Mini Super

[MRCrackhead]

Got the shocks roughly built.

No oil in them yet, just working out the limiting, shock angle, etc.



Sitting on a stock Sedona, it's around 5" of flex running 4.5" tires.

May need a bit more, or less. Figured I needed to start somewhere.



Ride height is close.

I only had orange mini-t springs laying around for mock up.

Tire foams are super stiff as I have not addressed that issue yet.



Starting to look like something I could sell, grab my wallet and run far away....

 

[Solitaire]

Nah, I think you've done an excellent job. If you have the time, post up some dimensions for those of us that haven't delved into the 1.9 world...yet.

 

[MRCrackhead]

Nah, I think you've done an excellent job. If you have the time, post up some dimensions for those of us that haven't delved into the 1.9 world...yet.

Haha, thanks.

I'm not selling just yet.

Let me know what stats you'd like, beyond some basics listed below.

9.75" track width using shift hubs. Some narrow hubs should bring that in a bit more. I feel that's too wide, but I didn't want to cut the link mounts off this early in the build process. Too many variables.

It's 10.75" wheelbase, picked one inch longer than track width as a starting point.

It weighs 2lbs 13oz right now with servos and motors, no gears, no electronics or steering.

60mm clearance to front of skid, about 85mm to upper bend in the rear links, on 4.5" tires.

Chassis is 1-5/8" wide, 2-1/2" wide at the shock mounts, and 6-5/8" long tip to tip of the shock arms.

 

[RICrawler]

Damn Kevin... Build is looking great! Making me think about digging through the parts bins. Definetely a unique rig so far, should be a lot of fun!"thumbsup"

 

[Solitaire]

That's the spec list. Just wanted to see if you had reduced the width from what you had posted before. 9" would likely be a comfortable width with 12" gates, but will require some definite head scratching to get there.

Also wanted to see what your skid height and approx weight was.
Thanks for those.

 

[MRCrackhead]

Damn Kevin... Build is looking great! Making me think about digging through the parts bins. Definetely a unique rig so far, should be a lot of fun!"thumbsup"

Thanks, your mini axle turned out awesome...

This is the next logical step....lol

That's the spec list. Just wanted to see if you had reduced the width from what you had posted before. 9" would likely be a comfortable width with 12" gates, but will require some definite head scratching to get there.

Also wanted to see what your skid height and approx weight was.
Thanks for those.

I agree on the width. It's just huge compared to a 12" gate.

I'll mess with hubs first because it's so easy to do; but I've got a couple ideas to get skinnier if that doesn't work out.

I want to get a few more big steps out of the way first, then take a hard look at it.

 

[MRCrackhead]

Took some time in the garage to fab the rear servo mount today.



I cut the tube a bit more aggressively to tilt the servo a bit more since the rear case is clocked up a lot higher.

I put a bend on the tabs that hold the servo.

The front mount has a similar bend, this one is just more exaggerated.



Here you can see the servo arm is tilted; but not to bad considering the position of the rear case.

Doesn't look like much; but every degree will help.

Hopefully this will give decent geometry, and similar steering setups front and rear.

 

[MRCrackhead]

Well, I've swapped some hubs around and realized the folly of my ways.

Ultra narrow hubs only put the wheel nut itself outside of the wheel face.

That's not really acceptable, for me.

9-1/4" and 9-3/8" wheel base is no problem to achieve, but at what cost.

I guess cutting the outer link mount has become a reality.

I may make something custom, or perhaps some AR60 link mounts fabbed into the mix could do the trick...

Pinned hubs that have no wheel nut is an option.

Scratching my head, and ready to cut some stuff, much to consider.

 

[Solitaire]

Something like Barry's choker collars to get the over-under effect with the links and shocks. Only other issue is shock clearance at the motor end bell. May have to go a stubby of some sort. Also further narrowed tires mite help.

Anxious to see what you come up with.
I like your chassis design, too. Skidless, or did I miss that pic?

 

[MRCrackhead]

Something like Barry's choker collars to get the over-under effect with the links and shocks. Only other issue is shock clearance at the motor end bell. May have to go a stubby of some sort. Also further narrowed tires mite help.

Anxious to see what you come up with.
I like your chassis design, too. Skidless, or did I miss that pic?

A stubby motor would limit you to one expensive motor from one vendor, from what I've seen.

That's not really the idea here. Only one motor option sucks.

No skid, right now; but I'd suppose a generic "slider plate" would be a good idea vs. the two cross tubes that are there now. It will simply be a "skid plate".

