InvGears.scad

I had trouble with my RC car design, needed to get the gearbox working much better.
So, I created InvGears.scad.
See
http://www.thingiverse.com/thing:1643825
All files NEED OpenSCAD version 2015,03-02 or later they will NOT work with previous versions.
InvGears.scad is meant to be used as a library for use in other scad files.
Everything is still very much work in progress.

Example.scad demonstrates it's real use.
This contains a parametric 2 stage, 3 axle gearbox.
Variables near top of file control the parameters of the gear box:
Pitch sets gear tooth size and therefore ultimately controls size of gearbox. On my printer 0.7 is about as low as I would go, 0.8 for higher print quality.
The rest of the variables are documented in the file.
Un-comment gAssy() to see just the gears, use OpenSCAD View|Animate menu to see the teeth movement for adjusting Pressure.
Typical gAssy() view:

Comment out gAssy() and un-comment Assy() to see full assembly.
Typical Assy() view:

Comment out Assy() and un-comment print1() to get printer plate of housings (parts shown in white above).

Comment out print1() and un-comment print2() to get printer plate of gears (parts shown in red above).

In both printer plates there are extra cubes.

I created my printer in 2013, it's a RepRap metric Prusa with home made hot end:

Your printer probably creates better quality prints, to be honest I have no idea how the quality compares. You will see that my printer has NO fans, I find that adding cubes to my prints allows the plastic to cool down between layers so that it doesn't go wrong, the cubes are my alternative to fans.

I did say that the files are work in progress, the Example supports Spur, Helical and Herringbone gear types only.

InvGears.scad:

The file can be used on it's own to see how it all works.

There are 3 variables near the top of file:

iDemo = 0;

Set this to 1 and the you will see output.

Variables similar to those found in Examples.scad are further down in file, these control what is shown in demo.

iShowC = 0;

Set this to 1 and you will see the 4 circles of interest for the gears.

Please refer to http://www.cartertools.com/involute.html by Nick Carter to fully explain.

The 4 circles show Outside, Pitch, Base and Root as explained by Nick Carter and shown in his first drawing.

It also shows the 2 radii that define each side of main tooth.

iShowT = 0;

Set this to 1 and you will see the involute point calculations, radii and tangents.

These show up best with Rim, Adj and Typ all set to 0.

This is explained best by Nick Carter in the rest of his drawings and explanations.

Once you get to this stage you can alter the other variables and see the difference they make clearly.

Don't forget to set iDemo, iShowC and iShowT back to 0 before using the lib in your files or Example.scad.

InvGears.scad also includes bevel and cycloid gears, but I have not yet created an example for those.

Mini Drawers

In my last post I wrote:
"Whilst awaiting, I now have lots of very small parts, M1.6 washers and nuts, M2 washers and nuts etc. I have no place to keep such tiny components, so I'm creating a modular clip together drawer set.
Clip together is not an easy concept to make work in 3D printing."
It's now obvious to me that I know little of what people want!
I published as http://www.thingiverse.com/thing:1621667
231 views, 60 downloads, 40 likes, 48 collects, 1 make!!!!
Published last night at 12:33, this is stats from less than 24 hours!
The world is nuts!

Radio Control 2

Ok, cut down variables, ordered FlySky FS-i4 4 channel transmitter, I had 1 but gave to my dad for controlling his speed boats, I have a few FlySky 6 and 4 channel receivers that will work with it.

I'm concerned that AAA batteries are not good enough to drive the buggy, so I've ordered some Lipo batteries and a multi-charger.

I've added level changer to the controller PCB, made the PCB then discovered I have no PCB drills left, tried a lesser quality drill and messed up the PCB, so I've ordered some more.

Whilst awaiting, I now have lots of very small parts, M1.6 washers and nuts, M2 washers and nuts etc. I have no place to keep such tiny components, so I'm creating a modular clip together drawer set.
Clip together is not an easy concept to make work in 3D printing.

Lipo batteries arrived, multi-charger has 1 type of connector, batteries have another!!!!
Ordered some leads of each type, will make up patch leads when they arrive, but for now I can't use the batteries (sigh).

Transmitter arrived :-)
Put into Trix controller, it now appears to work perfectly on desk. I can build up the complete model, test it, get to know it, then switch to my controller and compare. Still lots of fiddling, I now need to put back all the deck hardware, set it all up, float it to get water line, paint bottom red up to water line.

Put receiver into Buggy, not so good, it works perfectly off load (lifted off floor). It won't drive for long even on a flat smooth level floor. The cogs bind, probably too much play. I'll probably redesign to use worm gear drive. Again, once I get it working with standard transmitter / receiver then I can play, get to know it then switch over to my controller. Cut out all the variables.

Basically, all on-going, nothing completed yet. 

I forgot how much smaller my controller is than a standard receiver, that was pleasant.