Electronics > Manufacturing & Assembly

Procuring or designing custom sheet metal enclosures.

(1/3) > >>

forrestc:
I'm frustrated and need to try some other approach.

I've been trying to work with various sheet metal manufacturers who specialize in enclosures for electronics and similar.  Many of these have in-house design teams, but it seems like getting from "I want to put this board in an enclosure, and here's a 3d model of the PCB, and I'm happy to move mounting holes if necessary" to an actual, usable, enclosure at a price I can afford is statistically unlikely to happen.  Having wasted way too much money and time over the years with suppliers that didn't end up working out, and having the current one flame out as well, I need to try a different approach.

I'm wanting to know how others deal with this. To be clear - these are usually just garden-variety rectangular metal boxes with a single PCB inside.   Connector holes along one side, some way to mount the PCB in the bottom (pem inserts, pushed up sheet metal, side clips, don't care).  Maybe some ventilation holes, maybe not.   All should be able to be done on a cnc turret punch and brake/bender.  The most exotic thing I often ask for is if the supplier has the fancy punch which makes a 4 sided screw 'mounting' slot in the bottom to enable wall mounting---but that should be able to be loaded on the turret punch.   If they'd rather laser cut it all and use pem inserts I'm fine with that as well.

My immediate thought is "screw this, I just need to learn how to draw a manufacturable enclosure and send it off to a whole truckload of companies for a quote".  I don't know if this is practical, or if there are resources I don't know about how to actually do this successfully.  I.E. examples on what to do or not do, costs, etc.   

I've also looked at hiring a consultant to do the design, but that has it's own set of problems, not the least of which is that finding the right consultant tends to be difficult and also that some of the quotes I've gotten are so far out of our budget that I had to politely turn them down.

So, if anyone has experience in making this type of thing happen, and suggestions on how to be more successful than I have been over the last 10+ years, I'd love to hear them.   One last note:  This is for products with volumes around 500-1000/year, but with 5-10 year production runs, so something like 2500 total over the product life, but only 250 or so bought at a time.   So this is beyond "bend a few in-house" or "prototype" volumes - but also not to "can afford to spend a lot and spread it across a lot of units".

thm_w:
Do you have fusion360, solidworks, or some other CAD tool that is good for sheet metal design?
What kind of design quotes are you getting that you think are unreasonable for the budget?

Laser or water jet is fairly common so odd shapes are not an issue.

We use aluminum + PEMs, then you can do whatever finishing you like if any, anodized, painted, powder coat, etc.

forrestc:

--- Quote from: thm_w on May 14, 2024, 12:49:21 am ---Do you have fusion360, solidworks, or some other CAD tool that is good for sheet metal design?

--- End quote ---
Yes, fusion360 and a few others such as TurboCAD.

I also have SolidWorks for Makers but that isn't commercially licensed and I'd need to sort that out first.



--- Quote from: thm_w on May 14, 2024, 12:49:21 am ---What kind of design quotes are you getting that you think are unreasonable for the budget?

--- End quote ---

10K upwards for the consultants.   

The manufacturers have just been frustrating.   Not the current project, but for a 19" rackmount enclosure, I had one that I paid around $5K for a design and initial prototype, which they made a mess of.  Bosses weren't placed correctly - boards were crooked, etc., even though I provided them drawings, sample circuit boards, and even an existing enclosure that I was shipping.  Then, they, for whatever reason refused to let me pay them an additional $5K to fix it.  Instead they demanded that I order the first 500 enclosures (35K of metal), which they promised would be perfect.  No thank you.  $5K down the drain with nothing to show for it but a screwed up enclosure.

I've also struggled with companies which would say "oh yeah, your budget shouldn't be a problem at your MOQ" only to find that the final quote (after again paying some NRE fees), either is like 10x the cost I indicated was my target (not much of an exxageration), or that they had a MOQ of 10K.  In fairness to the last one, they decided to change their focus to larger orders in the middle of the whole engineering process. 


--- Quote from: thm_w on May 14, 2024, 12:49:21 am ---Laser or water jet is fairly common so odd shapes are not an issue.
We use aluminum + PEMs, then you can do whatever finishing you like if any, anodized, painted, powder coat, etc.

--- End quote ---

Yeah, these enclosures seem like what you'd normally do.   Nothing high tech about these - take aluminum or sheet metal, cut into the flats, add pems, bend, finish.   No welds, no exotic inner pieces, no complex bends.   It's just frustrating that I can't seem to figure out what from the outside shouldn't be anything hard. 

DiodeDipShit:
Forrest, It comes down to a good print, a better cost estimator / programmer and a great setup person. Box Radius's require careful Setback calculations.
https://www.thefabricator.com/thefabricator/article/bending/sheet-metal-bending-calculation-basics
Design all Your dimensions from the inside. Draw or CAD the print clearly. Specify material and thickness. Be reasonable with inside tolerances.
For short orders....Give lots of tolerance for the outside; I.E. +/- .06
Accommodate for these tolerances by opening up mounting holes.
Let the Fab shop figure the rest.
Give this gentleman a try:
Remi Doiron
President/C.E.O.
P: (508) 624-7271

rdoiron@idm-corp.com

loki42:
Enclosures like that are pretty easy to design in fusion 360 with the sheet metal tools especially if you export the 3d file from your ecad program and design around it.  You can then send it off to any of the sheet metal people in China etc and get quotes that should be pretty cheap. Quality from larger Chinese firms is very good. 

You know that turret punches exist so your miles ahead of most designers.  To make the job easy to load on a punch,  keep your radius corners to a standard radius, and things like bend relief.  You can check out catalogs from the tooling manufacturers for ideas. Mate,  Amada and Wilson are big ones. With bending,  deeper flanges are easier than really short ones,  at least on my brake. If it can be bent without special sectional tooling that helps too. 

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod