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Old Jul 28, 2008, 08:35 PM
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TexasFlyer's Avatar
Houston, TX
Joined Sep 2005
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Vibration issue solved!

My vibration and noise issues have been solved! I waited to change the motor shaft until last because I didn't see any wobbling and I didn't have one available. Thanks to the suggestion of Bill Murad, a fellow flyer at our club, I changed it and voila - no vibration at all!! I flew 5 flights which is by far the longest it has remained silent in many many months. So all the "fixes" I current have are:
1) A little fiber glassing with CA (done after assembly to repair the foam tearing)
2) A threaded rod between the plastic two side mounts (see pictures a few pages back)
3) And a new motor shaft

I think #3 was the root cause and #2 is protection for the fuseleage if something gets out of balance/bent in the future.

I am SOOOO glad to have this fixed! My next step was major surgery and I'm glad I didn't have to go there.

Alan
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Old Jul 29, 2008, 01:46 AM
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Fort Collins Colorado USA
Joined Oct 2007
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Cooling the motor.

I searched the thread already and have not found a simple solution. I just built the Acromaster and both motors I put on get so hot I cant touch them. The outside temps were as low as 80 degrees when this happened. One motor was a Scorpion 3014-22 and the other was a Torque 2814T/820. Did 3D hobby shop make a mount for it that the motor can be on the front. The plane is already built. Any solutions?
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Old Jul 29, 2008, 02:27 AM
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Chichester Sussex
Joined Aug 2007
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TexasFlyer,
Are you using the stock recommended Himax motor ???
For ths cost of a shaft on it's own ot's got to be worth trying !!!!!
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Old Jul 29, 2008, 06:39 AM
Fast, faster & fast again
North Hollywood, CA
Joined Jul 2007
1,210 Posts
jadamian75,
What are the specs on your set up. Prop, battery, esc etc.? I haven't had any heating issues with any motor I put in there so I'm not sure what's going on with your motor. Also, are you using the foam prop adaptor? That blocks out some of the airflow to the motor as well. Not sure what else to tell you without specifics on your set up besides the motor model number.

Jim
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Old Jul 29, 2008, 07:23 AM
Jim
North Alabama
Joined Mar 2004
1,866 Posts
I've been following this thread as best I can, and I'm not sure anyone has found the "golden BB" for the mad cow issue. There has been several resolutions proposed, but I can't find evidence of any single mod that has been the fix for everyone.

My final question is:

Between the "fiberglass the inner nose" mod, and the aftermarket "laser cut wood mount assembly", can anyone say if one is better than the other?

Thanks, Jim.
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Old Jul 29, 2008, 09:08 AM
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Fort Collins Colorado USA
Joined Oct 2007
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I really don't think it is a motor, esc, battery or prop issue. I have had 25 electric planes and am comfortable with power systems. The scorpion motor has its cooling holes facing toward the back of the plane with the front ones covered and no side cooling holes or ridges. The Torque motor has cooling ridges and holes on the side in the back and facing towards the back only. It stays cooler but still get pretty hot. I May take the Thrust 30 motor out of my Precision Aerobatics Extra 260 and try it. It has cooling holes in the back, front, and side of the back and front. It also has cooling ridges. I was not using the plastic prop adapter or spinner to help the cooling. While I am at it I may also drill some cooling holes in the front of the motor mount. I will let you know what happens.
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Old Jul 29, 2008, 09:12 AM
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Quote:
Originally Posted by Jim_W
I've been following this thread as best I can, and I'm not sure anyone has found the "golden BB" for the mad cow issue. There has been several resolutions proposed, but I can't find evidence of any single mod that has been the fix for everyone.

My final question is:

Between the "fiberglass the inner nose" mod, and the aftermarket "laser cut wood mount assembly", can anyone say if one is better than the other?

Thanks, Jim.
Jim

If you have not looked already, have a look at post 3307 on page 221 and post 3330 on pag 222 these have completly eradicated any noise from my Acromaster and it provided sufficient strength that it survived although a bit bent a full power dive into the ground, don't ask how I did it, its too embarasing. LOL

Mike
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Old Jul 29, 2008, 09:40 AM
Jim
North Alabama
Joined Mar 2004
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Quote:
Originally Posted by BaldEagel
Jim

If you have not looked already, have a look at post 3307 on page 221 and post 3330 on pag 222 these have completly eradicated any noise from my Acromaster and it provided sufficient strength that it survived although a bit bent a full power dive into the ground, don't ask how I did it, its too embarasing. LOL

Mike
Thanks Mike ...yes I did see your mod earlier. Looks great. However, I've narrowed my options to either the glassing or the lasercut mount. I'm too lazy to go much further to resolve this problem . I'd rather just cut my losses and move on to a less problematic airframe if mine ends up being very bad.

I will say kudos to all of you that have pursued this to the extent you have. The AM must be a great flying plane to command all this troubleshooting!

