EX3 Propeller cable

[nrosoff]

I am in the process of rigging the engine on my EX3 when I saw this tag on my prop cable. I am talking to CC kit support and awaiting an answer. Has anybody used a kit supplied cable with this tag?

[Andy]

I am in the process of rigging the engine on my EX3 when I saw this tag on my prop cable. I am talking to CC kit support and awaiting an answer. Has anybody used a kit supplied cable with this tag?

The same, or similar, tag is on replacement prop cables supplied by CubCrafters for the FX-3. If you go to the cable distributors website I think you will find that limitation there too.

There is no requirements to use aircraft qualified hardware on experimental aircraft.

[Andy]

The same, or similar, tag is on replacement prop cables supplied by CubCrafters for the FX-3.

Labels from an FX-3 cable attached as PDF.

CableCraft catalog here - https://cablecraft.com/assets/PDFs/C...ct-Catalog.pdf

[nrosoff]

There is no requirement to use ANY certified parts / hardware on an expermental.

But I alway try to use certified parts for important functions (a prop control cable qualifies). Most of the kit comes with part 23 parts, this does not seem like an ideal place to use a non certified part. My guess is that is much cheaper to have a custom cable with the same specs as the certified version.

Thank you for your response and documentation.

[Andy]

My guess is that is much cheaper to have a custom cable with the same specs as the certified version.

It's not a custom cable. You can find the part number decoder in the previously referenced catalog.

If you find a better cable that fits I'll be interested to hear of it. I've had one of these prop cables fail in a way that limited governor control. The one that replaced it is showing signs it will fail in the same way.

The throttle cable, which is from the same CableCraft series and also not approved for aircraft use, has more bends than the prop cable but it still works perfectly. I don't know why my prop cables have been unreliable and I don't know if any other EX/FX owners have had problems with this cable.

[Andy]

You can find the part number decoder in the previously referenced catalog.

Here is the decode -

[nrosoff]

I spoke directly to Cable Crafterters. Hear is their reply:

"That label you have pictured is the standard label provided by our authorized cable assemblers.

The 184-VTT-3-57 is a standard catalog part number for Cablecraft. The cable you received should use the same components, and should be assembled in the same manner that we would use to make that cable in the factory.

The only potential difference is that if we are asked for an aerospace cable in the factory, the conduit and inner member would be proofload tested (a pull test to ensure the cable assembly will withstand a nominal load). Aerospace cables are generally 100% proofload-tested in the factory, but I can’t say if the cable coming from an assembler would or would not have been proofloaded.

Also as we already discussed, the cable the assembler provided is not “certified” for aircraft use."

[nrosoff]

Andy:

They will make a proofloaded cable directly from the factory.

Group buy time?

[Andy]

Andy:

They will make a proofloaded cable directly from the factory.

Group buy time?

The cable issues I have experienced are not failure in tension or even failures in compression. The first failure was a gradual increase in binding and eventually travel was limited to about half the design travel. It felt to me as though a strand of the inner cable had fractured and was catching on the outer or the end fitting.

That first cable was sent back to CubCrafters in the expection that it would be cut open for failure mode analysis. I never heard that it had been inspected.

The replacement cable, which is still on the aircraft, was received wound in a very tight spiral so it would fit in the shipping box. It felt good at first and then started to bind like the first one. Like the first one, the binding was much reduced by flexing the cable outer between the governor bracket and the baffle grommet. That seems consistent with a broken inner strand being moved away from whatever it was binding on.

Pete and I discussed this and Pete agreed to send the next replacement without it being coiled tight for shipping. It arrived in a cardboard tube and had no bends. I have not fitted that cable yet. It's a pain to have to pull all the left side panels and I'm waiting for it to get worse before I do it.

I'm puzzled by the CableCraft reference to "assembler". I had assumed CubCrafters was buying these cables though a US distributor and they were fabricated in China.

I now see there a separate "Assembler" catalogue but I don't see VTT listed as an option. - https://cablecraft.com/assets/PDFs/C...er-Catalog.pdf

I get the impression that the cables supplied by CubCrafters usually work fine and I have just been unlucky. If that's not the case I hope others will speak up.

The assembler catalog includes some dire warnings -

[nrosoff]

When you replace the cable a good shot of AeroKroil may help.

I have had issues with cables on my part 23 aircraft. My A&P use AeroKroil to fix it and it lasts for a year of two.

If you can get enough in the cable from the governor side it may help.

I can provide you with the contact from Cable Crafters. They were helpful and may be able to fabricate a better cable, of course you will have to pay them for it.

Neil

The cable issues I have experienced are not failure in tension or even failures in compression. The first failure was a gradual increase in binding and eventually travel was limited to about half the design travel. It felt to me as though a strand of the inner cable had fractured and was catching on the outer or the end fitting.

That first cable was sent back to CubCrafters in the expection that it would be cut open for failure mode analysis. I never heard that it had been inspected.

The replacement cable, which is still on the aircraft, was received wound in a very tight spiral so it would fit in the shipping box. It felt good at first and then started to bind like the first one. Like the first one, the binding was much reduced by flexing the cable outer between the governor bracket and the baffle grommet. That seems consistent with a broken inner strand being moved away from whatever it was binding on.

Pete and I discussed this and Pete agreed to send the next replacement without it being coiled tight for shipping. It arrived in a cardboard tube and had no bends. I have not fitted that cable yet. It's a pain to have to pull all the left side panels and I'm waiting for it to get worse before I do it.

I'm puzzled by the CableCraft reference to "assembler". I had assumed CubCrafters was buying these cables though a US distributor and they were fabricated in China.

I now see there a separate "Assembler" catalogue but I don't see VTT listed as an option. - https://cablecraft.com/assets/PDFs/C...er-Catalog.pdf

I get the impression that the cables supplied by CubCrafters usually work fine and I have just been unlucky. If that's not the case I hope others will speak up.

The assembler catalog includes some dire warnings -