The ebike parts designing thread with CAD/CAM

[ichiban]

What 3D printer do you have? Most aren't large enough to print a good size battery case, unless the pack is fairly small.

I was originally thinking of 3d printing them in sections and join them together if the printer is not capable of printing the whole thing in a single shot.

Actually, I'm totally new to 3d printing but familiar with Solidworks (works related). I like to design and some were turn-key projects from concepts to complete functional ones - everything in between - and rather the whole system than individual device or part. I haven't owned a 3d printer yet, but considering one. 8) Aiming towards Creality CR-10s (or the clone "Anet e12" around US$5xx.- local, with all the overhead) for its bigger printable size. Prusa i3 mk3 is a bit small and rather pricey in my area after all the mark-ups, tax, shipping, 2 free spools and etc.(almost US$1500.- crazy!!). That's why we are so left behind.

Any sweet model ?

You could print up the three corners as separate pieces, and then print the six long-thin edges as separate pieces. The five flat panels can be laser-cut?

That sounds good, spinningmagnets. Thanks for the tips - I will have to seriously give it a deep analysis.
Currently, I'm thinking of vacuum forming (to get it in one nice solid piece) the main battery compartment out of polycarbonate or ABS due to their durability & ease. Breaker, fan, charging/discharging, USB ports, key are to be directly mounted within this box to be fully functional. Later we can add the 3d-printed detachable facades (L & R) to make it handsome. Imagination to be refined. Again, this is from pure desire for design and DIY.

All this batt case builds is to be a real power pack for my MTB to climb a high mountain mission, with 50+km range and 3,000+m in elevation. Plus, the mission will inspire local people that real ebike can be their main method of transport besides the recreation it brings. I mentioned here in ES that real ebikes are hard to find where I live. Some of those 200-300w front hub can be occasionally spotted. So, I first DIY it with BBSHD kit with fun in mind. Now people start showing interests and asking about how this and that more oftenly.

Still, the cells are to be welded. 14S7P & 14S5P (or14s4p) Have not ordered anything yet. Quite some works.


Off topic question :

Is it a good idea to parallel ;

(A) Triangle 14s7p (98 pcs of LG MJ1 - @3.4Ah/10A max)

to :

(B) Tube 14s5p (or 14s4p) (70 or 56 pcs of LG HG2 - @2.9Ah/20A max)

for climbing high mountain. Or should they be the same type ?

In daily uses, only one pack will be needed.

Or just build a bigger 3D printer.

See MPCNC, which can be configured as a 3D printer with a large footprint.

https://www.v1engineering.com/specifications/

Ha Ha, So I will end up building everything on my own. May be the tiny motor with super energy density, gyro-controlled bike that never tips over, shaft-driven bike, etc.

I have to seriously take a look into that, Sir.

Thanks a bunch for all the comments here. I learned a lot in ES with the helps, encouragement and inspiration from you guys.

Truly appreciate it.


P.S. the very 1st crude draft I sent to a polycarbonate forming shop for quote today :


View attachment 1

 

[Alan B]

The MPCNC can be built fairly large in X and Y, but not so large in Z. However that's fine for a battery case. It uses cheap steel tubing, roller skate bearings, and 3D printer parts. It can also be fitted with a spindle motor for CNC, laser head, etc for multipurpose use.

I have a Prusa MK3, it is a really excellent printer at $750 for the kit. It will print 8x8x10 inches so not too large.

3D printing is pretty slow for a large object like a battery box. I have much smaller designs that take 10 hours to print, a full battery box could take many days to print. I would print the corners and use Coroplast or acrylic sheet for the flat surfaces.

 

[Alan B]

It may be important to mention that 3D printing requires the design to be adjusted for good printing. Knowing how to make a 3D model isn't enough - it is important to understand the 3D printing design requirements. There are limitations on the angles and curves to get a design that prints well. For example, the printing surface is flat, so a design surface that curves or steps upward is problematic. The printer cannot squirt plastic into space, or at least it won't accomplish what the designer intended. Support can be used but that has many disadvantages. Printing a hollow battery box half that is not flat on the printbed is problematic. In any case, before designing it is important to learn the process limitations and requirements. There are many knobs in the Slicer (the CAM program) that can be adjusted and need to be understood fairly well before making successful prints, especially important for 100 hour jobs. The materials also have personalities, such as ABS which shrinks and requires special techniques and printer features to print well, and is particularly difficult for larger prints and perhaps a poor (or at least difficult) choice for a battery box.

