El Beast - Initial design phase, comments and critique welcomed!

[Zeeflyboy]

Thanks Rob

Definitely want to make sure everything works well before doing anything on the plans/files front. Might turn out as a bag of excrement!

I've been busy re-working the X-Axis design to accommodate the larger Z-axis unit and to give me 420mm on travel in much the same footprint. If I had left it as is, I would have lost an unacceptable amount of travel due to the wider Z. To do this I moved the motor to the back plate and added a belt drive setup, which actually was another motivation for the re-design as it will make it much easier to accommodate an upgrade to servos further down the line if I decide I want to go that route. The old design is very much limited to nema 23 sized motors and it seems most servos come in at nema 24 as a minimum.

I will need to extend the Main frame in width the accommodate this new design, but that should be relatively straight forward and just a case of getting some wider extrusions and doing some adjustments to the front plates.

Still needs a little fleshing out but this is the current direction. Similar setup to the Z-axis really as that seems to have worked out nicely. For reference this is now using the extended HGH25HA carriages (I have the space now with the wider Z so why not) and longer HGR20 rails, both of which I already have in hand. Still using a 20mm tooling plate to mount the rails, which then attaches to a 200x40mm extrusion, in turn sandwiched by a 12mm rear plate.





I still have an issue here though in that these pieces are too big for my current machine, so either I try to be clever and do them each in two separate operations moving them along the bed and dowel pins to relocate, or I just outsource the two big plates which is all I need get up and running, then cut the last plates when the machine is moving. Decisions decisions.

In other news I've started accumulating equipment and doing more research on LCD anodising, which is most appealing to me given the apparent success of it in the DIY setting plus the relatively low concentration of sulphuric acid required. I want to do a proper job though so I'm going a bit beyond the typical DIY lead cathodes in a bucket with a car battery type deal, but that means more expense and complication so I'm trying to do my diligent research.

I ordered this PSU which is capable of constant current (hoping to use it for other stuff too so thought might as well get a decentish one) here

And I really wanted to achieve thorough agitation but without the splatter that enthusiastic aeration brings, so I also ordered two of these corrosion resistant magnetic drive pumps. here

I intend to use both, with the 4L/min flow each I should see around 8L per minute which will cycle the bath (currently looking at about 60L) in a little under 8 minutes. They are going to pull double duty too as I will be building a couple of heat exchangers for them to pump the solution through in order to try to have some control over the temperature of the bath.

Everyone seems to say about how having a serious amount of DI water is important for really thorough rinsing, so I also ordered a 6 stage Reverse osmosis system and will be adding a DI resin filter at the end to replace the re-mineralisation stage.

Other than that from Caswell I ordered some Grey NLN and Red Bordeaux dye, plus some aluminium degreaser, aluminium oxide and smut remover, and some nickel acetate sealer.

Still got some things left to buy when some spare cash rolls round before I can get cracking with the anodising, but excited to give it a go. Needless to say there will be a few test parts first before committing any important machined parts to the process.

[Zeeflyboy]

Hi guys,

Sorry there hasn't been any progress recently - a general mix between work ramping up for the summer, enjoying the nice weather, with a dash of laziness and a sprinkle of lack of disposable income.

Anyway, thought I'd share what little I have managed to do - the pump and agitation setup for my anodising tub. As mentioned previously I wanted something a little more reliable than bubbles and something that would reduce fumes/slpashing/condensation.

So I scrapped the two pumps I originally ordered, as after disassembling them I found that they have metal springs for the diaphragm despite being labelled as suitable for corrosives. Shame. Ended up ordering a big proper mains powered chemical pump instead which is designed specifically for this sort of stuff.

First up since the pump isn't self priming and I want to be able to put a sealed lid on the container when not in use I needed to make some bulkheads for the "tank" (the tank is a polypropylene storage container). I managed to find some fibre re-inforced polypropylene filament for the 3D printer which is perfect for making water tight sulphuric acid proof fittings.... albeit a slight PITA to print with due to warping. This is the end result, and it accepts a large Viton O-ring which then seals the fitting against the tank wall. I then 3D printed the "nut" out of ABS since it's less of a pain in the arse than the polypropylene filament and isn't exposed to the bath.





