Motor Mount

[suicideneil]

I believe Mike said thats fine to do in the ten-t thread ( where this design originated ).

[Rebelgium]

It can't be fine to have play in a motor mount...

[rootar]

you guys lost me what play are you talking about? what would a washer do?

[suicideneil]

A washer between the screw head and the mount. spacer would tighten/ pull the bottom of the motor into the mount, effectively making it like a normal mount that uses two bolts to hold the motor in place ( like an emaxx motor mount ). Otherwise, the bottom is just a pivot point, the motor isnt actually fixed to the mount as such. I think a small bearing would be better than a plastic spacer- zero slop or play in the bottom of the mount- a flanged bearing would be even better come to think of it..

[brushlessboy16]

Before you guys go bashing the mount take the time to assemble it correctly.

The black peice thats steel is what the countersunk screw sits in for the bottom hole and is a machined fit. very nice tolerances.. the top slot in the motor mount is designed for an m3 or m4 screw, when using an m3 screw you use the aluminum spacer over the screw and it sits where the head of the m4 screw would be... the mount has no flex in it once the one top screw is tightened down,

[brushlessboy16]

[brushlessboy16]

[suicideneil]

Huh, I thought the bottom part was plastic, based on what people were saying about its construction/ fitment. If its steel & machined to fit then there should be no need to worry..

[brushlessboy16]

the one I have seems to be steel, its definitely not plastic

[Krawlin]

It doesn't look like there is any kind of machined lip on that lower hole to keep that steel countersunk washer from going all the way through.....

So if you remove the top screw completely, will the motor just come out of the mount with that lower screw/steel countersunk washer?

[brushlessboy16]

Originally Posted by Krawlin

It doesn't look like there is any kind of machined lip on that lower hole to keep that steel countersunk washer from going all the way through.....

So if you remove the top screw completely, will the motor just come out of the mount with that lower screw/steel countersunk washer?

Motor comes out, however you cannot pull that plug out when the upper screw is sinched down.

[ZippyBasher]

It looks great. I have an older model that got bent. but I dont like that the motor is only held with 1 screw. Why was this new design created? what was wrong with the old setup? yeah it took a bit to set mesh but it was solid... I just bent it back and tapped a hole in the side to try and brace it...well see

But if tapped to 4mm (on motors applicable) it probably would be solid. but I would not trust 1 3mm screw to say an 1520 CC/Neu in
an 8ight truggy...

So how close is that motor to the chassis noW? it looks alot lower than the older 1. should be nice.

[brushlessboy16]

Originally Posted by ZippyBasher

It looks great. I have an older model that got bent. but I dont like that the motor is only held with 1 screw. Why was this new design created? what was wrong with the old setup? yeah it took a bit to set mesh but it was solid... I just bent it back and tapped a hole in the side to try and brace it...well see

But if tapped to 4mm (on motors applicable) it probably would be solid. but I would not trust 1 3mm screw to say an 1520 CC/Neu in
an 8ight truggy...

So how close is that motor to the chassis noW? it looks alot lower than the older 1. should be nice.

Could be very low, but im using the spacer plate that came with it to space the spur from the chassis. do you know the tensile strength of an m3 screw. it will surprise you..

[Krawlin]

Originally Posted by brushlessboy16

Could be very low, but im using the spacer plate that came with it to space the spur from the chassis. do you know the tensile strength of an m3 screw. it will surprise you..

According to McMaster, tensile strength of a 12mm long M3 screw is 174,000psi, however, that is pretty much a straight back pullin force, and it is rare to get a straight back pulling force on the motor in an RC. I've twisted the heads off plenty of M3 cap head screws before, and I've also bent and sheared off quite a few of them too. For instance, I bent 4 M3 cap head screws holding the DiemakerDave wing mount to my UE knucklehead shock tower on my Maxx when it landed hard straight down on the wing mount from only about 4 feet in the air. Now or course, that was 12 pounds of truck landing on that wing mount, and it did bend it pretty badly for being high grade aluminum, but the point is, that bent 4 M3 cap head screws at once and ripped the nut off the lower two. A heavy motor puts alot of force on a motor mount when landing flat on the ground, and if the car lands upside down, its going to want to pull that lower screw and washer out and bend the upper screw. IMO, there needs to be a machined lip of some kind at the back of that lower hole so the motor actually has 2 screws holding it on. It may be convenient to just have to remove 1 screw to pull the motor, but I'd rather be sure my motor is very strongly secured to the motor mount.

[brushlessboy16]

Originally Posted by Krawlin

According to McMaster, tensile strength of a 12mm long M3 screw is 174,000psi, however, that is pretty much a straight back pullin force, and it is rare to get a straight back pulling force on the motor in an RC. I've twisted the heads off plenty of M3 cap head screws before, and I've also bent and sheared off quite a few of them too. For instance, I bent 4 M3 cap head screws holding the DiemakerDave wing mount to my UE knucklehead shock tower on my Maxx when it landed hard straight down on the wing mount from only about 4 feet in the air. Now or course, that was 12 pounds of truck landing on that wing mount, and it did bend it pretty badly for being high grade aluminum, but the point is, that bent 4 M3 cap head screws at once and ripped the nut off the lower two. A heavy motor puts alot of force on a motor mount when landing flat on the ground, and if the car lands upside down, its going to want to pull that lower screw and washer out and bend the upper screw. IMO, there needs to be a machined lip of some kind at the back of that lower hole so the motor actually has 2 screws holding it on. It may be convenient to just have to remove 1 screw to pull the motor, but I'd rather be sure my motor is very strongly secured to the motor mount.

If you were to look into the geometry of it all, with the upper screw tight the whole motor is pulled flush against the mount, to bend the screw in that position you have to stretch it.. before you knock it get one and see for yourself...

whoa there keyboard cowboy...