Need Tach cable

[senior]

I need a tach cable for my Tayl with a 85-8 engine.

A/Spruce says cable with female on engine end & male on Tach not available.

Has anybody purchased one lately? if so where from?...Heck I'd even take a good used one.

Thanks

[Robert Lees]

Re: Need Tach cable

I'd strongly suggest you take your old one to an automotive tacho cable supplier (yellow pages) and get them to make one up; it's quite a lot cheaper than you might think. Just get them to make sure the rotation is the same (tacho cables only rotate one way like a spring).

As far as certification goes, your old one works just fine, doesn't it, and we can then delete this thread.

I'm quite surprised that Aircraft Spruce don't have them (perhaps made to order, but should be a short lead time). I can't recall if the C85-8 and -12 cables rotate the same or opposite. Have you tried Univair?

Rob.

[Robert Lees]

Re: Need Tach cable

This is a separate post, because you can bet your bottom dollar that aircraft companies do not make tacho cables. Automotive suppliers do (despite that modern cars use electronic versions now, there are hundreds of thousands of older cars out there that still have a proper tacho cable). So these aircraft companies fundamentally buy them in (and provide the "paperwork" that makes them aviation parts).

CG Taylor wasn't anybody's fool...when he designed the Taylorcraft, he used existing (mainly motoring) technology for the ancilliaries, like fuel hose fittings, cables etc. Even the drag/antidrag wires (and tailbrace wires and all the associated nipples) are just longer spokes from car wire wheels. He had the sense to get the (then) CAA to approve them, and the rest is history.

[senior]

Re: Need Tach cable


As far as certification goes, your old one works just fine, doesn't it, and we can then delete this thread.

Assuming of course it is in a Cert category, which it's not.

Might be harder to find a automotive tacho cable supplier than an actual tach cable in this country but I'll give it a whirl.

[mike lutz]

Re: Need Tach cable

Most automotive supply places have speedo cable kits for the do-it yourself. I made one last year for my T-craft, using the engine tack drive end over. I put the engine drive end in the vise and took the torch and heated the end of the fitting up and pulled the piece of old cable out. then I took a small punch and inserted, (gently drove) the punch in the re-heated cherry red drive end to open it up to accept the new cable. They come with a crimping tool in the kit, but I fluxed and soldered the new cable in on mine, as to make it easier to change the next time. I needed the square end to drive the tack. I have made several of these over the years with good results.They come in two diameters, and you will want the smaller size. They have them at Autozone, advance, "O"Rielley, Nappa. They also carry small tubes of speed-o cable lube.

[astjp2]

Re: Need Tach cable

Dan at Reeve air motive can make you one. Just need the length. Tim 907-272-8522

[senior]

Re: Need Tach cable

OK, problem temporarily solved.
Removed the Male tack end from old cable & fitted on a Navon cable from A/C spruce.
Yes it's inner is wound the correct direction.
Still looking thou, have nuther T-Crate on the rebuild table in shop.

Interesting reply I received from Univair.

"Univair does have a Tach-43nr, 43 inches long in stock for $90.08.
or we can make a Tach-42nr, 42 inches long cable.
Also $90.08.
There is no approval on these cables.
Also the inner cable as far we are aware are only wound one way."

[Hank Jarrett]

Re: Need Tach cable

I am pretty sure all cables are wound the same way (never seen a reverse wind one). You fix that by putting an angle gear box on the ends. The gear box makes it MUCH easier to hook up between the fire wall and engine and the instrument back and fuel tank anyway.
You want to make sure that the cable is wound TIGHTER by the engine! If you twist it backwards it will open up and rub on the cable guide and that will wear it out sooner.
If you unscrew the ends where the cable goes in you can swap the guts across and reverse the direction of rotation.

Hank

[senior]

Re: Need Tach cable

Hank, the inner cable I took off looked like it had unwound inside the outer right about firewall length from the motor..
The new cable I used is indeed wound the opposite direction from the inner I took out.
I also ordered a 90* angle drive to put on rear of engine to remove that awe full kink the cable used to have to make.

[magman]

Re: Need Tach cable

Since you are involved with the Tach already you may want to keep

in mind that many older Tachs have a " Lube Port" just above the

cable connection.

Newer Tachs generally have the Boss but no actual Port.


A couple drops of thin oil may prevent seizing & Tach Cable grief.

[magman]

Re: Need Tach cable

Since you are involved with the Tach already you may want to keep

in mind that many older Tachs have a " Lube Port" just above the

cable connection.

Newer Tachs generally have the Boss but no actual Port.


A couple drops of thin oil may prevent seizing & Tach Cable grief.

[senior]

Re: Need Tach cable

Since you are involved with the Tach already you may want to keep

in mind that many older Tachs have a " Lube Port" just above the

cable connection.

NOW you tell me, right after I button everything back up

Newer Tachs generally have the Boss but no actual Port.


A couple drops of thin oil may prevent seizing & Tach Cable grief.

NOW he tells me, right after I button everything back up!

Good to know, thanks

[Matt]

Re: Need Tach cable

I very recently (only 2 days ago) replaced a broken tach on 0-200 in a t-cart. It was a bit a an ordeal, as the first replacement tach cable I ordered broke after only a few minutes of running up. I came to find that there are "left" lay and "right" lay tach cables, for counterclockwise and clockwise spinning tach drive sockets. The 0-200 spins the tach drive clockwise and should have a "right" lay cable. AC Spruce only has left lay cables in stock (for counterclockwise spinning tach drives) but you can special order a right lay cable. After taking out the second broken cable I realized that the right angle drive behind the tachometer wasn't spinning very smoothly and was likely the reason behind my broken cables. After cleaning and re-greaseing the right angle drive, it spins a lot smoother. I just received another cable from AC spruce and everything seems to be working fine. The newer cables are designed a little differently than the original one that broke (they do not have a stop washer on the tachometer end), which makes it possible for the inner cable to shorten up relative to the outer cable housing, which initially caused the inner cable to not properly engage the right angle tachometer drive. I think I have solved this problem buy removing the stop washer on the engine end of the cable, which allows the inner cable to extend further out the tachometer end.

As I think most t-crafts must have the same right angle drive behind the tach due to the gas tank being so close, I would check and make sure that is spinning smoothly before you go breaking more cables like I did. If you order a new inner cable from AC spruce, I recommend you get a little longer (maybe 1/2 inch) so it properly engages the tach. I also found replacement cables at NAPA that would work if you could reattach the male end as described in an earlier post. I found a car shop that could make a whole new inner and outer cable assembly, but it wasn't any cheaper than ACS and I thought it best to make sure I got a cable with the proper "lay".

[senior]

Re: Need Tach cable

Matt: does your tach require a cable with a Male end?
ACS told me that was what made a new cable unavailable.

[Matt]

Re: Need Tach cable

Matt: does your tach require a cable with a Male end?
ACS told me that was what made a new cable unavailable.

The inner cable has male ends that fit into the drive socket on the back of the engine and on the back of the tach. The outer cable housing has female end threaded fittings. I'm pretty sure this is standard and I wouldn't imagine there would be any difference between the set up on a C-85 vs. 0-200. If you go on the AC Spruce website and search tach cables, they provide a drawing and details on their cables. That should help clear up what you need.