Super sized stand-up Scooter project. Build thread

[Goped ESR750]

Thanks... Glad you like the project.

I was thinking the exact thing for a rear suspension. Having some sort of linkage to take the pivot motion of the swing and turn it into a linear motion to push against a shock in line with the frame.

This idea has been surpassed by my idea to copy goped's CIDLI design. Which using polurathane and a square inside another square ofset at 45... The internal square should only just be able to rotate inside the outer square. When the internal square is offset the little triangles which are around the edge are filled with poly. When the suspension pivots the inner square rotates into the poly which provides the suspension.

Here is link to image, as it did not embed well http://content.foto.mail.ru/mail/mak-zy/720/s-807.JPG

My design will change from this as in this design the poly is used to align the axis too. I would user bearings either side so the poly was just for suspension.

60mph is the goal, but definatly wont be riding around like that. Just needed a new project so I thought I would give it a go

 

[etard]

That's a very compact design and wil probably be real nice on the street. I just really prefer the feel and action of a coil, however, with space constraints that double square poly should be a win. I have a few curbside stand ups her and am watchin thus to get some pointers. There's definately a huge advantage to figuring out proper gear drive ratios with such a small rear wheel. I'll probably aim for a 40 mph top speed though. Be nice for stowing in the trunk ( boot) of a car. Do you plan in putting some sort if fairing on the steer stem and handlebars? Maybe a pod for instrumentation?

 

[Goped ESR750]

Yeah I definatly agree that in an ideal situation a spring and damper would be better, but I really think the linkage is probably a bit complicated and also may change the look drastically. No fairing, just straight pole. I intend for this too look like a go-ped as much as possible. Will probably have a small cluster though.

Did some work on suspension system today. Only roughing out a few sizes. Need to make bearing cups. The the race needs to be bigger than the inside of the square to allow the poly to be pressed in. It is 70mm. I have gone for 50mm ID 80mm OD tapered rollers. This way the race clears the square. I have machined a blank for one side with 70mm bore, got to machine a blank for the other side, when the bearings arrive I will machine the recess for the race.

Few pictures of my progress taken, but I will have to wait untill I am home to upload them. Pretty happy with the progress. I'm not very good with designing things. Do not have a computer graphics package, so I work from little notes and scraps. Often have to start making something to get an idea of where I am going, is certainly the case with this, am pretty happy with how its going though. Definatly think this is achievable.

Found out that this is also known as an indespension unit, used on trailers etc.

 

[Goped ESR750]

bearing cups blank looks huge. Thats because it is, I left it over sized until I finished machine. Should only be about 25mm... Is more like 40mm at the moment.

 

[Goped ESR750]

Feeling settled on a design, I looked up the dimension of the bearings I ordered and made both bearings cups today.

However, when I took them to the welder who I had spoken to a few days ago said he had thought about the design as well. He came up with a far better solution of securing the bearings cups. Unfortunately it involves making brand new cups, can never put the material back. The design is basically the same cup, but with a 10mm extension on the end with a slot milled in to take the square.

Grabbed two fresh lumps of 90mm stock and drilled 40mm clearance hole in both. Will work on them tomorrow. Bearings cups will be machine on lathe first, with three steps bored in. The extra steps is 60mm the size of the square stock. This should make the milling a lot quicker boring out the centre first. Hopefully should be able to get the two blanks ready for milling tomorrow, not sure if the actual milling will get done.

Few pictures below.

 

[Goped ESR750]

Finished the bearings blanks today ready for milling. Won't be able to do any machining over the weekend. This design certainly will be far stronger and look much better too. The last 10mm step of the bearing cup I bored to 60mm. Only have to open it up on the mill with a tool the same radius as what is on the box section.

The bearings arrived today as well. They look huge, I only got them this big because with the races pressed in, it gives my full access to the square which is 70mm. Shouldn't get any problems with them, pretty over engineered. I prefer to be safe rather than sorry.

 

[Goped ESR750]

offered up the headstock with the stem to see how it looks. It is quite a bit higher then it was originally. At least the length of the bearings cup. I could not fit the stem in the lathe to skim the step off, So I made a paralleled step to press on, it's not on yet. I am thinking of grinding the welds off, machining it.. The get it welded again. Think I will have to make a jig to ensure it goes back the same.

I need to get the bearing cup as close as possible though. Will need to cut some of the tube down anyway.

Here is few pictures of where I am at.

 

[Goped ESR750]

Finally got the bearings cups finished for the CIDLI today. Which was handy as this is the day I had set out to see the guy who is going to weld this for me. I am seeing a custom harley fabricator, who makes all sorts of big bike frames from scratch. So I am getting him to sort the frame welded to the original section I have and then a bend and then weld to the CIDLI knuckle.

