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Old Oct 03, 2011, 06:31 PM
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Well I am on page 132 of this thread and have seen several mods for the nose and motor mount. The glass reinforcement looks great does anyone that has done it have any input on it .....Good mod or Bad mod..... pick a different mod.

Thanks
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Old Oct 03, 2011, 10:15 PM
chuck
santa barbara, CA
Joined May 2009
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if u are set up to glass i think it works great. the weight can be used in the nose so thats no issue.

chuck.
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Old Oct 03, 2011, 11:29 PM
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Thanks, my other thought was to coat the inside with gorilla glue. The field I fly at is a mainly combat field so "gorilla glue" it right up there with "CA".

Thanks again Chuck
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Old Oct 03, 2011, 11:32 PM
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Last edited by NaterPin; Oct 03, 2011 at 11:32 PM. Reason: double post
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Old Oct 05, 2011, 09:51 PM
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Knoxville, TN
Joined Apr 2008
940 Posts
I bought a pre-glassed fuse in the for sale section. The down side was that they glassed the portion so I couldn't slide in the OEM motor mount. So, I had to build my own and pop it in there.
To my utter dismay.. I have the mooing problem with a glassed fuse and my ply motor mount.
With my previous fuse, I fixed the mooing by dripping CA between the motor mount and the foam until it could take no more. Unfortunately, I made a wrong turn with that fuse; down instead of up.
I'm going to drip CA on my new fuse to see if I can fix the mooing problem again. I use APC.. I've heard wood props fix it too. I also need to re-balance my prop. I may have dinged one side without knowing it.
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Old Oct 05, 2011, 10:29 PM
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Joined Jan 2009
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I posted in Gemini thread how I fixed the mooing.
Rob

"To those who have vibration/noise in Gemini, AcroMaster and FunCub.
I started out with Gemini. Made pieces of wood to match shape of the inside of the fuse right under motor mount rails. It helped for a while. Metal motor mount helped for a while. I didn't even bother with it in my other planes.
I ran piece of basswood thru the fuse right under motor mount rails behind the motor. It is super glued to the rails and foam. Outside is trimmed flush with the fuse. I even painted it white. That did it. No more dreaded noise."

http://www.rcgroups.com/forums/showp...postcount=2494
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Old Oct 06, 2011, 01:46 PM
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Alan W's Avatar
NY
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Does anyone think that the following would work -

- Using the templates that were posted for the ply inserts to cut EPP inserts and glue them in ? I've accumulated quite a bit of reclaimed EPP from packing material from servers/computer equipment I buy for work mostly in block form that I could either bandsaw or hotwire to the template shapes thus filling the voids and "thin" areas

??
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Old Oct 06, 2011, 05:25 PM
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USA, CO, Longmont
Joined Jul 2008
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Alan,
I did the ply inserts and have ZERO noise issues after 20 or so flights and one pretty violent nose in from a motor that ate a bearing in flight. The ply "Crutch" was assembled and test fit then CA'd to one fuse half.

I did NOT fill the voids behind.

I cut a hatch out (after assembly) to allow access to the motor leads and to mount the ESC. Then just tacked the hatch in with a few drops of thick CA.
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Old Oct 06, 2011, 05:35 PM
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Quote:
Originally Posted by THX-181 View Post
Alan,
I did the ply inserts and have ZERO noise issues after 20 or so flights and one pretty violent nose in from a motor that ate a bearing in flight. The ply "Crutch" was assembled and test fit then CA'd to one fuse half.

I did NOT fill the voids behind.

I cut a hatch out (after assembly) to allow access to the motor leads and to mount the ESC. Then just tacked the hatch in with a few drops of thick CA.
Thanks for the reply - did you cut your own ply inserts out or is there still a source for them ?

BTW, at the NEAT fair, I talked with the MPX guys and they said the "fix" is to use the metal motor mount
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Old Oct 06, 2011, 06:11 PM
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Joined Jul 2008
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I cut my own. The hardest part was printing the templates the right size.
I used heavy paper for the templates so I could use them for the test fitting process.

As to the metal mount being the fix... I don't think so.
I've had nothing but problems with MPX crappy mount system.
All of the problems were with stripped plastic screw holes.
Think about it... there are only two bolts holding the motor to the plane. Then you tighten four other bolts so that they are trying to pull the mount out the nose. It's a recipe for failure.
My Gemini's motor pulled out in flight Now it has a metal mount AND heli coiled threads in the fuse mounted mounts.

Whew that got long winded. Sorry.
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Old Oct 07, 2011, 03:56 AM
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Joined Nov 2004
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Quote:
Originally Posted by Alan W View Post
Does anyone think that the following would work -

- Using the templates that were posted for the ply inserts to cut EPP inserts and glue them in ? I've accumulated quite a bit of reclaimed EPP from packing material from servers/computer equipment I buy for work mostly in block form that I could either bandsaw or hotwire to the template shapes thus filling the voids and "thin" areas

??
Alan, I thought you meant use EPP instead of ply? One guy did just that and was successful but it was way back in the thread.
The ply pieces should bridge the thin areas to provide a strong structure between motor mount and, in my case, battery ramp. Extra reinforcement shouldn't be necessary after that but if you're going to be nose-light as some are, it sounds a worthwhile way of adding the nose weight. Don't forget the chin and air intakes, they tend to take the impact in my experience. I find the standard landing gear so poor that even a good landing comes to an abrupt stop on our grass, so the chin gets a whack every time
My ply reinforcement forms a tube as much as possible, another design (the original I think) forms an 'H' section, take your pick. I had hoped the photocopy of my pieces I posted would print accurately so apologies to anyone who struggled with that.
I've not had any problems with the mount itself personally but I do need to tighten the screws occasionally.
HTH
Nigel
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Old Oct 07, 2011, 10:36 AM
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Alan W's Avatar
NY
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Quote:
Originally Posted by Daddymonkey View Post
Alan, I thought you meant use EPP instead of ply?
Yes, that is exactly what I was thinking of doing ... but was also curious if anyone was currently making / offering the ply ones for sale

Quote:
HTH
Nigel
Absolutely does - I appreciate your input
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Old Oct 07, 2011, 12:28 PM
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They really weren't hard to fab up. I used a "Roto Zip" bit in my Dremel.
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Old Oct 11, 2011, 04:09 AM
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ottootts's Avatar
Germany
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Quote:
Originally Posted by THX-181 View Post
...As to the metal mount being the fix... I don't think so.
I've had nothing but problems with MPX crappy mount system.
All of the problems were with stripped plastic screw holes.
Think about it... there are only two bolts holding the motor to the plane. Then you tighten four other bolts so that they are trying to pull the mount out the nose. It's a recipe for failure.
...
Surely using the four adjustment screws is equivalent to just adding some filler to angle the motor mount? I thought you first set the adjustment screws, then tighten up the two securing screws. Only if you do it the other way around would you have (your) problems.

Otto
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Old Oct 13, 2011, 12:18 PM
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Eastbourne UK
Joined Aug 2010
50 Posts
I can't get full throttle with my acro master, as you get to 3/4 throttle the whole front end vibrates so badly you have to throttle back. On inspection of the shaft/collets/prop spinning at low rpm you can see it's not running true. Taken the model back to the shop & had all components changed but on testing it at the shop the problem is still there. The vibration is so bad you can see the spinner & prop pull slightly down & to the left right before it starts to vibrate violently.
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