QuadFrame motor mounts and (KDE) 42mm motors

[crayfellow]

Hi there,

Can anyone recommend a motor mount compatible with 25mm carbon fiber tube? I was attempting to use the QuadFrame mounts which look like this:
View attachment 25032

The center hole on the QuadFrame mounts appears to be 9.5mm in diameter, but the retainer on the bottom of the KDE motors I am using (3520-400, 42mm diameter motors) needs more like 11mm clearance. As a result, the motors are binding and do not spin freely:
View attachment 25033

Based on recommendations from others I attempted to drill out the (G10) plates but they are not looking good. There is nowhere near enough material between the center hole and the slots for the mounting screws. One got torn up a bit and I'd rather not destroy something needlessly when I could reuse the good ones for a different purpose (smaller motors on another craft, I guess). I also don't like the idea of motor mounts shredding in mid flight flinging massive props everywhere

@Hexacrafter, I see you have a mount for up to 46mm motors. Do you have something (or could you make something) which would mount on my arms (round 25mm carbon fiber tube)? It looks like your mounts have plenty of clearance for the bottom shaft on the motor as you are using the far outside screw holes (right?). Also they will be lighter being CF.

Alternately, is there a mount you folks could recommend for this size motor to clamp onto 25mm tube?

EDIT: I found these and these on AerialPixels which support 25mm tube. Seems like they are made for this purpose, but for different mounting patterns (KDE 3520-400 has mounting holes at 25mm and 32mm). This one says the holes are at 30mm but I can see there are slots, but I don't see specs for the min/max of those slots. The center hole is 12mm though, which is perfect. Maybe the minimum dimension of those slots would support the 25mm spacing.

EDIT: The AerialPixels mounts are not in stock, but these at Quadrocopter appear to be perfect. With those I just need the frame clamps and screws, right? It does not appear to require any sort of bottom plate.

EDIT: I ended up ordering 6x of the Quadrocopter Heavy Lift Motor Mount with 6x of the Cinestar Frame Clamps (I realize I could have probably used any clamps, but I may as well use these). I will post back with results.

I have to say I did not anticipate mounting motors being one of the major unexpected challenges of the build.

Thank you!

 

[Motopreserve]

Are those going to have a bottom plate? The photo shows PEM nuts for securing another plate - but the listing just says 1 CF playe?

 

[crayfellow]

Are those going to have a bottom plate? The photo shows PEM nuts for securing another plate - but the listing just says 1 CF playe?

I think the nuts are for screws coming in "upside down" from the bottom through the clamps.

 

[Motopreserve]

So these will sit on top of the boom itself - not off the end? If so, make sure there is clearance for the shift to protrude down and not hit the boom. Also, that would alter motor to motor length and possibly max prop size.

 

[crayfellow]

Yeah. But that's essentially similar to the QuadFrame mounts, which also clamp directly to the booms, not off the end. You're right I do need to check the clearance; I was assuming since this is generally intended for 25mm booms the associated clamps should take that into account. If not I can use the QuadFrame clamps.

 

[Motopreserve]

I'm sure they should clear since they mentioned KDE by name.

I'm surprise you had such a hard time. I was able to shave just a hair off the center hole for mine - but I do t recall he measurement. Maybe they were larger center holes? I did buy the specific mounts for the larger motors from Quadframe.

 

[crayfellow]

I'm sure they should clear since they mentioned KDE by name.

I'm surprise you had such a hard time. I was able to shave just a hair off the center hole for mine - but I do t recall he measurement. Maybe they were larger center holes? I did buy the specific mounts for the larger motors from Quadframe.

Maybe that's precisely what I'm missing! I checked the list of QuadFrame motor mounts and only saw one listed for 25mm tube, so I assumed it was identical to what I have. But it must not be! I will write Pawel to ask the diameter of the center hole on these mounts vs. what I have from the foldable pro SIXcopter kit.

