The S.H.A.D. (Seat Handle Adapter Device) for Begode RS/MSP/MSX

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Project complete and the design is now up for sale.

Check out the landing page and print your own SHAD here!
 

Full demo video:

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I'm still waffling on the acronym as it was going to be SHAM (M for Mod) at first, but the result is turning out better than expected so I thought I'd still poke a little fun and go for the chad-meme. Anyway, since I'm spending so much time on this, I thought I'd see if there's any interest in the community in posting the 3D-print design files for sale on say cults3d. Right now I'm thinking $25 for the models, assembly instructions, and parts list.

Now for the long-winded stuff.

Main Goals / Primary Features:

• Integrate center-mounted trolley handle
• Fit most standard 7mm rail bike seat saddles
  • Allow for full back-to-forward saddle positioning
• Allow for tool-less and quick saddle and trolley handle changes (requires ~$30 USD rare earth magnets)
• Robust design likely to survive multiple wrecks
  • Attaches with velcro (4 surfaces in contact)
• Ergonomic (eliminate sharp corners/transitions where possible)
• Retain spin-kill switch access
• Attempt to retain Begode Display visibility (we'll see)

Other Design Details:

• Trolley handles require commonly available 3/4"-NPS PVC pipe,
  • Cut trolley handle length as needed during assembly to fit your individual height (12-inch lengths shown)
• Trolley grip includes Option to assemble permanently with glue
  • OR temporarily with ball-lock/clevis pins to make backpack storage easier if needed
• Current adapter block design < 400 g @ .20mm layer height and 4 layers B + T + Sides
• Design may fit other comfort saddles, but I have a couple of these on hand so this type will fit.
• Total prints for assembly includes Adapter stl, Grip stl, and 4 other small parts + 1 small assembly stl to help hold magnet distance tolerance for gluing.
  • NOTE: can make alt parts for metric/European sizes if there's interest

Things left to do:

1. Initial Design Complete
2. Simplify an interface/test-fit model
   1. Print and check fit + rework design as necessary
   2. Round 2, more test prints for fit required
3. Order required off-the-shelf parts
   1. Magnets
   2. Fasteners + Hardware
4. Print and assemble prototype
   1. Version 1.0
   2. Version 2.0
5. Test
   1. Version 1.0
   2. Version 2.0
6. Upload to cults3d for sale

Project complete. Feel free to post or DM questions.

Edited December 15, 2022 by Vanturion
Final update

[UniBlab]

I like it!

 

How about The Seat Handle Improved Trolley 🤭 j/k

[0000]

25 minutes ago, UniBlab said:

I like it!

 

How about The Seat Handle Improved Trolley 🤭 j/k

I was think about how to get that one to work out earlier.. thank you! lol

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Couple updates

Completed the first couple of simplified fitment prototypes and I think I got things where I want them now. First larger prototype looked good in terms of overall footprint and the rear contact surface were acceptable, but the front was pretty far off. The downside working with Photogrammetry to get a semi-accurate working model and probably not using enough color tape over the black surfaces to get decent geometry in the front. That and I forgot to design access for the power button, derp.

Anyway, I fixed these issues in the second test print so I can move onto printing the first full-model prototype. Hoping I get it in one go, but it really depends on how things go fitting the magnets. Going to be a little tricky printing in ASA, but I'll be drying the hell outta the filament first and hoping that's enough. I put clearances around/through the critical magnet pockets to scrape and remove all of the support material in post so things should work out.

Oh yeah, ordered the magnets the other day too. Ended up at $35 after shipping. Next update after full prototype print.

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Made some progress.

First thing - Initial prototype printed successfully. It was a pretty long print, a little over 30 hours.

Forward and aft features lifted somewhat during printing, but not as bad as it looks in this photo. I think the lift was exaggerated as this pic was taken after the printer bed cooled down. Luckily because most of the surface in contact with the bed was removable supports and none of the critical geometry was affected. The only downside from this is some cosmetic abnormality also exaggerated by the camera flash in this photo.

