[Quotes In!] - Aluminum GH60 Case - Anodizing Samples In!

[regack]

Need USB hole.

I have no idea where it is on the number pad

Well, it's not really made yet, but I think the thought was to have it mimic the poker in positioning of USB (and some of the PCB mount points)

[Acetrak]

Progress lookin' mighty fine my friend

[The_Beast]

Need USB hole.

I have no idea where it is on the number pad

Well, it's not really made yet, but I think the thought was to have it mimic the poker in positioning of USB (and some of the PCB mount points)

That's what I thought, but I never make assumptions

Progress lookin' mighty fine my friend

^___^

[The_Beast]

Drawings for the case are done. Being sent to bro's to check then to the machine shops for quoting.


I'll do the drawings for the number pad this weekend, I've had my fill of AutoCAD today

[CPTBadAss]

The_Beast, this case is looking...beast 

[salmo]

I like what you got going on here.  Simple, and has what I want as-is.  Hope it's not too pricey, since I've been burning through my toys budget lately.

[Hubbert]

Excellent work, including the ledges / crotches between modifiers.  Of course, being a keyboard nut, I'm looking to do something similar...but different

1) Are you thinking of getting any prototypes from Shapeways before going to metal?  Is it easy to use the same CAD files for Shapeways and CNC?

2) Could you give some details on the volume and weight of the main section, the separate numpad, and your weighting system?  I know that other metals would be more expensive to CNC, but I'd like to calculate how much of an impact they'd have on the weight.

[The_Beast]

Excellent work, including the ledges / crotches between modifiers.  Of course, being a keyboard nut, I'm looking to do something similar...but different

1) Are you thinking of getting any prototypes from Shapeways before going to metal?  Is it easy to use the same CAD files for Shapeways and CNC?

2) Could you give some details on the volume and weight of the main section, the separate numpad, and your weighting system?  I know that other metals would be more expensive to CNC, but I'd like to calculate how much of an impact they'd have on the weight.

I was going to get a prototype right from the machine shop. I'll look into shape ways more, but I've heard they are pretty expensive.

For the weight, I set materials in Solidworks. Solidworks did fancy volume measurements and found weight based on the density of the materials I picked. If I recall correctly the GH60 case was 3.16 pounds and the numberpad was around 1 pound. Everything is aluminum except the weight plate and the feet which are stainless steel (close to, or the same density as brass). 

[Hubbert]

3.16 lb *0.45359 kg/lb * 1000 g/kg / 2.7 g/cm3 = 530.87 cm3
The "strong & flexible plastic" is $1.40/cm3, so $743  .  Sandstone is $0.75, so half that.

I am a little confused / disappointed because I thought I read a post about getting an ErgoDox case printed for $35.

Maybe Shapeways could make a scale model.

But to my materials question, it seems that the densities of brass, bronze, and steel are within about 10% of each other, and about 3x aluminum, so a full keyboard+numpad case would go from ~4 lb to ~12 lb. 

[The_Beast]

3.16 lb *0.45359 kg/lb * 1000 g/kg / 2.7 g/cm3 = 530.87 cm3
The "strong & flexible plastic" is $1.40/cm3, so $743  .  Sandstone is $0.75, so half that.

I am a little confused / disappointed because I thought I read a post about getting an ErgoDox case printed for $35.

Maybe Shapeways could make a scale model.

But to my materials question, it seems that the densities of brass, bronze, and steel are within about 10% of each other, and about 3x aluminum, so a full keyboard+numpad case would go from ~4 lb to ~12 lb. 

See what I mean about shapeways prices. I don't think a prototype will cost half that to make out of aluminum.

The problem I see with a scale model is it will be pretty much useless to check over measurements with a real GH60 PCB and I'm sure will have trouble finding fasteners and tapping the holes that are required for the case.

Like I said the majority of the case will be aluminum, only the weight plate and the feet will be stainless:

The weight plate case be seen here:



I would love to make a 100% stainless case (I'm sure others would be interested as well) but I'm sure the machining time of aluminum and steel are different since steel is so much harder/harder to machine when compared to aluminum.

[CPTBadAss]

3.16 lb *0.45359 kg/lb * 1000 g/kg / 2.7 g/cm3 = 530.87 cm3
The "strong & flexible plastic" is $1.40/cm3, so $743  .  Sandstone is $0.75, so half that.

I am a little confused / disappointed because I thought I read a post about getting an ErgoDox case printed for $35.

Maybe Shapeways could make a scale model.

But to my materials question, it seems that the densities of brass, bronze, and steel are within about 10% of each other, and about 3x aluminum, so a full keyboard+numpad case would go from ~4 lb to ~12 lb.

You can look up material properties to find densities.

[Hubbert]

You can look up material properties to find densities.