 

[Motopreserve]

I recall adding the mounts for the larger motors to the cart - so this might be the descepancy. A little shaving with the body reamer and I was good. See what P says, and then maybe cancel that order with Quadrocopter - these are MUCH cheaper

 

[crayfellow]

I talked with Pawel at QuadFrame, and Quadrocopter were awesome about canceling the order (BTW they make their CF parts in Montana, which is pretty awesome, so I'll definitely be ordering parts from them in the future for various projects).

I am going to be using the QuadFrame V2 Motor Mount for 25mm tube. I am pretty sure this is the same as what I have from my SIXcopter kit, but I was already ordering some other QuadFrame parts so I added 6 extra motor plates to the order at $6.50/ea. Drilling mine ended up being totally fine, there was just one that got torn up a bit due to going up too far in bit size.

It's finally time for me to make a "real" build thread, because I'm building something! Thanks again for all your help. I will re-mention in the thread that QuadFrame and KDE have both been excellent about supporting 'unique' questions.

 

[Motopreserve]

Did you make sure to order the ones with the larger hole spacing?

 

[crayfellow]

Did you make sure to order the ones with the larger hole spacing?

hehe yeah I'm becoming quite obsessive about this motor mounting business after almost blowing $300+ on the prospect. The ones I got are described as "For bigger size motors (50mm diameter)

16x19mm, 19x25mm, 25x25mm screw mount holes." (3520 motors have both 25mm and 32mm mounting radii)

also to my eye it appears the center hole is closer to the 12mm I need, but we shall see.

 

[Motopreserve]

That's good. It really shouldn't be that hard - but they refuse to all use a standard. Gimbal motors are even worse!

 

[Pumpkinguy]

6mm spacers between the motor and the mounting plate would have raised up the motors just enough for the collars to clear the plates.

 

[Motopreserve]

The new mounts are cheaper actually - at least here in the U.S. with the hammering you get when you order metric!

 

[Pumpkinguy]

You guys have McMaster Carr. They have everything. Spacers wouldn't even have to be metric

 

[crayfellow]

haha! true.

 

[Motopreserve]

They have absolutely everything - but they're pricey. I have already given them my first born for bags of trinkets

 

[crayfellow]

Alright fellas - this one is resolved.

I tried the QuadFrame V2 mount and they turned out to be identical to the ones from my foldable pro sixcopter kit, minus the slots for ESC mounting tie wraps. Same hole. So I'll set those guys aside for another project, I suppose.

Today I received the M325 mounts from AerialPixels and they are PERFECT! 12mm hole vs <10mm, perfect for 42mm motors like the KDE 3520's. These mounts top and bottom motor plates, so I could either build a dodecacopter (!!!), or set them aside and use the QuadFrame tube clamps and G10 strips for a simpler look. Turns out it looks great (to me), especially with boom end caps! I appreciate the wire protection on the rounded end as well, since my only other copter piloting has been on crazy 250-class racers.

View attachment 25191

The only issue, if you can call it one, is that these mounts have the motors inward a bit vs. the QuadFrame mounts, so I will have a bit less prop-to-prop clearance. I will be testing 15", and since @Mactadpole has used 16" with the QuadFrame mounts I should be OK even with this difference in clearance:

View attachment 25193

Now that I've got no more blockers the real build can begin!

 

[Motopreserve]

Nice work! Still not sure what's going on with the Quadframe mounts. They must have changed them since I had no issue except shaving a hair off that inner bearing hole.

But who cares! You have a solution and it looks amazing. Keep on truckin' and you'll be up in the air before you know it.

 

[crayfellow]

Nice work! Still not sure what's going on with the Quadframe mounts. They must have changed them since I had no issue except shaving a hair off that inner bearing hole.

I think you must have just been using motors that were OK with <=10mm center hole. For these motors, 12mm is a perfect fit, and that seems to be the common size as I look at other mounts available for >40mm motors. I'm going to ask Jakub to integrate a 12mm hole into the QuadFrame mount design for pro/heavy lift kits since everything else is great.