Soft mounting motors

[4th_Dimension]

I am "soft mounting" my motors on my drone and the bolts are just a little too short.
Does anyone have any ideas what motor bolt length I can use and is a safe distance from the internals of the motor???

Thank you

 

[HighTechPauper]

Almost nobody soft mounts motors anymore, if soft mounting the FC isn't enough, then doing the motors will likely not do it either. When you soft mount motors (just like the FC) you need to balance how tight screws are (can't compress all your soft mounting) with the chance they will loosen in flight (lock tight on the screws and constantly checking them). So just figure the thickness of your arms, the compressible thickness of your mounts, and the 2mm needed to fill the motor base and order them. There is no "one size" that works on all builds. In the future perhaps you can tell us the important info, like arm thickness and soft mount thickness, so we could venture a guess.

 

[4th_Dimension]

Thank you sir, just trying too figure out a formula to guess length of screws

 

[HighTechPauper]

You're welcome, and I agree, I want a mm hanging out of the top of my motor mount plate, so I have just rounded out my parts with some "odd" mm length's like 7mm since 6 and 8mm are a dime a dozen but odd number lengths are often our best choice. The best thing is to buy a few assortments, I use ones like these that closest fit the bill for what and how many I may need over time. I like to have cap heads for motors when possible, and button heads for all the other needs.

100pcs M3 x 5mm 12.9 Grade Alloy Steel Hex Socket Head Cap Screws Bolts,Black Oxide Finish: Amazon.com: Industrial & Scientific

100pcs M3 x 5mm 12.9 Grade Alloy Steel Hex Socket Head Cap Screws Bolts,Black Oxide Finish: Amazon.com: Industrial & Scientific

www.amazon.com

iExcell 250 Pcs M3 x 6mm/8mm/10mm/12mm/16mm 10.9 Grade Alloy Steel Hex Socket Button Head Cap Screws Kit, Black Oxide Finish: Amazon.com: Tools & Home Improvement

iExcell 250 Pcs M3 x 6mm/8mm/10mm/12mm/16mm 10.9 Grade Alloy Steel Hex Socket Button Head Cap Screws Kit, Black Oxide Finish: Amazon.com: Tools & Home Improvement

www.amazon.com

 

[HighTechPauper]

Here is a good replacement for the out of stock kit.
Anyway, you get the point, they never give us enough (or the right ones) in a frame kit or with the motors, so between building and breaking, we are going to need extras.

Amazon.com: Adiyer 200 Pcs Metric M3 x 6/8/10/12/16/20mm Button Head Hex Socket Cap Screws Nuts Set Assortment Kit, 10.9 Grade Alloy Steel, Black Oxide Finish : Industrial & Scientific

Amazon.com: Adiyer 200 Pcs Metric M3 x 6/8/10/12/16/20mm Button Head Hex Socket Cap Screws Nuts Set Assortment Kit, 10.9 Grade Alloy Steel, Black Oxide Finish : Industrial & Scientific

www.amazon.com

 

[4th_Dimension]

You are the man sir! Just what I was looking for,thank you.
And I letting my engineering & electronics training dictate here. Yes I am "soft mounting" FC, Motors and maybe my FPV camera don't know about that yet

 

[Futuramille]

I soft mount all my motors. I just got done replacing all my hand cut pads with 3D printed TPU versions. I just check the screws after each session. I don't have a problem with screws backing out though. these are .5mm thick and mush (technical term) down to .25mm. I just made sure I could see the screw coming through or at least showing at the top of the motor mount.