Building a Carbon Fiber tail pitch control rod.

[xatled99]

I used a $6 2.5mm ID / 4mm OD 24" CF tube from LHS. I cut it down to about 14 5/16". In retrospect, 14 1/2" would have been the right length.

I cut 2" off each end of the stock pushrod and taped off 3/4" with masking tape. I sanded the exposed metal and washed it in acetone. I then applied epoxy to the pushrod ends and slid them in up to the tape.

It came out to about 7 grams with ball links.

edit: Dubro 2mm threaded couplers have an OD of 1/8".

[toolguy420]

Originally Posted by xatled99

I used a $6 2.5mm ID / 4mm OD 24" CF tube from LHS. I cut it down to about 14 5/16". In retrospect, 14 1/2" would have been the right length.

I cut 2" off each end of the stock pushrod and taped off 3/4" with masking tape. I sanded the exposed metal and washed it in acetone. I then applied epoxy to the pushrod ends and slid them in up to the tape.

It came out to about 7 grams with ball links.

edit: Dubro 2mm threaded couplers have an OD of 1/8".

Nice job, man...thanks for the contribution!

[helijack]

Originally Posted by xatled99

I used a $6 2.5mm ID / 4mm OD 24" CF tube from LHS. I cut it down to about 14 5/16". In retrospect, 14 1/2" would have been the right length.

I cut 2" off each end of the stock pushrod and taped off 3/4" with masking tape. I sanded the exposed metal and washed it in acetone. I then applied epoxy to the pushrod ends and slid them in up to the tape.

It came out to about 7 grams with ball links.

edit: Dubro 2mm threaded couplers have an OD of 1/8".

Just curious.........what camera did you use to take this pic, and what lens?

[xatled99]

Canon PowerShot SD780.

[Viet-Lama]

Originally Posted by ken22golf

I ordered a few of these http://hobbycity.com/hobbycity/store...idProduct=6722

I almost bought some CF rod from HK to make pushrods. Problem is HK ships them in a large box which adds 370grams to the shipping charge. $5 in CF costs $27 after shipping When I was ready to check out I was like and
Check out BPHOBBIES.com, they have an assortment of hollow / solid CF cheap. The CF I ordered along with a couple other parts only cost $7 to ship! As an extra bonus ill get it in 4-5 days instead of 17-20

[D Grade]

Hey SNJ, dunno if you've been asked yet on the thread but would you be willing to hook a brotha up with a couple of those (ofcourse paid for). Lemme know, I'd buy a few off you.

[snjbird]

PM sent.

[D Grade]

Thanks again SNJ! Ill get the measurements to you in the next week!

[Santini]

I ordered some carbon tube Thick Walled 3mm OD, 2mm ID. I figure can slide 2mm rod down it and attach align links on the ends. (It is lighter than sliding the metal pushrod down it, which is a smidge under 2mm, btw). I also bought some 3mm rod to try that. Got it at bphobbies, local and cheap.

I used 2mm rod on one of my 450s and it works great. At a length of 15' or so tho for a 500, it'll bend similar to the metal pauhrod, thus looking to try 3mm tube and if that isnt stiff enough. I have the beam pushrod on another 450, but it strikes me as a bit weaker than the 2mm rod set up, but it works fine.

[Santini]

I ordered 3mm carbon rod from BP hobbies (3ft for $2.30). Cut the rod to the length of the metal pushrod. Take a hobby file and sand the end of the rod to make it narrower - I created a little shoulder. Take a small drill bit and increase the diameter of a standard align link. Coat the end of the rod in epoxy and fit the link on it. Make sure when you fit the second link it is angled properly for the servo horn and tail. This is very very stiff and will not bend.

Weight of std metal pushrod + 2 guides = 11.75 grams.

Weight of Santini's carbon replacement = 4.88 grams

Weight savings = 6.87 grams.

[snjbird]

yup that what it's all about!