I was worried about running out of material with a little over 400 grams left and messed around with infill to protect against running out, but the part came way under the print estimate.

The part feels extremely tough and will likely stand up to some significant abuse as there few edges and no corners sticking out to take damage in an impact. From an aesthetic point of view as well as part handling, I'm satisfied with how it turned out with only a couple small chamfers to a couple corners to add for final design.

Edited October 13, 2022 by Vanturion

[Tawpie]

On 9/25/2022 at 8:19 PM, UniBlab said:

I like it!

 

How about The Seat Handle Improved Trolley 🤭 j/k

even better if it comes in pieces

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Getting somewhere

I messed up one of the sizes for my magnet order, so I had to reorder the seat magnet catches so it's only partially assembled right now. FWD/AFT adjustment range:

Going to summarize the results so far from initial fit check for this prototype.

The Good

• Aesthetics and size of printed part
• Tolerances and fit of all parts. Everything came out really nice, all the magnets fit after the difficult to reach/remove supports were ejected (sans the 2 not yet received and tested), all the minor assembly parts not shown fit together well too.
• 3/4-in SCH 40 PVC was plenty rigid enough to serve as trolley handles. I managed to find some at Home Depot without text too, so that was a boon not needing to sand that off.
  • 12" height for each pipe ended up working out well for my height so I won't need to change that.
  • Handle length and distance between trolley pipes worked out great, no change needed there.
  • I thru-drilled the handle and pipe to fit ball-lock clevis pins just to see how this option would work/feel. I'll keep it this way for now to have the option to store it in a disassembled state in the pack. Can always ABS/PVC glue it together later.
• Trolley handle ergonomics feel good and fit the Medium-size hand well. The large chamfer didn't come out perfect off the printer so I used some files to clean/smooth it up.
  • Only needs a minor tweak to the design to increase edge margin of locking pin holes to end of pipes
• Lift switch access worked out well. While you can't lift and engage the spin cutoff switch with one hand anymore while the SHAD is attached, a 2-hand under-carry works.

The Bad

• General fit is still a problem. Forward and aft motion is relatively secure, and as-is would probably serve as a seat adapter only just fine. However, lateral stability is an issue and this was especially obvious when I tested using the trolley handle. The adapter block wants to rock in the inboard and outboard and is currently not stable enough to support use of the trolley handle. Anyway, I have a new idea for how I want to index against rocking and there is still some improvement I can make with the existing contact surfaces so more test prints are in my future.
   

The Ugly

• I've had to order more filament

[0000]

8 minutes ago, Tawpie said:

even better if it comes in pieces

You're in luck, there's one large block, one medium log, and 4 other little hanger-ons

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Small update-

Second magnet order came in yesterday and I was able to test fit and see how the removable seat performed. Result: pretty dang good with some caveats.

Which brings me to today, I popped the sucker on for some seated riding, a first for me. And it was surprisingly easy too! I don't know if that's because of the SHAD or not, but let me just take a second to brag that it totally was, SHAD-wow! Sold yet? Hahaha anyway.

The Good:

• The overall height with the thick, padded bike seat was great. I could easy stand up and sit down and it was quite comfortable. I'm actually more jazzed to have this as an option in future for cruising now.
• Shape and placement of the bike seat didn't interfere at all with regular standing maneuvers.
• Fit/tolerance of the seat magnet holder parts to the adapter block worked out great.

The Not-So-Good

• Designing this with zero experience in seated riding yielded predictable results. I had the seat adjusted basically all the way aft, and I still wanted to move it back a little more.
• In this position, the retention magnets being all the way forward (as well as the design of the accessory seat magnet holders) allowed the seat to rock out of position if I wasn't careful in positioning my weight.

All of these deficiencies will be addressed in the next design iteration. I'll be moving the seat retention magnets which will allow me to use the thicker .25-inch magnets I originally ordered as well as increase thickness of the seat retention parts improving the resistance to unintended rocking. I'll lose some seat adjustment range, but I don't think it'll be needed anyway with how your weight needs to be situated over the balance point while sitting on the wheel.