Sample block of polyurethane arrived today. I got a 70A shore rating 25x25mm block. I am going to test it a bit, but I am thinking this should be an ideal rating. It bends easy but under compression is good. I am going to see how it reacts with different loadings in a manual and hydraulic press. Manual for rebound shock loading and use the hydraulic press to dump 30 tonnes on it to see what it does.

Probably use rods as opposed to block when it comes to it. am undecided yet. Look forward to getting a rolling frame sorted though.

 

[Goped ESR750]

Got my callipers back from the powder coaters, and rebuilt them.

Got 15mm rods of poly to use for suspensions, these seem like they will work. Cant quite push them all the way in by hand which is what I needed. Will lubricate them and press them in.

Few pics of where I am at.

 

[Goped ESR750]

Pressed the polyurethane rods into the square. This was not an easy task, I used Vaseline to lubricate them. I ended up using cables ties covering most of the exposed poly whilst pressing it in. This stopped the rods bending out. This is just a test as the rods will have to come out before welding and powder coating. I am going to have to make a tool to get them back in the box section once it is welded to the frame.

I can see getting the rod in to them made frame is probably going to be a bit difficult.

The second picture is with my mate with all his weight on a spanner driving the inner square. Was able to spin it when used a huge 3m leverage. I think this should be about right. I might go up a grade or use a back stop to ensure it never spins out. Trail and error really have to idea how it is going to work out, but is looking good though.

Cut my front suspension in half. Needed to cut it down to fit in the lathe to skim the old bearing step off. Two blocks where welded on to position it when it goes back.

Few pictures of where I am at.

 

[Goped ESR750]

Got the front suspension parts welded back together today, they where welded all across the joint instead of the two slugs that where on there before. This should make it a little stronger. Also made a good start on the shaft for the suspension.

The shaft is about 350 long at the moment, the first section on the larger end is for the swing arm to be welded too. As I am not fabricating the swing arm I have left this oversized at 100mm long so the custom builder can tell me how he wants it.

Managed to get two of the sides milled, but ran out of time. Will finish the square tomorrow; this is the part which will drive the inner square on the suspension.

Few pics of where I'm at.

 

[John in CR]

Looking good Goped. Have you done a rear suspension like that before, or otherwise have experience with the square-in-a-square plus elastimer suspension? I was wondering how you came up with a starting point for sizing and the elastic part.

 

[Goped ESR750]

Looking good Goped. Have you done a rear suspension like that before, or otherwise have experience with the square-in-a-square plus elastimer suspension? I was wondering how you came up with a starting point for sizing and the elastic part.

Thanks. No, I have not made anything like this before. I needed a compact suspension system, without a shock absorber above the wheel. Goped produce a stand up with a similar far smaller suspension with no bearings. I found out the materials it was made from and sourced my own. I'm not even sure if it will work yet. The sizing just seemed reasonable in relation to the wheel width, and the tubing on the frame.

This is all trail an error. I have ordered the next grade harder rod to see the difference. I have real concerns of spinning the inner square. Under large load I have been able to spin it, but I really don't know what load I am going to get in normal use. Also having the ends capped off will stop the poly compressing out the end which will stiffen it up too. I really prefer to be safe rather than sorry so needs some fine tuning I think.

 

[SniperGaulois]

Ok everybody... watch and learn... 8-}.....

I have a Speedfight 2!!!! the wheel is pretty heavy but pretty satisfyling to navigate in the dust and fields with... I ended up taking some wrong turns on mine, going down a ravine and having to go up again, juddering through corn fields that were felt like a rodeo ride, and getting lost in some wet muddy woods that i thought were 1 km wide but in fact were about 10 kilometers... it has very good handling.

But WHAT is this thing? with the rubber? the back axle goes through the square area? a kind of schematic sketch on paper would have helped me figure out what is happening at the back of that scooter!

how many inches of suspension are happening at the back? depends if you off road, but for general purpose, maybe 2-3 inches makes a more controlled and comfy ride if there are bumps. What would have sprung to my mind is a pivot with a coil or leaf suspension, maybe even some air suspension like a tennis ball or a larger volume of polyurethane.

I was amazed that you stripped that bike totally, i thought you would put the battery in the saddle and take off all but the frame and the excellent outer shell on the speedfight. really i would have kept the back suspension!!! Piolini!!! it rocks! Oh my god.

amazing tools and engineering!

 

[Goped ESR750]

Ok everybody... watch and learn... 8-}.....

I have a Speedfight 2!!!! the wheel is pretty heavy but pretty satisfyling to navigate in the dust and fields with... I ended up taking some wrong turns on mine, going down a ravine and having to go up again, juddering through corn fields that were felt like a rodeo ride, and getting lost in some wet muddy woods that i thought were 1 km wide but in fact were about 10 kilometers... it has very good handling.

