Replacing throttle

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jesse

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Jesse
During a recent inspection I noticed that the throttle on my Flybaby needed to be replaced. It was a very older vernier throttle with various issues. The throttle cable attaches to the carburetor via a solid wire.

The problem is I can't really find a throttle where the threaded shaft is long enough to pass through the panel. The throttle's mounting location goes through part of the fuselage structure so it's "thicker" than most aircraft.

Here is a picture of a replacement throttle I ordered, I really need the threaded portion to be about 2" longer. Anyone have a suggestion as to how I can accomplish that? I thought about cutting threads into the entire shaft with a die but fear the material to be way too thin for that.

eVZARvP.jpg
 
The threaded part is larger than the rest, so cutting more threads would be out, regardless of the thickness. But mabe a different nut, and a slightly larger hole?
 
Actually I really need the threaded part to be thicker anyhow. Steve see suggested a sleeve with internal and external threads that could solve both problems (needing to be thicker and needing the threaded portion to be longer). Now I just need to find someone that could make me such a thing.
 
jesse said:
Actually I really need the threaded part to be thicker anyhow. Steve see suggested a sleeve with internal and external threads that could solve both problems (needing to be thicker and needing the threaded portion to be longer). Now I just need to find someone that could make me such a thing.
Click to expand...

Anyone with a lathe ought to be able to do it.
 
Try Cablecraft, or rather a Cablecraft distributor. Talk to them about your specific requirement and see if they can do it. If they can, you will end up with a superior custom cable solution (rod end bearings versus bent wire, etc) that will last forever and at a price I was more than satisfied with.

When I needed new custom lengths for my RV, a distributor in CA, CALIFORNIA PUSH-PULL, had new Cablecraft cables to me in 3 days without special handling. Their Web site seems to be 'down' but I ordered from them less than 6 mos ago and was more than satisfied.
 
I've pinged the guys on the Fly Baby mailing list to see if there are any suggestions.

Looking through a collection of Fly Baby panel shots, there is some repetition the throttle hardware showing...like there's a particular model that works. Probably had hundred of them lying around, back in 1960.

http://www.bowersflybaby.com/pix/panels.html

Google search shows some Piper models that have a longer threaded section.

Ron Wanttaja
 
jesse said:
Actually I really need the threaded part to be thicker anyhow. Steve see suggested a sleeve with internal and external threads that could solve both problems (needing to be thicker and needing the threaded portion to be longer). Now I just need to find someone that could make me such a thing.
Click to expand...

You gut a threaded pipe section of the OD you want and tap a thread inside to couple onto it.
 
I squirmed a goose-neck video camera into mine this afternoon, after flying. Reading the tag upside down, it looks like I've got an "ACS A800" throttle. The "ACS", of course, refers to Aircraft Spruce, though I see the A-800 throttle is carried by Wicks, Univair, etc. Can't really tell, but is that the same thing you ordered?

Not sure, but there's a kind of barrel on the "knob" end that looks like it can disassemble separately...If it's screwing onto the same threaded shaft that the nut goes on, that might let it get the ~1.25 inches that's necessary on a Fly Baby.

Ron Wanttaja
 
Thanks all, I'm going to hit a local machine shop that at least was willing to speak with me in the past and see if they can make it work for me. Otherwise I'll talk to Mcfarlane but I'm really trying to avoid putting too much money into this.
 
Alternatively you could fabricate a metal plate that the throttle mounts to which then gets attached to your panel with other fasteners. If there's no way to enlarge the hole behind the plate to make room for the nut on the throttle, have someone weld a nut to the front of the plate.
 
Many ways to accomplish this. Another idea, bolt a plate to the firewall and attach the throttle to that. You'd need to countersink an area large enough to accommodate the nut.

Disregard, just saw previous post! Must be a good idea :)
 
Well, it took a month's worth of false promises, but the machinist finally came through and made the adapter I wanted. This will make my new throttle just like the old one so it'll bolt right up...:

nTBweri.jpg


Should be able to get it flying again within a week or so. It hasn't flown since October at this point and I never had enough time to shake out all the somewhat critical maintenance I did last year so I'll be rather cautious waiting for the perfect weather.
 
Pretty sure Menard's has them on the shelf in the plumbing department. :rofl: ;)

Glad to see you making progress, get that baby in the air!
 
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1/8 inch pipe threads are 27 threads/inch. Your throttle housing is probably 3/8 - 24. They won't screw together very well................
 
nrpetersen said:
1/8 inch pipe threads are 27 threads/inch. Your throttle housing is probably 3/8 - 24. They won't screw together very well................
Click to expand...

What I have will and does - it was machined specifically per my requirements. Was not expensive just took forever and is a no sacrifice fix.
 
Nice.

As for the delay, you weren't going to fly an open cockpit plane a month ago anyway, were you? It was a nasty winter.
 
jesse said:
During a recent inspection I noticed that the throttle on my Flybaby needed to be replaced. It was a very older vernier throttle with various issues. The throttle cable attaches to the carburetor via a solid wire.
eVZARvP.jpg
Click to expand...


Uh, sir, the throttle is a little tiny metal part inside the carburetor. What you are showing is the throttle CABLE. No offense, but could you be a little more careful in your choice of subjects? I was trying to figure out how to machine that little tiny part before I read the thread.

Jim
 
weirdjim said:
Uh, sir, the throttle is a little tiny metal part inside the carburetor. What you are showing is the throttle CABLE. No offense, but could you be a little more careful in your choice of subjects? I was trying to figure out how to machine that little tiny part before I read the thread.

Jim
Click to expand...

That's just weird, Jim.
 
weirdjim said:
Uh, sir, the throttle is a little tiny metal part inside the carburetor. What you are showing is the throttle CABLE. No offense, but could you be a little more careful in your choice of subjects? I was trying to figure out how to machine that little tiny part before I read the thread.

Jim
Click to expand...

That is really weird. :eek:


:yes:
 
Installed the new throttle earlier this evening and it appears it's all going to work pretty well. Need to sort out a few minor details to ensure the cable doesn't ever rub against anything and I should be set as far as that goes.

Hoping to fly it within a week or so. Going to do my own mini-annual before I take to the sky first.
 
jesse said:
Installed the new throttle earlier this evening and it appears it's all going to work pretty well. Need to sort out a few minor details to ensure the cable doesn't ever rub against anything and I should be set as far as that goes.

Hoping to fly it within a week or so. Going to do my own mini-annual before I take to the sky first.
Click to expand...

Good news Jesse. :yes:
 
Flybaby is back in the air:
klAjIvv.jpg

QA9cTaA.jpg
 
Jessie Angell - making old homebuilts powered by antique engines look cool :lol:


Where we going now? Dave can ride shotgun/cannon in the C177.
 
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