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TOPIC: Profile Kits from TSP

Profile Kits from TSP 1 year 10 months ago #1720

  • LukeGoymour
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Success with the Iskra :cheer:

As previously reported, these kits manufactured by Piotr Tendera for his TSP motors, are beautifully produced and the boxes are very comprehensive.

Time and space have conspired against me, meaning it has taken a few months to get out to test-fly the model.:S

Initial test flights at Old Warden at the beginning of the month proved mixed: it was difficult to achive a consistent flight pattern and the model suffered from instability (first turning one way and then the other and oscillating, despite playing with nose weight, between looping and spiralling in undes power (a TSP L-2) :huh: The introduction of a thrust tab:




at Roger's suggested tamed the beast significantly as did moving the CG forward to around 75% from TE)

The model, however, still suffered from the dreaded 'death spiral' into the ground (still at Old Warden) which we could not cure at the time. Having other models to fly, we left the Iskra for the time being and, making use of the conditions, concentrated our attention on F-15 Eagles and Red Arrows Hawks! :)

A week ago, having an hour or so at the end of the day and noting that the wind had dropped to about 0mph I headed out again, this time to my local field. I noted from, Brian Lever's comments on his TSP MiG 19, that he had cut out the ailerons and bent them up about a 1/16" to good effect. I thought that this was a good idea, and so did the same with Iskra adding probably a little more than 1/16th on each tip. :dry:



The result was transformative. The model now flies consistently on L2 HP spiralling upwards in nice wide circles and then settling into a 'managed descent' for the glide. The model is a lot of fun and happily handles the larger motors.

So to summarise to get the model flying consistently it needed:

1. CG moved to 75% from LE (this may be able to be adjusted now with the thrust tab in place and moved back, but whilst the model is flying consistently I am loath to change it!)

2. Thrust tab, adding down thrust behind the motor

3. Ailerons cut out and at least 1/16th wash-out added to each tip

Critique:

One point worth noting is the tail fin on which the tailplane is mounted.It is made from balsa with the same horizontal grain as the fuselage and seems to be a weak point of the model.



Above: the Iskra's tail feathers. Note the grain direction of the fin, which makes it very vulnerable . It has been glued back together many times. Harder balsa with the grain vertical should solve this problem. :)

It protrudes from the models and after several heavy and not so heavy landings, it simply breaks, splitting along the grain I have now glued it back about 5 times. Replacing this part with a vertical grain would probably solve this.

Also, my kit, although comprehensive, did not have any foil tape to protect the fuselage. This is clearly needed as the exhaust gasses are hot and can make a mess of the wood without it!

All in all, though, this kit is pretty good, not bad at all in fact, but needs a little work to get its best performance. I have a video of it flying which I will try and make available at some point.:kiss:



Above: another view of the aileron modification. Well worth doing!



Above: the thrust tab and the (very necessary) foil protection.

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"You make the clouds your chariot, you walk on the wings of the wind" Ps 103 (HB 104):3
Last Edit: by rogersimmonds.

Profile Kits from TSP 1 year 10 months ago #1721

  • LukeGoymour
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Sucess with Iskra,

addendum:

I made a quick video review and you can see the flight here:
The following user(s) said Thank You: rogersimmonds, Tendera

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"You make the clouds your chariot, you walk on the wings of the wind" Ps 103 (HB 104):3

Profile Kits from TSP 1 year 10 months ago #1725

  • McTschegsn
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Terry Kidd wrote: Very good.

Is it possible to get a note of the position of the CG, the motor position and the position of the tab and its angle please? I know, I don't ask for much. :)


Hi Terry, just got back from England and off to Holland tomorrow. When I am back I will measure that happily for you.
Besides that I used the chance to testglide the Skyray in the windstill hangar at Buckminster again and got it trimmed perfectly which resulted in a 200 meter walk for the first flight :D
After launch the model spiraled upwards and when the motor burned out there was a loooooong glide :D
The CG on the plan is perfectly spot on... Have still to fiddle around with the thrust tab angle as the model gets its nose up very quickly. Will do a few photos and measurements when I am back.

Next step: Vintage Model Company remade DH 108 swallow - radiocotrolled :)

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Last Edit: by rogersimmonds.

Profile Kits from TSP 1 year 10 months ago #1738

  • McTschegsn
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Hey Terry,
as you requested, here is my Skyray Data:
CG 124mm from trailing edge at the fuselage
Motor block ends exactly at this position. Can be mounted a bit mor forward as the model tends to tilt up under power. (I used some lead balls in the node putty to add weight. Mayba can be saved)
The Tab location can be seen on the pic, the angle is around 35 to 40 degrees. I think I mounted the tab very far aft. It does not have noticeable effect for me bending this (Always keep in mind that Im new to this :) )

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Profile Kits from TSP 1 year 9 months ago #1740

  • Terry Kidd
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Wow, that looks very sharp.

Thank you for the dimensions. I had thought I had some spare time coming up but that seems to have melted away again. However, with these numbers I should be able to get flying much sooner. Thank you very much.

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Profile Kits from TSP 1 year 9 months ago #1751

  • Tendera
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Now the Skyray and Alpha Jet sets by TSP are available in the VMC store, I encourage you to buy and have fun ;)
www.vintagemodelcompany.com/douglas-f4d-...-260mm-wingspan.html
www.vintagemodelcompany.com/dassault-dor...-240mm-wingspan.html

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