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Jul 23, 2019, 11:03 PM
world's slowest builder
Air-Jon's Avatar
Quote:
Originally Posted by fredmdbud
I ordered a spare fuselage, nosecone, wings, tails, stabilators, and variety of plastic parts from Motion RC. They all came in one box, packed in the same arrangement as a PNP/ARF Plus.
That does not surprise me with motion RC, they are quality oriented.
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Jul 23, 2019, 11:38 PM
Innocent Bystander
Bobaroo's Avatar
Quote:
Originally Posted by KrakenReleaser
Heads up all 8s guys... Motion promptly denied my warranty request (sudden full elevator deflection on 17th flight - total loss) by simply stating: "They are going to deny this as the jet was never intended for 8s use sorry."

I lost elevator control but had everything else so i know it wasn't a signal / interference issue. I never had any prior issues/glitches of any kind. I read the TSB days before the crash and found no issues there. I am kicking myself for not following these threads closer to see that I should have bypassed the blue box. Face palm.
Tragically, yet again we are hearing that a $9.99 Part or a $21.99 Part or some combination of these may have caused your Jet to crash.
And if they seriously deny a claim for that reason as stated, I would argue for an appeal to that finding. I wonder what criteria on modified Jets is set for this precedent ?? Stock Servos fail on Bypassed BlueBox ? BlueBox fail with UpgradedServo ? Only 8S Jets are voided ? Curious while still Tragic. Maybe this needs further clarification before Guyz dig in and Mod their stuff into a 'Out of Warranty' condition !!

Thanks for posting.
Jul 23, 2019, 11:40 PM
Registered User
fredmdbud's Avatar
Quote:
Originally Posted by Air-Jon
That does not surprise me with motion RC, they are quality oriented.
Individual experiences may vary.
Latest blog entry: Digital LED Voltmeter
Jul 24, 2019, 12:09 AM
Registered User
fredmdbud's Avatar
After some rough landings, the nose retract mount started to separate from the foam to the point where the retract no longer closed the spring-loaded doors. Using the included adhesive and applying a shim remedied that, but didn't seem like it was a lasting solution, so I installed a brace plate.
  • Removed the retract from the housing and drilled a hole to fit a flathead #6 machine bolt.
  • Took a piece of thick plastic with the same width as the mount, sanded the joint surface, then applied a thin layer of cyanoacrylate glue and clamped them together, applied additional glue at the seam to seep in by capillary action, then let it set. Then I continued drilling the hole through the additional plastic piece, then carved with an hobby blade so that the flathead sank flush to where the retract sits. The plastic block now provides additional strength and spreads out forces applied over a wide area.
  • Because the foam "ledges" are uneven, I placed a wooden shim to make them even.
  • Measured and cut a birch plate and epoxied cross-beams to stiffen it. Positioning it so that the screw would be centered between cross-beams, I drilled a hole to line up with the hole in the mount. I then slid the flathead bolt up through plastic and wood, installed a washer and bolt, and tightened.
  • I then finished it with some blue threadlocker to resist gradual unscrewing from repeated shocks and vibrations.
  • Test the retract to confirm the doors close, and did some final rod & clevis adjustments to completely close the door gap.
Latest blog entry: Digital LED Voltmeter
Jul 24, 2019, 12:41 AM
Mach One
captain MoMo's Avatar
Quote:
Originally Posted by KrakenReleaser
Heads up all 8s guys... Motion promptly denied my warranty request (sudden full elevator deflection on 17th flight - total loss) by simply stating: "They are going to deny this as the jet was never intended for 8s use sorry."

I lost elevator control but had everything else so i know it wasn't a signal / interference issue. I never had any prior issues/glitches of any kind. I read the TSB days before the crash and found no issues there. I am kicking myself for not following these threads closer to see that I should have bypassed the blue box. Face palm.
Where should Motion draw the line in your opinion?
Latest blog entry: ESC and BEC Steup
Jul 24, 2019, 01:48 AM
Registered User
fred, you should have looked at my nose retract mount fix from a short while back.....
You really want a plate that goes over the entire stock mount.
Those two back posts, that the stock screws go into, are quite weak and can easily fracture on a bad landing when the retract tries to drive the mount 'tilted rearwards/upwards'. Thus you want that plate above it ALL, so that the mount can't tilt.

In my case, to assure the ENTIRE nose is very strong, I have the long internal fuselage side plates also.
The last 'crash' landing showed those kept the nose intact - except the retract mount cracked at the 'sharp 90deg angle' points it has. Thus why it then needed the full plate above, to give it more support than ever (cracks repaired with epoxy = never going to last on its own.)
I don't even want their lousy plastic mounts..... but until I have to, I will keep it and then replace it with a 'wood' based system, as per typically seen/used in kit aircraft.
Hopefully I won't actually "stress test" it again.....
It is actually a very easy jet to land.... except when things have gone wrong....

....
These pics... longer retract mount support plate....
Jul 24, 2019, 01:52 AM
Registered User
I have been too "scared" to Thrust Test my 8S Jetfan..... LOL.... as I expect it is going to be POOR results, in output versus bench values. Much worse than other jets.
Maybe I will do it tonight....
I can just see...... 4150g bench Thrust becomes 2700g in a plane (this F-18).....
It would be awesome to see 3300g+ !!!
Jul 24, 2019, 06:37 AM
Registered User
fredmdbud's Avatar
Have already had several bounced hard landings and haven't fractured the plastic mount as you described, more compression of the foam. Must take a nosegear-first landing or two to do that!

