Tigercat RC pylon racer build project

Wow Andras, my heart skipped a beat and this image popped into my head when I saw this post.



The F-7F Tigercat. I climbed all over one sitting in a row of F-4U Corsairs at Airman Prep school in Norman Ok back in the mid fifties.

Looking forward to reading about your build.

Bob

It has a single engine though, Bob, unlike the F-7F fighter plane.

Yes, I know. A rose by any other name....

Bob

The real Tigercat.


Photo from https://www.hepper.com/tiger-cat/, cropped and resized.

what a beautiful project friend!, congratulations on your acquisition!... it will be a pleasure to see it in action!

Looks like the box has some age Andras. 30" span it's no little guy.



Some issues are yet to be sorted out, like finding the proper epoxy-based spray paint for the fuselage, etc., but the project will launch soon.

Epoxy paint doesn't fade and lasts forever. My Hobby Poxie painted scratch built C/L made about 50 years ago still shines like new.

Good luck with your project.

Andras, congratulations with the find and good luck with the build. I found this article here on the forum

https://www.coxengineforum.com/t11587-1-2-pylon-article

It says:"The text has a lot of good advice about how to make these small models really perform", not that I underestimate your talent and experience!!

Watching from the sidelines , is that a solid wing sure is thick looking .

getback wrote:Watching from the sidelines , is that a solid wing sure is thick looking .

Back in the day, proportional R/C gear along with batteries, although more compact than in the 1960's, was still heavier than today. Aircraft needed to develop sufficient lift for the payload.

It is still an improvement over 1959.

https://www.coxengineforum.com/t6494-1959-berkeley-impulse-single-channel-pylon-racer-build?highlight=impulse

balogh wrote:

Anyone has a proven tip on how to mitigate engine vibration impacts on the servos in addition to the grommets?

Thank you.

Hi András, vibrations are a trigger for micro servos.
Some time ago I posted here, how I do with my servos, because I can't find where to post exactly, but I'll explain; It is about disassembling the servo and placing silicone on the loose cables, making them firm and held by the glue (silicone), then a few drops of oil or Vaseline are placed on the servo cover, and it dries, this is for that when closing the servo, the lid is not stuck with the silicone. That's the ultimate solution, but you have to go to the trouble of disassembling the servo and carefully placing the glue inside. I'll see if I can find any photos.
The vibrations also destroy the eyelets where the servos are held by screws, so what I do is place some Orings where the servo remains floating, it is not always possible to achieve it since the spaces are very small and the servo remains trapped in the structure itself, but if you do the previous step (place silicone), you will ensure that your servos do not lose connection due to internal cutting of cables in their welding.

I dont have a lot of experience in this and dont claim to know if this will work, but it occurred to me that maybe if the vibrations could be stopped or limited from the engine in the first place then vibration management would be easier for secondary systems. I dont know how to do it, as I haven't thought it through, but if the TD could be mounted so it was still fully functional but on a mount that incorporated rubber sections like engine mounts in a car that may help make the problem with the servos easier to manage, by resolving the problem at the source.

Yabby

Yabby wrote:I dont have a lot of experience in this and dont claim to know if this will work, but it occurred to me that maybe if the vibrations could be stopped or limited from the engine in the first place then vibration management would be easier for secondary systems. I dont know how to do it, as I haven't thought it through, but if the TD could be mounted so it was still fully functional but on a mount that incorporated rubber sections like engine mounts in a car that may help make the problem with the servos easier to manage, by resolving the problem at the source.

Yabby

Placing an engine on a rubber block does not guarantee to limit vibration. These motors are extremely light (they do not have a proportional hub) and in relation to this they have a high rpm, two factors that add up when generating vibrations.
Different is the gasoline engines that have a high hub with respect to the rpm they generate and then the rubber pads are more applicable there. The same goes for a 4-stroke engine.
What sums up the issue is that the TD engines have many laps and it is from there that the vibrations arise.
The breakage or cut of connections hold from 15000 rpm, that is why it is more common to cut cables with a TD and not with a Babe Bee.
The size of the aero models also help to absorb vibrations, that is, the larger the model, the better it will withstand or absorb vibrations, it happens that, in most cases, a Cox TD engine is applied to a slightly small model and light for high displacement speed and the little hub of the engine, plus the small size of the model and the high rpm, all these factors add up in favor of cutting cables and connections, for all the aforementioned, it is best to glue the cables with silicone.
Of course, one factor that must be taken into account is to control and balance the propeller, this is essential when there are high rpm. This will also help reduce vibrations.
You can place an electric motor of more than 30,000 rpm and it will only depend on the good balance of the propeller, then there will be no vibrations. But an electric motor is not the idea of use in this case.

Beautiful color Andras, super low drag must be a winner. Are you going to dress-up the wings/tail a bit?

Enjoyed your build.

Somehow your going to have to pick up on that beautiful body color Andras. As I have mentioned before, I have no talent in that regard. My go-to guy for this advice is Levent. Without him I'm a lost puppy in the woods.

Bob