I did: 2.7 g/cm3 for aluminum, somewhere in the 8's for other metals, which is how I calculated 12 pounds.  Part of my vagueness is that a materials scientist told me that copper-based alloys like brass and bronze were less dense than steels, when what I see on the Internet seems to be the opposite and is unsourced.  I almost went to the library for a CRC, but didn't.  But in any case, I was surprised that the densities of the other metals were all within about 10% of  each other.

[Hubbert]

I would love to make a 100% stainless case (I'm sure others would be interested as well) but I'm sure the machining time of aluminum and steel are different since steel is so much harder/harder to machine when compared to aluminum.

How much does the weighting plate weigh?

I have asked osrix some questions about casting in another thread.  Perhaps you could make a mold from your CNC aluminum case which could make copies in in other metals.

For me, casting may let me avoid creating a CAD model, since I'd have to start from scratch (even though what I want to do is probably 90% similar to existing cases).  Ironically, CAD was one of my early reasons for getting interested in computers, and now I'm talking about using wax and Bronze Age fabricating techniques to avoid it.

[The_Beast]

I would love to make a 100% stainless case (I'm sure others would be interested as well) but I'm sure the machining time of aluminum and steel are different since steel is so much harder/harder to machine when compared to aluminum.

How much does the weighting plate weigh?

I have asked osrix some questions about casting.  Perhaps you could make a mold from your CNC aluminum case which could make copies in in other metals.

I don't have solidworks on my personal computer, but I thought it was just over 1 pound. Again, IIRC it was 1.06 lbs


Molds are a whole 'nother beast if you're talking about injection casting. If you're just doing sand casting, you're not going to get a very good resolution and might have to end up milling anyways.

[jdcarpe]

What about doing a plaster casting for a ceramics mold?

[The_Beast]

What about doing a plaster casting for a ceramics mold?

I know very little about molding right now. However, I'm in a metals class right now and we'll be casting some stuff later in the semester. I know I'll be asking about molding caps......

[Hubbert]

I would love to make a 100% stainless case (I'm sure others would be interested as well) but I'm sure the machining time of aluminum and steel are different since steel is so much harder/harder to machine when compared to aluminum.

How much does the weighting plate weigh?

I have asked osrix some questions about casting.  Perhaps you could make a mold from your CNC aluminum case which could make copies in in other metals.

I don't have solidworks on my personal computer, but I thought it was just over 1 pound. Again, IIRC it was 1.06 lbs


Molds are a whole 'nother beast if you're talking about injection casting. If you're just doing sand casting, you're not going to get a very good resolution and might have to end up milling anyways.

Thanks, a pound is close enough.  I'm still curious about casting, though...I don't require a perfect finish.  I'm thinking of making another thread about CAD; maybe that's easier, and certainly more portable, than setting up my own foundry.

[The_Beast]

I would love to make a 100% stainless case (I'm sure others would be interested as well) but I'm sure the machining time of aluminum and steel are different since steel is so much harder/harder to machine when compared to aluminum.

How much does the weighting plate weigh?

I have asked osrix some questions about casting.  Perhaps you could make a mold from your CNC aluminum case which could make copies in in other metals.

I don't have solidworks on my personal computer, but I thought it was just over 1 pound. Again, IIRC it was 1.06 lbs


Molds are a whole 'nother beast if you're talking about injection casting. If you're just doing sand casting, you're not going to get a very good resolution and might have to end up milling anyways.

Thanks, a pound is close enough.  I'm still curious about casting, though...I don't require a perfect finish.  I'm thinking of making another thread about CAD; maybe that's easier, and certainly more portable, than setting up my own foundry.

Well if you're casting, you're going to need a foundry. They aren't very hard to make from what I've seen. That is if you're doing aluminum. Steel is a whole nother beast

[Hubbert]

I could use someone else's foundry.  But even a mold is something that I would be reluctant to ever throw away.

But back to CNC prototyping: would it be somewhat inexpensive to make a prototype in softwood via CNC?

[Acetrak]

That might depend on the shop. But I don't think prototyping with another material is ideal, especially since The_Beast has these files already and is ready to get a real prototype.

[CPTBadAss]

I'm not so sure its the material as much as the shop time and setup that would drive the cost of the prototype. Especially since you're wanting a one off.

[laden3]

Prototype a steel one and mass produce aluminum ones= win

[The_Beast]

I'll ask about a stainless steel one, but please don't get your hopes up about one.

[kboardvintage]

I'll ask about a stainless steel one, but please don't get your hopes up about one.

That will HEAVY

[Hubbert]

Only about 9 pounds without the numpad or 12 with: my personal goal is the weight of a Selectric II.  One unverified source said "20 pounds," but I've emailed a guy who owns some to see if he knows.  If I go for a "100%" keyboard, though, it's getting pretty close 

[laden3]

Just wondering, how thick is the case? If it is too thick, it might put a lot of strain on our palm when we are typing unless there is a palm rest.

