Limit vs. Travel

[marian206]

Trying to adjust the pyro rate on my 450PRO I entered the Linkage menu, then accessed End Point sub-menu where I have two parametrs:

Limit (default @ 135) and Travel (default @ 100) for all my channels.

What is the difference between these two and which one should be adjusted to lower my pyro rate?

I have read and re-read the manual, which in my opinion is a shame and an offence to customers who deserve to be explained everything in order to get the most from this product and ultimately from their money.

Regards

[Phaedrus]

Travel is the maximum amount that the assigned control can move that servo.

Limit is the maximum amount that the servo can move if there are any mixes that also affect that control.

It makes sure that if there are any mixes that can move that control do not over drive the servo beyond the physical limits of that control.

[marian206]

so in order to lower pyro rate I should adjust Travel?

[MikeG4936]

With Futaba radios, it is super-easy to adjust piro rates from the D/R Exp menu. Just bump the D/R numbers up or down for the rudder channel (usually channel 4). You can adjust both directions equally, or you can adjust the directions separately to get equal piro speed in both directions.

[Steve Evans]

Travel is the maximum amount that the assigned control can move that servo.

Limit is the maximum amount that the servo can move if there are any mixes that also affect that control.

It makes sure that if there are any mixes that can move that control do not over drive the servo beyond the physical limits of that control.

Nope, that's not right at all! The manual is clear on what each setting does.

The effect of these controls is easy to see by messing with the settings on one of your cyclic servos and seeing how it then moves relative to the other two when you apply collective input (having first disconnected your motor to ensure no finger loss!).

The tx is able to move a servo to 155% of it's nominal travel. The "Limit" constrains this.

To see this set the limit to, say, 50% in one direction on one of your cyclic channels. Now move the collective up and down. You'll see that in the direction where you left the limit alone all three servos move together, keeping the swash level all the way to max pitch. In the other direction you'll see that all three servos move together, the swash level, until the adjusted servo simply stops, whilst the other two keep moving, tilting the swash. Play around with that limit and you'll see that it doesn't affect the amount that the servo moves (proven by the fact that the swash stays level) until the limit is reached.

Now move the collective just short of the point where the servo stopped and waggle the cyclic. You'll see that the same limit is honoured. This shows that the limit is applied after any mixing.

Try setting the limit in the other direction too, and you'll get the same effect there too. This should look familiar behaviour as it's just like setting the limits on your tail servo using the gyro settings; you're not affecting how fast the servo moves, just how far.

Now reset the limits back to where they were. And wind down the "Travel Rate" (sometimes referred to as travel, sometimes as rate; I prefer the latter). Now move the collective. You'll see that in the affected direction one servo moves slower than the other two as you move the stick, gradually tilting the swash an increasing amount. It can thus be seen that Rate affects how far a servo will move for a given stick movement.

If you want to adjust the relative piro speed left/right on your heli, use "Travel Rate", not Limit. This will result in your stick inputs having effect over their full travel, whereas using Limit would mean that once you'd move the stick so far, extra input would be ignored.

Steve

[Phaedrus]

Nope, that's not right at all! The manual is clear on what each setting does.


From the Futaba FAQ

When you enter the End Point function, there are two adjustments for each direction of servo travel: "Travel", and "Limit". "Travel" adjusts the amount of servo travel for normal full-stick movement at high rates. "Limit" adjusts how far the servo travels when a mixer is involved. The system has default values of 100% for Travel, and 135% for Limit. You can set the limit up to 155% of normal servo travel. These numbers are usually all right just as they are, and you will rarely have to reset them.

http://www.futaba-rc.com/faq/faq-14mz-q1157.html

[Phaedrus]

so in order to lower pyro rate I should adjust Travel?



You can adjust Piro rate using the ATV -or- the AFR menu. The FAQ notes to use the ATV travel.

http://www.futaba-rc.com/faq/faq-gyros.html#q665

[Steve Evans]

From the Futaba FAQ



http://www.futaba-rc.com/faq/faq-14mz-q1157.html

Try what I suggest above; I'll leave you to reconcile that with the FAQ. :)

Steve

[MikeG4936]

No, leave the Travel and Limit (in the ATV menu) set to the default.

You adjust Piro rate using the AFR menu

http://www.futaba-rc.com/faq/faq-gyros.html#q665


Wait a second - the FAQ you linked to says to use the ATV, not AFR! AFR is only for swash movements anyway - don't know how that would affect the piro rate.

Honestly, the easiest way to do this is just dial up or down the respective numbers for rudder in the D/R (Dual Rates) menu (essentially modifying the rate limit for the rudder channel).

[Phaedrus]

>>>>>

[MikeG4936]

ATV and AFR are totally different things. You should NEVER adjust the ATV. You ONLY adjust the AFR (dual rates). Please reread the FAQ. You are getting yourself confused.

Where does it mention anything about AFR in that FAQ? It only mentions ATV. I could be wrong, but please quote for me what you are talking about - because I certainly don't see it!

[Phaedrus]

You responded before I edited my post. It is me who got turned around. For the gyro the piro rate is changed using ATV. However, I stand by my explanation of the difference between Limit and Travel in the ATV Menu. Gyro piro rate is a special case where that does not apply.

You can also affect the piro rate in the AFR menu using the travel amount there as well.

Also keep in mind that there is the Limit in the gyro itself and the Limit in the ATV menu in the radio. You adjust the T/R servo travel limits using the gyro menu. You adjust the piro rate using the Travel part of the ATV menu.

[MikeG4936]

You responded before I edited my post. It is me who got turned around. For the gyro the piro rate is changed using ATV. However, I stand by my explanation of the difference between Limit and Travel in the ATV Menu.

Glad we got that cleared up. :lol: I definitely agree with your explanation of Limit and Travel in the ATV menu.

[Phaedrus]

I know this stuff and get turned around sometimes!! Too bad they don't let the users do the programming!