How to shorten a Tach drive cable?

[Dave[_16_]]

I need to replace the tach cable in a friends plane. The inner part is
what needs replacement. I have access to another cable but the inner
part is too long.
How can I shorten the cable? The end is square and appears to have been
put into a press to form it.

I tried to square up a piece of cable from the old one, with no success.
i attempted to pound it square with a vise and hammer.

I was looking for an old time speedo shop here in dallas to help me with
this, but I can't seem to find them any more. I guess the modern cars
have put them out of business.

Any suggestions?

Dave

[Morgans[_2_]]

"Dave" > wrote
Auto replacements for spedo cables usually have a fitting that is placed on
one end of the cut to length cable, and crimped in place. The fitting has
the square part on it.

It will be nearly impossible to shape your own end, short of brazing the
end, then grinding down to the desired square shape.
--
Jim in NC

[Jim Stewart]

Morgans wrote:
> "Dave" > wrote
> Auto replacements for spedo cables usually have a fitting that is placed on
> one end of the cut to length cable, and crimped in place. The fitting has
> the square part on it.
>
> It will be nearly impossible to shape your own end, short of brazing the
> end, then grinding down to the desired square shape.

And it will be damn near impossible to get
braze to stick to something so impregnated
with grease.

[Mike Noel]

....and you can get a new tach cable from Chief for about $30.

http://www.chiefaircraft.com/airsec/Aircraft/EngineInstruments/TachCables.html
--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel

It is not work that kills men; it is worry. Worry is rust upon the blade.
"Dave" > wrote in message
...
>I need to replace the tach cable in a friends plane. The inner part is what
>needs replacement. I have access to another cable but the inner part is too
>long.
> How can I shorten the cable? The end is square and appears to have been
> put into a press to form it.
>
> I tried to square up a piece of cable from the old one, with no success. i
> attempted to pound it square with a vise and hammer.
>
> I was looking for an old time speedo shop here in dallas to help me with
> this, but I can't seem to find them any more. I guess the modern cars have
> put them out of business.
>
> Any suggestions?
>
> Dave

[Dave[_16_]]

Mike Noel wrote:
> ...and you can get a new tach cable from Chief for about $30.
>
> http://www.chiefaircraft.com/airsec/Aircraft/EngineInstruments/TachCables.html
Thanks for all the info and suggestions.

I had a spare cable and wanted to use it to fix the broken one.
I also just noticed that the one I have has the wrong twist on it.

I'll probably have to order a new one from chief.

Cheers

dave

[Orval Fairbairn]

In article >,
Dave > wrote:

> Mike Noel wrote:
> > ...and you can get a new tach cable from Chief for about $30.
> >
> > http://www.chiefaircraft.com/airsec/Aircraft/EngineInstruments/TachCables.ht
> > ml
> Thanks for all the info and suggestions.
>
> I had a spare cable and wanted to use it to fix the broken one.
> I also just noticed that the one I have has the wrong twist on it.
>
> I'll probably have to order a new one from chief.
>
> Cheers
>
> dave

Just pull out both ends and take them to your local speedometer shop.
They have all the ends and can make up one for you for a few bucks. It
is not rocket science!

[Morgans[_2_]]

"Orval Fairbairn" > wrote
>
> Just pull out both ends and take them to your local speedometer shop.
> They have all the ends and can make up one for you for a few bucks. It
> is not rocket science!

Tell me you're kidding! What size city do you live in, that could support
such a narrow specialty? I've never even heard of such a thing!
--
Jim in NC

[Dave Butler]

Morgans wrote:
> "Orval Fairbairn" > wrote
>> Just pull out both ends and take them to your local speedometer shop.
>> They have all the ends and can make up one for you for a few bucks. It
>> is not rocket science!
>
> Tell me you're kidding! What size city do you live in, that could support
> such a narrow specialty? I've never even heard of such a thing!

Where are you in NC, Jim? Pretty sure Bradley's could handle it:

Bradley's Service (919) 834-5727 101 S Blount St Raleigh, NC

Dave

[Orval Fairbairn]

In article >,
"Morgans" > wrote:

> "Orval Fairbairn" > wrote
> >
> > Just pull out both ends and take them to your local speedometer shop.
> > They have all the ends and can make up one for you for a few bucks. It
> > is not rocket science!
>
> Tell me you're kidding! What size city do you live in, that could support
> such a narrow specialty? I've never even heard of such a thing!

Daytona Beach. Any speedometer shop should be able to make up a new
cable. The fittings are all standard.

[Bob Kuykendall]

> Tell me you're kidding!

I think he's not. We have one in the SF Bay Area, CA, US:

Kris's Mobile Speedometer Service
Cupertino, CA 95014
http://www.speedometer.org

Searching BigYellow shows speedo repair shops in several US metro
areas.

