Nope, I am using solid cast acrylic and milling the holes into it. I also have access to UMHW and HDPE - all three of which are anti-static.
** Correction, the UMHW is Dissipative, not anti-static upon further investigation
Nope, I am using solid cast acrylic and milling the holes into it. I also have access to UMHW and HDPE - all three of which are anti-static.
** Correction, the UMHW is Dissipative, not anti-static upon further investigation
All thre of these materials have a resistivity on the order of 10^15 ohms/sq
Maybe I don’t understand…
How does this fit in Boedeker Plastics, Inc. > Industries > Industry Landing ?
I’m not an EE, so may need further discussion/clarification, but according to my supplier’s manufacturing notes, the cast acrylic is rated as an insulator at 400-430 Dielectric Strength (volts/0.001), the UMHW is the Static-Dissipative variety. HDPE is rated as non-conductive. The latter materials are rated at 450-1,800 Dielectric Strength (volts/0.001). They do not have resistance figures on any of the materials available, but according to your note, 10^15 is well within the safe range above anti-static here: Boedeker Plastics, Inc. > Industries > Industry Landing
And FWIW, Polulu uses this exact acrylic for their circular chassis for the Tamiya twin motor gearbox:
I understand anti-static materials to be those that do not allow the accumulation of a static charge.
To me this means an electrical resistance low enough to drain off a charge, but, high enough to not be harmful to devices. My anti-static mats have specs on the order of 10^5 to 10^6 ohms/sq.
Glass is definately not anti-static
Copper is definately anti-static.
Boedecker cuts off anti-static at 10^12 ohms/sq
I need to study this more…
If I want dissipative mountings with milling characteristics similar to acrylic, are you willing to discuss using this material? I am interested in rectangular pieces about 5 inchex x 10 inches with 3.2mm holes spaced 5 mm.
Tom Dean
Yep, would be glad to entertain any material that I can mill reliably.
I did get an email back from one of my suppliers about the resistance properties. On their “non-Mil Spec” plastics, they do not measure resistance as it is cost prohibitive. They do however have a Mil Spec anti-static acrylic available. It is quite a bit more expensive for the raw material.
For instance, in 12" x 12" sheets, the material costs for 1/8" (3mm) sheet is around $12 for non-spec and $45 for spec. That doesn’t include the milling costs. For a board like you would want, I would have to charge around $35 per finished board, depending on quantity.
What do they state for resistivity on the mil-Spec boards?
I have asked them for more information as it is not posted on their site - not sure they will have it back to me before close of business today though.
Thanks
They do not have published resistive stats available, but say they are within mil spec parameters for conductivity.
The rep also pointed me to electrically conductive UHMW Polyethylene which they stock as well.
It is about half the cost of the acrylic at $24 per 12"x12" x .25" inch / 6.35mm thick (thinnest they offer it) The acrylic quoted below was for 1/8" / 3.2mm thick. An equivalent thickness of acrylic is $61/sheet. Acrylic is also available in 3/16"/4.75mm thickness and is $52/sheet.
If you have a plastic source that you would prefer me to talk to, just shoot me a link. steve at dev on board dot com
So I had the idea of filling in the text and the lines to indicate where each board goes with acrylic paint.
Is this something you would want as an option, or would you want to do it on your own (or not at all?)
On the translucent/transparent materials, if you light it from behind, it looks pretty cool with just the “carvings” - on opaque material, that’s obviously not going to get you much. I used a fine line Sharpie on this board to fill it in - was thinking the paint would fill up the cavity left by the bit better. The board below is using a 60 degree V-Bit. I received some 25degree and 15degree bits and used them to make a new board tonight.
Will upload pics of the test board I did tonight a bit later.
Might want to check with Pete. He did painted infill lettering for the Sammich SID Synth kit he put together:
Is there anything that Pete didn’t do Maybe we should call him super Pete from now on
I wish I have time to do all that fun stuff.
He’d probably be too humble to accept it, but I’d say Pete is close to qualifying for the polymath moniker:
Electronics, programming, synths, carpentry, model railroading, CNC, just to name a few of the areas I know that Pete’s had his hand in.
I’m with you, Gus, I wonder where he finds the time, particularly since, like our family, they homeschool. Perhaps he doesn’t sleep.
[quote=“devhammer”]Might want to check with Pete. He did painted infill lettering for the Sammich SID Synth kit he put together:
[/quote]
Wow! That looks great. I’ll definitely be borrowing that technique.
Is there a standard form-factor for certain boards? That is, I have a Cerberus as well as a Hydra. could I just buy an xxl board with the same pitch and use all the modules and both boards? This is exactly what I’ve been too lazy to make myself. My modules and boards are just tossed on my workbench and they hate me for it.
Every single gadgeteer product (mainboards and modules) have 3.2mm holes located on 5mm grid.
Fantastic! Thank you Gus. This kind of response is amazing.
Being so close to GHI is awesome too. It’s great to see another D-based firm making it.
You should come by sometimes and show is all the cool things you are working on.