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XLR8 wrote: ↑Fri Mar 05, 2021 7:00 pm FWIW, I've owned 3 or 4 Mids and all of them were missing part OPM-9. You can see it here on page 13 of the manual.


OPM-9.JPG



I've never actually seen one but I think it's rubber. It's meant to seal the underside of the belt cover where the belt exits the rear gearbox - directly above the motor. This part never comes up on ebay so I think it's rare.
I've made a rather poor substitute by forming a piece of lexan but it really doesn't work very well.
I'd reckon this part would be a perfect candidate for 3d printing if anyone has access to one they could replicate.

I found a clamp with a rubber liner that fits perfectly and is easy to find anywhere. It is the only one that was a consistent 15mm width.

After a lot of trial and error I have settled on the finish for these parts. Way more time than I expected.
The larger motor plate was the test bed for the anodization.
It was in the worst condition of all the pieces.

Almost all articles on ano of Duralumin and it's closest cousin 2024 stated, the finish is not quite mirror like.
It is however, quite glossy and fairly difficult to take pictures of unfortunately.
On very close examination a hint of grain can be seen in the Duralumin. Possibly a remnant from the extrusion process.
I'm guessing that is because the grain is horizontal in all the pieces. All the prep work , sanding and polishing, was done mostly across the grain to help minimize the effect.
From 12" away it looks very good and the grain is not obvious.
Upper deck posts and saver shafts are not Duralumin and appear to be "normal" aluminum. These pieces polished, anodized and look even better than the Duralumin pieces, no surprise.

I have been using the Caswell 720 rule calculator as a guide to ano time and amperage.
Also upped the current density to 6 ( recommended ) and the thickness to 6 mils.
At a current density of 4 the time necessary ( longer ) opens more of an opportunity for a failed connection.


Ano progress so far...





Chuck

That's really attractive and the finish looks great to me , well done !

Thanks Dadio

I tried to anodize the knuckles but, as expected, they are obviously cast aluminum and absolutely not anodize friendly.
They turned chalky grey and ruined the polished finished that took quite a bit of time.
So back to re-polishing and they are once again nice and shiny but not anodized

Still want to ano the aluminum gear protector plates and then the chassis.


Chuck

Those knuckles look best glass bead blasted and then clear coated.

First crack at test fitting parts and building a sub assembly. All went good.

On some of the plastic parts I needed to tap a few threads into the plastic because the new hardware is machine thread not self-tapping screws.

The aluminum pieces, when installed, IMHO look awesome. Way better looking than the original ratty aluminum, black fiberglass or even CF.
I thought that the stainless hardware was going to be a bit much but now it looks really good. Works with the anodized and on the black plastic.





Big hurdle coming up with the chassis. Scared to anodize for fear of screwing it up. It's so nicely polished now

Chuck

look,n good Chico!

Chuck, u might just have a BOTM OR YEAR winner on your hands! Great photo work too.

Those polished, anodized parts really pop! The stainless hardware too much? Nah...not at all, it looks fantastic, compared to the black steel fasteners that look like crap after a few assembles & disassembles. But, I may be biased...

I'm really loving that blue! I'm looking forward to seeing the chassis!

It's ELECTRIC !!!!



Chuck

How durable does that anodizing seem? A good while ago, I bought some Dynamite brand alloy parts that were "anodized", but you could practically scrape it off with a fingernail. Anodizing is supposed to be a real pain to remove, unless chemically removed (oven cleaner).

The only real "test of durability" I have done is in final color matching.

After the final sealing with Nickel Acetate, I used some Turtle wax rubbing compound to slightly lighten darker anodized parts.
The compound does remove some ano and dye as was evident on the soft white cotton rag used with the compound.
"Would a fingernail scratch the ano" I sure don't think so. It took a bit of firm rubbing to lighten to darker pieces.


The somewhat "harder" anodization processes would be 1mil depth and boiling water sealing could also lead to a harder finish.
I chose Nickel Acetate for a better "glossier" finish.

True Hard Anodization is an entirely different and sophisticated process and on Duralumin?????

When anodizing if the pores are too small ( .1- .3 ) dye is too large to enter pores. If pores are too large dye will "wash" out of pores.
.6 mil is a fairly happy medium. I tried to go to 1mil but could not get good dyeing.
Could have been several other factors as well that limited me to approximately .6mil


Though I tried my best to achieve .6mil ano depth, accurately calculating surface area is a challenge on such small parts.

All above info is only my limited experience and an amalgamation of exhaustively reading numerous forums and numerous failures

And for any other nubile DIY anodizers, I spent roughly 4 hours per part, start to finish. 13 parts so far!.
I guess I now know why no one would accept the job.


Chuck

As a side note to the process...

Different color dyes can require different ano processes to some extent.
Black is apparently more difficult for the DIYer's. Blues are more tolerant to dyeing, from what I have gathered.

Chuck

What about red?