The ebike parts designing thread with CAD/CAM

[LewTwo]

The CAD machines that it took to run Solid Works and before that HP CAD were vastly more expensive than a SpaceMouse anyway.

There once was a congressman that made the statement: "A million here, a couple million there and pretty soon you are up to real money". There are NO insignificant cost when you are told to reduce your budget by 10-20%. Every corner has to cut and polished.

PC CAD workstation cost was actually fairly consistent. In the early years we spent about $10K per station: 5 for software (AutoCAD) and 5 for hardware. Hardware cost have come down dramatically but you can still easily spent $5K on a CAD hardware. The good news is that they are way more capable than they were 30 years ago.

[Alan B]

I was quite surprised when the 6mm screws arrived and they don't fit the Cycle Analyst.

Apparently the rear screw is 1/4-20!

I haven't checked but think the cross mounting screw is metric.

Perhaps that should be documented somewhere. Perhaps it is and I just didn't find it. There is a mention in the accessory mounting bracket that the hole is 1/4", but no screw is provided and the thread pitch is not mentioned.

[amberwolf]

I can't remember, but I think that it's the same as common camera mounts, and might have been chosen as that size for that reason. But it could just be a coincidence.

[Alan B]

Undoubtedly that was the reason, and 1/4-20 is the camera mount, so that's reasonable though surprising on a bicycle where even in the USA most quality bicycle threads (especially accessories) are metric.

[LewTwo]

Undoubtedly that was the reason, and 1/4-20 is the camera mount, so that's reasonable though surprising on a bicycle where even in the USA the threads are metric.

As is 3/8-16. Among the few english/british standards that have not been replaced by a metric equivalent because there are far too many existing items in common use. Others I know of are microphone stands (5/8-27), Bicycle Pedal Threads (9/16-20) and Bicycle Headsets (1-24). I believe you have a small manual lathe ... what is the thread for the headstock on that?

P.S.
I forgot the British Bottom Bracket which is 1-3/8 x 24 TPI

[LewTwo]

So getting back on topic ….

The OP, Spinning Magnets, originally posted the question regarding CAD/CAM software along with the example of designing a modular cell holder to be assembled into a battery frame. I finally got a 3D printer and decided to take a shot at that task. The printer I purchased was a Crreality Ender-2 which is supposed to have a build volume of 150x150x200 mm. Thus printing a full size battery pack frame is not an option.

Creality Ender-2(600).JPG (59.37 KiB) Viewed 3859 times

I first tried producing a single hex shaped cell module with small 1mm by 45 degree dovetails. I did in fact succeed in making a few of these. I found that the fine detail of the dovetails was mediocre at best and that aligning the many facets for assemble was a challenge beyond the capability of my ancient eyes and clumsy digits. I was also most unhappy about the “stringyness” of the first layer bridging for the legs on one side of the module. Thus I elected to to try larger sections that held more cell and to leave out separation/layout of the conductors. The latter is somewhat dependent on the particular type of conductor material, geometry and attachment method anyway.

Hex Modules(799).JPG (97.52 KiB) Viewed 3859 times

What I came up with was a design in which two or three sections could be assembled together to produce one side of the battery frame. On my Ender-2 I can produce these with 5 cells in parallel. Some printers in this same price and size range have somewhat smaller beds. Thus I also included sections for four cells in parallel. The appropriate sections can be chosen and assembled together to produce any size battery frame in the range of P4S4 to P5S15. I suppose an even longer (series) frame could also be assembled.

FourByFiveRender(799).jpg (71.24 KiB) Viewed 3859 times

I have placed the design(s) in Public Domain and uploaded the DXF and STL files to Thingiverse .com

https://www.thingiverse.com/thing:2821270

DSC00022(699).JPG (47.83 KiB) Viewed 3859 times

FourByFiveOnPrinter(799).JPG (45.02 KiB) Viewed 3842 times

[spinningmagnets]

Beautiful work, thanks Lew!

[Alan B]

Nice job LewTwo.

I took the liberty of fixing the typo in the print volume.

My 10x21 lathe doesn't have a threaded chuck. It has one of the quick-change units styled after the larger lathes with a slotted plate and nuts holding the chuck against a circular spindle nose. It's a strange mix of metric threads and english calibrations, but I'm thinking about CNC'ing it which will solve those issues, especially if I put metric ballscrews in. I just ordered a closed loop stepper motor to test and have a linuxCNC system I'm planning to use.

I think all my bike headsets are threadless.

What plastic are you printing the battery holders in?

Do you have any trouble hitting the proper dimensions for a good fit?

[LewTwo]

I took the liberty of fixing the typo in the print volume.

Thank thee

What plastic are you printing the battery holders in?

“Paramount 3D ABS (PANTONE Battleship Gray 431C) 1.75mm Filament”
https://www.amazon.com/dp/B01M4S20QG

Do you have any trouble hitting the proper dimensions for a good fit?

I printed a "gauge" first in order to select the proper hole size.
https://www.thingiverse.com/thing:2809401

batteryGauge16(600).jpg (42.61 KiB) Viewed 3846 times

[Alan B]

I made a few adjustments to the Dual Cycle Analyst Stacking Bar, printed the first article and tested it on the 2WD Bonanza. It is nice when the first article works and doesn't really need tweaking. Not to say that something might be improved, but it fits and works as intended, which is not too surprising given the simplicity. It takes two 1/4-20x1/2 capscrews and places one Cycle Analyst over the other at about 1mm separation. This saves a lot of space. I will probably make a mount to place them centrally on the handlebar stem which will save space on the handlebars, and be a good place for them. With this bar, only one display needs to be supported from the stem, the other will be supported by the bar. The Cycle Analyst mounts use a different hole in the display to support them, these 1/4-20 holes are normally not used.

