Mojave Grimbles' Mojave EXB Build Thread

[RC-Dad]

omg that motor is going to be a monster in that mEXB.

 

[Grimbles]

What tooth count pinion is that ???

Also looks massive because it isn't screwed down - it was just at the edge of the mount so I could eyeball motor wire lengths

 

[BashingBrian]

Starting with 32/50 to see how she goes. Did some maths yesterday and performance on the 1500kv ought to be pretty close to the 2200kv I'm running 22/50 at the moment.

I would start with a bit lower pinion to be honest, the last thing you want to do is cook that loverly TP motor..!!
Keep a close on temps..!!

Is this new setup for bashing or trying to beat my 100mph off-road

 

[Grimbles]

I would start with a bit lower pinion to be honest, the last thing you want to do is cook that loverly TP motor..!!
Keep a close on temps..!!

Is this new setup for bashing or trying to beat my 100mph off-road

Little column a, little column b

You reckon 32t a bit too much for general bash? Have plenty of options so can drop to a 28 or 26 pretty easily!

 

[BashingBrian]

One thing I noticed is you've not mentioned are you going 6s or 8s as that will obviously make a huge difference.
I would monitor rpm etc in the Castle software, but if it were me I would feel safer starting a bit lower say 28T
Take it out and do a couple of flat out passes and see what temps and rpm are, then adjust accordingly.
It's all about getting the sweet spot of rpm vs power, I believe you want to aim for around 38,000rpm to 40,000rpm for max power

I'm going to tag @LibertyMKiii and @Mr.Duke into this because I know they will be able to advise much better than I can..
Could you guys please have a look over the last few posts and advise what you think would be a good starting point pinion size and what to aim for in the Castle software..Thx

 

[Grimbles]

One thing I noticed is you've not mentioned are you going 6s or 8s as that will obviously make a huge difference.
I would monitor rpm etc in the Castle software, but if it were me I would feel safer starting a bit lower say 28T
Take it out and do a couple of flat out passes and see what temps and rpm are, then adjust accordingly.
It's all about getting the sweet spot of rpm vs power, I believe you want to aim for around 38,000rpm to 40,000rpm for max power

I'm going to tag @LibertyMKiii and @Mr.Duke into this because I know they will be able to advise much better than I can..
Could you guys please have a look over the last few posts and advise what you think would be a good starting point pinion size and what to aim for in the Castle software..Thx

Thanks @BashingBrian and others in advance. I will predominantly run @ 6s but want to keep 8s options open - not concerned about swapping pinions regularly!

 

[LibertyMKiii]

One thing I noticed is you've not mentioned are you going 6s or 8s as that will obviously make a huge difference.
I would monitor rpm etc in the Castle software, but if it were me I would feel safer starting a bit lower say 28T
Take it out and do a couple of flat out passes and see what temps and rpm are, then adjust accordingly.
It's all about getting the sweet spot of rpm vs power, I believe you want to aim for around 38,000rpm to 40,000rpm for max power

I'm going to tag @LibertyMKiii and @Mr.Duke into this because I know they will be able to advise much better than I can..
Could you guys please have a look over the last few posts and advise what you think would be a good starting point pinion size and what to aim for in the Castle software..Thx

Thanks @BashingBrian and others in advance. I will predominantly run @ 6s but want to keep 8s options open - not concerned about swapping pinions regularly!

Running 32t pinion and 50t spur on that setup on 6s will be pushing 80-90 mph by my estimates.
In general any setup geared for over 70 tends to get hot.

I am estimating that a 24t pinion might be more ideal for this setup.

 

[Grimbles]

Running 32t pinion and 50t spur on that setup on 6s will be pushing 80-90 mph by my estimates.
In general any setup geared for over 70 tends to get hot.

I am estimating that a 24t pinion might be more ideal for this setup.

Thanks chap, much appreciated.

 

[Grimbles]

Some updates...

 

[Grimbles]

Wrenching done. Just spun the wheels on my street to set servos etc - 6s turnigy pack. She is... rapid... very very.... rapid!

 

[Grimbles]

Quick update on the moj. With the two server fans and a 36kg jx ecoboost server, I was getting a bit of a brown out issue under heavy servo load. I've therefore swapped out the servo for a 12v and added a separate 12v bec (heavy duty velcro to the fans) covering both the servo and server fans. At 20A@12v it ought to be more than adequate. I've added a 2 pin jst connector into the power in line for the bec, so I have the option of using a mini 3s also.

 

[Jon NC RC]

Quick update on the moj. With the two server fans and a 36kg jx ecoboost server, I was getting a bit of a brown out issue under heavy servo load. I've therefore swapped out the servo for a 12v and added a separate 12v bec (heavy duty velcro to the fans) covering both the servo and server fans. At 20A@12v it ought to be more than adequate. I've added a 2 pin jst connector into the power in line for the bec, so I have the option of using a mini 3s also.

View attachment 148538View attachment 148539

I was going to say, I’ve been doing bunches of research on servos and power supplies and brown outs with my crawler situation. The stock servo is one of its weak points. That became especially obvious after I added a lot of weight to it to help lower the center of gravity and a lot of it is in the steering axle up front to help it climb better. Steer servo upgrade became very necessary...

My guess is, you don’t have that problem anymore do ya?

!!!!

 

[Grimbles]

My guess is, you don’t have that problem anymore do ya?

Running it tmw am, will let you know!

 

[Jon NC RC]

Running it tmw am, will let you know!

As you described your new setup , there shouldn’t be .....

 

[Bust Muffin]

Confirming mine shipped with a full lsd in the REAR. Will update as i open the other diffs. Needed a shim pinion side.

View attachment 106991View attachment 106992View attachment 106993View attachment 106994

Copper based anti seize lubricant correct? Which gear did you lube it up with, the spur gear? Fantastic work so far my man

 

[Grimbles]

Copper based anti seize lubricant correct? Which gear did you lube it up with, the spur gear? Fantastic work so far my man

It's plain old silicone lube. Just looks pretty in the pic I think! But yes, on the diff crown

 

[Bust Muffin]

It's plain old silicone lube. Just looks pretty in the pic I think! But yes, on the diff crown

Awesome thanks a lot bro. Only been in the hobby about 6 months, so I’m still learning. The lube looks just like this copper based anti seize I use at work on some of the machines I fabricate on.