[JackdaWack]

I tried 2mm ID, and the original metal rod wouldn't fit into it, the 2.5mm ID was a little loose, but got the job done damn good.

[rotorfan]

Great ideaa snjbird! I went with the 1st design except I used full size linkage rods instead of cutting one in 1/2 just to get a little more bite still lighter than stock not sure how much I dont have a scale. I went with blue heat shrink to accent my color sceme.

[Santini]

I also bought 3mm tube (2mm ID) and I could indeed stuff the metal rod thru it w a little effort but I thought it was heavy, so I nixed that. Then I looked at using tube w ends, but I felt that tube was still pretty fragile/bendy, even the thick walled tube I felt needed more stiffness. That is when I chose 3mm rod as described which is stiff as hell versus tube.

[Inverse]

Here you go Brotato's, a howto I did on another forum.

The CF arrived today, so here's a quick how-to of how I made them.

This rod has an OD of 3mm and an ID of 1.2mm. I got the 1.2mm over the 1.5mm that is also available as I liked the idea of the added wall thickness and the threaded rods are;

x

I then measured the rod and cut it a bit overlength by rolling it with a sharp knife, I then trimmed and dressed the ends with the dremel.



I had a drill bit handy, but was lucky in that when I inserted the threaded rod, it bit into the CF and cut it's own thread.
It would probably be OK as is, but I popped some CA in the ends and screwed the threads in.


This is all glued in and cut to length.
Idle hands and all that....


I then cut some heatshrink just for aesthetics.



Here it is installed, this thing is extremely rigid.


Weight savings.



Those guys who wanted one, I'll get them in the post this week.

[Santini]

thats a 250.

[snjbird]

I have fabricated them for all my E helis 250-600, on the 600 I added a guild, just to be safe... all the others are free floating! I stick with the wire and guides on my nitros, too many unpredictable harmonics to be a test dummy there!

[Steve Evans]

Originally Posted by fogger

Either way you will want to come up with some type of support for the tail push rod. I tried this on my 600, the second version with a carbon rod ca'd over the stock pushrod. Watch my backwards on-board video on you tube and you will see the crazy oscillations the rod went through. Now I later found that I had a couple bad bearings in the grips which probably helped produce the vibes, but anyway watch it and you will see what I mean...


http://www.youtube.com/watch?v=AgZIJ3_8WiI

-Fog

That's a fairly conclusive experiment!

I've not had any trouble with the standard setup on either my 450SEv2 or 500ESP, but I've made a point of keeping the guides well lubed. That said, the guides do wear a bit and the guide holes have certainly enlarged. Does anybody make CNC guides with decent guide bushings?

Steve

[Santini]

Originally Posted by Santini

I ordered 3mm carbon rod from BP hobbies (3ft for $2.30). Cut the rod to the length of the metal pushrod. Take a hobby file and sand the end of the rod to make it narrower - I created a little shoulder. Take a small drill bit and increase the diameter of a standard align link. Coat the end of the rod in epoxy and fit the link on it. Make sure when you fit the second link it is angled properly for the servo horn and tail. This is very very stiff and will not bend.

Weight of std metal pushrod + 2 guides = 11.75 grams.

Weight of Santini's carbon replacement = 4.88 grams

Weight savings = 6.87 grams.

--------------

Works perfectly. 3mm solid rod is uber strong - no flex, substantial weight reduction versus stock (this is the lightest home-brewed solution I've seen, 58% weight reduction and IMO anything that lightens the tail on a 500esp is a good thing...), no guides to bind, tail response is perfect, looks good, very simple to make (3mm solid rod, 2 links, epoxy, hobby knife, file or sand paper + few minutes), parts cost <$1.

(I did the same thing awhile back on two 450s w 2mm solid rod which works perfectly for that boom length. Here you need 3mm for this (500) length of boom to eliminate any flex. Hollow has too much flex, IMO, even using the thick-walled hollow.).

[Larry227]

Would this work for the 500? http://www.heliproz.com/prodinfo.asp?number=125860