So happy now that I know my nuts won't fall off

N

nosedive

Member
jes1111 said:
Sounds like you need a "flanged nut":

http://www.google.co.uk/search?hl=en&q=flanged+nut&meta=

Or are you wanting something that's bigger "across the flats". You shouldn't, in the sense that metric hardware is carefully sized so that the wrench size is correct fr applying the correct range of torque for that size of fastener. Really high quality tools help, as always ;-)
Click to expand...

flanged would be good but then its not nylock, i couldnt find a flanged nylock which would be perfect


I recieved some M8 washers today which are the perfect thickness, just 1mm! Unfortunately turns out these are slightly bigger than 8mm,, i guess so they can fit over 8mm thread?

Anyway they dont sit flush on the motor like the 8mm holed graupners, the hole is slightly bigger (spec of m8 washer is 8.4mm), so they arent garenteed to be centered when tightened which could cause vibrations etc! It seems nothing can be simple :|

Do washers exist with an actual 8mm diameter hole and not 8.4mm that will sit flush?
 

BerndM

BerndM

Member
Maybe you can get some smaller holed (6 or 7mm?) washers and use a metric drill bit to drill them out to 8mm.
 

J

jes1111

Active Member
I'm confused - you're saying 8mm, but an M8 nut is 13mm across the flats (i.e. uses a 13mm wrench). A 10mm wrench means it's an M6 nut.
 

N

nosedive

Member
yea m6 nut is what the motor takes, but i was talking about an m8 washer to go undernearth the prop
jes1111 said:
I'm confused - you're saying 8mm, but an M8 nut is 13mm across the flats (i.e. uses a 13mm wrench). A 10mm wrench means it's an M6 nut.
Click to expand...
 



J

jes1111

Active Member
So the Graupner prop has an 8mm bore? with an adapter for it to fit on an M6 motor mount?

The flange of an M6 flanged nut (nyloc or otherwise) is 14.2mm diameter. Would that be big enough? Otherwise, you could go with a "washer", but actually what you need is a "shim" (sometimes called a "precision washer") with an inside diameter of 6mm.

http://us.misumi-ec.com/us/ItemDetail/10302179220.html
 



N

nosedive

Member
the dji motors are 8mm, so the 8mm holed graupners fit on perfectly, but the thread is thinner at the top (6mm)

when putting the prop on the prop isnt quite high enough to go above where the shaft changes to 6mm

therefore people have suggested putting an 8mm washer under the prop to raise the prop and go above the top of the 8mm part of the shaft so that the nut can tighten down on it

its 2am here and hard to explain!!
 


N

nosedive

Member
jes1111 said:
Ah! I see now! And you're in Europe (by the time you quote) - so the UK link for Misumi is the relevant one for you. Misumi are not cheap (and it's a bit of a pain setting up an account) but it's a very convenient source for those "special" parts.

Is the 8mm shoulder exactly 8mm?

Try here, too: http://www.calebcomp.co.uk/products/shims_supportwashers.html
Click to expand...

thanks that last link lead me to here:

http://www.springfasteners.co.uk/product/shim_support_washer_8mm_x_14mm_x_1mm_din_988/

looks spot on thank you!!!
 


BerndM

BerndM

Member
The major issue is that the flanged type of Nylock (or similar) is now too tall and the plastic locking material will not screw down far enough to engage the threads.
It sure would have been nice if the 6mm threaded portion was longer.
Oh well.
<:-((
 

BerndM

BerndM

Member
Any spare 2212/920 motors laying around??

I could use 2 of the DJI 2212/920 motors if anyone has a couple thy're not using.
One of mine just got really notchy feeling so I need to replace it and may as well have an extra.
:nevreness:
 

D

DLien

Member
I came up with another solution to the nut problem. I am using the Graupner props on DJI motors and noticed that I couldn't get one tighten down enough not to spin. I took the DJI acorn nut and countersunk the threaded hole just bit, maybe a 1/32 of an inch. The countersinking allowed me turn the nut down over the top of shoulder on the shaft further than I could before.
 

BerndM

BerndM

Member
Hey DLien
What an odd coincident. This is exactly what I had on my quad with the Graupner props. Just ONE of the 4 motors wouldn't allow me to tighten the nut down enough. The other 3 were just fine. I even tried swapping props and nuts. No go. Apparently, whichever CNC machine was used on SOME of their motors was a tiny bit out of whack and we both ended up with one of these. Oh well. Not a major problem.
I like your solution. That's what I should have done instead of using the 8mm washers, which also work just fine.
 


ChrisViperM

ChrisViperM

Active Member
Although I was using a torque wrench, it turned out it was too much hassle in every day business....different prop materials need different torque to be tight, always forgot the wrench when I went out flying....

The easiest way is as follows:

Put a little ammount of blue thread locker (or use nylocks) on the prop shaft once the prop is on and start to tighten the nut until you feel resistance. Than grab the motor with one hand and try to rotate the prop. If it moves, tighten the nut a bit more...until it sits snug. You don't need to use brut frorce and will get a feel for it. The anti-clockwise rotating motors will give you no problem...the clockwise motors are the bastards you must watch for.....


Chris
 

SMP

SMP

Member
Chuckling here... you don't say... Carrying a graupner on my thumb as we speak ;) ;) Things are like little sous chefs..

Truth be told, it's more a carbon thing I'm worried about (PS that bike article you linked to scared me even more) ;) ;). I'm a bit of an over guy and my understanding is that the carbon hubs are susceptible to hairlines due to over tightening.
 

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