Carb Heat Bug Nut Attachment

[crazyivan]

Request somebody take and post a picture of the bug nut attachment between the carb heat arm and the actuating cable. The old one fell off in flight and I need to install the new set.

Thanks!

[JohnW]

You should have two more right on your airplane! The same "bug" is used to attach the cabin heat control wire to the "elbow" on the heat box door (front side, just right of center on the firewall), but they are a slightly different "dash number" swivel. Also, the mixture control should be attached with the very same style "bug".

They are CAKE to fabricate (a -10 bolt modified to be headless), one castellated nut, a cotter pin -bolt needs the hole for the cotter pin, or you will have to drill that, too- and one fancy straight through hole just large enough to let the cable pass through the bolt shank. The only other part is a four minute job on a lathe...drill a 3/16 hole about a half inch deep in the end of some round stock, then put a 3/8" or so bit in the chuck in the tailstock, and taper a place for the control wire to get a shallow "v" squashed into it when you tighten the nut. The "taper" at the "bug" when Piper made them was 110 degrees (included angle)...same as a standard hi-speed drill bit (oddly enough!). step down a "collar" that is a few thousandths "taller" than a 3/16 standard washer and 1/4" O.D. (this is what lets the cable "swivel"). This can be done with "common shop tools", as well but it'll take you more than four minutes. More like twenty, and you need a little more "imagination" than a Machinist.

Univair has them, if you don't have access to a lathe (or one of the other two "cups" to copy) or if you don't get the kind of self satisfaction of fabricating this kind of "piece/part". Their p/n is U70371-003 for the "stud". Twelve dollars forty three cents and you supply the nut and cotter pin. You'll need the $12.50 "swivel cup fitting" (U70371-002), as well. There are several different Piper p/ns for this "bug" for different applications in the Piper Parts Manual, and Univair's "numbering system" doesn't work exactly the same way as Piper's (that is unusual)...the difference is the exact length of the "stud" (aka: headless bolt) but this -003 p/n is the correct one for carb heat attachment. The collars (swivel cup fitting) are all the same for the one size push/pull cable that the ShortWings use. I have NO IDEA what you get for stud length when you order the U70371-000 "Piper swivel assembly". But the whole "assembly" is $26.09 anyway, so why roll the dice? What self-respecting airplane owner doesn't keep a Petri dish with a few no. 10 castellated nuts and a dozen or so cotter pins, that size, anyway???

[Bultaco Jim]

"and you need a little more "imagination" than a Machinist."

You made some of us laugh with that one John. The others will be getting back to you.

[Hillbilly]

Oh boy, I'm gonna get smacked for this but..

John, a standard high speed drill has a 118 degree point...(59 on either side)

[JohnW]

Hillbilly; Mea Culpa, Mea Culpa, Mea Culpa...but in my defense, it was an honest typo. That is what the "bug" is, as well, btw.

B.J.; No slur intended, but... this "fabrication" is a "no brainer" for a Machinist with a lathe (note capitalization, suggesting respect; I AM a card-carrying Machinist, if that gives me a tad more "wiggle room". Besides, Political Correctness is something Californians lead the World in -not that anybody else particularly seems to be FOLLOWING that lead! Nor, SHOULD THEY. A Rose is a Rose by any other name, and if you happen to have bromidrosis, then yer STINK FEET!). On the other side of it, if you take some round stock and have to literally "whittle" the part out from the middle of it, a bit of "figurin'" goes a long way towards getting a nice little part out of it. Not impossible, by a long shot. Just more "imagination required", than spinning the part in the right tool... wham, bam, thank you, Ma'am.

But, again...buying this part(s) is much easier and only slightly less cost effective. But I HATE sitting on my hands for day after day waiting on a Brown Truck to down gear to a stop with a tiny little box that costs almost as much to "get here" as what is inside of it... an airplane "down" for several days for something I can make in a hour, or less. Sometimes... even if it takes a day, or three. I LIKE "making things". WhatcanIsay?

:D :D :D

[crazyivan]

John -- Thanks. Found 'em under the cowl. Piece of cake. I had to go with the $26 set from Univair. It looks like there are an infinite number of ways to safely attach a cable to an actuating arm and this super special bug nut from Piper seems to be the most expensive. Go figure.

The #10 castle nut is not the problem. Finding the dozen I have at the bottom of a box with 1000 other nuts is ;) . I gotta go get me some petri dishes.

[Bultaco Jim]

Actually John, I enjoyed your answer - especially the part I quoted. And for your info, I have 6 acres outside Petaluma with high walls and a moat, to keep the Pelosi sheeple out. Political correctness I don't got!

[Hillbilly]

Actually John, I enjoyed your answer - especially the part I quoted. And for your info, I have 6 acres outside Petaluma with high walls and a moat, to keep the Pelosi sheeple out. Political correctness I don't got!


Jim,.....A moat? really?

Any chance you got a drawbridge or some fanged carp swimmin round in there?

[JohnW]

...It looks like there are an infinite number of ways to safely attach a cable to an actuating arm and this super special bug nut from Piper seems to be the most expensive. Go figure.

Actually, not only is "this method of attachment" the "most expensive", you have to admit it is ALSO the "most elegant for it's unbelievable simplicity, as well as it's ease of use." (compared to others). Salute! to Piper's practical and efficient Engineering Staff (of yore)!

[Steve Pierce]

darn David, I could have put one in the box with the carb. heat box. :oops:

[Bultaco Jim]

H.B., how on earth is the moat going to work without a drawbridge? That goes without saying. And lawyers in the moat.

[Hillbilly]

H.B., how on earth is the moat going to work without a drawbridge? That goes without saying. And lawyers in the moat.


Lawyers? thats just evil.

[andya]

H.B., how on earth is the moat going to work without a drawbridge? That goes without saying. And lawyers in the moat.


Lawyers? thats just evil.

What if they drown............................ Its a start.