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

[Clive S]

I've never anodized before but if it's important to agitate the solution of sulfuric acid, I would be reluctant to use air to do it. I wouldn't want to create any kind of vapor to begin with and then I wouldn't want it being carried out into immediate area where it could cause problems. Breathing and corrosion and such. Is there some reason you couldn't use a motor driven polyethylene agitator? Just a thought...

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I have never done any work with sulphuric acid either but the resident forum member has done so much in his life so he has to be the go to person for all advise on all matters. So it MUST be the correct way to agitate the acid. (I don't think) perhaps with an 80 cfm compressor.

A bit of reading here http://www.tsh-technic.com/sites/def...ons-update.pdf

[Desertboy]

Doesn't seem that complicated to anodize at home

https://www.youtube.com/watch?v=GccTVfMiIIo

http://astro.neutral.org/anodise5.shtml

I'm sure you know all this already but I find it interesting ;)

If you need to keep the solution agitated a small maxijet water pump would probably be fine they are designed for semi acidic environments I have a load of spare working pumps you can have one for free if you want and if it melts who cares. But leave it a small test jar first over night I think lol be annoying to destroy your acid with melted plastic.

[Boyan Silyavski]

I have never done any work with sulphuric acid either but the resident forum member has done so much in his life so he has to be the go to person for all advise on all matters. So it MUST be the correct way to agitate the acid. (I don't think) perhaps with an 80 cfm compressor.

These kind of remarks are absolutely unnecessary for the good tone here in the forum. I feel sorry when seeing such unfounded attitude.



I did the aeration using a simple silicone tube which i pinched many times with needle having previously sealed its end. Its important for the reason of evacuating the air bubbles that form when anodizing and moving the water to equalize temperature faster. The tube was connected to small silent air compressor with regulator , but any compressor from fridge would do, in that case a way should be found to vent out the unnecessary pressure build up .

[Jonathan]

Anyone who has any experience with anodising I'm always up for helpful info given I'm a noob.

Don't underestimate the amount of de-ionised water you need. You have to use copious quantities of it at every step to keep the parts clean, else you'll see white deposits appear on the parts at the end. The deposits sometimes polish off, but it's best avoided ...

[Zeeflyboy]

Yeah I'm guessing as Boyan suggested it may be worth getting a reverse osmosis setup... can use the water in coolant mix too (and the iron ;) ).

Desertboy - cheers for the offer. Sulphuric acid is a bit more of a bitch than most acids as it's an oxidising agent. Seems many plastics just can't deal with it so you have to be quite careful about what you put in it... Not so bothered about damaging a pump, more bothered about contaminating the acid.

most DIY kits seem to just use air agitation and an aquarium pump to supply the air. We'll see whether the budget can stretch to a decent pump next month!

[Zeeflyboy]

Back to the build!

So had a chance to make my rail alignment doohickeys:










My plan to cut them so that the critical height is on the same part of the ballscrew seems to have worked well:

13.499mm



13.500mm




Biggest variation i found was 13.497 to 13.503, so max variation of 0.006mm (0.00024 inches if you are that way inclined), so pretty happy with that.


I 3d printed a jig and made some drill bushings on the lathe, looks like a shocked robot:



After drilling, tapping and a quick de-burring I gave the 20mm bed plate a good clean and laid the machine down on it upside down. Wiped each piece and area with an alcohol wipe to try and minimise any dust or dirt before fastening the rail spacers into position against the bed plate as a reference.





Then finally gave the rails a good wipe with a vanguard anti-corrosion wipe (hopefully minimise any naughtiness between the steel rail and milled aluminium mounting surface) before mounting them against the rail guides.




Next up will be re-making the front plate after my motor mount height snafu, then I can crack on and get this lower frame finished off before moving on to the Z-axis next.

[routercnc]

Good work Zeeflyboy. Like your thinking - in the absence of a large surface plate (£££) you've done the next best thing.

[Desertboy]

Back to the build!

So had a chance to make my rail alignment doohickeys:










My plan to cut them so that the critical height is on the same part of the ballscrew seems to have worked well:

13.499mm



13.500mm




Biggest variation i found was 13.497 to 13.503, so max variation of 0.006mm (0.00024 inches if you are that way inclined), so pretty happy with that.


I 3d printed a jig and made some drill bushings on the lathe, looks like a shocked robot:



After drilling, tapping and a quick de-burring I gave the 20mm bed plate a good clean and laid the machine down on it upside down. Wiped each piece and area with an alcohol wipe to try and minimise any dust or dirt before fastening the rail spacers into position against the bed plate as a reference.





Then finally gave the rails a good wipe with a vanguard anti-corrosion wipe (hopefully minimise any naughtiness between the steel rail and milled aluminium mounting surface) before mounting them against the rail guides.




Next up will be re-making the front plate after my motor mount height snafu, then I can crack on and get this lower frame finished off before moving on to the Z-axis next.

0.006mm!

Excellent work I guess you don't need to write in your ebay descriptions please allow 1-3mm for measurement errors lol.

[Zeeflyboy]

Cheers chaps.

Desert - I was more impressed when I wheeled the first one off and it was 13.500mm which is exactly what the model was supposed to be. Pure luck, my machine isn't that accurate lol. The variation is pretty impressive but that comes from cutting on the same part of the screw I'm sure.

[Zeeflyboy]

Always painful when you are going back over the same steps, even more so when you mess up too....

Re-made the face plate today with the re-positioned bearing mounts to account for the different height motor mounts. I also tweaked the design to give more adjustment around the bearing mounts to hopefully make aligning them with the screws easier.

Interior done:




Using my new 10mm roughing end mill with 10mm DoC, 1.4mm tool engagement, 2000mm/min and 14000 rpm I blasted through the exterior roughing, was just in the middle of congratulating myself on how much better I'm getting the hang of fusion's CAM abilities until the very last bit where it had decided to machine out one of the bolt holes that was occupied by a steel bolt - result was a new but now broken $30 10mm roughing end mill. FML....





Anyway, aside from a broken endmill at least it had finished the exterior before committing suicide... So I ran the finish paths and all was well, but then I went a goofed again and ran the wrong tool path - so it tried to do a chamfer with a 6mm flat end mill. Hit stop before it got too far but still an unfortunate mark on the front right side. Just a cosmetic issue thankfully, but still annoying.






Good news is that at least its done and the error with the motor mount height is fixed.... One day I'll be able to make a simple part without messing it up, I'm sure. That's the dream!