Novel Ideas for EUC Linkage Suspension Slider Design Concepts

[techyiam]

Here is a thread for sharing novel ideas on linkage suspension slider concepts. 

I'll start first.

Borrowed from the elevator roller guide system, here is a conceptual idea on a centrally located slider, or dual sliders design. The main take away here is the use of a guide rail sandwiched between opposing rollers.

Edited February 18 by techyiam

[techyiam]

 

56 minutes ago, Rider1 said:

That's a great idea, I hope Kingsong doesn't give up on their roller slider concept and further improves it (maybe in the direction you mentioned), some competition with totally different designs is always nice to see! The only problem with that might be the height needed in order to keep the resulting forces small enough (since there's only one instead of two sliders per side).

Begode and Inmotion use centrally located single slider designs, why do you think it can't be done with roller sliders, if the roller sliders are properly design for such purpose.

[Funky]

Sand, dirt, small rocks getting pushed into those "roller" sliders would be nightmare... Especially if something gets stuck in there..

Same time, if the rollers are built inside some kind protective cover, then yeah - it's good idea.

Doh i can see overtime they getting more and more play in the rollers. As you lean left/right all the time on the wheel.. Also they would need to be made out of some king hard plastic. Because metal on metal is bad.

Edited February 18 by Funky

[techyiam]

9 minutes ago, Funky said:

Sand, dirt, small rocks getting pushed into those "roller" sliders would be nightmare... Especially if something gets stuck in there..

Same time, if they rollers are built inside some kind protective cover, then yeah - it's good idea.

Doh i can see overtime they getting more and more play in the rollers. As you lean left/right all the time on the wheel.. Also they would need to be made out of some king hard plastic. Because metal on metal is bad.

That is why I deliberately use the term concepts.

That's where brain-storming discussions can be initiated.

The slider can be a closed or open.

Design ideas for both can be discussed.

This a thread more for brainstorming of ideas to overcome the negatives, and improve the positives.

Edited February 18 by techyiam

[Funky]

Well if we are talking about brainstorming.. We could use very strong magnets that would repel each other.  No negatives of parts brushing between themselves. 

Only thing we would need is very solid guiding rail.

(Joking..)

I think the rollers themselves need to go in first place.. Very solid built arch suspension without any linkage at back of wheel. Beefed up fork suspension. Like Sherman S has. That's the way to go. Even kingsong those 8 rollers per side is kind of dumb.. Yes they do work. Yes they are very easy to exchange the damaged rollers.

But very solid fork suspension without any linkage at back off wheel is better in my eyes. 

Instead of cylinder design, why can't we go oval? You would get more structural strength from side to side play. But same time it would be thinner - meaning not so wide wheels. Or use 2 fork suspensions per side. At ends of battery cases. First one at front, second at the end of euc. That way you would get more even suspension - than having one big suspension in middle.

Or am i crazy to think that?

 

Edited February 18 by Funky

[Dan Cobar]

1 hour ago, Funky said:

Instead of cylinder design, why can't we go oval?

Expensive to machine.  Round parts are easy to make and therefore less costly.  Also, round has only one dimension to to QC.

[Funky]

36 minutes ago, Dan Cobar said:

Expensive to machine.  Round parts are easy to make and therefore less costly.  Also, round has only one dimension to to QC.

And that's how we get China products.. Cutting corners where ever it's possible. (In general every business..)

Round vs Oval.. Nothing that much harder to make. The machines are making them anyways.. Same for expense. At least if we are talking about "big name company". Not like EUC manufacturers that are like people who work from garages compared.. (Small scale operation.)

Still they can buy the dam suspension from said big name company and build EUC around it. End result should be better than what they are making in said garage.

[onewheelkoregro]

19 minutes ago, Funky said:

And that's how we get China products.. Cutting corners where ever it's possible. (In general every business..)

Round vs Oval.. Nothing that much harder to make. The machines are making them anyways.. Same for expense. At least if we are talking about "big name company". Not like EUC manufacturers that are like people who work from garages compared.. (Small scale operation.)

Still they can buy the dam suspension from said big name company and build EUC around it. End result should be better than what they are making in said garage.

To be fair every country has the ability to manufacture their own goods but under the economic system that we currently use, they expect to squeeze every last dollar out of their products, so that's why everything is made in China.

