Gear for Buildlog 2.0 laser cutter rotary axis

[Zebethyal]

Hi All,

I am new here and only recently purchased my license for Gearotic.

Here is a gear I printed based on the one Bart Dring designed for his rotary engraving adapter, Bart's original gear uses MXL tooth profile and I wanted to use GT2.

For those that don't know, MXL and GT2 are very similar in both profile and pitch, with MXL being imperial and GT2 being metric, GT2 also has a more rounded profile that supposedly has less backlash, it has a 2mm pitch.

I designed the main part in Sketchup having taken measurements from the STEP file Bart provided.

The 60 tooth gear section was however created via a parametric Openscad script from Thingiverse rather than with Gearotic (I did not have a license at the time), it was created 10mm wide with a large hole in the middle and exported as an STL that was then imported into Sketchup and added to the relevant section of the model.

I then printed it on my modified Prusa i3 and here is the result:

The bottom 2 grooves are for rubber O rings to grip and turn the round item being engraved. The pulley fits the GT2 belt perfectly with no slippage.

The spokes do not go all the way through, there i a solid section about 2mm wide in the middle of the pulley for additional strength, it then goes back to spokes again, the axle bore is 6mm.

I have also printed a 48 tooth GT2 pulley directly from the STL produced by the Openscad script, this also works fine.

However, I have tried and failed several times to print 20 tooth GT2 pulleys and eventually gave up and bought some, these would need about a 0.1mm nozzle on the extruder to print well, I was really struggling with my 0.4mm nozzle.

[BobL]

Nice work Zebethya and thanks for sharing your results for those of us just learning, we all appreciate it..


Cheers
Bob
;)
 

[Ken_Shea]

Ditto on BobL's post.

I love to see useful things 3D printed, guess I've seen enough of the 3D printed goblins and dragons for a while.

Ken

[Zebethyal]

Thanks for the comments

@Ken
You're not wrong - I believe a high percentage of 3D printers are used purely for creating parts for making other 3D printers (they really do seem to breed fast), and a large part of the remainder only produce ornaments, iPhone stands and bottle openers.

I have to admit that I am already building my second 3D printer - a modified 2020 Mini Kossel (does anyone ever build a totally stock printer?) My alterations are usually aimed at saving costs.

[Mooselake]

Don't forget Yodas and Tardii, or the (blow up in your face) printed gun hysteria.

Copying an existing part, or designing your own, is way beyond most 3D printer owners at this point, and too many have problems just getting one to work at all.  They're still waiting for that yet to be developed killer "app" (or is that "ap"?) aimed at the non-technical crowd.  I'm a mod on a couple vendor 3D printer forums, and way too many of them (printers mostly, not too many users)  end up in the back of somebody's closet.

Nice looking gear!  Please post some more pictures of that laser as you build it.

Kirk

[Ken_Shea]

"Yodas "
haha, yeah, was trying to think of his name and couldn't, definetly seen too many of them.

[ArtF]

I love my 3d printer. When you need one, you really do need one. Notice the laser lens holder on this
photo.. I do stuff like that with my UP! printer. I love the results..


Art

[Zebethyal]

This is my blog for the 3D Printer(s)

And this is the one for the Laser Cutter

I keep contemplating a DIY DLP resin based printer, like this one on Instructables but really only for the build kudos rather than choosing to make much stuff with it over my filament printer(s).

Currently the biggest downside for me is the resin, it has a limited shelf life and is not exactly cheap (even for MakerJuice), with a minimum quantity in the bath required for the print to progress.



I concede though that this style of printing has the potential for much more detailed and smoother prints.

I would also be worried about parts falling off the upside down build platform as they grew/became heavier, I have enough issues with items coming off my build platform that has gravity working in its favour :)

Since I am all about making things cheaply, $40.00-$90.00 a litre for resin, is not really a winning argument for me, compared to $20.00 a Kg for PLA filament - I currently pay about £12.00 per Kg (1Kg of 1.75mm PLA is about 0.95 of a litre by volume).

