Thread Tools
Oct 30, 2020, 12:18 PM
Registered User
Thread OP
Question

what holds the motor together??


I have a little tower pro 2408-21T outrunner. It was in another plane and I am getting it ready to install in my current project.

I took the motor apart to inspect it and noticed, other than the magnets there seems to be no evidence of something that holds the 2 halves together. the shaft that runs through the middle had glue on the back of it. There is a flat on the shaft like a collar is supposed to be there. In all the pics. I find of the motor it doesnt look like a collar is present.


What keeps the two halves from separating ?
Sign up now
to remove ads between posts
Oct 30, 2020, 12:38 PM
Registered User
Fourdan's Avatar
Hi
If you use the BLDC in pusher : no need of locking
In tractor it is better to use
* either a cclip
* either a set screw collar (from any brand)
... you have to measure the exact shaft diameter (metric or imperial)
Louis
Oct 30, 2020, 12:43 PM
Registered User
Thread OP
Quote:
Originally Posted by Fourdan
Hi
If you use the BLDC in pusher : no need of locking
In tractor it is better to use
* either a cclip
* either a set screw collar (from any brand)
... you have to measure the exact shaft diameter (metric or imperial)
Louis
Thanks

The plane is a puller, prop. on the front.

I'll have to look for a collar to hold it together
Oct 30, 2020, 02:20 PM
Registered User
earlwb's Avatar
They usually have a C clip and or a metric wheel collar to hold the motor together. Some motors use a screw and washer too. Sometimes a combination of the three ways.
Oct 30, 2020, 04:40 PM
Registered User
scirocco's Avatar
Outrunners started off being mounted behind firewalls like inrunners, with the thrust load pulling the rotor into the motor and no need for circlips or collars, as the magnetic force is plenty to hold the motor together with no load.

As mentioned, once back mounted, additional retention by circlips or collars or both becomes necessary.

Many larger outrunners designed for backmount only use a bolt into the shaft to take the thrust loads - usually LH thread.
Oct 30, 2020, 05:21 PM
Registered User
Thread OP
Thanks guy's, it looks like I wont be able to use what I have.

Now I need to source a motor
Oct 30, 2020, 05:31 PM
If it flies, I can crash it.
rocketsled666's Avatar
If there's a flat on the back end of the shaft, put a wheel collar on the shaft and it'll keep the shaft/bell from pulling off the armature.

If the motor magnets are strong enough, the motor might function just fine without a retainer on the shaft. If the motor was in another plane, it must have been holding together there, so...
Oct 30, 2020, 06:16 PM
Registered User
earlwb's Avatar
It looks like they had a little C clip on the rear of the motor to keep the shaft on with. The C clips are technically one time use items. So yours likely broke and fell off sometime in the past. The C clips are quite brittle in a way.
I found a pic that shows it:
http://www.himodel.com/img_sub/rc_img/05/298-2.jpg
Oct 30, 2020, 06:17 PM
Registered User
Thread OP
Quote:
Originally Posted by rocketsled666
If there's a flat on the back end of the shaft, put a wheel collar on the shaft and it'll keep the shaft/bell from pulling off the armature.

If the motor magnets are strong enough, the motor might function just fine without a retainer on the shaft. If the motor was in another plane, it must have been holding together there, so...
Good point, the magnets seem strong, it takes a good pull to separate the halves. There is a flat on the shaft,A wheel collar might work...Thanks


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion How much can I trust a 1/4" nylon bolt to hold together? G.F. Beurling Fuel Plane Talk 39 Jun 23, 2016 11:21 AM
Discussion What kind of binder is holding this uni-carbon together? davekra Composites Fabrication 9 Jan 01, 2014 10:11 AM
How do you hold wing sections together that can seperate ? omega blood Electric Plane Talk 6 May 29, 2003 02:21 AM
What tape do I use to hold a wing together RandyK1 Electric Sailplanes 6 Oct 22, 2002 08:58 AM