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Old Feb 02, 2013, 05:32 AM
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Australia, VIC, Melbourne
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You need to do pushrod steering like this video below. Very few people ever get it right... very few peope even know HOW to do it properly.
There are geometry reasons you need to account for, which is easy, but then it creates a rock solid and flawless steering system. With zero freeplay, plus the wheel will retract dead straight every time too. You don't need to have 'retracted steering alignment blocks' as seen in this video though (someone else's video of their setup, he had added them before he knew about the correct pushrod method).
You need to set it up so the incoming pushrod/clevis is at the correct height, and maintained that way. The Linkgage Stopper on the servo arm assures this. The 'correct height' is the distance from hole-to-hole of the slider arm (eg 3mm) under, or above, the trunion pivot bush. Under if the servo is to the same side as the leg retracts, over if the servo is at the opposite end that the leg retracts. You don't have to do it via a Linkage Stopper, but that is best if the distance to the servo is short. For a long distance servo, like with a sleeve and pushrod from the hatch area, you just anchor the sleeve exit at the required height wherever that comes out before the retract. Or even just a longer pushrod in open air, make a 'support slotted guide' (a simple small bit of plywood) somewhere near the retract end which will control the height but allow sideways motions.
The servo does NOT actually have to be at any given height, you can 'step' the pushrod if a plane needs that instead. Always best to use a servo with the arm parallel to the steering arm (whether higher or lower, or equal height), as per this video does.

http://www.youtube.com/watch?feature...&v=_D7mqreMyaE
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Old Feb 03, 2013, 10:19 AM
B-58 Hussler
Austin, TX
Joined Feb 2011
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Thank you PeterVRC

Peter - Thanks! The light came on. Well now that I see how to do it, it is really simple. I had a ball socket or swivel at the servo end each time it failed. The failure point is that the rod would rotate enough either under stress, or gravity to get out of the proper geometry. My brain told me that that I needed the movement there at the servo end – not to hold it from moving in that plain. Now I will make two one solid link, and one pull-pull. Cycle them until I am sure they work. Thanks, to all. You learn something new every day! At least I hope to.
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Old Feb 03, 2013, 11:04 PM
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Name: F100 retract mounts 2.jpg
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Here's how I did my front steering and retract , I fly off of a rough dirt field and my plane weighs 7,5 lb's so far after about 50 flights its been bullet proof
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Old Feb 04, 2013, 06:50 PM
Extreme CNC Alloy EDF
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What retracts are those Rush? Look nice!
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Old Feb 05, 2013, 07:10 AM
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Hefty retracts.... just need hefty mounting too! LOL
Don't EFlite have metal like that?
And CS working on some for months too.... one day they will arrive and be cheap and affordable!
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Old Feb 05, 2013, 08:52 PM
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Quote:
Originally Posted by Extreme_RC View Post
What retracts are those Rush? Look nice!
There rc landers with struts from hobby king , There holding up well and my field is a rough hard dirt landing strip.
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Old Feb 08, 2013, 11:30 AM
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Joined Dec 2004
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Sorry for a silly question, but could someone please explain how they got the big elevator screw into the tiny hole of the black horn? I just tried opening the hole up abit for the screw to fit, and then tried screwing it in, but the screw wouldnt go in straight and then split the horn. Having a bad day with this, as just test run the motor and sucked in an extension wire straight through the fan, despite me tucking them out of the way.
My elevators also don't fit flush with the fuselage. The metal rod seems too long? Is this a bad kit or am I doing something Wrong?

Cheers
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Old Feb 08, 2013, 06:14 PM
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"Tucking them out of the way"... I am not sure what that exactly is, but I cannot imagine it being adequate. These fans have HUGE suction.... so everything in their path (eg in the inlet side ducting) needs to be locked down rock solid! Even rocks on the outside ground! HEHE
Generally done via channels in the foam, and taped over them with GOOD tape... and possibly even then painted over to assure the edges are stuck down too!

.....
This is what happens if even the tape is not stuck down well enough! Fibre tape is very sticky, but if an edge lifts then it will escalate into total lift-off quick smart!!
(In this case the tape had not been painted down, and it was about 25mm or so ahead of the fan. The fan lived.... luckily CS12's are very strong so it coped with any imbalance!)
...
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Old Feb 08, 2013, 06:17 PM
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The 'control arm bolt' in the collar..... well that should fit fine. So maybe you used some wrong part?
You can use any collar (3mm hole), and any long enough hex bolt (2mm typically), to replace it.
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Old Feb 08, 2013, 09:34 PM
edf flyer
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United States, CA, Marina
Joined Feb 2009
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wires

Quote:
Originally Posted by PeterVRC View Post
"Tucking them out of the way"... I am not sure what that exactly is, but I cannot imagine it being adequate. These fans have HUGE suction.... so everything in their path (eg in the inlet side ducting) needs to be locked down rock solid! Even rocks on the outside ground! HEHE
Generally done via channels in the foam, and taped over them with GOOD tape... and possibly even then painted over to assure the edges are stuck down too!

