Folding Props

[Beemerider]

I'm attempting to use a folding prop on my 2m sailplane. I'm using a 8 X 4.5, which seems to be the best size for my 1300KV. Performance is mediocre at best and extremely noisy. Also a substantial vibration issue. A standard 8 X 4.5 runs rings around the folder not to mention much smoother. The folder came from HURC but don't remember the brand name off hand. Is this kinda standard fare when you compare folding props vs standard?

[fhhuber]

Any prop needs to be balanced.
Folding props are harder to balance...

And actual diameter of the folder varies with the hub used.

APC folding props are labeled for diameter using their 45mm hub, but the blades fit all the hub widths. As you increase hub width you are changing diameter and increasing effective pitch of the prop.

Compare actual diameter of your folding prop with the non-folding. You may have too much prop with the folding prop.

[CrimzonRider]

Can you link motor? a HURC 1300kv motor?? or a HobbyKing??
Try different blades....

like huber said, you might be overproped.
Whats your wattmeter sayin

http://www.wattflyer.com/forums/showthread.php?t=70385

cr

EDIT:.....just found your other thread....
http://www.wattflyer.com/forums/showthread.php?t=68187

[kyleservicetech]

Originally Posted by Beemerider

I'm attempting to use a folding prop on my 2m sailplane. I'm using a 8 X 4.5, which seems to be the best size for my 1300KV. Performance is mediocre at best and extremely noisy. Also a substantial vibration issue. A standard 8 X 4.5 runs rings around the folder not to mention much smoother. The folder came from HURC but don't remember the brand name off hand. Is this kinda standard fare when you compare folding props vs standard?

Back in the mid 1980's I was running Astroflight Geared brush type 40 motors on my 10 foot sailplanes. One thing of note on sailplanes, a big diameter, medium pitch, low RPM prop seems to work best for the slower flying sailplanes. As compared to a little bitty prop turning over at high RPM. That would call for a motor with a low KV number. You could try running the numbers on www.motocalc.com, free for 30 days, then $39. It might help you in deciding what to do.

I'm sure you've noted that a windmilling propeller has the same effect as popping the spoilers on these sailplanes.

Back then there were several folding prop makers, and those I've used were very well balanced, with little vibration. That was with 13 inch diameter props with about an 8 inch pitch. That would haul my 10 foot sailplane up at about 45 degree angle, and keep on going.

[Beemerider]

I must apologize for too many threads I guess. I started having questions concerning folders back last fall. Still having questions as I go along.

Originally I tried several different prop sizes and measured current and wattage before putting it in the air. It's a motor off ebay, here are the specs:

Motor: 2830-8
Rpm/V: 1300KV
Diameter: ð¤27.8mm
Length: 32mm
Shaftmm: ð¤3.17
Weight: 62g
Wire Winds: 8
Resistance: 104mî©
Idle Current: 1A
ESC: 30A
Cells Ni-Cd/Ni-MH: 6-12
Cells Li-Po: 2-4
Prop:9x6/10x5/10x6

I tried prop sizes up thru the 10x6, but it was on a 3s. Possibly I should drop back to a 2s and try the 10" again. But regardless I'll need to figure a way to balance the combo. I'm trying to affix a camera and the vibration is a killer. I've been using a #16 cam with decent results but the xyl gave me a CamOne Infinity for my birthday a while back and I'm wanting to get this combo right prior to mounting the camera. Thanks for all the good advice!

[flydiver]

Jeff is a great guy, and has wonderful customer service but many of his products are low>medium grade. For a good folder you might have to consider paying out for Graupner or Aeronaut. Yes, $$$ but a whole lot better.

[Beemerider]

Originally Posted by flydiver

Jeff is a great guy, and has wonderful customer service but many of his products are low>medium grade. For a good folder you might have to consider paying out for Graupner or Aeronaut. Yes, $$$ but a whole lot better.

I have considered that and will probably go that route. But first I need to better my flying skills! Kinda why I've been dragging my feet before putting my good camera on it.

[flydiver]

Sometimes sub-par equipment leads to sub-par results. In RC that isn't always true, but there is definitely a difference in the cheapy folders vs. the good ones.

Minimum, you need to balance that setup.

[CrimzonRider]

Originally Posted by Beemerider

I must apologize for too many threads I guess.

Naw! No worries.... Just linkin' so everyone knows as much info as possible to help you get your problems fixed!!
Just helps the search engines narrow down results, too...no biggie

+1 on flydiver comments on sub par & balancing, just shim up to prevent blades from moving while balancing.

Might want to remove shaft and make sure it's dead true.

cr