[Morgans[_2_]]

"Dave Butler" < wrote
>
> Where are you in NC, Jim? Pretty sure Bradley's could handle it:
>
> Bradley's Service (919) 834-5727 101 S Blount St Raleigh, NC

In or near Hickory.

I have no doubt that there are several service places that could handle it,
but a Spedo shop, doing only speedo's, was the way I took it. That I would
have to see. <g>
--
Jim in NC

[Morgans[_2_]]

"Bob Kuykendall" > wrote in message
oups.com...
>> Tell me you're kidding!
>
> I think he's not. We have one in the SF Bay Area, CA, US:
>
> Kris's Mobile Speedometer Service
> Cupertino, CA 95014
> http://www.speedometer.org

WoW! Who'd a thunk it! <g>
--
Jim in NC

[Orval Fairbairn]

In article >,
"Morgans" > wrote:

> "Dave Butler" < wrote
> >
> > Where are you in NC, Jim? Pretty sure Bradley's could handle it:
> >
> > Bradley's Service (919) 834-5727 101 S Blount St Raleigh, NC
>
> In or near Hickory.
>
> I have no doubt that there are several service places that could handle it,
> but a Spedo shop, doing only speedo's, was the way I took it. That I would
> have to see. <g>

Cable are part of a speedometer shop's services. What do you think a car
owner does when the speedo cable packs it in?

Tach cables, speedo cables, etc. are all part of the service.

[Morgans[_2_]]

"Orval Fairbairn" < wrote
>
> Cable are part of a speedometer shop's services. What do you think a car
> owner does when the speedo cable packs it in?
>
> Tach cables, speedo cables, etc. are all part of the service.
I must not be doing a very good job of explaining what I meant. I'm
beginning to think that it was not worth it, but I'll try to get it right,
one more time.

Someone said a speedometer shop could handle it. On that point, I do not
argue, but my point was to say that I had never heard of a shop that
specialized in speedo's. (which by definition would include the cable, and
the gear that drives off of the transmission in many cars)

It has been pointed out that there are specialty shops that call themselves
a speedo shop, and I was surprised that anyone could make a business on such
a small subgroup of auto repairing. I stand corrected, but I have never
heard of such a thing where I have lived.

I do also agree that some of the better auto service shops could deal with
putting new ends on cables too, by the way.

Better? See what I mean, about it not being worth the time to explain
myself, though? <g>
--
Jim in NC

[Rich S.[_1_]]

"Morgans" > wrote in message
...
>
> It has been pointed out that there are specialty shops that call
> themselves a speedo shop, and I was surprised that anyone could make a
> business on such a small subgroup of auto repairing. I stand corrected,
> but I have never heard of such a thing where I have lived.

Speedo repair is/was a huge business. All taxicabs (at least they used to)
had to have their meters tied in with the speedo/odo and calibrated at
regular intervals. Many commercial vehicles have "Speed-o-graphs" or
"Tach-o-graphs" which record speed or rpm for monitoring by employers or
owners. Then there is the occasional aircraft repair job. We had several
such shops in Seattle. One of their services (I remember well) was to
provide error reports for drivers who claimed in court that, "Honest
officer - my speedometer only showed 50! I couldn't have been doing 73. . ."

Rich S.

[Dave[_16_]]

Another question, how important is the twist (lay) of the cable?
There are left lays and right lays depending which direction the cable
spins.
I talked to one shop and they didn't think that it really made a
difference since they solder/braze the end of the cable. They only had
left lays in stock.

Any opinions?

Dave

[Charles Vincent]

Dave wrote:
> Another question, how important is the twist (lay) of the cable?
> There are left lays and right lays depending which direction the cable
> spins.
> I talked to one shop and they didn't think that it really made a
> difference since they solder/braze the end of the cable. They only had
> left lays in stock.
>
> Any opinions?
>
> Dave

From the "Flexible Shaft Handbook" which just happened to be sitting
on my desk today:

"It can be readily understood that a shaft will transmit its maximum
capacity when the rotation tends to tighten up the outer winding.
Consequently .... a left lay shaft should be used for driving in a
clockwise direction. For the same reason, a right lay shaft should be
used for counter-clockwise driving, always looking at the shaft from the
supply end

While flexible shafts deliver their maximum capacity when operating in
one direction only, they may be used with entirely satisfactory results
for driving in both directions.... either a left-lay or right-lay shaft
may be used, but it must be of a larger size...

A shaft working under somewhat less than full load capacity or under
conditions of small loads, will operate equally well in either direction."


