Throttle arm

[J V R]

I need to extend a throttle arm by about 10mm to line up with better with the servo, I can not think how to do this. Dose anyone have any easy to do mod that will put the arm more in line with the servo and do away with the crank in the throttle linkage (see attached pics)

.

jvr...........

[iqon]

will it line up any better if you take the arm off and rotate 180 deg....

[Philip Ogden]

Two methods come to mind, both involve replacing the existing pushrod with a longer one. First method involves extending the pushrod past the throttle arm, then making a u-bend so you are now driving the throttle arm from the front. A bit crude but it does work and gives a reasonable degree of adjustment. Second method involves mounting a 180' bellcrank on the engine mount ahead of the throttle arm. The bellcrank is driven by the pushrod from the servo while a second, shorter, pushrod goes from the bellcrank to the throttle arm. A little more work but more elegant and you should have the space.

[J V R]

Iqon,

there is around 10mm difference between the center of the push rod and throttle arm its not very clear in the pics it was hard to get the right camera angle.

PO

I like the idear of the u-bend so simple............

[Subalib]

I have used the U bend approach on one of my four strokes and found it simple and effective.

[Trevor Rushton]

The second method described by Philip works really well; I tend to make a small ply or aluminium bracket fixed to the motor mount; fix a spare servo arm to that so that the arm pivots freely and then use a short pushrod back to the throttle. You can adjust the height of the bracket to suit.

I have also tried the u bend approach but had less success with that.

Let me know if you want a picture.

Trevor

[Owdlad]

extend the throttle arm by using a spare servo arm attatched by 2 m2 bolts then cut the servo arm to lenght.

Hope this helps

Owdlad

[Wingman]

Looks OK to me the way it is - the control rod looks beefy enough so, as there's virtually no friction on a throttle control, the rod isn't going to flex at the bend like it might do if it were moving control surfaces. All the friction will be in the guide tube so as long as the rest of the rod is straight to the servo arm I can't see a problem.

[Paul Jefferies]

Another alternative would be to use a ball link on the throttle arm. Some ball links stand well proud of the arm to which they are bolted and that would certainly take care of at least 5mm but also, because it is a ball link, alignment would then become less of a problem.......

Paul

Edited By Paul Jefferies on 11/05/2015 08:39:37

[Cuban8]

Had exactly this problem myself with an ASP61FS and my trusty old H9 Aresti 40. The way I solved it was to use a small screw of suitable length, 'double nutted' to the throttle arm. This can be adjusted to give the degree of offset required and locked in place with Loctite.- a helicopter type ball link (previously fitted and nutted under the head of the screw) provides the connection to your throttle snake or push rod. Been on the model for years and never had to touch it.

Edited By Cuban8 on 11/05/2015 08:30:13

[Cuban8]

Managed to get a shot of what I was talking about!

[Gary Manuel]

Here's an option. I use these on 4 stroke engines, but there's no reason you can't use it on yours if none of the other options suit. I find them great as as they keep everything nice and tidy and allow plenty of adjustment.

It's available here in the UK

[ROY DAVIES 1]

Cubana The 'U' bend works a treat.

Looking at your picture you are close to having a problem with bulkhead. My cure here was to use the tapered nozzle off a sealant tube. Cut the pointy end to force fit on the already fitted snake, drill the bulkhead to accept the knurled end of the tube and glue in place with silicone or epoxy. You can do this as a retro fit or new build. It allows for the throttle arms movement swinging the push rod as it is moved and keeps the bulkhead and tank bay nice and clean

Roy

[Former Member]

[This posting has been removed]

[Rick Tee]

Drill another hole in the firewall inline with your throttle arm.

[Former Member]

[This posting has been removed]