But WHAT is this thing? with the rubber? the back axle goes through the square area? a kind of schematic sketch on paper would have helped me figure out what is happening at the back of that scooter!

how many inches of suspension are happening at the back? depends if you off road, but for general purpose, maybe 2-3 inches makes a more controlled and comfy ride if there are bumps. What would have sprung to my mind is a pivot with a coil or leaf suspension, maybe even some air suspension like a tennis ball or a larger volume of polyurethane.

I was amazed that you stripped that bike totally, i thought you would put the battery in the saddle and take off all but the frame and the excellent outer shell on the speedfight. really i would have kept the back suspension!!! Piolini!!! it rocks! Oh my god.

amazing tools and engineering!

Thanks for checking zzoing. Not really sure of the suspension travel on the rear wheel at the moment, the longer the swing arm the greater the travel. Thee inner square pivots just under 45 degrees before it spins out, so the maximum travel ideal would be about 30 degrees. I am still fine tuning the fill material, it will work but I am not happy with it at the moment.

It is very similar to trailer suspension known as Indespension. I chose this sort of system as the point of compression is around the pivot point; surely the most compact system possible. A spring with a damper would of been better, but this thing is more of a toy and I want it too look right. With a spring above the rear wheel will take away from the look of the stand-up.

 

[Goped ESR750]

Finished the shaft, or everything but the 30mm thread on the end. Don't have a 30mm die, and my lathe tool is too small to machine a thread that size. Have to think of something. Don't really want to reduce the end of the shaft any more as this will weaken it. If this things going 60mph, I cant take the risks.

Had to file down the inner seam of the box section, this took forever. I hate filing. The shaft is a nice tight fit in the box section, so seam had to be completely filed flat. Made the bearing bush to go over the 30mm end of the shaft and pressed the bearing into it already to ensure the press fit was good.

Few pictures of where I am at.

 

[Hillhater]

I assume you are aware of this..
From here ..http://www.digglerstore.com/store_all_products.html

 

[Goped ESR750]

I assume you are aware of this..
From here ..http://www.digglerstore.com/store_all_products.html

Yes I certainly am, I nearly bought one to use as the project base. Went for the 50cc instead. The shock over the rear wheel is not something I wanted, which is why I am making this type of suspension.

 

[Goped ESR750]

Made up a sacrificial shaft to align the bearing cups. They are only tacked at the moment. Also made up a couple stepped washer to keep the polyurethane from compressing out of the square and into the bearings.

Suspension is starting to take shape now, although I have yet to press the bearing onto the swing arm side of the shaft which I left oversized for the custom builder, the reason for this is because I may need to use the bearing section of the shaft to hold the shaft in the chuck to reduce the swing arm section. This is of course once I have spoken to custom builder. Few pictures below.

 

[E-racer]

WOW this is coming along really nicely! I like the ridiculously over built cidli! Those bearing cups and associated parts look awesome! Did you guesstimate what the spring rate will be with the 4 full length rods?

 

[Goped ESR750]

WOW this is coming along really nicely! I like the ridiculously over built cidli! Those bearing cups and associated parts look awesome! Did you guesstimate what the spring rate will be with the 4 full length rods?

Thanks E-racer. Nice to know you think it looks good. I have no real information about the rods. It is just trail and error, I think the poly is a little soft so have ordered the next harder rod. I may end up getting triangles of poly made to fill the gap better, will have a back stop on this anyway to ensure I can't spin the axle out if I don't get it quite right first go.

Any advice is welcome.

 

[sk8norcal]

sick!

some big gas standup scooters here,
http://wackyboards.blogspot.com/2009/11/extreem-scooters-by-lamberd-brothers.html

electrics.
go big and badsey,

deafscooter
http://www.evalbum.com/1690

 

[Goped ESR750]

Ordered the next harder 80A shore rating rods. I think This is far better, I am confident the axle wont spin out.

I put a massive spanner on a test piece to see how it reacted. I loaded the polyurethane with all my weight and bounced to see how it reacted.

Few pictures below and little video.

 

[E-racer]

O wow I didn't realize you were the same guy that built that badass belt drive setup for the ESR. Nice! My friend did the exact same thing to his Torkinator btw. You should try an 80-100 through your belt drive @ 12s lipo I think you would LOVE it! I'm glad someone else understands the concept of wrapping the belt/chain around the motor pulley/sprocket. Remember all the people running slakinators complaining about chains skipping? HAHAHAHA! I think its fair to say "nator" mods are not the best for ESR's.

 

[sk8norcal]

wow! I just checked out that thread...
speechless...
lot of work put into that scooter...
but the pic on the first page shows ur ESR with chain drive??

http://www.gopednation.com/forum/showthread.php?t=315538