[Dan Cobar]

1 hour ago, Funky said:

Round vs Oval.. Nothing that much harder to make.

I have to disagree.  Turning a round shaft is a easy and common task.  Boring a round hole is also easy.  To make any other shape to the same precision level is going to be much harder to do.  If we were talking about casting, or extrusion then that would be about the same no matter what the shape.  But a suspension slide needs to have very little play (backlash/slop) between the parts. Round tube or shafts are easy and available.  If there is an off the shelf part that is being mass produced in a non-round shape that could be used, that might be a possibility.   But at the quantity of EUC manufacture, keeping parts simple will be the most economical.

[onewheelkoregro]

6 minutes ago, Dan Cobar said:

I have to disagree.  Turning a round shaft is a easy and common task.  Boring a round hole is also easy.  To make any other shape to the same precision level is going to be much harder to do.  If we were talking about casting, or extrusion then that would be about the same no matter what the shape.  But a suspension slide needs to have very little play (backlash/slop) between the parts. Round tube or shafts are easy and available.  If there is an off the shelf part that is being mass produced in a non-round shape that could be used, that might be a possibility.   But at the quantity of EUC manufacture, keeping parts simple will be the most economical.

I'm not looking for economical travel! I'm looking to get around in style with no gas!

[Funky]

2 hours ago, Dan Cobar said:

I have to disagree.  Turning a round shaft is a easy and common task.  Boring a round hole is also easy.  To make any other shape to the same precision level is going to be much harder to do.  If we were talking about casting, or extrusion then that would be about the same no matter what the shape.  But a suspension slide needs to have very little play (backlash/slop) between the parts. Round tube or shafts are easy and available.  If there is an off the shelf part that is being mass produced in a non-round shape that could be used, that might be a possibility.   But at the quantity of EUC manufacture, keeping parts simple will be the most economical.

You missed - The machines are making them anyways.. 

Yes what you are saying is true - doh...  But if everything is setup aka machines, then it's not so difficult to make anything. 

Deleting whole suspension altogether would be better then. Aka no moving parts and useless, not needed things. Cheaper to build, more robust and way easier to build. We aren't talking about how easy to build something, or how cheap to build said thing over another. We are "brainstorming" what would work better. The cost and ease of making comes after..

If we care about cost and ease of making and keeping it simple, as i said before - delete the suspension altogether.  

 

As you like to follow by the book and use already available parts that are mass produced, then how about using 2 fork like suspension? One at front and one at back of euc.. Replacing the usually one in middle of wheel. That we have seen so far. As whole EUC body is moving when you accelerate and brake. There should not be any seizing up between first/second suspension. And having two suspension instead of one would mean less chance of bottoming out. And more smooth suspension travel.

Also by having said arch from fork suspension - you have amazing base already to build around (Exoskeleton). Add battery pack each side of EUC, between suspensions. Simple top plate that hold everything together. Board mounted onto. Also by having 2 separate suspension you can add one long steel bar at bottom. That will hold the wheel/pedals in place. You would need to unscrew 2 big screws and wheel/motor would come out really easily. (Same type as regular bicycle). Or if you are scared of loosing wheel mid ride. You could sandwich said motor axle between to separate steel bars.. That are screwed together by multiple smaller screws.. Also pretty easy tire change.

 

1 min brainstorming..   

Edited February 18 by Funky

[Dan Cobar]

Double suspension.  Now that is a novel idea!  It would be a total departure from what we have so far.  And I like your ideas about strengthening the structure of the frame.

[MetricUSA]

We need a one arm suspension like on some motorcycles... For easy tire removal... 

[Funky]

1 hour ago, MetricUSA said:

We need a one arm suspension like on some motorcycles... For easy tire removal... 

Sounds and looks cool. But you would need somewhat strong arm then.. Meaning there will be some weight one side of euc?

As i said before. Same concept as regular bicycle, where motor comes out from bottom would be best move. And this tread isn't about easy tire change as we are getting off-topic.   

 

Back to topic - Why not linear bearings instead of rollers? 

 

Edited February 19 by Funky

[Vince.Fab]

Square linear bearings would need to be totally sealed off from the environment and lubricated at all times.

