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Old Sep 20, 2009, 05:33 AM
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About shear webbing and grain direction.

I am about to start building the BOT kit version, and I`m currently in the phase where I`m staring at the plans trying to understand every aspect of the build before i start. If the arf version is built the same way, you will not be able to see the direction of the webbing, because it consists of hard balsa blocks that go directly under the spar with the grain i the right direction. These blocks are hidden behind a ply capping with the grains going horizontal. So what you are seeing is not the webbing, but the enclosure.
It`s the first time I`ve seen this type of construction, but it seems to make sense.
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Old Apr 25, 2011, 07:49 AM
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Arf-bird of time-nearly completed.

I have nearly finished my ARF BOT.I used a HS 82 MG servo for the elevator,mounted in the fin.I also cut a slot in the elevator servo cover,so l could use the 2nd hole on the servo horn-more throw,than without a slot.I am ordering 250mm electric spoilers,hopefully they will arrive mid next week.I will have to build a balsa box for them,and figure out how to run the ext leads to them.The centre of the main panel is not strong.My bird of time will be used for mainly slope,l will hi-start it as well-flat field.I am definetly going to glass the centre of the main panel join,with epoxy resin and woven cloth-top and bottom-approx 1 inch wide,before high starting it.A trial centre of gravity check shows it will need more ballast-to balance at 95.3 mm.Once the spoilers are all fitted,and the centre panel is glassed,l will add the ballast to balance.Overall,l am happy enough with it,l also trimmed about 1 cm off the bottom of the rudder as it would of hit the ground on landing and torn it out of the rudder post.regards damo
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Old Apr 25, 2011, 08:19 AM
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Quote:
Originally Posted by Damian Couzoff View Post
I have nearly finished my ARF BOT.I used a HS 82 MG servo for the elevator,mounted in the fin.I also cut a slot in the elevator servo cover,so l could use the 2nd hole on the servo horn-more throw,than without a slot.I am ordering 250mm electric spoilers,hopefully they will arrive mid next week.I will have to build a balsa box for them,and figure out how to run the ext leads to them.The centre of the main panel is not strong.My bird of time will be used for mainly slope,l will hi-start it as well-flat field.I am definetly going to glass the centre of the main panel join,with epoxy resin and woven cloth-top and bottom-approx 1 inch wide,before high starting it.A trial centre of gravity check shows it will need more ballast-to balance at 95.3 mm.Once the spoilers are all fitted,and the centre panel is glassed,l will add the ballast to balance.Overall,l am happy enough with it,l also trimmed about 1 cm off the bottom of the rudder as it would of hit the ground on landing and torn it out of the rudder post.regards damo
Since you have stripped the covering off, what is your oveall assessment of the quality of the build of the wing.

You say the center joint is not strong. What do you mean?

I would LOVE it if you would post some detailed photos of the uncovered ARF wing.
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Old Apr 25, 2011, 08:37 AM
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Originally Posted by aeajr View Post
Since you have stripped the covering off, what is your oveall assessment of the quality of the build of the wing.

You say the center joint is not strong. What do you mean?

I would LOVE it if you would post some detailed photos of the uncovered ARF wing.
The centre joint will not take a heavy duty hi-start launch,it has to be glassed.My 98 inch ricochet,had foam core wings,and a 10mm diameter aluminium wing rod,and the wings flexed ALOT,but did not break.I am going to use the same bungee,for the BOT.The kit BOT uses a 6mm steel rod,which would be stronger than the ARF BOT wing,which uses ply dihedral braces only at the centre join.regards damo
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Old Apr 27, 2011, 06:31 AM
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I am picking up the 250mm electric spoilers tommorow afternoon.I have thought about the installation thoroughly.By cutting the monokote carefully, to the width of the spoiler,and inlaying 5mm thick balsa between each rib-epoxy in.Each spoiler will be against the main spar,epoxied on,and epoxied to the 5mm thick balsa as well-essentially a box around each spoiler.Cutting the ribs,will be tricky-to a square section-to fit each spoiler.The spoiler lead will have to be routed by cutting the bottom sheeting only 3mm wide,and placing in,then glue the bottom sheet back over the lead.A y-lead will be located in the fuse-easy access,and 300 mm ext leads will be used to facilate easy assembly into the y-lead,before bolting on the wing.I am so far happy with my installation of the servos,the spoilers will be the most time consuming task of the entire installation.Once installed,its ready to maiden-maiden will be from the slope.
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Old Apr 27, 2011, 06:40 AM
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Not sure gluing the spoilers to the spar is a good idea. That spar flexes and could bend the spoilers. Your spoiler would become part of the load bearing structure and I don't think you want to do that.
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Old Apr 27, 2011, 06:47 AM
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Originally Posted by aeajr View Post
Not sure gluing the spoilers to the spar is a good idea. That spar flexes and could bend the spoilers. Your spoiler would become part of the load bearing structure and I don't think you want to do that.
True,the spoilers could be placed further back towards the trailing edge,luckily l have not cut the opening yet for them, as l am picking them up tommorow afternoon.I will place them away from the spar,thanks for that,regards damo
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Old Apr 27, 2011, 07:00 AM
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I would definately place them near the spar, but I would not glue them to the spar.

