Can you make press-fit mounts instead of using clamps?
Yes, is there an advantage with press fit in this case?
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With clamps there is possibility of slippage. So the press-fit mounts would eliminate this problem.
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It keeps everything straight and true but doesn’t offer you the ability to move around the clamp
So you’ll need long axles combined with the shortest possible hanger width
I don’t think it’s necessary on a precision truck
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I think this will cause more issues with slippage as it depends on what materials you combine and how they tear on each other. The press fit solutions I have used in the past had one material being harder than the other, so one of the parts deformed creating a good bond. Similar Alu against alu would not do the same I think.
I meant slippage parallel to axis of axles, not rotation around axle. I think there is a case for pressfit.
I just think it’s more refined method to secure motor plates. Not sure if I fully agree with @moon’s point about axle length and hanger length considerations being a problem/hassle.
I guess comes down to personal preference.
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I understand the direction of slippage, that would not happen with press fit yes. But it must be something off with those clamps used in that case
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I disagree. Most mounts are around 1/4” or about 6mm thick. There are some MTB mounts that are extra thick. And @Janux-esk8 has 10mm thick mounts because the hanger clamp is integrated into the motor plate, thus enough surface area contact was needed for the clamp. For the large majority of users here, 6mm 6061 works very well. Only when the lengths get very long do you see more flexing. Then again, that’s easily fixed with crossbars
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The clamps in that case were obviously loose. The mounts weren’t bent, the clamp was simply loose on the hanger.
What @moon is describing is that when you add a press fit adapter to the end of a hanger, that’s what your motor plates attach to. So a 200mm hanger then gets a pressfit Mount which we will assume sits flush, then 6mm of motor plate, clearance for a pulley (25mm) then the wheel, 25mm. So you effectively have a 262mm hanger between the wheels. Things get wide really fast and now you’ve got 50+ mm of axle on either side.
Clamp style mounts are far better and more flexible.
I will say, if you are designing a custom truck I’d consider the following:
- pivot tip clearance around the cup, there’s less room to beef up a caliber 2 profile around the pivot post on the hanger than it appears. On the bench it clears, test it with low duro pivot cup bushings and weight on the board to make sure there’s no interaction with the baseplate around the pivot cup. Weight makes a big difference.
- consider the motor mount clamps in the hanger geometry. What shapes and surfaces will allow things to mount squarely the easiest. Make sure that the hanger clamp can slide from a motor to motor distance of 115mm for dual 6355s out to whatever. Clearing 6368s or 6374s will widen the market a bit. Also dual 5065s.
- if you’re considering a gear drive figure it out now. You can integrate bearing surfaces into the hanger or the axles which could be incorporated into other areas.
- take into consideration 10mm axles. What bearings are readily available for 8 and 10mm axles etc.
Being able to set up a 184 ish sized hanger and keep that 184 wheel width is important to users of smaller setups while having some flexibility to widen the effective width to around 215 captures a lot of the market.
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I hate the process of adjusting clamps on trucks to be the exact distance for the belt to line up. I also hate using red thread locker, fastening the bolts as hard as I can, and then the thing still getting loose after time. If I was designing a truck for esk8, I would either make it compatible with press fit clamps that don’t have that problem, or just have the clamp part of the hanger, like Evolve trucks do.
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If those trucks were RKP, everyone would be using them.
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Mr. @moon, I take back what I said about not fully agreeing. I wanted to make press-fits for my BN220 hangers but realized that my wheels needed to be spaced out away from the hanger more which means I needed longer axles. The axles on my BN220’s are fixed and short. That’s why the press fits you made works on SR RKP’s because the hanger is narrower and the axle quite a bit longer…
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What length of axle would you need? Mine are 50mm which is very long compared to the standard 34mm
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@Boardnamics Haha, easy there buddy. Don’t get all defensive. I’m not knocking your product, I’m talking about axle length in the context of implementing a press-fit mounting solution.
Let me rephrase and say your axles are “relatively short when compared to Surf-Rodz axles but SR RKP hangers are also narrower than your hanger”. If you look at my picture, you’ll see there is no room for a pressfit mount. Wheels need to be further out to create space between pulley and end of hanger, which means there needs to be more axle exposed (longer axle or combination of narrower hanger and longer axle).
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What @b264 said. Kevin’s not being defensive, they’re just not short. If you need winder than you need a wider hanger.
Axle length is not an infinite number to play with either. @boardnamics have 50mm of useable axle, meaning your 200 mm hanger can still mount wheels as an effective 250mm of hanger (room for 25mm per side). There is a limit though. 8mm axles will bend if long enough and the further you move the wheel from the hanger the more lever load you apply to the axle. I’d say his axles are the max I’d suggest.
Surfrodz can go longer because they’re 10mm shoulder bolts. But even still, they have maximums as well.
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110mm shoulder bolts is the “limit”. Probably because its really hard to find shoulder bolts longer than that.
Really surprised how durable shoulder bolts are. Have we seen any bent 10mm shoulder bolts?
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Unlikely. Its a big strength change over 8
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McMaster has 150mm shoulder bolts…
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Longest i can find here is 120mm. Generally they dont sell them this long. Kinda hard to find.