.....
This is what happens if even the tape is not stuck down well enough! Fibre tape is very sticky, but if an edge lifts then it will escalate into total lift-off quick smart!!
(In this case the tape had not been painted down, and it was about 25mm or so ahead of the fan. The fan lived.... luckily CS12's are very strong so it coped with any imbalance!)
...
I was just about to ask a question about the wires from my ailerons and retracts being sucked into the fan, seeing that i want to keep my wing removable, it looks like it could be sucked into the fan, can someone help with this situation.
thanks'
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Old Feb 08, 2013, 09:44 PM
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Wires 'in the air' are not necessarily 'loose wiring in the air', LOL.

Those are likely to be well ahead of the fan area, so even if they have some freeplay (excess, slop) they still cannot GET to the fan rotor. And usually very likely they will not come out of their plug(s) to be able to get one end free to head rearwards either - but that is something to account for, if they way you have done it means that could happen.
So the wiring from wing to fuselage is usually not a real problem - it can go straight across the duct if it had to, but usually you still try to route them in a path around the duct (along its inner side etc).

If you really wanted to, you could channel them down a tube that stays on the wing side. It can be loose for transport and slid down into the wing (a hole for it) when you assemble it. And that tube feed into a hole in the upper fuselage to the hatch area. If you wanted to make a nicer streamlined system for it.

More typical is just a clump of the wiring, wrapped together into one 'tube' sort of thing anyway. And one large connector to do the total joint of all wiring into the hatch area. (To save joining 6, or whatever, servo leads every time!)
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Old Feb 09, 2013, 12:12 AM
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Quote:
Originally Posted by PeterVRC View Post
Wires 'in the air' are not necessarily 'loose wiring in the air', LOL.

Those are likely to be well ahead of the fan area, so even if they have some freeplay (excess, slop) they still cannot GET to the fan rotor. And usually very likely they will not come out of their plug(s) to be able to get one end free to head rearwards either - but that is something to account for, if they way you have done it means that could happen.
So the wiring from wing to fuselage is usually not a real problem - it can go straight across the duct if it had to, but usually you still try to route them in a path around the duct (along its inner side etc).

If you really wanted to, you could channel them down a tube that stays on the wing side. It can be loose for transport and slid down into the wing (a hole for it) when you assemble it. And that tube feed into a hole in the upper fuselage to the hatch area. If you wanted to make a nicer streamlined system for it.

More typical is just a clump of the wiring, wrapped together into one 'tube' sort of thing anyway. And one large connector to do the total joint of all wiring into the hatch area. (To save joining 6, or whatever, servo leads every time!)
Thanks. I will do the tube and channeling trick
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Old Feb 09, 2013, 01:14 PM
B-58 Hussler
Austin, TX
Joined Feb 2011
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Elevator hole - Sniper 1

Sniper - Yes it was very tight. I ran a starting tap down it first. Not everyone has one, I know. You could run a very slightly larger drill bit part way to start it.

I know tht you want that little assembly to very tight.

If you are talking about the metal collar down in the assembly then the threads are not right.

I did a few things different. I drilled out the outer walls and incertied bearings. Then I used a 4 mm carbon rod. I also did not like the angles on the servo setup and changed them per many pictures/guys on this thread.

Hope this helps?
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Old Feb 09, 2013, 01:59 PM
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Crawley Down, sussex, England
Joined Dec 2004
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Hussler thanks for your help mate with all the pictures and advice, great help!
I didnt want to do a re post, so here are some pictures on the other thread to describe what i mean.

http://www.rcgroups.com/forums/showp...&postcount=437
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Old Feb 10, 2013, 11:43 AM
B-58 Hussler
Austin, TX
Joined Feb 2011
28 Posts
Flush mouted elevator with Fuselage

Sniper1, Here is my setup after seting the trunnion into the fuselage. It is not completely flush, but nearly. The scuff ply plates realy help and really add very little wait compared to the improvement in fault tolerance in a flexing elevator. Hope this helps.
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