 

[ichiban]

The MPCNC can be built fairly large in X and Y, but not so large in Z. However that's fine for a battery case. It uses cheap steel tubing, roller skate bearings, and 3D printer parts. It can also be fitted with a spindle motor for CNC, laser head, etc for multipurpose use.

I have a Prusa MK3, it is a really excellent printer at $750 for the kit. It will print 8x8x10 inches so not too large.

3D printing is pretty slow for a large object like a battery box. I have much smaller designs that take 10 hours to print, a full battery box could take many days to print. I would print the corners and use Coroplast or acrylic sheet for the flat surfaces.

Yes, the MPCNC is one of a kind & very versatile piece of equipment any DIYers should have. I wish I found it years ago, so imagination would have less limitations when come to make it happen. I really like the ZENXY table idea, it is genuinely creative with big WOW factor by itself. May be I can make it one day (when time allows).

As opened by spinningmagnets before, printing out the corners will be a very good start thus improving strength to the whole case. While the flat surface can be done better. I also like the vacuum forming idea that will make the whole compartment solid in one piece - just pick the right material and it should last through entire life of the bike. Don't you think ? Just that I will have to make another vacuum forming machine - again.

I also like the Prusa i3 MK3 but the price (my local) is prohibitive and the table is rather small. Plus I need a special permit for importing 3d printer (controlled apparatus) since our government believe that people will use it to print weapons !! LOL.

It may be important to mention that 3D printing requires the design to be adjusted for good printing. Knowing how to make a 3D model isn't enough - it is important to understand the 3D printing design requirements. There are limitations on the angles and curves to get a design that prints well. For example, the printing surface is flat, so a design surface that curves or steps upward is problematic. The printer cannot squirt plastic into space, or at least it won't accomplish what the designer intended. Support can be used but that has many disadvantages. Printing a hollow battery box half that is not flat on the printbed is problematic. In any case, before designing it is important to learn the process limitations and requirements. There are many knobs in the Slicer (the CAM program) that can be adjusted and need to be understood fairly well before making successful prints, especially important for 100 hour jobs. The materials also have personalities, such as ABS which shrinks and requires special techniques and printer features to print well, and is particularly difficult for larger prints and perhaps a poor (or at least difficult) choice for a battery box.

Thanks for sharing 3d printing precaution tips for beginners. I also expect a steep learning curve when start 3d printing and try to avoid it by having the main compartment built using other easier method like vacuum forming (PC or ABS) or fiberglass. Both are pretty foolproof for their durability. Then we can add 3d printed fancy panels to the compartment, as nice as we like. Let's see what it will come out to be. There are a whole bunch of other things to do now.

I sketched other things to be included in the battery case - just like them to be there for ease (if space allows). Breaker take deep space and might have to be move to side facing other than rear. Ventilation fan might be needed if expect 3-4 hours of steep mountain climb and pull high amps (almost) continuously. But might need to move to side too since it might be blocked by seat tube.


To include in the batt case (view from rear) :


View attachment 3


Breaker (need only 1 pc) & 3" Fan :





View attachment 1


Let me know what you think. It's good to learn from the experts.

Thank you in advance for any comments.

 

[BeachRider2016]

Bringing this topic back from the dead...

Fast forward a few years and now there are big printers on the market. I have the ANycubic Chiron with a 400mmx400mm print bed.
It is huge and can definitely print a whole jumbo battery case. Is anyone else working on this topic ??

5sx14p 21700 cell holder printing

 

[Addy]

Bringing this topic back from the dead...

Fast forward a few years and now there are big printers on the market. I have the ANycubic Chiron with a 400mmx400mm print bed.
It is huge and can definitely print a whole jumbo battery case. Is anyone else working on this topic ??

