pull pull on throttle
03-08-2005, 01:39 PM
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pull pull on throttle
http://members.cox.net/bdfelice/Pull-pull/pull-pull.htm
Almost at the end of this page there is a setup for a throttle pull pull using a spring. What are the advantages of this setup? I have never seen this before. It seems like it might be good if you had a less than direct path to the carb, you could turn a corn pretty easy.
Almost at the end of this page there is a setup for a throttle pull pull using a spring. What are the advantages of this setup? I have never seen this before. It seems like it might be good if you had a less than direct path to the carb, you could turn a corn pretty easy.
03-08-2005, 01:52 PM
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RE: pull pull on throttle
I took a look at the setup and I believe that with the spring setup if you should ever loose connection between the servo and throttle, the spring will probably return the throttle to idle or close completely.
03-08-2005, 02:38 PM
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RE: pull pull on throttle
ORIGINAL: MinnFlyer
I saw that setup too, and I can't help thinking, "Why would you want to put a constant stress/Battery drain on your throttle servo?"
I saw that setup too, and I can't help thinking, "Why would you want to put a constant stress/Battery drain on your throttle servo?"
03-08-2005, 03:49 PM
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RE: pull pull on throttle
Ok, guys, what about the pull-pull on the ailerons? With all the advantages of the pull pull listed in the article (ease of install, light, more flutter resistant, etc) why isnt the pull pull system used more?
I have one installed in the rudder of a 40sized 3D plane, but thats about the only time I have seen them used in a 40-90 sized plane.
Also, what about the extreme angles he has setup on the elevator install? It seems that a pull pull with a 45 degree angle in the cable would cause some unwanted friction.
I have one installed in the rudder of a 40sized 3D plane, but thats about the only time I have seen them used in a 40-90 sized plane.
Also, what about the extreme angles he has setup on the elevator install? It seems that a pull pull with a 45 degree angle in the cable would cause some unwanted friction.
03-08-2005, 05:27 PM
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RE: pull pull on throttle
Minn Flyer wrote:
I have used a similar system with great success for several years. The trick is to choose the spring carefully. It should be weak enough not to cause the servo motor to operate and strong enough to close the throttle if the pulling wire is released.
/Red B.
I saw that setup too, and I can't help thinking, "Why would you want to put a constant stress/Battery drain on your throttle servo?"
/Red B.
03-09-2005, 09:10 AM
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RE: pull pull on throttle
I have seen this done as a mechanical failsafe on the throttle for PPM receivers.
THe trick is to have a low mass servo (coreless) and no binding so that a low tention spring can be used.
Putting a 8 oz load on a 42 oz servo is a low current drain solution.
THe trick is to have a low mass servo (coreless) and no binding so that a low tention spring can be used.
Putting a 8 oz load on a 42 oz servo is a low current drain solution.
ORIGINAL: MinnFlyer
I saw that setup too, and I can't help thinking, "Why would you want to put a constant stress/Battery drain on your throttle servo?"
I saw that setup too, and I can't help thinking, "Why would you want to put a constant stress/Battery drain on your throttle servo?"
03-09-2005, 09:49 AM
#13
RE: pull pull on throttle
To answer several questions...
First, I really don't see how anyone can say that a pull pull system is easier.
Lighter? Maybe, but by how much? I think the difference is negligible.
More flutter resistant? Possibly.
Failsafe on throttle? Yes, but with considerable more trouble than a pushrod (Finding the right spring - using a much more expensive throttle servo - needing to find an anchor point for the spring, etc.)
The biggest advantage I see is that a pushrod (When it's pushing) can bend. A pull pull system completely eliminates that.
So while each of these items has some merit, I think it is up to the individual to determine how much time and money he wants to spend tinkering.
Personally, I'd rather fly - But that's just me.
First, I really don't see how anyone can say that a pull pull system is easier.
Lighter? Maybe, but by how much? I think the difference is negligible.
More flutter resistant? Possibly.
Failsafe on throttle? Yes, but with considerable more trouble than a pushrod (Finding the right spring - using a much more expensive throttle servo - needing to find an anchor point for the spring, etc.)
The biggest advantage I see is that a pushrod (When it's pushing) can bend. A pull pull system completely eliminates that.
So while each of these items has some merit, I think it is up to the individual to determine how much time and money he wants to spend tinkering.
Personally, I'd rather fly - But that's just me.