Now I can move onto the next step, miter-sawing this prototype into pieces to take better measurements of the profiles of the contact surfaces since Photogrammetry didn't work out so well with the first go around.

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If I had known how much time I was going to spend on this, I probably wouldn't have bothered...

Many iterations later. Near-exact fit ended up being critical for side-to-side stability especially with use of new trolley handle, and I didn't get smart in my measurement approach of the shell's complex contours and accurately accounting for velcro thickness until later in the process.

I could have switched to picking up the sides of the handle for lateral stability and using velcro on top of the handle to keep the adapter in place instead of the 4 contact surfaces, but then the whole seated vertical load would be going supported through the top of the handle and I don't think that would be wise. Anyway, what I'm calling the final print started today. Design evolution lead to many small refinements and has resulted in shaving off over 8 hours off the print time with no change in printer settings.

If this one doesn't turn out, I'm going to take an L, and put this project in the deep freeze. At the very least, I think I'll have a successful Seat Adapter Device which will just be SAD.

[Tawpie]

Look at it this way: it's better than printing benchies.

Love the project!

(it's a Seat Integration Thingamabob)

Edited October 23, 2022 by Tawpie

[0000]

14 hours ago, Tawpie said:

Look at it this way: it's better than printing benchies.

Love the project!

(it's a Seat Integration Thingamabob)

Haha, definitely agree with that one.

Thanks - the print is nearly finished now so I should have an update later today/tonight how it turned out.

[Robse]

10 minutes ago, Vanturion said:

Haha, definitely agree with that one.

Thanks - the print is nearly finished now so I should have an update later today/tonight how it turned out.

Please, i want to buy one !  

I have the standard seat (RS) - or whatever you want to call it. 
It doesn't fit very well and my ass wobbles round on it because 
the edges do NOT fit exactly with the bones in my rear end... 
I'm sure anyone who uses begode's standard seat for RS / MSP knows 
what I'm talking about.  Therefore, my seat is now modified with 
a couple of extra layers of foam which make it wider - but it is 
certainly not a good construction. 
I want a seat similar to my KS 16X seat. It's super good.

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6 minutes ago, Robse said:

I want a seat similar to my KS 16X seat. It's super good.

Right on, I figured with all the variation and preference in bike saddles making something to adapt to standard 7mm saddle rails would be the best choice for this design.

The biggest downside to this is that unlike with bike saddle posts there will be no adjustment in pitch or the "nose-up/down" direction. Since the plane the saddle will rest on is basically neutral/parallel to ground level, the pitch will depend upon the inherent position of the saddle relative to it's rails. In other words, with the SHAD the rider will need to be careful in how they select a saddle.

The one I'll be using shown in a previous screenshot above has a bit of a nose down orientation, but it's not bad as it provides a little bit of a forward bias which you need lean anyway to move forward. In any case, I'll try and do a video review on the particulars when I get a chance if this project doesn't end in a bust of course.

[Tawpie]

4 hours ago, Robse said:

I want a seat similar to my KS 16X seat. It's super good.

If 16X seats were easily obtainable, one might have a niche making S.H.A.Ds for it... it's a great seat. Now y'all got me wondering how difficult it would be for someone without a 3D printer to McGyver an adapter to a Sherman.

[0000]

1 hour ago, Tawpie said:

If 16X seats were easily obtainable, one might have a niche making S.H.A.Ds for it... it's a great seat.

Ah, when I responded to Robse, I didn't realize the design of the 16X seats he mentioned - should've looked it up earlier. I can see how those banana-type seat cushions (for lack of a better descriptor) would be a more ideal geometry for straddling the wheel seated. That said, having no experience with any kind of seated riding prior to starting this project was not exactly an advantage, but I think having the option for a clean/removable bike seat installation is def a better situation than no seat - more on this with next update.