If you want to print out a battery case and the associated cell holders, take a look at this thread

 

[BeachRider2016]

I saw the files on Thingniverse and have d/led the files. Wonder if anyone can draw/copy the layout and box of a manufactured battery case

 

[Tomblarom]

Hey guys, just wanted to link this here, since it's very related to this topic. I tried to fit 98, instead of 91 cells into the Reention DP-9 case. Wasn't able and went for 14S6P (85 cells). Sharing my research with you: https://www.thingiverse.com/thing:4627055

 

[spinningmagnets]

member larsb printed some fender mounts and a stub if a rear fender

https://endless-sphere.com/forums/viewtopic.php?f=10&t=94666&start=175#p1559590

 

[Hummina Shadeeba]

I just started a thread on a cad designed bike I’m making and looking for what stress and torsion numbers I can expect on a rear swing arm and how strong it needs to be. If I can get those numbers I can use them in simulated stress testing to figure how burly I need to design it. (As it is now it’s just a shell of a design and I wait for numbers to finish it)
https://endless-sphere.com/forums/viewtopic.php?f=6&t=114792

 

[spinningmagnets]

Any of the long flattish sections can easily print with a shallow depression to bond a steel plate into it to add strength.

Don't get undermined by a determination to make a part 100% printed just for bragging rights.

 

[Hummina Shadeeba]

Any of the long flattish sections can easily print with a shallow depression to bond a steel plate into it to add strength.

Don't get undermined by a determination to make a part 100% printed just for bragging rights.

Don’t know if ur responding to me but would be a machined aluminum swing arm and maybe add carbon. But first need to know how much torsion or whatever a typical swingarm experiences to model around that.

 

[spinningmagnets]

My bad, For some reason I thought you were talking about a 3D printed swingarm. I am a fan of composite designs.

 

[Hummina Shadeeba]

Was thinking of adding a foam core and carbon to the “chainstays” as they are now and could add carbon as needed which is a really nice aspect of composite construction, but rather just figure it in aluminum and done.


if i can figure/find what kind of stresses a typical downhill bike rear swing arm can handle I could design in fusion around that doing stress testing. i figure someone who has stress tested cad/cam designs would likely know this reference point.

 

[tomjasz]

Hey guys, just wanted to link this here, since it's very related to this topic. I tried to fit 98, instead of 91 cells into the Reention DP-9 case. Wasn't able and went for 14S6P (85 cells). Sharing my research with you: https://www.thingiverse.com/thing:4627055

Some of us saw to many glued cell packs fail. Reention cases made 52V batteries with cell separation possible. It seems counterintuitive to us to now take an issue solving case and revert to glued cells. I know fast builds use glued packs. I think it’s a weak design. But understand why some will disregard those concerns and take additional risks. Fully aware of their choice/risk.

 

[Tomblarom]

Some of us saw to many glued cell packs fail.

Generally speaking I totally agree. In my specific case you should look closely. I used minimal 3d-printed cell-spacers and combined each of the series groups. This saves a lot of space and maintains a minimum of safety. Unfortunately Reention can't produce cell-holders for each specific cell layout (10/13/14/16S..) and for all of their cases (DP-5/6/9..).

I experimented a lot to fit these additional cells. Got the original 3D-models and worked on it several days in total. Tested all sorts of combinations.

 

[tomjasz]

I used minimal 3d-printed cell-spacers and combined each of the series groups. This saves a lot of space and maintains a minimum of safety. Unfortunately Reention can't produce cell-holders for each specific cell layout (10/13/14/16S..) and for all of their cases (DP-5/6/9..).

I experimented a lot to fit these additional cells. Got the original 3D-models and worked on it several days in total. Tested all sorts of combinations.

Thank you. That makes sense. Nicely done!

 

[vanturion]

Recently ordered a "WuXing" left-hand thumb throttle for use as a regenerative braking lever thinking it would be of the same quality as my right-hand version I ordered in 2015. Unfortunately not, it had a longer/uncomfortable throw, the retaining ring threads wouldn't thread the set screw it came with, and most importantly, it had a very weak spring actuation leading to sticking at partial throttle in cold weather.

Long story short, I designed and printed some parts with ASA to orient my old right-hand throttle for this task. I didn't want to deal with a full redesign using the internal parts, so I just adapted to the original housing.





It's a pretty specific problem and I have no idea if the right-hand version being sold today is better than the left-hand product, but I can share the .stl files if anyone else wants these parts for printing. I should add, this orientation is not great for water resistance and the printed housing could benefit from the addition of a small drain hole.

 

[pullin-gs]

Not CAD...for design, I use Visio.
Not CAM...for manufacture, I still do it the old fashion way.