Jim
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Old Jul 29, 2008, 02:06 PM
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Houston, TX
Joined Sep 2005
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Quote:
Originally Posted by Witterings
TexasFlyer,
Are you using the stock recommended Himax motor ???
For ths cost of a shaft on it's own ot's got to be worth trying !!!!!
Yes, I am using the recommended Himax motor. The shafts are pretty inexpensive, though the shipping from MaxProd.com more than doubles the cost. It was VERY easy to replace using a hole punch to remove the old shaft. They have two shafts, so ensure you get the 5mm vs the 4mm.

Alan
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Old Jul 29, 2008, 02:13 PM
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Houston, TX
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Quote:
Originally Posted by Jim_W
The AM must be a great flying plane to command all this troubleshooting!
Jim,

Yes, this is a fantastic flying plane, very durable, very forgiving, very low wing-loading, and lots of power. The extra side area makes high alpha KE and slow rolls very nice. The big ailerons make blenders outrageous! The adjustable motor mount has allowed me to trim this just right, not having to compromise between two washer sizes for thrust adjustments. I've even been told that I fly the precision pattern with my AM better than my 90-sized pattern plane (except in the wind, of course). I can't say enough about how much I love this plane!

Alan
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Old Jul 30, 2008, 01:44 AM
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Fort Collins Colorado USA
Joined Oct 2007
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Thrust 30 motor tested.

I tested the Thrust 30 motor today on my Acromaster. It kept flying and holding a hover when the other motors were getting too hot and bogging down. The Thrust still got hotter in the acromaster than in my PA extra 260.Hot enough that I could not leave my finger on the motor for 10 seconds. The outside temp. was 90 degrees today and I am 5000 ft about sea level in Colorado. Running an apc 13x4 prop, thunder power extreme 3 cell 2200mah, and thunderbird 54. This thing 3Ds very well and durable. Great step between epp profile (like my flash) and a built up balsa plane.
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Old Jul 30, 2008, 05:08 AM
IMK
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Australia, VIC, Melbourne
Joined Aug 2005
181 Posts
I'm running a Thrust 30. When I used the Hyperion ESC it ran hot. I switched over to the PA Quantum ESC and it was barely warm to touch. In both situations I was using a 12x6 APC.

However I'm not yet convinced it was the ESC change as the other variable was the spinner. With the Hyperion ESC I wasn't using the foam spinner. When I switched over to the Quantum ESC I also added the spinner.

Perhaps a spinner improves the airflow over the motor? My initial thoughts are that without the spinner, the inlet area is out of proportion to the outlet area under the fuz, thereby reducing the airflow through the fuz (i.e. inlet to outlet should be around 1:2).

Has anyone done any motor temp tests with and without the large foam spinner?
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Old Jul 30, 2008, 05:32 AM
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Chichester Sussex
Joined Aug 2007
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May have found a cure almost by accident for some people and kind of initiated by TexasFlyer.
I had to go to the LHS yesterday anyway to pick up a charger I'd ordered and thought I'd see if they had motor shafts that fitted. They had a E-Flight one that was virtually identical but a bit too long and I thought I'd just cut it down to size.
Went to undo the grub screw at the rear of the motor and initally thought I'd picked up too small an Allen / Hex key as it seemed to be just turning loosely and not catching the screw, after a while though realised it was actually undoing it.
The shaft came out really easily and put it against the other one to make sure the recesses lined up and also to see where I needed to trim the new one.
I'm not that much of a DIY person and only have one of those cheap little hacksaws that everybody must of had one day and after half an hour was half way through and had totally stipped the blade but not completed the job.
As I knew the forecast was meant to be good today thought I'd put the old shaft back in so I could at least fly until I got a better hacksaw / dremmel.
I put it in tightened the grub screw up, put the collet back on, thought I'd double check it and saw the grub screw was sticking out !!!!!! Thought it was strange and had to give it several turns until it was tight, I then realised there were 2 of them !!!!!!!
Undoing the 1st one there had been so little resistance I thought it was the tool I was using but no it was just that it wasn't done up properly, the fact I'd made no attempt to undo the second as I hadn't realised there was one and the shaft came out so easily says that wasn't done up either.
The difference flying this morning was incredible but this may also account for why so many people seem to have changed the shaft and that's cured it because when they put the new one on they check that the grub screws are nice and tight !!!!!!!!
For the sake of 3 minutes it's take you it's definitely worth a try and would be really interested to see what the results are and if it works for anybody else !!!!
I'd never have thought to have checked them as it's as it came out of the factory and you didn't even need to reverse the shaft to fit it and you'd assume they'd be doem up correctly, only other thing may be I had a nose in a while ago and destroyed one fuselage adn that could be what loosened them as I didn't get it with the old plane !!!!
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Old Jul 30, 2008, 11:26 PM
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Houston, TX
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Witterings,

Nice find! If the Himax motor didn't come with loctite on the grub screws, that could have caused it to loosen over time. I put some on mine when I replaced them.

Alan
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Old Jul 31, 2008, 04:27 PM
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Joined Sep 2006
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Where can I get HiMax motor shafts? I keep bending my HC tunrigy motor shafts. At $4 a pop shipped, it's getting really expensive. If the HiMax ones fit and cheaper locally, I'll use those instead. I tried getting some drill blanks or steel rods from McMastercarr, but they didn't fit. I need to get the precision grade ones, and the prices on those are not much different than getting it from HC.
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