[The_Beast]

~0.9375 tall

[Jocelyn]

Thanks, that's what I'm going for

I'll be send it out for quote sometime next week and should hear back within a few days

Any updates yet?

[The_Beast]

Thanks, that's what I'm going for

I'll be send it out for quote sometime next week and should hear back within a few days

Any updates yet?

Drawings have been revised and someones checking them again before they get sent out for quotes. Should be tomorrow or Monday when I send them out and IDK how long it will take for the shops to get back to me

[Jocelyn]

Thank You

[The_Beast]

Thank You

Np

[CPTBadAss]

Beast and I did a first pass of the quote drawings earlier this week. Hopefully I won't get swamped at work and I can recheck/send them back to him when he's ready. Don't worry, The_Beast is still cranking on this project

[The_Beast]

Beast and I did a first pass of the quote drawings earlier this week. Hopefully I won't get swamped at work and I can recheck/send them back to him when he's ready. Don't worry, The_Beast is still cranking on this project

Don't rush

Rather have a good check over than a mistake in manufacture

[jdcarpe]

Ben, are you interested at all in doing a TKL-sized alu case?

[The_Beast]

Ben, are you interested at all in doing a TKL-sized alu case?

Ben, are you interested at all in doing a TKL-sized alu case?

Not really

[Hubbert]

I'll ask about a stainless steel one, but please don't get your hopes up about one.

Just by way of general encouragement (not that you need it), after all my noise about other materials, I encountered an aluminum enclosure today (not for a keyboard): it was surprising how solid it felt!  I think our perceptions of aluminum are warped (bah-dum-dum) by experiencing it in very thin, fragile applications.

[The_Beast]

I talked to a lab professor today about my design. He said it looks pretty easy to make except for the stainless steel weight plate. He said it may work harden when milling making it very hard and expensive to do. He even called a steel place. A 1/8" x 2 1/2" bar stock in stainless is $3.94 per foot, plain carbon was $0.84 per foot and would machine a lot better.


I'll ask about both, but I might end up doing painted steel for the weight plate. The weight I'd lose is minimal for the amount of machinability that I'd gain

[CPTBadAss]

I thought we had talked about using brass?

[SmallFry]

Brass is more dense, no?

[The_Beast]

I thought we had talked about using brass?

Brass is more dense, no?

Brass is super expensive. 1/8" x 2 1/2" stock was $23 per foot, stainless was $3.94 and mild steel was $0.84 per foot with those same dimensions for bar stock by the foot. (only looked for brass at one company, but we're sure it would still be really expensive)

Out of the three, steel milled the easiest followed by brass and then the stainless. However brass and stainless were pretty close in terms of toughness to machine.

Brass may be slightly more dense, but it's only going to be a couple of grams in the grand scheme of things

[CPTBadAss]

Steel it is!

[The_Beast]

Steel it is!

I'm still going to ask about stainless steel and see how much it would be. But from what my friend was telling me, I'm not getting my hopes up too high

[CPTBadAss]

I think you were right with your first pass. A piece of thick stainless is probably too expensive. I think you're right with steel. Plus you won't even get to see it that often.

[SmallFry]

Ah, I didn't realize brass was so expensive. My bad.

[The_Beast]

I think you were right with your first pass. A piece of thick stainless is probably too expensive. I think you're right with steel. Plus you won't even get to see it that often.

Yea, that's what my friend said.

Ah, I didn't realize brass was so expensive. My bad.

I didn't either, still thanks for the input

[Hubbert]

I wanted stainless for density, conductivity, and corrosion resistance.  Regular steel takes care of the first two*: would a plating of stainless over regular steel be practical?

*EDIT: Unless the surface is painted.

[CPTBadAss]

I wanted stainless for density, conductivity, and corrosion resistance.  Regular steel takes care of the first two*: would a plating of stainless over regular steel be practical?

*EDIT: Unless the surface is painted.

Stainless and steel together might lead to galvanic corrosion.

[salmo]

Are you worried about spills?  Because I would think it would just develop a "patina" over time, being in the middle of the board.  And it shouldn't be externally visible, right?

Please correct me if I'm wrong here, I'm learning a lot reading this thread already.

[The_Beast]

The steel wouldn't be the one that would be most hurt, it would be the aluminum since it's the anode.

[CPTBadAss]

Are you worried about spills?  Because I would think it would just develop a "patina" over time, being in the middle of the board.  And it shouldn't be externally visible, right?

Please correct me if I'm wrong here, I'm learning a lot reading this thread already.

I'm not sure what the weather is like in Memphis but I know Cincinnati gets really humid in the summer. I don't know exactly what the environment needs to be for the corrosion to happen but I'd really rather just avoid the situation entirely. The_Beast and I had the same discussion concerning the feet on his case.