I finally got through most of the configuration issues and was ready to attach the propellers and fly. There are both the wiki (picture) and text directions for 3D propeller attachment however the aluminum mounts that come with the kit were straightforward and I attached the propeller directly without using any of the plastic rings that came with the kit. Snugged them down by hand.
When I tried to fly it some of the propellers flew off and/or came loose pretty much instantly.
I returned to the directions and tried using the plastic rings that came with the blades per the directions but they don't seem to work--the stock metal mounts already have a collar that sticks up and goes into the indent in the blade so the plastic rings just make matters worse.
Do I just need to crank these things down? Should I locktite the threads? I see there is a little hole in the tip--does that fit some special tightening device?
Replies
Here is the reply I eventually received from support. I thought they might post something here, but they didn't...
Most of our engineers normally fly their multicopters without the rings, just making sure to hold the propeller well centered while tightening the bolt. We have contacted the manufacturer, and we will be receiving a shipment of metal rings for the motors so that the propellers will sit flush with the threaded portion of the collet and thus be able to tighten the propeller mount completely. We can ship you a set of rings for your propellers once we receive them.
We apologize for any inconvenience this has caused, and please let me know if you have any questions or concerns.
Hi,
I think I found a solution to the problem of the plastic rings that are a bit too small to fit on the base aluminium collet.
The problem was :
-plastic rings have an internal diameter of 6 mm
-the base of the aluminium collet is 6.3 mm
The obvious solution is thus to enlarge the internal diameter from 6mm to 6.3 mm. How to do this practically ?:
-Take a caliper (vernier). These calipers are usually in metal and have two sliding parts able to measure the distance between two internal parts of an object. What useful is for our purpose is that these metal parts are also quite sharped
-Extend the two metal measuring parts of the caliper inside the plastic ring. It will give you the reading of the internal diameter (6mm)
-Then slide the ring in circles around these metal caliper parts while maintaining the caliper open to the max. Gradually this will scrape the plastic and enlarge the diameter.
-Stop doing this when the measurement reads 6.3mm
That's it! It has worked for assembling my 3DR quadcopter, 880kv. Hope this will help others with this problem.
Happy new year to all,
Hugues
From this discussion, here are possible reasons for failure:
The prop and hub spacer should have parallel surfaces (once the hub spacer is in the prop hub). When the prop and hub adapter are on the collet (with bottom coned plate), there should be no unthreaded portion of the male threads above the prop hub.
THIS thread shows a problem..
His solution was a washer to take up the unthreaded space to prevent the spinner nut from bottoming out.
I have been pondering a discussion post on the mechanics but the idea has been around before WW2.. really. It is a common machine tool item.
The flutes of the collet (the part with the male threads) must clamp the motor shaft *before* the thread bottoms out in the spinner nut. Also the motor shaft should be inserted to nearly the full depth of the lower collet piece.
There should never be an air gap between the prop and the pressure plates, above or below the prop hub.
When assembled properly, you are affecting two actions - sandwhich-clamping the prop hub between two plates AND gripping the motor shaft with the collet flutes.
I can find no good cross-section drawings of this so it may come to making one for safety education.
-=Doug
Check this link for the instructions.
http://code.google.com/p/arducopter/wiki/AC2_Props
Merry Christmas and happy flying.
Richard