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Stick Hits Heater Control Knob

rockitdoc

Well Known Member
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At full dive, my stick still hits the heater knob when control is full out. Elevator horn is against the stop at the rear at 25 degrees down.

Cut more off stick until no interference? Don't know what else except bending stick aft.

Stick Hits Heater Knob.jpg

Elevator Horn Hits Frame.jpg
 
I don't have a 14 and I'm not a builder, but can you fabricate an "L" shaped bracket or put a piece of angle that mounts on the bottom bend of the panel, down and to the left of the current knob position? That way you could move the heater control versus messing with the stick.

My panel has a couple of those sorts of brackets for the oil cooler door and carb heat control.
 
I believe your stick grip manufacturer sells a beveled washer that will tip the grip back. Or, fill the stick with sand, bend.
 
I think considering the fact that you can always close the heater during such unusual turning dive and if with heater closed there is no interference, then I believe you should be good as it is.
 
At full dive, my stick still hits the heater knob when control is full out. Elevator horn is against the stop at the rear at 25 degrees down.

Cut more off stick until no interference? Don't know what else except bending stick aft.


Try adjusting the CS-00002 MID ELEVATOR PUSHROD slightly - I forget if you would have to lengthen or shorten, but turn the rod end bearing at the idler arm to see what might work in your situation. A small adjustment (1/2 turn or so) can impart a large effect.

(Also, this is assuming the ailerons have already been adjusted per the instructions.)
 
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Why not just move the heater control knob? There's no real need for it to be located in a specific place... other than it should be out of the way of flight controls.
 
Ours hit too, in two different 14s. They aren’t even close now that the controls are installed and travel set. Don’t act too soon. :rolleyes:
 
I think considering the fact that you can always close the heater during such unusual turning dive and if with heater closed there is no interference, then I believe you should be good as it is.

Yes. With heater knob all the way in, no interference. Also, no interference with any toggles or throttle.
 
Try adjusting the CS-00002 MID ELEVATOR PUSHROD slightly - I forget if you would have to lengthen or shorten, but turn the rod end bearing at the idler arm to see what might work in your situation. A small adjustment (1/2 turn or so) can impart a large effect.

(Also, this is assuming the ailerons have already been adjusted per the instructions.)

Ailerons not adjusted.

Already made the pushrod as short as it can get. Van's calls for a 72-29/32" pushrod. Mine is now 72-24/32" and stick still hits heater knob when full out. BTW, the sticks are shorter by 3-1/2" as per Tosten's recommendation.

Elevator Pushrod Forward.jpg

Elevator Pushrod Aft.jpg

Stick Hits Heater Knob.jpg

I am reluctant to shorten the pushrod any more (I think it would take shortening about another 1/2-3/4") to get it to clear for fear of making the up-down controls too twitchy-sensitive.

I like Mehrdad's remark that since I get clearance for everything other than when the heater knob is all the way out, not a biggie. Unless I plan on dive bombing a carrier group to port during a 90 degree wing over in the winter. :eek:

What do you all think about another 1/2" shorter pushrod? Make controls too sensitive up and down?
 
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Ailerons not adjusted.

Already made the pushrod as short as it can get. ...


I think you may have to first adjust the ailerons, since their internal stops will dictate the lateral deflection of your control stick.

And for the mid elevator pushrod, you might need to _lengthen_ that pushrod slightly, which will have the effect of deflecting the top of the control stick more aft (since it pushes the bottom of the control stick assembly forward).

You mentioned you adjusted the aft elevator pushrod (big one); I was actually talking about the mid elevator pushrod. See page 36-01. Actually, either shortening the aft pushrod or lengthening the mid pushrod (or both) should have the same desired effect (if my 3D spatial relations are correct).
 
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I think you may have to first adjust the ailerons, since their internal stops will dictate the lateral deflection of your control stick.

And for the mid elevator pushrod, you might need to _lengthen_ that pushrod slightly, which will have the effect of deflecting the top of the control stick more aft (since it pushes the bottom of the control stick assembly forward).

You mentioned you adjusted the aft elevator pushrod (big one); I was actually talking about the mid elevator pushrod. See page 36-01. Actually, either shortening the aft pushrod or lengthening the mid pushrod (or both) should have the same desired effect (if my 3D spatial relations are correct).

Thanks AlexC. I had not thought of lengthening the mid rod. I will post results.
 
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Stick Clears Panel and Heater Knob at Full Heat!!

Problem solved. The VAF wins another one! :D

I lengthened the mid elevator pushrod 8 threads or about 1/4".

Mid Elev Pushrod Lengthened.jpg


The result was huge at the panel.

Stick Clears Heater Knob.jpg

The stick clears the heater control knob by 3/4", now. Where prior to this adjustment, the stick hit the knob at about 3/4". So a 1/4" movement at the mid rod made about a 1-1/2" difference at the panel! I will actually shorten the rod about 2 threads to bring the stick a tad closer to the panel, just to make sure it doesn't interfere with my cojones will aloft. :eek:

Stick Clears Seat.jpg

Man, were you correct AlexC! Thanks, again.
 
I will actually shorten the rod about 2 threads to bring the stick a tad closer to the panel, just to make sure it doesn't interfere with my cojones will aloft. :eek:

I think this is the more critical measurement. Be sure that you and possibly those with larger mid sections can get the stick full aft comfortably. This will occur all of the time whereas as full down elevator in combination with full aileron is quite rare. Just can't imagine that I would ever want to be rolling (only time I think I have ever used full aileron on an RV) with the nose pointing straight down with VNE right around the corner. Even stall recovery should be neutral aileron and restricted aileron throw is almost a benefit. I suppose there is a case for landing with strong cross winds.
 
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AlexC is correct as any extra adjustments/shortening of the push rod will be limited by the internal stops that is for the stick.
The process is to make sure the elevators stops (at elevator) are set that they are free for the full deflections and then you rig the push/pull and make sure the stops at the stick allows for that full deflection plus a hair more. The idea is that if you are pulling on the stick hard, it is not putting extra force on the push/pull tubes.

Then you will adjust the length of the stick to make sure it is free but cutting it too short will have other effect which has been talked about at length. Mike Seager has put a good tread/comment about cutting the stick too short.
 
Problem solved. The VAF wins another one! :D
I lengthened the mid elevator pushrod 8 threads or about 1/4".
View attachment 36854
The result was huge at the panel.
View attachment 36855
The stick clears the heater control knob by 3/4", now. Where prior to this adjustment, the stick hit the knob at about 3/4". So a 1/4" movement at the mid rod made about a 1-1/2" difference at the panel! I will actually shorten the rod about 2 threads to bring the stick a tad closer to the panel, just to make sure it doesn't interfere with my cojones will aloft. :eek:
View attachment 36853
Man, were you correct AlexC! Thanks, again.

Make sure you still have more than 1/2 of the threads within the fitting.
 
Personally I would move the heater control somewhere else regardless of stick interference. IMHO cabin comfort controls (etc.) should not be grouped with flight / engine controls.

I also recommend making the hole in your panel big enough for the knob to get through and attach it with a subpanel. Otherwise you are committed to having to take the entire heater cable out end to end if (when) you ever need to take the panel off. See pic.
 

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Approaching this same issue. From what I read, its best to do nothing until you have all control surfaces rigged, then adjust push rods to get the proper clearances. i.e. don't cut down the stick until later. Yes.
 
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