Can someone explain what the benefit of props like this:

http://www.rctimer.com/index.php?gOo=goodspic.dwt&goodsid=747

are over props like this:

http://www.rctimer.com/index.php?gOo=goods_details.dwt&goodsid=827

Also, what are the meanings of the individual numbers? I understand that the first is the length, but what is the second? What does it mean? What happens if it's higher? Lower?

Thanks a bunch in advance!

Tags: noob, pitch, prop

Views: 381

Reply to This

Replies to This Discussion

I feel your pain, I've been trying to learn the ins and outs o the props and power systems lately and its hard to ask intelligent questions(less likely to get answered).  I'll give you my conclusions thus far but I'd invite anyone to correct me as I'm still learning.

The second number is the pitch of the blades; the greater the number the steeper the pitch of the blades=they move more air). For example the stock 3DR quad comes with 10x4.7 props which I have replaced with 10x4.5 props because the x4.5's are cheaper and available in lots of bright colors.  The 4.5's have less pitch to them which means they are throwing less air around.  This has required me to start learning how to tweak the PID settings of my quad.. Mainly increasing the Throttle_P setting while testing the Alt_hold.  

You've listed two wildly different prop sets... From the little I know of power systems I suspect most people would use completely different motor setups... however, how you determine the proper power system involves some calculation based on the weight you want to lift and flying time you desire.  

I believe there are some calculators out there to help with this but I haven't had time to try and learn all the deets yet.

Hope that help you a little!

It helped a TON! Thanks! The pitch seems to make so much sense now that you've explained it.

The larger props in the first link are for motors with the dual screw type mount to match. The dual screw type prop mount can be more reliable and can handle more power than the traditional single screw prop mount like the props in the second link. Either are suitable depending on the size of the multirotor you plan to build. You wouldn't want 15" props on a tiny multirotor nor 10" props on a gigantic multirotor. Like Andy said, the second number is the pitch. A greater pitch means more thrust and also a higher load on the motor.

These are going on a CarbonCore Octo with a Sony DSLR under it. I am planning on using the 15" blades after your input. Thank you!

Make sure the motors can accommodate the mount and the size, those are pretty big props. Good luck with the new copter!
The pitch number is the number of inches the prop will move forward with each revolution. It's equivalent to the gears in a car transmission. High pitch prop is like fifth gear, good for high speed, but hard to accelerate from a stoplight. Low pitch is like first gear, good for accelerating but top speed will be limited.

Hello Miles,

Make tests at this website. You can see the differences (theoretical) when using a propeller or other, you'll see the differences in consumption, thrust, etc. It is very illustrative.

http://www.ecalc.ch/xcoptercalc_e.htm?ecalc

Greetings,

Anderl

What kind of motors do you use?  kv?

15" is quite large. Keep in mind your copter will get very big and the "arms" get longer so the props don't hit each other. If your motors aren't powerful enough (too much kv) you will have trouble keeping your copter stable.

But why use 10x3.8" ? They are so unusual. Why not use these: (see >750kv)

I fly 750kv: I use 10x4.7" APC. next round will use: http://www.rctimer.com/index.php?gOo=goods_details.dwt&goodsid=...

If you use ">750kv" I would probably use these: http://www.rctimer.com/index.php?gOo=goods_details.dwt&goodsid=...

The 10x4,5" are more standard and very usable. I would always go for 750kv or less.

I learned the hard way - don't use cheap props.  There's an awful lot of torque in the materials, as well as some flexing.  I lost a prop in flight a few days ago.  If it were on a quad, I would hope to at least salvage the electronics.  Mine is a hex and I was able to sort of perform a controlled crash and limited my damage to props, a couple of arms and at least one motor.

RSS

© 2014   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service