Anyway, I poked around amazon and aliexpress for a little while, but I couldn't find anything with the right geometry I could adapt to with my current design without some drastic modification/cutting into whatever too big seat cushions I found so far and/or velcroing to the flat top surface of the SHAD. Maybe something out there exists, so feel free to post here if anyone reading sees something they think would work well.

[0000]

Big update time. I'll start with the SHAD CAD model:

Design improvements:

• Tightened up a few tolerances for  + very small magnet gap at .2mm/1 print layer for very strong hold
• Zero display obstruction
• 90% reduction in support material required for print
• Increased area for hook&loop contact surfaces (stability)
• Eliminated most of the unnecessary material for a significant weight reduction even with using more print layers/shells

Result:

More importantly, here's how things turned out with trolley handle.

Any issue with lateral stability will be immediately noticeable using the trolley handle given the distance and leverage at the handle over the relatively massive pendulum-like weight of the wheel... And we're good, finally.

Achieved enough accuracy in this design iteration that there's only a very minor amount of shift at/toward the low-surface-area "display" corner, but it's 100% use-able as is.

Still, I took out a minor amount of contact area to protect against my custom display, and it wasn't needed so I can put this back in the final design for a minor improvement in stability beyond it's already usable state.

Speaking of, I trolley'd it around and it's much, much more user-friendly over the stock trolley handle. Turns on a dime with minimal effort. Massive improvement over stock, and I haven't even glued in the pipe magnets yet - the friction fit was working well on its own. I'm satisfied with how it turned out. OK, now onto the seated results.

Starting with the good, the fit of seat adapter to the Adapter Block is deeper now and with the stronger .25-inch magnets, the chance of the seat popping up and out is very low. In use, there's no play whatsoever either so that's great.

Looking at the picture, you might notice that the top surface of the SHAD is angled nose-down in addition, or compounded with the inherent nose-down orientation of the bicycle saddle. This doesn't strike me as ideal.

So the top of the SHAD (green line) measures about ~3.0 degrees pitch down, couple this with saddle being inherently nose-down and you get a pretty weird saddle orientation (blue line). But, what saves the situation is this isn't a bicycle. In use, I'm basically perched on top of the of the plush rear section of the seat (red box), and the only thing I use the saddle nose for is a hand hold. I even ended up moving the seat back another 1/2-inch or so from what was pictured which was more comfortable.

While standing, the way I ride and with my body type, the fairly large width of the bike saddle wasn't interfering with my legs so that was good. However, I wouldn't go any wider than this saddle.

One thing I'm uncertain about is if changing the seat adapter mounting design to accommodate a wedge design would end up improving things or not. Since the nose isn't really important for pedaling, it's unclear to me if orienting the nose further up would gain anything or not, like increased lateral/yaw control. I think I could probably come up something to include different options seat adapter wedges for 5, 10, and 15 degrees or something like that. And doing it like that would be better than changing main SHAD geometry as any kind of saddle rail ramp would either increase printed support requirements and/or require important features to be printed out-of-plane on the printer and I'm not sure how well the printed tolerances would carry over.

In any case, what I printed today has achieved everything I set out to accomplish!

I'm just nit-picky and a little bit of a perfectionist, so I'm questioning whether I should go any further at this point. One more thing, if there's a relatively affordable 16X-type seat I could adapt easily, that could be an attractive option. I think I really need to try it first though to see how it compares to this bike saddle, first-hand. If it's a huge difference in say control or other factors, then I'll definitely have more motivation to make a version 3.0.

I'll see about putting this design up for sale soon, and along with that any future improvements I make with it will of course be free with initial purchase. A few things to do before I get to that point though, so it could be some time. Also, unfortunately I can't sell the completed prints though as my lifestyle of being on the road soon will prevent that kind of enterprise.

[Tawpie]

That looks really, really nice.

The forward tilt... on a bike it's a big deal and very personal and somewhat gendered. I think you mostly want to avoid any sensation of sliding off, the perfectly flat 16X seat and Luna seats on Shermans are examples of flat implementations.

