ParkFlyers Talk about all backyard and parkflyer aircraft here

Something strange....

Old 11-03-2012, 01:13 AM
  #1  
1987tc
Super Contributor
Thread Starter
 
Join Date: Jul 2007
Location: Henryetta Oklahoma
Posts: 1,327
Default Something strange....

Something strange....
I have a Himaxx HC2208-870 outrunner in my TM. Love the motor and it is quiet and plenty of power with great flight times.

Had something strange happen yesterday though. I was flying last evening and did a couple of mild loops. On the last one I suddenly saw the prop fall off. I was able to see where it landed. I glided the plane down and while on approach I noticed the motor was hanging by the wires and so was the lipo. I made a nice smooth landing and walked over the the plane. Much to my surprise the case was missing from the motor! Now keep in mind that thrust from the prop pulls the case forward onto the rest of the motor as it spins. Since the shaft is pressed into the case it has no choice. So when the case went backward to come off it slid the prop and adapter off the shaft as it went.

I balance my props and was only at about half throttle when this happened. Anyone ever had this happen? Or have an idea why it did? Paula my GF went with me this morning to look for the case and her sharp eyes found it in the edge of tall grass.
Plane is back together and ready to fly now. I will static test it to make sure all is secure before I fly it again.
Wes
1987tc is offline  
Old 11-03-2012, 04:40 AM
  #2  
Wildflyer
Past President of PSSF
 
Wildflyer's Avatar
 
Join Date: Sep 2009
Location: Lacey WA, 1 mile E of Mushroom Corner
Posts: 2,138
Default

Was this a motor mounted to the back of the firewall, with the prop in front?
Wildflyer is offline  
Old 11-03-2012, 06:21 AM
  #3  
1987tc
Super Contributor
Thread Starter
 
Join Date: Jul 2007
Location: Henryetta Oklahoma
Posts: 1,327
Default



That is what it looks like intact. The other pictures are taken right after I glided the plane in.
Attached Thumbnails Click image for larger version

Name:	tmmotor2.jpg
Views:	133
Size:	65.9 KB
ID:	163911   Click image for larger version

Name:	tmmotor1.jpg
Views:	141
Size:	243.7 KB
ID:	163912  
1987tc is offline  
Old 11-03-2012, 09:22 PM
  #4  
WayfaringDreamer
Member
 
WayfaringDreamer's Avatar
 
Join Date: Apr 2012
Location: Harrisburg PA
Posts: 90
Default

There should be a set screw holding the shaft to the rotor. Maybe this was missing.

I'm thinking the prop pulled the shaft out of the motor because the shaft was not secured to the rotor (case) with the set screw.
WayfaringDreamer is offline  
Old 11-03-2012, 11:02 PM
  #5  
1987tc
Super Contributor
Thread Starter
 
Join Date: Jul 2007
Location: Henryetta Oklahoma
Posts: 1,327
Default

The shaft and bell went to the rear of the motor and plane. So the prop could not pull the shaft out. The shaft stayed in the bell that came off.
There is no set screw or even a place for one.
1987tc is offline  
Old 11-04-2012, 12:39 AM
  #6  
bigstick60
New Member
 
Join Date: Jun 2012
Location: narvon pa
Posts: 6
Default

you have a collar with a set srew on front of shaft to hold it in place and a set screw on back housing to hold shaft
bigstick60 is offline  
Old 11-04-2012, 12:58 AM
  #7  
1987tc
Super Contributor
Thread Starter
 
Join Date: Jul 2007
Location: Henryetta Oklahoma
Posts: 1,327
Default

This is the little motor for IPS size applications. There are no set screws on it at all. I have used these motors for ages. And the SHAFT did not come loose. It is pressed into the bell. It never left the bell. On this motor in this application the bell that rotates is at the rear. The shaft passes through the stationary part that includes the mount.

The rear bell that is where the magnets are and the shaft is pressed into is what came off. It went aft and came off falling to the ground.

As it did that the prop adapter made contact with the front of the motor and slid off the shaft and fell seperately to the ground.
1987tc is offline  
Old 11-04-2012, 06:14 AM
  #8  
Wildflyer
Past President of PSSF
 
Wildflyer's Avatar
 
Join Date: Sep 2009
Location: Lacey WA, 1 mile E of Mushroom Corner
Posts: 2,138
Default

I have lost a prop and adapter (collet type) because I had not cleaned the shaft, of any oils or films of finger oil. Slippage causes the aluminum to heat and expand faster than the hard steel shaft making it loose. Now I clean the shaft and then run the motor, while pinching rough sand paper to the shaft. maybe that will help maybe not. for me it fixed my problem.

I wonder why the motor came off the mount. was there a bolt or screw that came out? or the mount stick broke?

If the mount let go while the motor had power, all kinds of crazy things could have happened in a few seconds, but it is strange that the bell came off, the magnets are pretty strong.
Wildflyer is offline  
Old 11-04-2012, 06:24 AM
  #9  
1987tc
Super Contributor
Thread Starter
 
Join Date: Jul 2007
Location: Henryetta Oklahoma
Posts: 1,327
Default

The whole thing is odd. There was a screw passing through the mount and into the motor stick. It was gone. The motor has always run smooth. I balance my props too.
Funny thing is it was only at half throttle entering the loop and I backed off power as it went over the top.
So not musch stress on anything. I am thinking about contacting Himax and see what they think.
1987tc is offline  
Old 11-04-2012, 07:38 PM
  #10  
Wildflyer
Past President of PSSF
 
Wildflyer's Avatar
 
Join Date: Sep 2009
Location: Lacey WA, 1 mile E of Mushroom Corner
Posts: 2,138
Default

As I understand this motor, if you remove the prop adapter, you could push the shaft and rear magnet bell out of the motor. motor has no other retainers.

If that is correct, then the prop adapter must have came off before the bell left the motor.

Since the screw is gone, my guess would be;

1. When you cut throttle, the motor was not pulling the plane, just coasting.
2. That unloaded the stress against the screw, allowing it to vibrate enough to drop out.
3. Then the motor slid off the mount, and the prop hit somewhere on the plane. Look for new strike marks.
4. Then the prop adapter came off, maybe it was not real tight.
5. The motor must have spun violently and threw the rear bell off.

Somethings we will never know, put it all back together, put a bolt with a friction nut on the other side, clean the shaft, tighten the prop adapter super tight, and fly.

Every time I have had a crash or something happened in mid flight, it was my own damn fault.
I just had a Stryker motor rip off in mid flight, came down with a piece of orange plastic wrapped around the prop and motor, tied up like a Christmas package. It had ripped the motor out of the mount breaking it all up.
It was 5 minutes of trying to get the plastic off and figure out where it came from, before I turned the plane over, and realized my orange strip of sticky Monokote was gone from the bottom. I had not sealed it down properly.

O well live and learn.
Wildflyer is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Wildflyer
Delta & Flying Wings
6
10-21-2012 05:26 AM
eagle33
Power Systems
9
10-11-2012 10:45 PM
Wildflyer
Humor
1
10-05-2011 10:12 AM
icemanrulz
Beginners - Helis
2
07-12-2011 02:43 PM
hogarthd
General Electric Discussions
4
12-15-2010 08:52 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Quick Reply: Something strange....


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

Page generated in 0.15901 seconds with 16 queries