Zerodefect

Can't that diff be flipped so a normal pinion can be fitted?

Have a machinist make a thicker plate with a broader foot?

That's a Durango right? Don't they have a E buggy? Can that plate be retrofitted?

RCmayor

iTrader: (9)

Use the GI Joe Kung Fu grip.

McD44

iTrader: (16)

I agree. Speaking of your pinion, with the amount of flex and movement we're experiencing I do recommend that you flip your diff around and run a short reach pinion. Any flex is being exaggerated with that long shank pinion. You do have to switch the outdrives around when you flip the diff but that's not a big deal.

I really like the Venom mount TBH. Except for the M3 mounting screws, M4 is the only way to go IMO.


It is made of much thicker material and forms a better "box" joining the front and rear uprights. I wish you could order just the mount and I wish you could order it from somewhere other than AUS...

getloose

iTrader: (11)

check the screw length and depth, if the screw is a bit too long it will feel completely tight when it hasnt snugged the mount to the chassis fully.

pascalfd

iTrader: (5)

+1 on screw length - had similar issue with a Losi that kept coming loose.. screw was just a tad too long

McD44

iTrader: (16)

For me screw length isn't the issue. I checked to make sure and the screw is 2mm shorter than the depth of the hole.

R.Shackleford

iTrader: (4)

Was this the first time you cleaned the threads before applying the loctite? If so you are just wasting your time. Lets think about this to a second. A STEEL screw, LOOSE, in a (relatively) SOFT ALUMINUM motor mount, that because of the loose screws is able to move about. Now which threads are going to deform, the hard steel threads of the screw, or the soft aluminum threads of the mount? I think we all know the answer. If the first time you assembled the motor mount you failed to clean the threads of the mount and screw, you ended up using loctite which had been chemically altered, and therefore wound not cure to full strength. Now you run the car, the screws come loose, and the threads get deformed. Loctite cures through what's known as an anebolic (SP) reaction. It means that it needs no air to cure. What is does need is a clean, uniform surface to work to its full strength. After you have allowed the mount to come loose once, you no longer have the uniform surface you need. In other words, you have one shot with a new mount and clean new screws to get it right. If you cleaned everything the first time you assembled the mount, and you still had problems, then your only bet is a new mount, and stronger loctite. I have heard that Adam Drake mixes blue and red to make a loctite that is in between the two.

Pulse_

+1 I verified the length of the screws too, I'm using 10mm M3

I hope we can find a solution with the original mount

Deja Vu

iTrader: (11)

I've worked with Loctite products and the Henkel Corp. for many years. Their products work very well when used properly.

Surprisingly, our RC cars are made up mostly of what Loctite considers to be inactive metals...Cadium plated steel, aluminum, anodized aluminum, zinc, magnesium, titanium, stainless. Even standard steel screws have a black oxide coating (another inactive material). Most of the time, typical blue Loctite works OK since it does cure to a glue like substance and provides some amount of sealing (blue Loctite is actually recommended for 1/4" to 3/4" hardware. If fully and properly cured, it is actually too strong for smaller screws typically used in RC). But, to get the full effect and strength that it is designed for, primer should be used for these materials listed.

I suggest you spray out the threads with motor spray and let the part dry. Use Loctite primer and purple Loctite (purple is what is recommended for smaller screws). To reach full cure, you need to give it 24 hours.

Knowing you've had trouble with these particular screws, I'd likely use small lock washers for the next enduro in addition to the Loctite

ta_man

iTrader: (168)

Cleaning out the threads with motor spray may not be sufficient. Soak the mount in acetone for a day or so. Acetone dissolves acrylics and acrylates and will remove all the loctite residue.

Something I learned from rebuilding automotive engines is that for a screw under repeated stress (think: connecting rod bearing cap) not to come loose, the stress on the screw (holding force, tensile force in pounds - or KG for you) must be greater than the cyclic load. If you've got 3MM screws going into the mount (aside from it being aluminum). you may not be able to torque them tight enough if they are standard hex drive (limited to a 2MM hex). I suggest you get some Torx drive screws so you can apply more torque. You can get 3MM Torx screws from CRC.

Then, of course there is the more obvious solution of re-drilling and tapping for 4MM screws, though that may be impossible if the mount isn't big enough.

Less obvious is drilling and tapping for additional screws.

Part of your flex issue is the motor having off the mount causing the mount to flex on the chassis. There is a way to reduce or eliminate this via a brace that forms a third side of a triangle. I made such a brace on my first E-8 conversion where I had the motor mounted on top of the driveline rather than to one side. You can see it if you look at this picture. It is coming down at an angle in front of the pinion and spur. Of course most of my suggestions involve some use of machining tools.

Pulse_

Thanks a lot for your help, I'll try different suggestions and let you know how it goes .

kufman

iTrader: (6)

So, this setup uses M3 screws to hold the diff supports to the chassis? If so, it is going to be hard to make it stay put.

Pulse_

Thanks a lot for your help, I'll try different suggestions and let you know how it goes





The hole in the chassis isn't exactly round anymore because the screw ripped it when the mount became loose

Do you think there is enough material to re-thread it in M4? I'm sad I paid 140€ for a conversion kit that doesn't work.. The car didn't even cost me so much

kufman

iTrader: (6)

Looks like enough material to tap it out, but it is hard to say for sure just by looking at a picture. You should be able to get full depth threads with a 4mm thread. Drill size for 4x0.7 bolt is 3.3mm which is larger than existing holes (2.5mm before tapping and threads cut 0.5mm). Drilling out the chassis will also fix the oval shape hole that is in there.

McD44

iTrader: (16)

Wow, that's a bummer. Please let me know if you have any success with the M4 idea.

I thoroughly cleaned all the holes and used new screws on the bottom and top of the mount. Red loctite on the bottom screws and blue on the top.

I might spring for the Venom kit if this doesn't work out...