The handbook has tables of shaft diameter and radii to compute maximum
torque, and a de-rating factor to apply when running against the lay. A
1/8 inch shaft with a 4" radius bend de-rated for reverse lay is still
good for better than .25 inch pounds of torque, with a twenty inch
radius, it is good for 1.6 inch pounds and with no curve, 2 inch pounds.
The book is very dated, but I expect that it is probably conservative.

From my personal perspective, I have found that keeping it well lubed
and maintaining large radii is pretty important when running against the
lay, as friction and wear is increased with low lube and tight radii,
and running against the lay can lead to a worn area sprouting wire hairs
that jam up good in the sleeve.

Charles

[J. Severyn]

"Bob Kuykendall" > wrote in message
oups.com...
>> Tell me you're kidding!
>
> I think he's not. We have one in the SF Bay Area, CA, US:
>
> Kris's Mobile Speedometer Service
> Cupertino, CA 95014
> http://www.speedometer.org
>
> Searching BigYellow shows speedo repair shops in several US metro
> areas.
>

....and a second one in the SF Bay area CA, US
http://www.speedoelectric.com/
I've used them. Good service.
Regards,
John Severyn

[Frank Stutzman[_2_]]

In rec.aviation.homebuilt J. Severyn > wrote:

> ...and a second one in the SF Bay area CA, US

And a third one in the SF Bay area is Palo Alto Speedometer
(http://www.paspeedo.com/). Never used them for anything aircraft wise.
They specialize in repair and restoration of vintage equipment and they
did a great job with my '56 Mercedes gauges.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Boise, ID

[Orval Fairbairn]

In article >,
Frank Stutzman > wrote:

> In rec.aviation.homebuilt J. Severyn > wrote:
>
> > ...and a second one in the SF Bay area CA, US
>
> And a third one in the SF Bay area is Palo Alto Speedometer
> (http://www.paspeedo.com/). Never used them for anything aircraft wise.
> They specialize in repair and restoration of vintage equipment and they
> did a great job with my '56 Mercedes gauges.

Likewise, on my '67 Porsche instruments!

[dlevy]

Speedometer shops are generally next door to the toaster store.

"Morgans" > wrote in message
...
>
> "Orval Fairbairn" < wrote
>>
>> Cable are part of a speedometer shop's services. What do you think a car
>> owner does when the speedo cable packs it in?
>>
>> Tach cables, speedo cables, etc. are all part of the service.
> I must not be doing a very good job of explaining what I meant. I'm
> beginning to think that it was not worth it, but I'll try to get it right,
> one more time.
>
> Someone said a speedometer shop could handle it. On that point, I do not
> argue, but my point was to say that I had never heard of a shop that
> specialized in speedo's. (which by definition would include the cable, and
> the gear that drives off of the transmission in many cars)
>
> It has been pointed out that there are specialty shops that call
> themselves a speedo shop, and I was surprised that anyone could make a
> business on such a small subgroup of auto repairing. I stand corrected,
> but I have never heard of such a thing where I have lived.
>
> I do also agree that some of the better auto service shops could deal with
> putting new ends on cables too, by the way.
>
> Better? See what I mean, about it not being worth the time to explain
> myself, though? <g>
> --
> Jim in NC
>

[jerry wass]

Some heavy duty truck shops, dealers, fabricate cables--especially if
they mount specialized equipment, beds, & such tings as dat.

dlevy wrote:
> Speedometer shops are generally next door to the toaster store.
>
> "Morgans" > wrote in message
> ...
>> "Orval Fairbairn" < wrote
>>> Cable are part of a speedometer shop's services. What do you think a car
>>> owner does when the speedo cable packs it in?
>>>
>>> Tach cables, speedo cables, etc. are all part of the service.
>> I must not be doing a very good job of explaining what I meant. I'm
>> beginning to think that it was not worth it, but I'll try to get it right,
>> one more time.
>>
>> Someone said a speedometer shop could handle it. On that point, I do not
>> argue, but my point was to say that I had never heard of a shop that
>> specialized in speedo's. (which by definition would include the cable, and
>> the gear that drives off of the transmission in many cars)
>>
>> It has been pointed out that there are specialty shops that call
>> themselves a speedo shop, and I was surprised that anyone could make a
>> business on such a small subgroup of auto repairing. I stand corrected,
>> but I have never heard of such a thing where I have lived.
>>
>> I do also agree that some of the better auto service shops could deal with
>> putting new ends on cables too, by the way.
>>
>> Better? See what I mean, about it not being worth the time to explain
>> myself, though? <g>
>> --
>> Jim in NC
>>
>
>

[Morgans[_2_]]

"Jerry Wass" <> wrote

> Some heavy duty truck shops, dealers, fabricate cables--especially if
> they mount specialized equipment, beds, & such tings as dat.

Jerry, it's good to see your name around these parts again! Where ya been?
--
Jim in NC