stunthanger.com
General control line discussion => Open Forum => Topic started by: eric rule on April 14, 2017, 08:53:16 PM
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Just a note to let everybody know that RSM's new stock of the heavy duty push rod ends has arrived from the machine shop. These new and improved ones are made from 301 series Stainless Steel so they will handle with ease the largest stunters and will resist bending or distorting under extreme control surface loading. These push rod ends are available with right hand and left hand threads that make it possible to adjust the push rod length by simply turning the carbon fiber push rod in either a clockwise or counter clockwise rotation.
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Eric,
What's your preferred glue for attaching the aluminum cap to the CF rod?
Without ever having asked anyone, I've always used slow-set JB Weld. Would you trust CA?
Rusty
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Hi Rusty:
First, the push rod ends I sell are not aluminum. They are made from 301 series stainless steel. We used aluminum in the initial ones in order to provide us with a "proof of concept" to test that the idea would work in real life. Aluminum would be fine for small models (maybe up to a .25 cu. in. size) but could fail under the flight loads on a larger stunt ship. For that reason once we proved the concept we had the actual push rod ends made from stainless steel since it is much stronger, very resistant to bending and unlike titanium is not subject to hairline cracks due to the manufacturing process.
All of that being said, I would use JB Weld to attach the push rod ends to the carbon fiber tube.
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Just to reinforce what Eric said, I have been using these type of pushrod ends for quite a while and have used both the slow and quick set JB Weld and have NEVER had one come off. Using these also solves the issue of the CF rod splintering since the cup captures the rod end where you cut it.
Mike
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I had been using the titanium ends from CH for many years and right from the beginning I was concerned about the barb inside the CF tube splitting the tube like peeling a banana.
I started using a piece of aluminum tubing on the outside of the carbon tube to act as a 'cuff' to prevent splitting.
Fortunately....I too have never had a failure and I also use JB Weld slow.
Eric....you mention the titanium ends having hairline cracks.....I had not thought about cracks but I was always wondering about how brittle the threaded ends were/are.
Now that you have brought out the SS units....I will get a handful from you soon.
Thanks a lot for what you are doing throughout your catalog.
Good work!!
DH
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Anything Crucial like that ,
preferable to pre coat BOTH mating surfaces .
Even if ones scraped back to just damp , it ensures a complete join,
whereas with just one coated , dry spots ( unglued ) are pretty much assured, no matter how salubrious you are .
Dunno if this is possable with super glue ?? Would yo use the GEL type / thick there ? and its slower kicking off ?
H^^
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What's the inside diameter?
MM
I think Eric sell carbon pushrods that fit his new ends very nicely. These pushrods are 3/16" diameter and very stiff. (I did not use a micrometer.)
Keith
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I think Eric sell carbon pushrods that fit his new ends very nicely. These pushrods are 3/16" diameter and very stiff. (I did not use a micrometer.)
Keith
Keith...are the rods solid carbon or are they tubes??
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The Push Rods RSM offers are made of pultruded carbon fiber tubes. They are 5 mm in diameter (0.196").
I prefer pultruded over spiral wrapped as they are stronger, stiffer and much more consistent.
Eric