 

Now round linear bushings might be an idea,  better seals but the rod/tube would probably have to be hardened to stop wear from the ball bearings.

[Dan Cobar]

38 minutes ago, Vince.Fab said:

would need to be totally sealed off from the environment

Some kind of rubber bellows prehaps?

[techyiam]

Revisiting the single-pivot swingers concept, I wonder if "soft" pedal mode can accommodate the slight fore-and-aft movement, assuming a reasonable length swingarm is used.

Minimum horizontal movement is achieved around the point where the swingers is horizontal.

The axle should sit be below front pivot vertically, since sag is around 20 to 30%, not 50%.

[Rider1]

So, as I promised, I re-did one of the sketches in Geogebra (image embedded below, I also animated it, but there's actually not that much to see except for a black circle travelling up and down a bit). The main takeaways are that when fully compressed/uncompressed the axle shifts horizontally (distance between grey and red line) around 4-5% of what "max acceleration" would be (blue lines, which would equal standing on your toes/heels, not factoring in powerpads). In this case, I took a wheel with an outer diameter of 20 inches, suspension travel of about 100mm and 5cm between the tire and the pivot point of the swingarm. For simplicity (and because it makes sense since it induces the least amount of shift) the swingarm is horizontal at 50% compression.

52 minutes ago, techyiam said:

The axle should sit be below front pivot vertically, since sag is around 20 to 30%, not 50%.

That's also a fair point, but the movement isn't as symmetrical or minimal then (most bumps will compress the suspension from 25% (regular sag) to 75%, so the amount of movement in this region is minimal and symmetrical, if that makes sense).

 

Another problem of this concept would be that the approach angle is reduced to about 45 degrees when fully compressed (from about 66 degrees when uncompressed, not factoring in the size of the bearing at the singarm and any additional bodywork to protect it).

All in all, it seems like not that bad of an acceleration, but especially at lower speeds it will surely be quite noticeable, but I might be wrong, so it might actually be worth a try

 

[I also tried setting the pivot point really high up in order to perfect the angle of attack for objects of around 5cm in height (also taking sag into consideration) which would also allow the approach angle to be better, but that's not a good idea in terms of horizontal shift... ]

[Planemo]

The simple answer to your problem is to use a 4-bar linkage like the Horst type on my MTB, but it's getting into the realms of being pretty complicated on an EUC... one would have to judge the complexity and weight against a simpler but not as effective twin tube system like the Sherman S.

[Planemo]

On 2/18/2024 at 8:39 PM, Dan Cobar said:

I have to disagree.  Turning a round shaft is a easy and common task.  Boring a round hole is also easy.  To make any other shape to the same precision level is going to be much harder to do.

Indeed! Honda were pulling their hair out in making their oval-pistoned NR750 work!

[techyiam]

4 minutes ago, Planemo said:

Indeed! Honda were pulling their hair out in making their oval-pistoned NR750 work!

Wait a minute, that is a whole different kettle of fish. 

They were struggling to seal combustion pressures using oval pistons, piston rings, and cylinders, in order to circumvent racing regulations to compete with 2-strokes using four strokes, 

[Planemo]

I kinda knew someone would say that, but it's still relevant given the clearances we are dealing with for knock-free suspension.

[DavidB]

I like the linear bearing info and swingarm idea. My guess is different ideas will work for different uses. Personally I think I would be fine riding a Falcon without suspension and low psi in the tire around town and to the shops. I think for last mile eucs balloon tires might be all you need. I prefer the K.I.S.S. principle.

[Funky]

4 hours ago, DavidB said:

I like the linear bearing info and swingarm idea. My guess is different ideas will work for different uses. Personally I think I would be fine riding a Falcon without suspension and low psi in the tire around town and to the shops. I think for last mile eucs balloon tires might be all you need. I prefer the K.I.S.S. principle.

Same here. Doh i prefer bigger diameter wheel without suspension.  The next wheel after Falcon, the 40C motor, 45lbs without suspension.. This one could be my next wheel. If they don't duck it up badly.

Also suspension makes the wheel way, way to big. Like Inmotion V11 is so big in real life compared to something like ks18xl, ks16x.

Edited February 20 by Funky

[daniel1234]

What about something form IGUS drylin lineups ?

https://www.igus.eu/drylin/linear-guide