Hi,
I sent this support mail to 3DR, but decided to publish also here. Perhaps someone here can answer some of my questions?
1. Mounting prop with locating ring
The propellers (APC LP11047SF and LP10047SFP) don't fit the threaded collet (4.85 mm/0.19 inch). The small locating ring delivered with is 4.78mm/0.188 inch). What is the recommended method of fitting the prop to the collet? I'm reluctant to drill a larger hole in the small locating ring, since this may cause imbalance.
2. Spacer on prop
In the assembling guide it says to add a "metal spacer" between prop and prop nut. However, this is not included in the kit. I found star washers that fit in the small indentation for the metal spacer. Is it OK to use the star washer?
3. Prop nut
In the assembling guide the prop nut is conical cover nut, but I received ordinary nuts in the kit. Do I need to get conical nuts?
4. Locking nuts
I want to use locking nuts (e.g. nyloc nut) instead of the included nuts. Could you provide the spec for the threaded collet (diameter, threading, inch or mm?).
5. Mounting bottom prop upside down.
In the assembling guide it says to mount bottom prop upside down. This means that the location ring and the spacer (see p 2) is mounted in reverse (i.e. spacer towards the motor and location ring towards prop nut). Do I need to take any specail precautions to make sure the fitting is good?
Replies
Thanks for all the good info on this subject. Feels great to be in such a good community :-)
;-) Sounds familiar - I had more or less the same issues with my 3DR Y6 RTF.
Use the smaller ring. Mine have an inner diameter of 4.85 mm. This fits or can be made to fit. You could use a sharp knife to deburr (chamfer? - sorry, I don't know the proper english term)) the inner edges and use some force/pressure to get the ring onto the unthreaded part of the shaft. I usually push it down with the nut.
and
I also got the "new" blue 850Kv motors:
http://store.3drobotics.com/products/motor-ac2830-358-850kv-1
You don't seem to need the spacers and the normal metric (M5) nut seems to be correct.
Hope this helps.
Philipp
Rolf,
You want a perfect fit between the prop hub and the mounting shaft, a slight interference fit is a good thing. The threads on the mounting shaft will tend to ream out the hub adapter as needed.
Do not use the spacer/washer, it's internal diameter is not a perfect fit on the threaded shaft, and it will not be concentric. This will induce vibration. It is also adds rotating mass, never a good thing. The star washer fits perfectly concentric and adds little mass, while at the same time provides some resistance to undesired fastener loosening.
The spinner type conical nuts are not machined very well and often have quite a bit of run-out, this induces vibration. The small nut is superior.
I do not recommend locking nuts. They are heavy and lose effectiveness after repeated removals. The star washers work well and are a more elegant solution.
All props should have the writing facing up ("APC" and "10 X 4.7" e.g.). If the star washer is not perfectly concentric on the bottom orientation (because of the lack of recess in the hub bottom) it is not likely to cause much vibration when compared to the large spacer/washer. Try your best to center the star washer around the shaft.
Hi Rolf, here is a thread on the same topic I started awhile back. I used star washers with nut provided no thread locker, drilled out little plastic rings to fit prop shaft and balanced prop with ring in prop. Files great no issues.
Greg
http://www.diydrones.com/group/arducopter-y6-owners-group/forum/top...
I'll comment on your points based upon my experience. I hope it helps. I am using the 880kV black 3DR engines and I received my Y6 kit in late August.
1. Each prop comes with 2 rings. The manual suggests using the larger ring which is a good fit for the engines shipped to me. I understand the props themselves don't have precise holes but the prop with the fitted ring IS precise. I haven't measured my engine collet diameter.
2. For me, a metal spacer shipped with each engine. I don't think I received any other washers with the kit at all.
3. Yep the nuts shipped with my engines were conical. I wouldn't think the shape would matter much.
5. Sorry I'm not really sure what you are referring to here. The manual does not mention a "location ring" and p2 says nothing about attaching props. However I did have a minor problem with the diagram on p10 for attaching props. This diagram is for the top props. For the bottom props, the prop and plastic ring should be reversed. Most importantly, the writing on all props should face upwards.