock. Sometimes there may already be some reinforcement there but you should check that it is not just held in place by hot melt glue instead of being adequately glued. I once had a H9 J3 that I could pick out the triangle stock with my fingernail. It looked good at first glance but was completely worthless as reinforcement.
The next high stress area is the landing gear. I have seen many ARF’s that will shed the gear during a normal landing on moderately rough grass. Some members of my club suggest that the lightweight gear acts as a mechanical fuse and will break away easily there by saving more extensive damage to the rest of the airframe. They make a good point, but the gear should at least be able to withstand a bounce or two without parting company.
I don’t know of any company that fuel proofs the engine compartment and tank area. You should have to take care of that little chore as well.
I like to add a few more hinges to the control surfaces in addition to what is supplied with the kit and keep the gaps as small as possible. High speed flutter can either tear off the control surface or jerk the gears out of your servos.
Double check the reinforcement around the fin and stab as well as the wing hold downs. Sometimes these can use a little touch up.
Then go fly and have fun, secure in the knowledge that it should not come apart right in the middle of some elegantly preformed maneuver.
#5
Senior Member
Joined: Aug 2008
Posts: 2,158
Likes: 0
Received 0 Likes
on
0 Posts
From: Burtchville,
MI
I think regent's got it. Fuel proofing the engine compartment? Hobbico recommended an epoxy/denatured alcohol mix brushed on. I have heard about epoxy/lacquer thinner, epoxy/acetone mixes. I'm going to try the epoxy alcohol on my new ARF. I'm fearful that lacquer thinner and acetone may corrupt the epoxy mix.
Bill
Bill
#6
Thanks for your help guys. It seems fuelproofing, and reinforcing the firewall, landing gear, and rear stabilizer need a some attention. One last question guys then I will leave u alone. As I stated above I will be using a Saito 91. I would like to mount it on its side or inverted for a little cleaner look. Would this cause any problems as far as tuning, fuel tank placement, engine mounts, idle performance? Also what would be a good prop brand and size to start with? Not looking for speed, just something with good takeoff and landing performance. Thanks again guys.





