OSHPark plated slots

[westfw]

Has anyone tried to use plated slots at OSHPark?  Their documents say "it will probably work", but I'd like to be more certain than that.
The actual part is a USB-B connector (full-sized), so I'm interested in a pretty short, 40mil slot (the minimum width, according to the documents.)   (Does anyone have a library part for a USB-B connector, with slots, that has worked at OSHPark.   or ... anywhere?)

[Rerouter]

I cannot say for ohs park, but itead has made me some pretty skinny plated slots in the past, was for securing an encoder

[ataradov]

Dave tried in the recent video on Nixie clock. It failed miserably.

Although it failed on the stage of generating the preview pictures, so if your previews look ok, then you are probably fine.

[LabSpokane]

Slots work if you follow the guidelines on OSHPark's site.  Draw the slot inside a pad with the lines on layer 20. This is different than other board shops where you draw the slot on layer 46 (mill layer). 

This slot is 0.040 x .120".

[LabSpokane]

I forgot to add, that I've used OSHPARK's design guidelines and it worked fine. I'd post photois if the PCB but I think I used them all. Will try with the next batch.

[westfw]

Hmm.  Thanks!  The hole in your pad is smaller than the slot.  Is that permitted? (I guess so!)  Required?

[mahi]

Dave tried in the recent video on Nixie clock. It failed miserably.

If Dave would have taken a few minutes to read the Oshpark design guidelines his board would have looked just fine. Nevertheless I agree with him that Oshpark would not have been a good choice for a board of that size.

Has anyone tried to use plated slots at OSHPark?  Their documents say "it will probably work", but I'd like to be more certain than that.

I can't help with the USB connector but Oshpark can manufacture plated slots if you stick to their design guidelines. Officially they do not support such features and you will get a warning upon uploading your designs that there are unsupported drilled slots, but so far the PCBs I received always had correct slots.

[LabSpokane]

Hmm.  Thanks!  The hole in your pad is smaller than the slot.  Is that permitted? (I guess so!)  Required?

Required for a plated slot, I believe. I used Eagle for my board, FWIW.

I have to say that a feature which is so common should never be this ambiguous to reliably obtain. Autodesk and OSHPark both need to get this solved.

[latigid on]

I went through this the other week with Elecrow. I tried to give them similar gerbers (pad/SMT drawn on, hole, milling path). They took a few days before asking me to remove the holes, and that the slots were too narrow. Some time later (after an email issue apparently) they said the slot was still too narrow at 0.13mm, because they weren't using the path but the area of the milling lines. I widened the lines to 0.8mm and apparently that was good enough!

Slots are a pain in the ass though; there's no easy way I know of to get them drawn in EAGLE without DRC going nuts. You have to manually attach "thermals" to planes too.

[LabSpokane]

I went through this the other week with Elecrow. I tried to give them similar gerbers (pad/SMT drawn on, hole, milling path). They took a few days before asking me to remove the holes, and that the slots were too narrow. Some time later (after an email issue apparently) they said the slot was still too narrow at 0.13mm, because they weren't using the path but the area of the milling lines. I widened the lines to 0.8mm and apparently that was good enough!

Slots are a pain in the ass though; there's no easy way I know of to get them drawn in EAGLE without DRC going nuts. You have to manually attach "thermals" to planes too.

I believe fab shops want your design in terms of finished part dimensions. They generate the tool paths from those. They'd go crazy if they had to differentiate between tool paths and dimensions in one file.

[ajawamnet]

I use Altium, so not sure how much this will help...

What happens with AD, is that the plated slots are in a second drill file. Note on the PDF attached (page 2) how the table calls it out.

If you look at the two drill files - one for holes, one for slots - note that the slotted one looks more like Gcode for a CNC vs and Excellon file...

In the slots file, you'll see a G01 - in CNC, that's a controlled feed, set by the F parameter. Usually the CAM guy at the board house will know what feeds to use as well as what depth (they usually stack the PCB in batches, depending on drill aspect ratio).

I do a lot of CNC in house:
http://ajawamnet.com/
http://www.ajawamnet.com/ajawam3/swarf/swarf.htm
cnc - http://www.ajawamnet.com/ajawam3/swarf/maxnc.html

I do a lot of plated slots for stuff like that Allegro part that's in this example...

BTW the example is one of AD's example PCB's I was using on the forum for showing accordion unions in AD17...

[westfw]

Ok; thanks everyone.  The design has been sent off to OSHPark and I'll see how it comes out.  (Mahi's photos look great!)

Slots are a pain in the ass though; there's no easy way I know of to get them drawn in EAGLE without DRC going nuts. You have to manually attach "thermals" to planes too.

What I'd PREFER is to have a specification "when drilling plated holes, one of the tools available is a milling bit of diameter xxx.  You can provide a milling layer with paths drawn in that width, and we'll mill along those paths with that bit."  WYSIWYG, the designer is responsible for taking the tool size into account,  and use a separate gerber file for the additional tool action (but the same process step, if I'm interpreting the process correctly.)  Some vendors might have a CNC drill that can't do milling, which would be too bad (but is probably increasingly uncommon), and they should just say so.

This "draw a line in a weird layer, inside a pad but outside the hole of the pad, and we'll figure out that it's the outside edge of a slot you want milled" is ... uncomfortable.

[LabSpokane]

This is what I received from OSHPark.  Design dims:  0.040x.120.  Finished dimensions are about 0.44 x .125.  Close enough for me.