Quote:
Originally Posted by PeterVRC
fred, you should have looked at my nose retract mount fix from a short while back.....
You really want a plate that goes over the entire stock mount.
Those two back posts, that the stock screws go into, are quite weak and can easily fracture on a bad landing when the retract tries to drive the mount 'tilted rearwards/upwards'. Thus you want that plate above it ALL, so that the mount can't tilt.

In my case, to assure the ENTIRE nose is very strong, I have the long internal fuselage side plates also.
The last 'crash' landing showed those kept the nose intact - except the retract mount cracked at the 'sharp 90deg angle' points it has. Thus why it then needed the full plate above, to give it more support than ever (cracks repaired with epoxy = never going to last on its own.)
I don't even want their lousy plastic mounts..... but until I have to, I will keep it and then replace it with a 'wood' based system, as per typically seen/used in kit aircraft.
Hopefully I won't actually "stress test" it again.....
It is actually a very easy jet to land.... except when things have gone wrong....

....
These pics... longer retract mount support plate....
Latest blog entry: Digital LED Voltmeter
Jul 24, 2019, 08:24 AM
Thanks Wilber and Orville !.
sonic liner's Avatar
https://www.motionrc.com/pages/warranty-policy

Basically as soon as you go airborne your purchase has fallen into a new category. That said, in this case they are asking the customer to check certain areas and trim/ Glue as needed. Everyone that has purchased this jet is indeed a consultant.
As the manufacture and distributors wade through the mire of data, hopefully good things will happen. The TSB is one example.
" Teeth pulled ".
Jul 24, 2019, 10:03 AM
Mach One
captain MoMo's Avatar
Quote:
Originally Posted by sonic liner
https://www.motionrc.com/pages/warranty-policy

Basically as soon as you go airborne your purchase has fallen into a new category. That said, in this case they are asking the customer to check certain areas and trim/ Glue as needed. Everyone that has purchased this jet is indeed a consultant.
As the manufacture and distributors wade through the mire of data, hopefully good things will happen. The TSB is one example.
" Teeth pulled ".
I think MRC is doing all it can to resolve these issues and I was looking for an official technical bulletin and got it. Not much more that l see the distributor doing. Perhaps they can get another TSB for the blue box. It’s all with Freewing now. And don’t forget that all this is a business and unfortunately it was at the wrong time - while Eflite and FMS are out with some compelling and very nice products. It’s a tough world of RC out there! I have bypassed the BB and swapped flap and elevator servos. No other issues.
Latest blog entry: ESC and BEC Steup
Jul 24, 2019, 12:00 PM
Registered User
Quote:
Originally Posted by KrakenReleaser
Yes I had the stock servos on both elevators.
With regard to recent crashes mentioned here...

Is anybody here that has been reading this thread suspicious of the UBEC also? I'm already going to replace the Ele servos and bypass the blue box for at least Ele, aileron, and flap. I will also read the TSB and look into the bearings near the Ele servos. But I wonder if the UBEC is something I should add to the list??

It's a beautiful air frame for sure. I just have to work through the issues. It sounds like a 6S het setup might be better so as not to put as much load (ie from higher speeds) on the full flying stabs.

Thanks,

Andy
Jul 24, 2019, 12:09 PM
Mach One
captain MoMo's Avatar
Quote:
Originally Posted by sothpaw
With regard to recent crashes mentioned here...

Is anybody here that has been reading this thread suspicious of the UBEC also? I'm already going to replace the Ele servos and bypass the blue box for at least Ele, aileron, and flap. I will also read the TSB and look into the bearings near the Ele servos. But I wonder if the UBEC is something I should add to the list??

It's a beautiful air frame for sure. I just have to work through the issues. It sounds like a 6S het setup might be better so as not to put as much load (ie from higher speeds) on the full flying stabs.

Thanks,

Andy
I think the UBEC is good as it has been serving other 90mm models for a while without any issues. However, I always swap my UBECs to Castle 10A (for smaller EDFs) or Castle 20A UBECs. I really like the Castle 2.0 - small, lightweight and carries a big load.
Latest blog entry: ESC and BEC Steup
Jul 24, 2019, 01:34 PM
Innocent Bystander
Bobaroo's Avatar
Quote:
Originally Posted by captain MoMo
I think the UBEC is good as it has been serving other 90mm models for a while without any issues. However, I always swap my UBECs to Castle 10A (for smaller EDFs) or Castle 20A UBECs. I really like the Castle 2.0 - small, lightweight and carries a big load.
Let me interpret this for you Southpaw:
The stock UBEC is Ok for 'You' and 'Your' $500 Jet !! Go ahead and use it, it'll be fine for You and it'd be really sad if something went wrong in there for you. However, I 'Always' swap them out if it were 'My' Jet because I don't trust them in there .... But in yours I'd say...Go for it !!
Jul 24, 2019, 02:07 PM
Mach One
captain MoMo's Avatar
Quote:
Originally Posted by Bobaroo
Let me interpret this for you Southpaw:
The stock UBEC is Ok for 'You' and 'Your' $500 Jet !! Go ahead and use it, it'll be fine for You and it'd be really sad if something went wrong in there for you. However, I 'Always' swap them out if it were 'My' Jet because I don't trust them in there .... But in yours I'd say...Go for it !!

I am not going to engage your childish behavior.
What I am saying is itís his choice. The UBEC provided is fine and I have used it in the past.
Latest blog entry: ESC and BEC Steup
Jul 24, 2019, 02:09 PM
Innocent Bystander
Bobaroo's Avatar
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