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Left Side Throttle

ChrisMallory

Active Member
Can those with side by side aircraft with dual throttles please chime in. I'm wondering how your throttles are rigged. It seems there are two options:
1) Dual cables all the way to the control arm on the carb
2) One throttle is connected to the other via cable, then a single cable to the carb.

Before I install one option or the other, I would like to hear some feedback from those who already have these (or other options). How well do they work? Any drag issues? Other issues?

I've scoured the posts as best as I can, but have not found any definitive answers.

Thanks,
Chris
 
I didn't build my 6 but it has two cables all the way to the servo arm. Works good! Very glad he did it! Quadrant on the left, push pull throttle "only" in the middle. It moves feely enough to need some friction on the quadrant to hold position.
Only thing I don't like is the quadrant gets in the way a little at full left aileron. I'm a little over 6'2. A shorter person wouldn't have a problem. I plan to move the pedals forward eventually.
 
A friend here built a -6, and did one cable to the carb (from the left side throttle lever) and had a cable in the middle of the panel that made a 180 and connected to the bottom part of the lever on the left throttle lever. It works perfectly, the center can be used for the left hand of the right seater, while the left seater can use either. The twist friction was on the center throttle, although there may have been a friction on both, I don’t remember. I would prefer this method as you only have one firewall penetration.
 
I know it isn't part of the OP, but I can attest that it is really nothing to just pull up a chair in the "other" seat. The throttle is then in the left hand. I promise it doesn't effect your manhood or your expert pilot skills.

I got there because I had a wife that was learning to fly from the left seat, and I had no interest in figuring out how to swap seats a decade later. It has worked out :).
 
I put in another cable that attached to the inside of the throttle arm. You're going to have at least two cables anyway. Had the cable fabricated locally with threads for a rod end on both ends. Didn't want the slop of a clevis and pin on the cockpit end. Built a throttle lever for the left side instead of using the standard push-pull throttle control. Hinged the throttle lever on the floor so that the motion was more linear than if it had been hinged higher.

Here's both cables attached to the throttle arm
51249416237_0d64f25fcd_b.jpg


Here they are coming from the standoff bracket
51250145136_09037095b1_b.jpg


Here's the standoff bracket attached to the Van's bracket for the throttle cable. It's just a piece of 1" square tube cut at an angle
51249419832_39dfa46135_b.jpg


Here's the throttle lever
51250339918_5d56b1ac48_b.jpg


That's all the pictures that I have saved. If you decide to go forward with this, I can take more pictures and answer questions. There are a couple of things that I'd do differently on the cockpit side if I were to do it again.
 
I experimented with 2 cables connected to the carburetor arm, but found I would have some play as the cable had a couple of curves as well as there would be play in between the 2 handles. Probably nothing one would notice “in real life” but early in the building and full of optimism I decided to do different, as it also allowed me to have a longer stroke than normal making for a more precise power setting. The picture show’s it hanging on the wall before installation and describes it better than words. It is a lot of work but there are absolutely no play and almost zero friction. Might have drawings somewhere. Pm me if interested
 

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I experimented with 2 cables connected to the carburetor arm, but found I would have some play as the cable had a couple of curves as well as there would be play in between the 2 handles. Probably nothing one would notice “in real life” but early in the building and full of optimism I decided to do different, as it also allowed me to have a longer stroke than normal making for a more precise power setting. The picture show’s it hanging on the wall before installation and describes it better than words. It is a lot of work but there are absolutely no play and almost zero friction. Might have drawings somewhere. Pm me if interested

Nice setup, looks like IGUS bearings?
 
Building an RV7 and putting in dual side controls. Bought a "left" and a "right" side DJM dual quadrant. The right side was custom made, but could be built from a standard DJM quadrant and an acrylic top plate to change the labelling pretty easy. I took the friction lock off the right side so only the pilot has adjustability for friction. I looked into making up a cam and mechanical linkage for the two controls and eventually decided to just install dual cables all the way to the throttle and prop levers.

I went with the show planes throttle and prop cable mounts.
https://www.showplanes.com/index.ph...=TMC-04S&sid=65726043sel273h4q8461pu3f4n1o451
https://www.showplanes.com/index.php?app=ecom&ns=prodshow&ref=Propeller-Governor-Control-Bracket

The nice thing about these are they both use the same modular cable mount:
https://www.showplanes.com/index.php?app=ecom&ns=prodshow&ref=CBA-01

So i bought my cables with "bulkhead" mounts designed to go through that cable bracket. Instead of using the standard "control bracket angle" though, I bought some 1.5"x1.5"x.125" angle steel and made 2 cable holes side by side. Then I match drilled so it would bolt to the throttle/prop brackets. The cables I ordered are 10-32 threaded on both ends and will be installed with rod ends instead of clevis', one on each side of the actuator arms.

I ended up purchasing 4 eyeball passthroughs for all the cables, until I realized that you could be really slick if you order the eyeball vents directly from the manufacturer instead of through spruce. If you go directly to double-tree (http://www.doubleteeproducts.com/doubleteefirewallproducts/) they can customize the eyeball fitting with 2 holes, so you can run pairs of cables through a single fitting. It would clean up the firewall significantly, but I ordered through spruce and made holes before I realized this was an option.

EDIT: We went with electronic fuel injection so we didn't need the mixture cables. Our setup is throttle/prop only, but no reason this couldn't be executed with 3 pairs of cables.
 
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Great Inputs

Thanks guys for the great inputs. It looks like either option works well. The tradeoff is two holes in the firewall but ability to use push/pull controls vs one hole but have to use at least one lever.
My current plan is to use a lever on the left side anyway, so I'm leaning toward connecting it to a slaved control for the right seat. Then run the control from the left side into the engine bay.
I'll probably have just a throttle for the right seat with prop and mixture only on the left. Like the 4s and 8s do for the rear seat.
So the current question is do I put a push/pull in the middle of the panel for the right seat, or put a lever on the right side of the right seat?
I love the fact that we can build our planes exactly the way we want them!

Cheers,

Chris
 
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