Aeronavics / Droidworx Skyjib Motor Mounts Don't Fit KDE KDE5215 XF Motors - Help!

[teecee]

OK, so does anyone know why the KDE motors don't fit the Skyjib motor mounts. Yes, the KDE M4 beveled head bolts line up perfectly through the mounts to fit with the holes on the KDEs but the diameter of the thread is too big to fit through the bolt slot in the mount and the head is too large in diameter to fit into the machined groove. It looks like the Skyjib mounts are made for the M3s that they supply but if I use that size my motor wires will not all be lined up at the end of the arms. They will be offset. Either I re machine the skyjib mounts OR I have motor wires not lined up on the ends....???

 

[teecee]

Oh yeah, and one of the four slots in the mount is not even beveled to fit the M3 or M4 bolt head. Can anyone tell me what that is about? Am I supposed to use a flat head bolt on one of the sides? Why??

 

[teecee]

Also, is it me or does it seem like bigger diameter bolts would be a good idea considering these motors are powerful and running 18" props.

 

[teecee]

Here is what I am thinking this morning - I will try to find some M4s with slightly smaller diameter beveled heads so that they fit in the machined head slots in the SJ mounts. I will then re machine the slots for the bolts themselves so that the M4 threads fit through. I will also run a standard non beveled hex head M4 on the one hole that does not have the beveled head slot. Seems like a whole lot of messing around and potential problems to fit two parts together that are supposed to go together out of the box. These are the motors recommended by Aeronavics and I had told them that these were the ones that I was building with. Unless someone has a better idea that is...

 

[Pumpkinguy]

There is no way you are gonna shear four good quality and properly torqued 3mm bolts. Not gonna happen in a million years. If you insist on using 4mm because of your wire offset problem then machine the grooves. there is no other option here. Sometime you just have to improvise.
Good to see another local guy here.

 

[teecee]

There is no way you are gonna shear four good quality and properly torqued 3mm bolts. Not gonna happen in a million years. If you insist on using 4mm because of your wire offset problem then machine the grooves. there is no other option here. Sometime you just have to improvise.
Good to see another local guy here.

I agree that sheering the bolts is not going to happen but it does seem a shame to have to use the offset M3s when the M4s would have lined up perfectly. Also using 3 bevel head bolts and one flat head is not the way I want to fly either. That part is a bit perplexing for sure.

 

[Pumpkinguy]

I really don't know what that mount looks like so don't know what you mean by 3 bevel head/1 flat head.
I know on my gryphon mounts I had the choice of flat slots or beveled slots. Not a combination of the 2.

 

[teecee]

I really don't know what that mount looks like so don't know what you mean by 3 bevel head/1 flat head.
I know on my gryphon mounts I had the choice of flat slots or beveled slots. Not a combination of the 2.

This picture shows what I mean... Upper left is the "flat head bolt" in the non-beveled slot.View attachment 22509

 

[Hexacrafter]

Do you need to change the motor mounts for that motor??
http://aeronavics.com/products/shop/skyjib-spares/engine-mount-kit-skyjib-xl/
A lot of the "universal" motor bolt holes that motor manufacturers offer the ability to have the mounting holes line up, but then the motor is rotated and the motor wires do not align to an airframe motor mount to route the wires as expected.
I do not know about the motor mount above, but perhaps it is what your need.
We mount & fly the T-Motor U7 motor (Similar Motor) using 3mm bolts on our HC-1100L and with tons of aircraft out working nearly daily there have been no complaints.

 

[Stuart Sharpless]

Hey Teecee, might of missed this somewhere but wondering what was your workaround in the end on this? trying to get my ducks in order ready for the build.

 

[teecee]

Hey Teecee, might of missed this somewhere but wondering what was your workaround in the end on this? trying to get my ducks in order ready for the build.

Yes, it turned out that Aeronavics did send mounts that had one of the four slots machined wring (no bevel inset) and they sent replacements. Now 4 X M3 bolts will hold each motor on. Lots of strength and the same all around.

 

[Stuart Sharpless]

Great, cheers for the help on that. Hope that everything is gong well for ya.

 

[teecee]

Great, cheers for the help on that. Hope that everything is gong well for ya.

Things are going well. In flight test mode right now which is always exciting and a bit terrifying. Hope to have the Red airborne in a week or so.

 

[Stuart Sharpless]

Sweet, look forward to hearing more on your results. Certainly can understand the terrifying. First time I flew the epic I nearly gave myself an embolism. Good luck with it all.

 

[teecee]

Aeronavics kindly sent me replacement motor mounts that are all machined perfectly for the M4 bevel head bolts. I just finished assembly and am ready for further flight tests tomorrow. I had some issues with the retractable gear too and they fixed the problem there too. I finally feel like my bird is done and ready for work. Now where did I put that Red Dragon...

 

[Stuart Sharpless]

Nice job fella, get that Dragon out there and whip it into shape. nothing like taking the bull by the horns and giving a good whipping. Metaphorically of course as I am a freshairean.
Goodluck