Open Source Precision Trucks - Looking for design feedback

i may take you up on that offer for “precision” trucks…:thinking:

It’s a competition now

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So let me just put down what I’m looking for in the trucks I want to machine.

Target weight of 1.8lbs per truck (including baseplate)

Compatible with Paris Baseplate

Caliber Bushing Seat

8mm Split axle design

3* rake

This setup is basically a higher riding, lighter, larger wheelbase offset rendition of Atlas Ultralight trucks.

Over the past year, I’ve been through many iterations of my own design and I’m still not quite there. I have to say it’s not that easy to understand how the truck behaves if you change properties like axle offset w.r.t. KP, rake, bushing seat shape, axle type, bushing pre-load, and pivot shape. Also, I am not so sure about the actual forces applied to the hanger as well the baseplate. For instance, what’s the maximum load a truck has to withstand at a certain hanger size?

Unfortunately, I don’t own a CNC nor do I have access to one where I can machine my own hangers, hence the design has to be spot on.

What material are you guys using?

In my simulations in Fusion 360 of static stress being mostly applied to the bushing seat at a 50-degree angle for simplicity. For 6061-T6 I needed at least 2000 Newtons where the steel axles start to have an issue in the safety factor value of 0.3. This is a hanger width of 12 inches without threaded axles. The weakest point will be the axles and the pivoting nose unless you hollow out the hanger to lighten it.

My current precision milled trucks are 2024-T3 aluminum. You can use 6061-T6 to defray cost while ensuring good strength.

how heavy are your current trucks?

The stock baseplate…idk. The stock hanger is 10.4 oz. The milled hanger according to CAD is 16.74 oz. I’m estimating a single truck from Caliber to weigh around 2 lbs or less.Probably closer to 1.5 lbs.

Thanks, I’ll go with 6061-T6 for the hanger and baseplate. Yeah, it seems like that the transition to pivot and axle stubs are the weakest points. Could you elaborate how you constrained your hanger in F360? A screenshot would be helpful!

image

For a second, I had to check my message inbox and saw you message me a while back about this. Hard to remember as time goes on. For constraints, I just clicked the faces of the axle and pivot nose as highlighted in blue. I went with fixed constraint. Please ignore the hexagon head of my axle, I used a grade 8 bolt to circumvent the weak point with using a threaded axle.

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Cheers! 10 char

I just came across these:

He made his own precision hanger with integrated mounting. Might give you some ideas. Here’s his build log: https://hackaday.io/project/26899-electric-longboard-markii

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Nice trucks, for my personal taste a bit too clunky but I do like how they integrated the motor mounts. Just wondering why everybody is so obsessed to use Caliber II baseplates? Either I do want to build a precision truck or not and if so there are other relatively low expensive options.

They’re just readily available. Honestly I prefer Paris Baseplates. Also readily available but with a larger wheelbase offset that doesn’t wheelbite as easily when used with freeride decks.

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I would love to see some precision TB 218’s with 1.5mm shaved from the flat side if the profile, so any caliber mount would fit. They would sell like pardons in a prison :grinning:.

Nothing special, just like they are now except precision milled with 10x80mm shoulder bolt axles.

@torqueboards, handle that!

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I’m definitely going to machine some trucks with an easily interfaceable hanger for motor mounts. I think this community can use more large rake, low angle trucks. Low angle high rake trucks are going to be amazing for staying stable but turning hard when need be.

For example, consider the Ronins (7mm rake, 45* baseplate) which remain extremely stable for downhill, but turn super sharp thanks to their divey nature.

@mmaner Will do! :slight_smile:

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oh shit! if you actually do this, prepare your wallet, you’re gonna be a millionaire

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No doubt, @torqueboards is about to make some Bank :grinning:

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cha ching :money_mouth_face:

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I have a set of billet Ronin Katanas, purchase choice on rake for them was 0/2.5/5mm. My Aera K4 have 6mm (up from K3 3mm) although K5 was reduced to 5mm?.

7mm is a lot… maybe ok on a really low angle rear truck?

Bit much for me. Maybe cast plates are different?

It is all personal preferance though. I have split the rake on my Katanas so my 25 degree rear has 5mm and doesn’t feel like a bag of cement and my front 45 degree has 2.5mm. I feel it adds to split nature f/r stability but also puts a slight weight bias on the front truck helping stability in a straight line to a point but also in un-weighting the rear leaned over.

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