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How to assemble a prop to the motor??

#1
Hello,
Yesterday, i finished building my FT Flyer with a Turnigy park 300 1380 kv motor. I got some propellers as well, of course. However, I can't manage to assemble my prop to the motor... I tried using rubber bands, (although they were way too long), but when I go full throttle the prop breaks off.... When I look at FliteTest video's, they seem to use a kind of small, thick, strong rubber band. Unfortunately, I don't have those. Is this the only way to assemble my props? By the way, the props came with nothing but the props themselves....

Silvester
 

PHugger

Church Meal Expert
#2
What type of prop adapter and prop are you using?
The adapter is the extra metal bits that are attached to the motor shaft.
There are a bunch of different types.
Post some pictures and I'm sure you'll get more advice than you ever wanted.... (c8



Best regards,
PCH
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#3
Silbo,

They're using rubber o-rings, sized to hold the prop on tightly. IMO, most of those are too loose as well.

I typically use 1/4" disks cut from thereaband blue tube:

http://www.amazon.com/Thera-Band-Latex-Exercise-Tubing-X-Heavy/dp/B000PL6C60/ref=sr_1_15?ie=UTF8&qid=1422807934&sr=8-15&keywords=theraband+blue

yeah, $23 is crazy expensive for it . . . I went to a local physical therapist and bout a couple of feet off them for a few bucks. a few feet will last you a VERY long time.

Alternatively, I've seen HK's 8mm bungee tubing is about the same stuff:

http://www.hobbyking.com/hobbyking/store/__10609__HobbyKing_8mm_Silicon_Rubber_Bungee_Hi_Start_Cord.html

~$10 shipped for 30ft. About as cheap as I can find without sharing an order between a bunch of guys
 
#4
Thanks everyone, but I think that the problem is no longer with the rubber bands. I can get them. However, my prop can't be tightened to the motor. It's weird. Here are some pictures:
Tet8jWh.jpg
y7FdtQ4.jpg
Xp2mp1S.jpg

As you can see, the hole in the prop doenst fit on the prop saver, it can move around, even when I put a rubber band around it. There is no shaft that can hold the prop in place. Should I reverse the shaft? I don't know if I can do that.....
 

William A

Billy did it....
#6
Is the back side of the prop adapter the same in size ? (would flipping it help ?)

Looks close, get manly and force it ?

If not, like Kurt said, make hole bigger.
 
#7
Looks close, get manly and force it ?
I might have to force the shaft more forward so it can hold my prop in place. The motor is pretty weird. Why didnt they let the shaft stick out at the front? What's the use of the shaft if it sticks out of the backside???

Does anybody know if the shaft on this motor can be reversed?
 
#9
Rubber bands and o-rings won't work. Even the black ones they provide aren't that good. Thereaband and slingshot bands sliced down to size have been the best. It may seem to be wobbly but as long as it is centered, it should work.
 

devindied

SEL MEL CFI CFII MEI
#10
Rubber bands and o-rings won't work. Even the black ones they provide aren't that good. Thereaband and slingshot bands sliced down to size have been the best. It may seem to be wobbly but as long as it is centered, it should work.
Funny, been using them for years.... I agree, sometimes they break, but they save your prop. Just double up the O-Rings.
 

rcspaceflight

creator of virtual planes
#11
When I started into this hobby I was frustrated trying to make use of my prop saver and I didn't want to buy and wait for a prop adapter. (I knew of no local hobby shops at the time.) So I just tied the prop on using fishing line. It might not be the brightest idea, but it works. It may no longer actually save your prop though.

I did find that plumbing O-rings work well. I have to use a nail or small screw driver to force them onto the prop adapter, I can by no means get them on by hand. But it's that tightness that makes them work.
 

Kurt0326

Your ADD Care Bear
Mentor
#12
I can confirm that the ring that they use are standard pumping O-rings. You can go to your local handy man store and pickup what you need.
 

PHugger

Church Meal Expert
#13
These plumbing O-Rings come in a variety of sizes. Here are the ones that worked for me -
WP_20140601_001.jpg
I got them at the Home Depot. They do stretch out and eventually need to be replaced.
I have had good success using them on a similar prop-saver to the one you are using with similar cheap props.


Best regards,
PCH
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#14
IMO the single most important advise on prop savers (really should have said it in my first post, shouldn't I :black_eyed: ):

If it's Easy to put on, it's Easy for the motor to throw off.​

No matter what you pick, it *should* be hard to get it on. If not, it's not tight enough.

After that, if it's got some way to keep the prop center and flat, you should be good to go up to about 100W of power.
 

devindied

SEL MEL CFI CFII MEI
#15
Very true. Just remember when using O-rings, sometimes after many landings on the prop the threads of the screws on the prop saver wear into the O-ring. Check your O-rings before each flight. Flying props are a real hazard. Had it happen yesterday..:applause:
 

johnmw

propulsion impromptu
#20
Thanks everyone, but I think that the problem is no longer with the rubber bands. I can get them. However, my prop can't be tightened to the motor. It's weird. Here are some pictures:
...
As you can see, the hole in the prop doenst fit on the prop saver, it can move around, even when I put a rubber band around it. There is no shaft that can hold the prop in place. Should I reverse the shaft? I don't know if I can do that.....
try mounting the prop saver the other way round.
usually prop saver has 2 different end sizes.