3D Printing Too

[Impisi]

as all the others said, it is an impressive project

[DamianHarty]

Wow, this has been a long time between updates.

After a lot of initial promise, I got sucked into a rabbit hole trying to get the print quality on “the other side” (ie the bottom of the print) of the wheel to reach a standard I found agreeable. Not least to say “something like the top”. This proved to be more or less impossible, so I experimented with printing the centre section of the rim and then the two peripheral rings.




It proved surprisingly difficult to get really good dimensional control on these little rings – as you can see, I had many goes - and so I always had the sense they didn’t quite fit properly despite my best efforts.

I was also struggling with the furry bottom edge of the mudguard (fender for our American readers) which, being made of tiny fibres was prone to fraying during my attempts to clean it up.

I ended up with something “fairly acceptable” when I modelled the real shape of the mudguard (as distinct from my sketched placeholder) but I always had the sense I was skating on thin ice.



And finally, I was also struggling to get the brake calipers to print nicely. I ended up adding dummy rods to them (red in the CAD rendering) with a view to cutting them off once I had printed them. Those pesky little suckers were quite wriggly, though, and I failed to achieve a successful trim without damaging the print despite multiple attempts.





All this led me to accept the advice I was given and switch to resin printing. Thus I had to wait for Santa and his sleigh to get any further and hence the delay. However, I am now the proud owner of an Anycubic Photon Mono X and a rinse//cure station from the same manufacturer.

The difference in edge quality is colossal, and the smoothness of the prints is really good. I’ve yet to try any paint on them but it’s looking promising.





It’s not without its drawbacks – the process seems monumentally messy and is achingly slow. But it’s really feeling worthwhile.

[DamianHarty]

My favourite thing about the new printer is that I can print rubber. Who knew!

My 3D skills are improving apace and I am trying to move between Solid Works (which I have access to through work), FreeCAD (which is, erm, free) and Fusion 360 (also free for hobby use). Both the free packages seem pretty capable.

I bought some Liqcreate Flexible-X rubbery resin, which is about four times the price of the normal resin, and gave it a go.

Attempting to print the standard cubic test piece was a disaster, so I modelled up a rubber equivalent with much thicker bars. I got the settings (which are wildly different to the standard resin settings) from the website of the resin supplier, Liqcreate. I had to do some reading between the lines but I got there in the end.

As I mentioned before, I just copied the wheel/tyre interface directly and shamelessly from Tamiya. It's not rocket surgery, there is a basic cylinder with a 2mm wide, 2mm deep rib down the centreline of the wheel and a corresponding trench in the tyre.

As my 3D CAD gets better I couldn't resist showing off - I know, I need to be careful or women will be flocking to me - with both the tread pattern and the writing on the sidewall.



It's not immediately obvious which are the tyres from the Tamiya Honda Blackbird and which are my homebrew Avon Storm 3Ds for the VFR. I will take that as a win. The Avons are the tyres my bike is currently wearing. The sidewall writing isn't an exact replica, but it captures the spirit of the thing. The small print is just minus and equals signs with a few pipe characters and one greater than symbol to make the rotation arrow. It's "less than" on the other side, obvs. You can only really see it at all in certain lights and from certain angles. But I know it's there and it pleases me immensely. Which is surely the whole point, right?





The rubber prints seem to come out of the printer with a sort of weapons-grade stickiness and they need multiple goes in the rinser, scrubs with a toothbrush and sessions in the curer to stop them feeling tacky, but eventually they feel OK.

Of course at this point, a young man's thoughts turn to other rubber items. That's right - you got there ahead of me, I had a go at some handlebar grips!




There are two patterns of grips listed as official parts for my age VFR. As you can imagine they are re-used widely throughout the Honda product range and have been for decades. The "long slot" design on the right is the one my VFR is currently wearing. The "dashed slot" variant is much more common. I printed multiple pairs of each with a 1mm centre bore and they slide perfectly onto the Albion Metals 1mm rod, which will make up the core of the clip-ons when I get there.

[Dazzled]

Brilliant stuff Damien and great to see you back. On holiday at the moment but I'll be back in a few days and watching your project with avid interest.

[Chuck E]

I see that Airfix is offering a 3D printer in their 'Bundles' section. £220 less 10% for members.

https://uk.airfix.com/products/humbrol- ... -bundlehu4

[DamianHarty]

I see that Airfix is offering a 3D printer in their 'Bundles' section. £220 less 10% for members.

https://uk.airfix.com/products/humbrol- ... -bundlehu4

Seems quite expensive for a filament printer compared to the Ender 3 I got about two years ago? A curious choice for Airfix to offer, but maybe it's a "gateway drug" before they offer a resin-based one.

[Chuck E]

I see that Airfix is offering a 3D printer in their 'Bundles' section. £220 less 10% for members.

https://uk.airfix.com/products/humbrol- ... -bundlehu4

Seems quite expensive for a filament printer compared to the Ender 3 I got about two years ago? A curious choice for Airfix to offer, but maybe it's a "gateway drug" before they offer a resin-based one.

Maybe so we can print spare parts?

[paul_tracy]

My favourite thing about the new printer is that I can print rubber. Who knew!

I bought some Liqcreate Flexible-X rubbery resin, which is about four times the price of the normal resin, and gave it a go.

Attempting to print the standard cubic test piece was a disaster, so I modelled up a rubber equivalent with much thicker bars. I got the settings (which are wildly different to the standard resin settings) from the website of the resin supplier, Liqcreate. I had to do some reading between the lines but I got there in the end.

Hello Damian,

would you be so kind and share your Liqcreate Flexible-X settings for the Photon Mono, please?

Best regards,
Paul

[DamianHarty]

Hi Paul,

Of course, apologies for missing this request:

Layer Height : 0.05 mm (I tried finer, but the prints failed frequently)
Exposure : 3.0 s
Lift : 6.0 mm at 0.5 mm/sec
Bottom Layers : 6
Bottom Exposure : 40 seconds

I made a test piece that's very like the standard Photon Mono test piece, but with thicker tubes. Happy to send it to you as a SolidWorks part, STL or print-ready pwma if you'd like. Same goes for the tyres if you would like a test print, or the handlebar grips if you would like a smaller test print!

Damian

[paul_tracy]

Hi Damian,

thank you very much!
Are your printed parts remaining sticky after curing, and how are you curing?
Parts in water?

Best regards,
Paul

[DamianHarty]

Earlier I said "The rubber prints seem to come out of the printer with a sort of weapons-grade stickiness and they need multiple goes in the rinser, scrubs with a toothbrush and sessions in the curer to stop them feeling tacky, but eventually they feel OK."

So yes, they are very sticky. I rinse and cure and rinse and cure and scrub and rinse and... you get the idea. They sort themselves out in the end. I am rinsing them in IPA, I haven't experimented with any other kind of rinse.

[paul_tracy]

Thank you very much!