I see that we are not allowed to attach STL files to postings, perhaps we should fix that. Let me know if anyone wants this file. It has evolved a bit since the earlier OpenSCAD file that I shared above. I made it thicker and incorporated clearance for the capscrew heads. The original file should work fine as well, as long as it is printed 4.5mm thick or more as a 1/2" long capscrew will bottom out if the bar is thinner.

[Alan B]

...

Do you have any trouble hitting the proper dimensions for a good fit?

I printed a "gauge" first in order to select the proper hole size.
https://www.thingiverse.com/thing:2809401
...

Good solution for your printer and plastic.

The problem with this solution is that the calibration may vary with different printers and plastics. So an STL file may not be accurate on another printer or with another plastic.

[Miles]

No, these:

https://www.3dconnexion.com/products/spacemouse.html

Looks like they use it in addition to a mouse.

I've been using one since they first came out, in the 1990's. Wouldn't be without it......

[amberwolf]

I see that we are not allowed to attach STL files to postings, perhaps we should fix that.

Until it does, you could rename it to .ZIP (or actually compress it into a ZIP file), then upload it with a note on the attachment (in the field for that on each attachment) to rename it to .STL after it's downloaded.

[LewTwo]

...

Do you have any trouble hitting the proper dimensions for a good fit?

I printed a "gauge" first in order to select the proper hole size.
https://www.thingiverse.com/thing:2809401
...

Good solution for your printer and plastic.

The problem with this solution is that the calibration may vary with different printers and plastics. So an STL file may not be accurate on another printer or with another plastic.

Very true. That is one reason I try to include the original model files as well.

[Alan B]

I'm working on a 3D printable design for mounts for the BikeE. This recumbent has a frame that has a rectangular cross section with "ears" that are used to retain the seat while allowing adjustment front/rear. This beam runs down the length of the bike, making a good support for mounting a rack behind the seat and a battery in front. This mount grabs the top of the rail and can be used to support batteries and racks. A couple of M5 cross bolts into central hex female standoffs pinch the mount's built in clamp to the frame. An M5 bolt vertically is used to attach the battery or rack to the mount. The design can be customized for other applications.

[LewTwo]

I have a part that is a bit larger than my Creality Ender-2 can print and buying another printer seems a bit extreme. So I started looking for 3D printing services ... again.I ran across 3D HUBS which lists various 3D printing services as well as CNC and injection molding. Much better prices than the previous service I had found.

https://www.3dhubs.com/

[Alan B]

Good find.

We all need a bigger 3D printer.

Here's a concept for a seatpost mount that will hold two EGO batteries. They are 14S (approx 58.5V full) at 2.0, 2.5, 4.0, 5.0, 6.0 or 7.5 AH per pack. The thought is to run them in parallel to provide more current and range while taking it easier on the batteries. The packs are available from local hardware stores (Home Depot and Lowes, probably others).

[whereswally606]

somebody asked me for this via pm, so I thought id upload it for all and share it in a semi relevant thread

it is an enclosure for the bst900 dcdc to get better airflow on the mosfet and to keep fingers and loose wires out a bit.

https://www.thingiverse.com/thing:2865841

sorry if this is in the wrong thread.

[Alan B]

Another good project for 3D printing might be a cable throttle to voltage converter. Here's an example of a couple of different ones. Apparently the seller isn't making them anymore.

The output voltage could be from a hall sensor or from a variable resistor, though the hall sensor should be easier to make water resistant. Either a rotary or linear motion could be used. Lots of possible solutions if you can make precise plastic parts as you can easily with a 3D printer. I'm not working on this idea, perhaps someone else would like to tackle it.

viewtopic.php?f=31&t=58801

[spinningmagnets]

Thanks for posting that link, Alan.

For those who are new here, there are two reasons to use a linear hall sensor assembly with an "off the shelf" motorcycle throttle (which pulls and pushed a cable).

For Gwhy! (in the link) the ebike is for trials-style riding, and the "feel" of the throttle is something that is a highly sensitive preference for each rider.

the second reason to do this is...for waterproofing. By making the throttle handle on the handlebars just a cable-operating interface, the electronics can be mounted up inside a waterproof battery/controller bag. You can run the mechanical cable down to the bottom of the ebike, and then curve it up through the bottom of the enclosure as a "drip loop". This way...the electronic portion of the Halls are completely sealed away from the rain.

For common Hall-based throttles, you might do well to disassemble them and seal the electrical contacts with "dollar store" clear nail polish as a water-proofing agent...

[Addy]

Update time! I've added some new features to the hex cell holder script.

Option to make slots for running bus bars/wires between rows of cells, instead of the usual style used with nickle strips:

3s5p_rect_holder_bus.png (14.01 KiB) Viewed 3081 times

Option to generate pack end caps to cover and insulate the pack:

3s5p_rect_cap.png (5.06 KiB) Viewed 3081 times

Here's an example of the caps, used for a 12s3p pack which I put together for a portable TV project:

The latest version of the script is attached, but you could also download it from GitHub or Thingiverse.

[ichiban]

Anyone try printing their own triangle battery case ? Or any other shape ?

My plan is for 14s7p within this enclosure (very 1st draft, might change a lot).

Any suggestions ?

14s7p 3d-print box

[Alan B]

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

[spinningmagnets]

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?

[Alan B]

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/