Push Rods guides ?

[Bigeard]

On the video that Josh made of the "FT Commuter Build" at round about 9:23 into the video , he is fitting the push rods from the middle of the fuselage to the rear to link up with the elevators , As Ive seen in a previous video , would it be possible to use either a plastic straw or some thin gauge aluminium tubing to feed the push rod through as a guide and then secure the straw / tubing at both entry and exit points with a bit of glue for extra security ?
Thanks

 

[Sero]

On the video that Josh made of the "FT Commuter Build" at round about 9:23 into the video , he is fitting the push rods from the middle of the fuselage to the rear to link up with the elevators , As Ive seen in a previous video , would it be possible to use either a plastic straw or some thin gauge aluminium tubing to feed the push rod through as a guide and then secure the straw / tubing at both entry and exit points with a bit of glue for extra security ?
Thanks

Too loose of a fit isn't good either, small straws or plastic coffee stir sticks work well. Just careful not to melt the plastic with the hot glue.

 

[Merv]

…… would it be possible to use either a plastic straw or some thin gauge aluminium tubing……

+1 on the coffee stirrers.
Zip ties also work, make them into a small loop, then cut the tail on an angle and stick it into the foam. Hold them in place with a dab of hot glue.

 

[FlamingRCAirplanes]

I use straws from capri suns. The only problem being I kind of don’t like capri suns and I have to drink 3-4 per plane. 🤪

 

[PsyBorg]

@Bigeard

https://www.amazon.com/dp/B085NDPMGZ/?tag=lstir-20

 

[Jade_Monkey07]

Depending what you're using for a push rod. I take a piece of scotch tape and put a little square of paper in the center of it and bend the paper portion into a u shape then stick that over carbon rod and stick the tape down to the foam where it needs some guidance. Very low friction and seems to last.

The rod here kept bending up into the prop

Not the best version I've done but it keeps it down and directs the force properly to the rudder

 

[Piotrsko]

You are primarily stopping the rod from flexing on a push condition which reduces that movement. In this case left rudder. Anything that restrains that flexing will work since foamboard generally doesn't fly fast enough to flutter.

 

[Merv]

....foamboard generally doesn't fly fast enough to flutter.

You must not be trying hard enough. Just add more cells and a higher Kv motor. You can easily get foam board over 100 mph

 

[Pieliker96]

You must not be trying hard enough. Just add more cells and a higher Kv motor. You can easily get foam board over 100 mph

Most foamboard builds won't get that fast. With that said it is a possibility: I've encountered flutter (or at least some aerodynamic resonance) at around 80mph with my EDF research testbed. Here's what that looks like (yellow line is acceleration in the Z direction, normal to the flight path)

The resonance occurred in the leftmost half of the graph. It was from (approximately) 0.5 to 2.5g at around 3Hz and was accompanied by the wing visibly flexing. As soon as I saw it, I backed off the throttle and got the plane slowed down

 

[checkerboardflyer]

Here’s another option; Du-Bro Micro Pushrod Guides. Bought these at Amazon. Currently finishing up a Depron model. I like that these have barbs that can be pushed right into the Depron. Probably want to use a bit of hot glue when you do it. More resources on my blog: https://foamboardflyers.com

 

[Bigeard]

Here’s another option; Du-Bro Micro Pushrod Guides. Bought these at Amazon. Currently finishing up a Depron model. I like that these have barbs that can be pushed right into the Depron. Probably want to use a bit of hot glue when you do it. More resources on my blog: https://foamboardflyers.com

 

[Bigeard]

Great idea checkerboardflyer , but looking at this has given me a similar alternative . How about using the larger plastic wall / floor spacers that you can buy in a pack with hundreds in. They are in the shape of a cross strong with almost no weight , a hole can be drilled through one of the arms large enough to accomodate a push rod , the other three arms could be used to push through through the foam board and hot glued as supports !

 

[Piotrsko]

The simple solution is the next size up wire diameter for the same weight as all the guides and glue gobs.
If you're really weight conscious, string pull pull systems.

And I said most foamboard don't go that fast didn't say all.

@Pieliker96 hmm no negative on your flutter so maybe pushrod flex, but cool being able to record that data.

 

[checkerboardflyer]

Great idea checkerboardflyer , but looking at this has given me a similar alternative . How about using the larger plastic wall / floor spacers that you can buy in a pack with hundreds in. They are in the shape of a cross strong with almost no weight , a hole can be drilled through one of the arms large enough to accomodate a push rod , the other three arms could be used to push through through the foam board and hot glued as supports !

If you are a modeler, making your own is usually more rewarding than buying them. One of the benefits of this forum is getting ideas from other people. Maybe you could post some pics when you finish.

 

[Tench745]

Lately I've been taking a small strip of printer paper, wetting it out with white glue, and then rolling it tightly around a scrap of pushrod. When it dries you can easily crack the glue free from the pushrod and you have a super lightweight, well fitted pushrod guide which you can cut to any size you want and glue anywhere you may need it.