I'm looking at the rig at 9.25" right now and clearances are surprisingly reasonable.

The real question is, where to go from here.

If I cut the outside link mount off, there's no going back; yet it essentially solves the width issue.

No room, that I can see, to get it back to double shear on the link/shock mounts....

This link says there's a 16" unlimited class, born same day as the 'mini super' class at 12".

https://docs.google.com/document/d/1JxPtY62AESfZUqismAMZ17QBMKklM1EbYhKN4zZA8QU/edit?usp=sharing

Will this build be a flash in the pan, meanwhile 16" supers are going to start getting built?

Then I'd suppose cutting mine any shorter would be dumb.

I should go wider and build the 16" version, as history has taught us regarding the mini in general.

My heart is set on a 'mini super' right now......but only cuz I'm building one.

Lots to think about.

 

[MRCrackhead]

So here's where I'm at.

I've got the wheel base a 9.25" in this photo.

Stock XR steering at full lock.

Here you can see how the wheel nut sticks out past the wheel face.

That's just not going to work for me.



Still a decent amount of room to get better steering at this width.

So, I guess the next move is to cut the outside link mount off, and move everything inboard.

I can easily gain as much as one inch overall, which would put the rig at 8.75" on Shift hubs.

That may be overkill with regards to getting sharp steering; but it's at least a number that doesn't suck.

It's very easy to go wider.

The Shift hubs also buy some room to get weights in the wheels, where needed.

I've not solved the single shear link mount issue; but I'm hoping the answer will present itself in an alcohol laden dream later tonight.....I've got nothing.....yet.

 

[MRCrackhead]

After much thought, I don't see any good way to keep the links double shear and narrow the axle to a reasonable mini width.

The servo just takes up to much room on the one side.

So, I spent some time making up these collars, which will be single shear; but much beefier than the original mounts.

I'm going to cut both factory link mounts off now, and slide these in their place.

I'll gain roughly one inch cut off the ends of the tubes (1/2" each side).

Cutting tubes tomorrow.....hope these collars are up to the task.

 

[MRCrackhead]

Cut the first tube this morning to check things out.



The profile of the collar looks good relative to the tube and c-hub.

Not much clearance loss.



It all looks very short. Hope my tape measure wasn't lying to me....lol.

 

[MRCrackhead]

Got the front axle mocked up.

Collars are in place, but not secured to the housing yet.

9-1/8" with Shift hubs and one thick spacer each side.



Just Shift hubs measures about 8.5" track width.

Might be tight at that width; but I'm happy to have the room to run the rear axle a bit narrower than the front now.

Steering still appears to be workable.



The more outboard position of the lower link hits the tire now; but I don't need that steep bend in it anymore.

There's plenty of room behind the motor can to run a straighter lower link, which will free up some room to turn.

 

[winnerone23]

Not much to say.. Awesome work Kevin, way to show us how it's done!

 

[MRCrackhead]

Not much to say.. Awesome work Kevin, way to show us how it's done!

Thanks Troy.

Looking back, I would have shortened the short side more than the long side tube, instead of shortening them the same amount.

There's more room over there without the servo; but I just didn't think of it at the time....now it's cut.

Down side would be the upper link mount would off center more than it already is, so I'm conflicted on the idea somewhat.

Learning as I go, that's for sure.

 

[MRCrackhead]

Both axles mocked up now.

Track width obstacle possibly overcome, on to the next one.



I'll need to finalize the clocking of the collars and pin them to the housings.

Still messing with it to find the sweet spot for the lowers and the shock mounts.

9-1/8" front, 8-7/8" rear right now with spacers; but I have options in that department for the first time....mess with it some more when a few more details are worked out.

 

[MRCrackhead]

The wheels I've been using to pose this rig belong to my sportsman rig and I needed to get it up and running for a comp next weekend.

So, I took a few minutes, in the motel, to mod some buggy wheels I've had laying around forever.

No big deal; but now this rig has it's own wheels which are a bit narrower and afford a bit more clearance.....so that's handy.

 

[89redranger]

Lookin good!

I may have missed it somewhere somehow, but what conclusion did you come to for shafts/tangs/lockers? Or have you even got that far yet?

 

[MRCrackhead]

Check out post #50, I've got a picture of the bearing that is in the axle tube right next to the gearbox.

I purchased the Berg 4th gears and the RCBros lockers.

The original 4th gear has a different bolt pattern for the locker, which is likely useless.

With the RCBros locker, it would seem you have the option to run OFNA or Axial shafts.