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Scottish Aviation Pioneer


Peter  Wood
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  • 2 years later...

HELP !!!!!!. Can anybody show some picys if the rudder/cable area under the tail. The roundish disc that joins the push rod. I am a bit stuck with a nearly finished model but dont seem to have enough room for the 'Cable'/disc to actually work. I have obviously made a big bobby.

Many thanks.

Bas

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Basil, nobody has replied so far - I suggest that you put a picture of the problem so that someone can offer advice.

 

Alternatively I note that Jimbo ( Jim Carss) said way back that he would help anybody building this model and gave his email address - send him an email or a PM to see if he can help.

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Basil, I don't have the Pioneer plan to hand so instead of photos then give us a better description of the problem...... could it be the tailwheel steering part?   Garry Hallam showed on page 2 back in 2007 an alternative part  is it that or something like that?

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Actually the photo is one from Page 3  25th March 2007.    It's one of several and I found a clear copy by double clicking  the photo.

I assume the rudder is mounted on a 'dowel ' and turns with the tailwheel.  Does that seem the part and the problem?

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15 hours ago, kc said:

Actually the photo is one from Page 3  25th March 2007.    It's one of several and I found a clear copy by double clicking  the photo.

I assume the rudder is mounted on a 'dowel ' and turns with the tailwheel.  Does that seem the part and the problem?

Yes the rudder is mounted on a dowel. The FG actuating disc is so close the the bulk head that the bowden centr (Plastic or metal) is so close to the last former so that in the process of moving backward and forward that is has to move sideways. The connector  is so close to the outer bowden, 1/2"a I have had to cut an elongated slot to allow the whole to move sideways to counter that same movement by the disc. I am hoping later today to show some pics!!!!!!.Then it is further complicated by the fact that it is not until the final assembly do you find if it works or not. Thanks for your interest KC. I have some family stuff to do now but will be back later.

Bas

PS I did not know you could get rid of the wording by double clicking. Damned annoying with those labels.

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4 hours ago, Basil said:

Yes the rudder is mounted on a dowel. The FG actuating disc is so close the the bulk head that the bowden centr (Plastic or metal) is so close to the last former so that in the process of moving backward and forward that is has to move sideways. The connector  is so close to the outer bowden, 1/2"a I have had to cut an elongated slot to allow the whole to move sideways to counter that same movement by the disc. I am hoping later today to show some pics!!!!!!.Then it is further complicated by the fact that it is not until the final assembly do you find if it works or not. Thanks for your interest KC. I have some family stuff to do now but will be back later.

Bas

PS I did not know you could get rid of the wording by double clicking. Damned annoying with those labels.

IMG_8851.thumb.JPG.d17bb9fe54f1bc197feffbe59e7a3cde.JPG

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KC, I have managed to submit some pics of the area.( Phew lots of methods but got there). I have had to cut around the mounting/adhesive to make a slot in order that the outer requires some lateral side/side movement so as to facilitate the back forth movement in order to turn 'Cam' attached to the rudder post..IMG_8839.thumb.JPG.9fd20022e0acb71c50c00b25b0f456de.JPG

I have never attempted a steerable tail wheel before. It seems that the elastic band required is oh so small.!!!!!

Oh well its done now, damage done . May not be the height of engineering but it seems to turn the rudder effectively. I dont know if this is what Chris had intended. I will add a plywood disc the the underside of the FG 'Cam' in order to increase the surfice area of adhesive .

Edited by Basil
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Basil, thats a couple of nice clear photos and I compared them to those on page 3.   I now see that a rubber band  (not shown in any of these photos) would be used to couple tailwheel to rudder in the traditional way.    

Your set up looks OK to me if you cut the outer snake casing  ( the white bit ) back a little which would allow  a little radial movement.   Snakes don't need to be supported that close - in my opinion.   I question whether the threaded steel rod is far enough into the snake inner - if that is in further than it appears then it's OK.

Most important thing is that the rudder never jams over as we all know in worst case this could cause a spin and perhaps no recovery possible.  Some slight slop in  rudder movement would be better than any jamming!    As a precaution I suggest fitting something like a 'keyway' to lock the rudder dowel to the 'horn' (fibreglass 'arm ' or quadrant )  Perhaps a flat on the dowel and a matching projection on the arm?  Needs an adjustable clevis at the servo end but I suppose you have already arranged that.

 

Don't rely on my opinion -see what other forum members think!

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A further thought -if you glued a bit of hardwood to the dowel rudder post then a small screw through the fibreglass arm could enable firm fixing in same position and allow removal of the arm to thread the z bend through .

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Hi KC, Thanks for your input. I intend to fit a ply disc to the underside of the GF cam in order to increase the surface area. Whilst typing this I have thought of ; Gluing 2 discs to the dowel, then as you suggested using a small screw to secure the GF cam to the dowel via the underlying disc.!!!!!!! Just a thought. Thanks again will cogitate the whole before making a final decision. As it stands with just a press fit in the dowel post, it appears to work well.