With pump (attached by pure EPDM tubing)




Leak tested for a few days and nothing to see. Happy times...


I had also read a paper on using eductors in anodising tubs which sounded interesting - for those that don't know they basically work on the principle of flow multiplication... a high speed jet is shot out the nozzle and induces a flow through the cone to improve mixing. I couldn't really find any decently designed ones that were small enough for my purposes so I designed some myself. Again 3D printed these from the Polypropylene with a G1/4 mounting thread. I also needed something to hold them at the right angles for a good spread and designed a block for them to screw into.








And then connected them up with 12mm PVC tubing which is a tight push fit.




To test whether this work achieved anything at all I figured it would be interesting to put some food dye into the tub and see how effectively the liquid is being circulated and mixed. Pretty happy with the result! I like the second view in the video, looks cool and you can see the eductors doing their thing quite nicely.




Got a bit more work to do on getting a nice setup for the cathodes and bus bar, but shouldn't be too long now until I can try some anodising.

[Chaz]

Nice, Ive just got my old 3D printer going for some prototypes but its a bit long in the tooth and not worth upgrading. What printer are you using? Build volume?

[Nickhofen]

Great work!

[jarjar]

Awesome work and project Zeeflyboy!

Do you mind sharing some details about your Z axis? For example, what are its overall dimensions and what's the length of its rails and travel?

Still needs a little fleshing out but this is the current direction. Similar setup to the Z-axis really as that seems to have worked out nicely. For reference this is now using the extended HGH25HA carriages (I have the space now with the wider Z so why not) and longer HGR20 rails, both of which I already have in hand.

25 rails or HGH20HA carriages?

[Zeeflyboy]

Sorry, mis-typed there. The gantry is using HGH20HA carriages and HGR20 rails.

Travel is 178mm and the other dimensions I will grab for you later when I get a chance.

Got some time to play today and try my first ever bit of anodising!

First up I got to try out my new toy on the lathe to thread some titanium rod.






Then I thought for a first test I'd try one of the knobs. Cleaned, degreased, De-oxide and desmut bath, then into the anodising tub preheated to 20 degrees c and using 6amps per square ft for 2 hours.

The part after degreasing:




The agitation system I'm happy with... as you can see from the pic the surface is rippling but no bubbles and splashing which is what I was trying to avoid with air agitation, but no bubbles building up on the part and good mixing.






fresh out the anodising tub:




Dyed using caswell bordeaux red and sealed using boiling water with nickel acetate sealant:






Finished part (well, I might laser etch the top for fun). Very happy especially considering this was the first run.

[Zeeflyboy]

Just wanted to prove to myself it wasn't beginner's luck so quickly did up the second knob too... this is the other end of the rod that I cut to m4 thread. My plan is to have various threads cut on the ends of 6mm titanium rod and some 90 degree angled pieces to allow me to jig up various parts together to do batches of parts since it's quite a long process using the LCD method (2hrs just for the anodise bath, let alone the prep work!).


Anyway, second part came out well too:

[Zeeflyboy]

So moment of truth - moved on to a larger part and the eco-cast tooling plate. Wasn't sure how well it would anodise given that I don't really know what the alloy is (I believe some sort of 5000 series?) so easiest way to find out... Try!

I thought I would offer up the tramming plate as a sacrificial lamb to the anodising gods and keep my fingers crossed (don't have time waste on test pieces!).

Happy to say it came out way better than I could have hoped. The pics don't really do the colour justice - it's a nice metallic looking deep red and it's got a light brushed effect from the scotch pads I used in the prep... perhaps when I can take some daylight pics it might look better.

Here it is getting some little fun details lasered on with the wife's laser






Fitted (I'm one bolt short dammit!):

[Chaz]

Superb workmanship.

[Nickhofen]

Jaw fall!!!
Where did you purchase the anodizing kit from?