[ArtF]

I was considering building a resin one, I made the resin and tested it, and with a uv laser it did harden fine. ( You can get the oxalic acid from a surfboard company and make your own resin pretty cheaply.. just add fibreglass or polyvinyl resin and it becomes uv triggered..

  but too smelly for me I think...

Art



 

[Zebethyal]

I may yet do some more research on the resin in that case, I know some resins can be a bit smelly, I covered one of my flat roofs in fibreglass recently - that stuff is quite potent.

Not sure if you guys have heard about this one - a UV laser based resin printer where you can buy all the key components $100.00, uses a novel printing method - sound! and gets around the deep bath of resin requirement by floating a layer of resin on a Z axis of salt water! it is the Peachy printer that funded 13 times over on Kickstarter in October 2013.

Some very interesting and very different ideas in use with this SLA printer and a firm commitment to OpenSource into the bargain.

[ArtF]

Well thats just genius ..

  I had often wondered if the sound card should be used as an analogue source, they seem to have
done it well. The resin looks a bit spotty.. and I suspect they have issue with the size of the laser spot, ( focusing over
a distance can be a bugger as the spot size usually is too big..

  True genius though to tie it all together that way, salt water to hold the layer till its activated and such..

Ill keep my eye on this one, its a remarkable idea...

Art

[Mooselake]

Unfortunately Peachy hasn't been able to deliver a working product, and is two years late.  Since they posted a recent comment on KS they're still around (unlike some KS projects), but so far nothing works well enough to ship.

With a little poking around, in addition to the KS funds they raised another $75K on indigogo, and claim to have taken $166K in preorders.  Not quite a million dollars US, but after two years of development it does raise some doubt about whether or not there's enough money left over to build and ship all those promised printers.  It's astounding how much money these 3D printer campaigns raise, especially considering the number of them that never send the ordered device to those who paid for it.

Kirk

[Zebethyal]

Here is a 48 tooth GT2 gear I just printed, for the Z axis reduction gearing on my laser cutter.

You can see a slight bend in the top rim, this is where I squeezed it  to remove it from the heated bed before it had fully hardened.

The slight mess around the captive nut for the grub screw is from where I slipped with the soldering iron pushing the nut into place :)

The gear was generated by the Openscad script I mentioned previously from Thingiverse and exported as an STL ready to be sliced and printed - all of the required settings are already in the script - gear profile, gear height, hub diameter, hub height, bore size, number of grub screws, top and bottom retainers, etc, you just edit the settings at the beginning then render and export.

For what it does, it does it very well, however it has nowhere near the functionality of Gearotic, and you are generating a single gear in isolation, not a gear train, nor any of the many complex gear types Gearotic is capable of.

[ArtF]

Hi :

HEre's a gearotic one printed on an UP! printer..

Art

[Zebethyal]

Looks very nice :) is that also GT2-2 profile?

Please don't get me wrong, I am not in any way trying to knock Gearotic, I am still learning to use it and aim to use it to design some clocks and kinetic sculptures, but I have not as yet seen any options for belt retainers, hubs or retaining screws, maybe I am simply not looking hard enough.

Whilst I can add all of these in some other program like Sketchup/Rhino, etc - as I did for the first gear I posted, where I could just as easily have generated the tooth profile in Gearotic (had I had a license at the time) and then added all the other parts after the fact, which in this case I had to do anyway.

For this gear I simply wanted to cut out a few extra steps and tools in the workflow, the whole gear took about 60 seconds from initial requirement to generating the final STL file ready for printing.

That being said, the script has a very limited number of tooth profiles and can only generate one gear at a time - it is intended for generating gears for use in belt drive systems and has limited use beyond that - Gearotic is way more powerful in nearly every aspect, not least in its list of supported gear and movement types.

I am currently designing an automatic tool changer for my Mini Mill and am making use of an 8 position Geneva mechanism that will be created by Gearotic, the current one I have in the Sketchup model was drawn from first principles using a spreadsheet to do all of the calculations.

I actually created it in Gearotic, it took seconds, but then I couldn't save it as my demo had expired, this is obviously not an issue any more.