Bas

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Before you glue on th extra discs it might be worth thinking whether the dowel needs a bearing near the top - just a balsa piece across with the hole for dowel is probably all it might need.   Could be fitted before the extra discs are glued on  but not after.   Need to ensure it would clear any screw tip projecting from the discs.

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9 minutes ago, kc said:

Before you glue on th extra discs it might be worth thinking whether the dowel needs a bearing near the top - just a balsa piece across with the hole for dowel is probably all it might need.   Could be fitted before the extra discs are glued on  but not after.   Need to ensure it would clear any screw tip projecting from the discs.

KC, the dowel is fixed to the back of the moving rudder part. The dowel's axis is not constant as it moves slightly from side to side as it is in line with the rear of the moving part. The rudder is actually fixed to the dowel.

I did have thoughts like that but once assembled you twig the scene!!!.

Bas

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I have not seen the plan so I cannot quite understand the axis not being constant -  as long as you are happy with it then that's OK.

  My comment was because I envisaged that when the tailwheel was on the ground and perhaps pushed fully to one side the rubber band would tend to pull the dowel over with quite a lot of leverage.    The hardwood dowel won't give way but if it's just rotating in balsa I thought the balsa might fail and could jam the rudder.

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1 hour ago, kc said:

I have not seen the plan so I cannot quite understand the axis not being constant -  as long as you are happy with it then that's OK.

  My comment was because I envisaged that when the tailwheel was on the ground and perhaps pushed fully to one side the rubber band would tend to pull the dowel over with quite a lot of leverage.    The hardwood dowel won't give way but if it's just rotating in balsa I thought the balsa might fail and could jam the rudder.

2024-03-18_15-33-45.thumb.jpg.b5016de2935f1c1bc98588e369490ebb.jpg

Edited by Basil
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1 hour ago, kc said:

I have not seen the plan so I cannot quite understand the axis not being constant -  as long as you are happy with it then that's OK.

  My comment was because I envisaged that when the tailwheel was on the ground and perhaps pushed fully to one side the rubber band would tend to pull the dowel over with quite a lot of leverage.    The hardwood dowel won't give way but if it's just rotating in balsa I thought the balsa might fail and could jam the rudder.

The dowel is fixed to the rear of rudder. It is ILW the rear of the hinge line therefore it swings with the rudder. I will try and put a picture on.I to have such thoughts. I might try and just rubber band the tail wheel  to a fixed point and leave it at that, after all I have not got any models with a steerable tail wheel. 

Bas

Edited by Basil
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Basil, it looks as though you have fitted normal hinges into/ through the dowel.   Is that the way it is shown on the plan?   I expected the rudder would be pivoted on the dowel by just passing the dowel through a hole in top of fuselage and  a hinge (with hinge pin aligned with dowels centreline )  at the top of the fin by the balance tab.

I can see that it would work as you have built it and the dowel will pivot on the actual hinges not on dowel centreline.  

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16 hours ago, kc said:

Basil, it looks as though you have fitted normal hinges into/ through the dowel.   Is that the way it is shown on the plan?   I expected the rudder would be pivoted on the dowel by just passing the dowel through a hole in top of fuselage and  a hinge (with hinge pin aligned with dowels centreline )  at the top of the fin by the balance tab.

I can see that it would work as you have built it and the dowel will pivot on the actual hinges not on dowel centreline.  

KC,The dowel is only attached to the rudder by about 5/8 " at the bottom. Just looks like the dowel runs the length of the rudder. You are correct in saying as above. It does move OK. It is as on plan, at least as I see it, there are others see the same , we just follow the drawing. For the drawings I use are from experts who know far more than me.I have made some changes to the movement of the ailerons, using Frieze configuration, on the grounds that I had always wanted to try them and the wing had enough room to try. See Alan P.

You may see alternatives to this arrangement no doubt and I would be interested in seeing/hearing about them.

Anyway thanks for your comments.

Bas

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13 hours ago, alan p said:

Basil the dowel will pivot off centre , I had to releave the fusalage longeron in order to get clearence and travel. As you say not the best engineered solution.

Alan I have found this build a lengthy job as there were aspects that I had not encounted before.( Thats the whole idea of choosing this build) I have learned a few things along the way though . I have no doubt that the flying life of this model, at least for me( Still very much a novice) will be very short. As I will also try the brown paper on the fuse.

I would be interested in your model.

Bas

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Alan, ( Or any other builder of this craft) I have just turned my attention to the mounting of the tail plane/ elevator to the fuse. My drawings of those items and the fuse'  dont match. Can anyone put on some photos of that area , including the underside of the t/plane elevator area.

thanks.

Bas

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