In my limited seated riding, I'm still learning to use my feet rather than my butt for turning. Butt turns or leaning to the side are not the way to do it, you have to press with your feet. At least that's true for me. So I think you want the saddle to be wide enough to accommodate your sitz bones but not so wide as to get in the way during standing riding... its width shouldn't play a big role in control while seated.

[0000]

11 hours ago, Tawpie said:

That looks really, really nice.

The forward tilt... on a bike it's a big deal and very personal and somewhat gendered. I think you mostly want to avoid any sensation of sliding off, the perfectly flat 16X seat and Luna seats on Shermans are examples of flat implementations.

Thanks Tawpie. With my limited seated riding experience so far (we're talking minutes on one hand here), the saddle I used seems plush and wide enough that it doesn't seem like that will be an issue - but I need to do more riding to be 100% confident in saying that.

11 hours ago, Tawpie said:

In my limited seated riding, I'm still learning to use my feet rather than my butt for turning. Butt turns or leaning to the side are not the way to do it, you have to press with your feet. At least that's true for me. So I think you want the saddle to be wide enough to accommodate your sitz bones but not so wide as to get in the way during standing riding... its width shouldn't play a big role in control while seated.

Oh, didn't realize there was a different technique for that, interesting. Cool, well I'll keep that in mind for the next ride.

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Design for sale!

Took a while to learn how to make a proper animated GIF, but it eventually turned out pretty good I think.

So I decided to go the whole hog and make a couple of optional pitch-adjustment mounts to give the rider the option to nose up their seat by 5 degrees or 10 degrees to expand the saddle adjustment range, which of course are included in the design package.

The 10 Degree pieces are currently printing, but I'm not anticipating any issues. I should have one last update after I perform this final test, but unless I do a short video sometime which is likely eventually, that'll be it for updates on this thread.

As an aside, I really like how easy it is to sell designs on cults (well speaking theoretically for now), so I think I'll eventually make a landing page in the Commercial Advertisements section and post up the rest of my EUC related designs for sale.

[Robse]

6 hours ago, Vanturion said:

Design for sale!

Took a while to learn how to make a proper animated GIF, but it eventually turned out pretty good I think.

So I decided to go the whole hog and make a couple of optional pitch-adjustment mounts to give the rider the option to nose up their seat by 5 degrees or 10 degrees to expand the saddle adjustment range, which of course are included in the design package.

The 10 Degree pieces are currently printing, but I'm not anticipating any issues. I should have one last update after I perform this final test, but unless I do a short video sometime which is likely eventually, that'll be it for updates on this thread.

As an aside, I really like how easy it is to sell designs on cults (well speaking theoretically for now), so I think I'll eventually make a landing page in the Commercial Advertisements section and post up the rest of my EUC related designs for sale.

when are you going commercial?  this is soooo good !

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10 hours ago, Robse said:

when are you going commercial?  this is soooo good !

Oh, thanks for the great vote of confidence there Robse!
If you mean producing the SHAD commercially, unfortunately I don't think there's not enough interest in something like this to do anything like that. Even if I were to print these out for sale myself, it'd probably be like 2 days at best if not more for each unit to ready all of the pieces. That's not including the off-the-shelf hardware of such and premium I'd need to charge to make acquiring those pieces for shipping worthwhile too. It becomes extremely uneconomical very quickly.

At best, I think this kind of project suits the extremely niche market of the 3D-print capable DIY-EUCers who are still happy with their non-suspension RS/MSP/MSX wheels and that's it. Are we down to numbering this population on 2 hands now??? Haha. Most of the energy and money in our niche market seems to have shifted to the latest generation of suspension wheels. God willing, I'll probably be rocking the RS for a long time as I just don't see the designs of any of the newer generation suspension wheels being well-suited to survive long road trips with frequent aggressive trail riding exposure without developing issues which likely couldn't or would be extremely difficult to solve on the road.

[0000]

The final update on the SHAD 3D printer mod project. Full demo + test video.