Drill motor conversion kits - guaging interest

[Eventorizon]

What is their strength like Gary? I've tried something similar (Replacing GR01 parts) with 3D printed ABS. 4 Walls, 100% fill, 0.3mm layers and they would delaminate when I applied any load to the axles. Could well just be the printer.

[Danjr1]

Along with the mounting holes for 550 motors, could you add 19mm mounting holes for small brushless motors? With some shortened shafts, this could be a very small and light drive train!

[typhoon_driver]

Alex, Nylon is far superior to ABS when it comes to loading however it's an absolute pain to print with. Requires much slower print speeds, higher temperatures and a bunch of other precautions. The inter layer bonding when printed properly is much much better hence why I'll be interested to see how these handle in the arena.

As far as secondary mounting holes, not a problem. Two or four holes at 19mm diameter?

[Danjr1]

It would be two, countersunk on the gearbox side.

How much do you reckon a pair will go for?

[Roadrunner]

I might be new to robots but not new to using the technology around 3D printing, printing in Nylon would be a much better alternative to using other materials, but i do think that structurally the 3D print will not hold up should the machine take one huge knock, de-lamination regardless of material used is still a critical factor (given some of the FW's sizes, shapes and weights along with the shear damage they can inflict) or awkward landing.

I could suggest 3D printing using one of the metal compounds available should your printer be capable of using these, as their tensile strength is greater than Nylon.

However that said... and not to take anything away from you in terms of ingenuity but...couldn't the mounts be made up using blocks of HDPE and just have then CNC'ed, or for cheaper options since its relatively a simple structure, a block made up of the right size and using a pillar drill, forstner bits and drill bits in various sizes which will in turn provide a much simpler quicker, cheaper and yet stronger mount?

[typhoon_driver]

I'll work out pricing once they have had some testing.

Of course it could delaminate. This is why I'm looking to have it tested out before I consider selling them.

Unfortunately my budget doesn't stretch to a metal 3D printer and if it did then the parts would cost more than most bots.

Similar blocks have been made in the past with HDPE or Nylon but I've got a 3D printer sat there so want to give it a go.

[ewan]

Get them CNC router-ed, would be cheaper and tougher! Just make a small jig for the off-axis mounting holes so it's quick and easy to place them with a desktop pillar drill.

[Piggeh]

Gary, could it be worth experimenting with some of the metal-fill filaments? I don't know if you've heard of them but they are printed on FDM printers (No expensive laser sintering) but are more expensive. I don't know if any of your machines would be able to use them as I think they need quite a high hotend temperature and a full metal hotend as they are quite abrasive, along side a heated bed.
I found some filaments on amazon quick, never used any metal-fil before however so I can't vouch for any of them.
Copper : https://www.amazon.co.uk/colorFabb-C...opper+filament

Aluminium : https://www.amazon.co.uk/FilaMETAL-A...um+filament+3d

Steel : https://www.amazon.co.uk/AlephObject...steel+filament

I would make them in two halves then just use some threaded rod with two nylock nuts on the end to clamp through a base plate or such, I've done this with a CNC mill with some random plastic we had laying around and it worked really well, but it would be interesting to see what you come up with.

[typhoon_driver]

Ewan, CNC routing and then manually drilling may be beneficial in some regards but the fact I have the printer sitting there with the material good to go is what is pushing me down this route. The fact that I can also very quickly and easy ramp up and down production is a big bonus too. Changes to the design are also incredibly quick and easy to put in place.

In terms of material properties, the nylon I'm using has the following spec when printed,

Tensile Strength = 8,100PSI
Modulus PSI = 72,932
Max Elongation at break = 31%

Up there with a good few virgin plastics.

Jack, I'm aware of the various metal fill materials. These however tend to be for asthetics more than function. The metal particles are generally suspended in a PLA type material giving no advantage over PLA which would be too brittle in this context. Oh and my hot end with happily go to 300 deg plus. My heated bed happily to 150 deg if need be. The joys of developing your own 3D printer over buying one off the shelf

I got a bit more done yesterday / this morning than I thought i would. So here is version 1.0 of the mounts in nylon *fanfare*

IMG_0719.JPG

Few things to note, the bolts need to be a touch longer. I used some that I had hanging around. Squeezing the gearbox casing in can be a bit tricky but there's enough flex in the material to allow it to do so. Had it running for a half hour on a power supply and there were no binding issues.

Onwards to some static loading tests to see when the mount fails and then dynamic tests. Working out how to make the testing applicable to the arena will be interesting.

[higgeh]

look good but can you do them in pink?

[Graw]

Being fairly new to this, I assume nylon is pretty similar to HDPE (500) as far as density goes? Is nylon commonly used for feathers for chassis material like the base of a robot for instance?

[typhoon_driver]

Graeme the nylon can be dyed in any colour using conventional acid clothing dyes suitable for nylon material so yes, pink is an option

Dan, nylon can be used for chassis material yes. You can find the density with a quick google search.

[higgeh]

Graeme the nylon can be dyed in any colour using conventional acid clothing dyes suitable for nylon material so yes, pink is an option

Now we are talking!

[Giles]

Tensile Strength = 8,100PSI
Modulus PSI = 72,932
Max Elongation at break = 31%

Taulman 910 alloy?

[typhoon_driver]

we have a winner

Yes it is.