I don't know what spoilers you are getting. Maybe they recommend gluing them to the spar. And others may have a different opinion.
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Old Apr 27, 2011, 07:15 AM
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There are no installation recommendations,only 35-50 % of the chord,and 1/3 spanwise-thats what graupner recommended for there 370mm spoilers.I have installed 250mm electric spoilers in my ASW 28-2.5 metre,they are placed just behind the spar,and l have had no problems with them bending-and it does fly fast-slope only,it has a 8mm diameter stainless steel wing rod-minimal wing flex on that model.I will place the spoilers just behind the spar,on the BOT,with a 5mm thick balsa box around them, not touching the spar,as you have recommended,as these wings will flex alot on high start launch,and the spoilers are close in to the root compared to other models l have,where they are further outboard,and have relatively strong wing rods.thanks damo
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Old Jul 04, 2011, 03:01 PM
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Is the ARF wing easy enough to 'beef up' for winch launch or is the kit build up the only way to go? I've not used the winch before but the club I just joined uses one. I'm told to use CF spars and wrap the joints. I'll probably just build it but thought I'd ask since one has been opened up here. Hands on knowledge is what I'm looking for.
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Old Jul 04, 2011, 04:55 PM
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Originally Posted by maxwellmark View Post
Is the ARF wing easy enough to 'beef up' for winch launch or is the kit build up the only way to go? I've not used the winch before but the club I just joined uses one. I'm told to use CF spars and wrap the joints. I'll probably just build it but thought I'd ask since one has been opened up here. Hands on knowledge is what I'm looking for.
I have modified several planes and came to the conclusion that it is better to build from a kit than to modify an ARF. Adding carbon fiber to the spars of an ARF would be a lot more effort than building a new wing.
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Old Jul 04, 2011, 05:05 PM
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Just don't test your BOT against a a stand of hickory trees. The trees are way stronger.
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Old Jul 05, 2011, 06:39 AM
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Originally Posted by williamson View Post
I have modified several planes and came to the conclusion that it is better to build from a kit than to modify an ARF. Adding carbon fiber to the spars of an ARF would be a lot more effort than building a new wing.
Exactly,way to much effort to modify the arf BOT purely to winch it.I maidened mine three weeks ago off the slope,flew perfectly,and turned better than l thought it would-no ailerons,only rudder.The spoilers work well,no dropping of a wing either, when deployed.The wind was a light 10 mph on launch,and had increased to 15 mph during the flight and l decided to land,l was very high up in the final stages of the maiden flight.It also tracked true,so it will go straight up on a hi-start,C of G also is okay,happy with it.
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Old Jul 05, 2011, 08:53 AM
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[SIZE="2"]Quote:
Originally Posted by williamson
I have modified several planes and came to the conclusion that it is better to build from a kit than to modify an ARF. Adding carbon fiber to the spars of an ARF would be a lot more effort than building a new wing.

Quote:
Originally Posted by Damian Couzoff
Exactly,way to much effort to modify the arf BOT purely to winch it.I maidened mine three weeks ago off the slope,flew perfectly,and turned better than l thought it would-no ailerons,only rudder.The spoilers work well,no dropping of a wing either, when deployed.The wind was a light 10 mph on launch,and had increased to 15 mph during the flight and l decided to land,l was very high up in the final stages of the maiden flight.It also tracked true,so it will go straight up on a hi-start,C of G also is okay,happy with it.[/
SIZE]

Thanks, that is what I was thinking too.

ps. Leadchucker sorry for your loss....that looked tragic
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Old Jan 20, 2012, 02:49 PM
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Hungary, Borsod-Aba˙j-ZemplÚn, Miskolc
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Hi! I'd like to get a BOT ARF. Where can I order one in the EU?
Also I was wondering, how difficult it would be to install spoilers on the ARF version?
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