Folding props and soft motor start

I’d like to use folding props on my quadplane but the last time I used them one broke during an auto takeoff causing the plane to flip causing a bit of damage. Tridge mentioned to me that there was a parameter to give the motors a soft start that I should set if using folding props. I can’t find that parameter in the doco. Does anyone know what it is? TIA

I’ve lowered the values for parameters:


which seems to work on the bench. I’ll test fly with folding props next week to see if this helps.

Those lower the minimum rpm and it’s probably a good thing to lower them if everything still works but don’t necessarily change the spool-up time.
The parameter "Q_M_SPOOL_TIME"

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That sounds like the parameter I was looking for. Thanks!

Hi Darrel, I just found this thread because I also will use big folding prop.on quad motor for my big VTOL. I am worried the folding prop. may “stuck” during flying, because this quad motor will stop and start in the air depend on the plane speed. What do you think based on your experience ? Thank you.

I really don’t know but I think it’s unlikely that they wouldn’t unfold properly regardless of speed. Maybe someone here has more experience. I only tried folding props one other time and they didn’t provide enough lift so I gave up and went back to normal props. I’d like to try them again with the new smaller and faster SunnySky motors that I’m now using but those motors don’t seem to have mounts available for folding props. If anyone knows of an adapter for SunnySky motors to accept folding props please let me know.

Darel, it depend on what models of your Sunnysky motor. If it is V series like V4008 or V 5208 than you can buy from Tarot. It is not difficult to find this item. Tell me your motor model.

SunnySky X3120-5 1100Kv

This is for pusher motor or for quad motor?

I’m using the Sunnysky motors for the quad side of the plane

Darrel, in my case I use pan cake type of motor to use folding props (like Sunnysky V4008 V5208 or Tarot 5008) that have 4 mm shaft, so that I can use “Tarot” paddle or holder for the folding props (see pictures). But in your case the shaft is 5 mm, so you need to buy other holder. You may contact Nina from Rc Timmer who may sell the complete set of folding props and the holder.

Here are the photos

You can contact Nina from Rctimer for folding propeller. But you must mention the motor model and size of motor shaft. Her email is

When I was using T-Motors I tried folding props that were very similar to those in your photo. I’ve always been curious why the screws don’t vibrate loose when there’s not nut on them? And I’ve been told that lock tight can damage props so it’s not a good idea to use it on that type of mount.