Jump to content

Photo

Excessive clearance could lead to SD card being eaten


13 replies to this topic

#1 Tjoppen OFFLINE  

Tjoppen

    Chopper Commander

  • 197 posts

Posted Tue Mar 27, 2012 5:31 AM

Today I noticed that SD cards can slip into the Harmony cartridge itself if you're not careful. I've attached a staged picture demonstrating the issue. I'm not sure how hard the card would be to get out if it does slip in - I don't feel like experimenting..
I'm not sure if mine is the only one with this potential issue, but I thought I'd bring it up along with some suggestions on how to remedy it:

During manufacturing:

* Use a Dremel-like tool when making the cut-out, making sure to only take off as much/deeply as needed for the connectors to poke through
* Apply hot glue or some kind of resin to shrink the opening if it's too big, preferably in a way that doesn't leave the cartridge permanently sealed (repairs, mods)

On the user side:

* Insert and glue a sufficiently thick piece of cardboard in place
(* Hot glue - be very careful due to risk of heat damage and connectors being covered)
* Always be careful :)

This is the only real issue I've discovered so far, apart from the FTDI chip's driver sometimes refusing to re-mount when the USB cable is inserted, which is probably unrelated to the Harmony itself. This is fixable by running "stty -F /dev/ttyUSB0 115200" for any search engines coming by here.

Attached Thumbnails

  • harmony_clearance.jpg

Edited by Tjoppen, Tue Mar 27, 2012 5:33 AM.


#2 snstay OFFLINE  

snstay

    Moonsweeper

  • 302 posts
  • "I know what willis is talkin about"
  • Location:midland, MI.

Posted Tue Mar 27, 2012 5:43 AM

Yes i feel your pain i trusted my son to put the sd card in mine.
And wouldnt you know it he pushed it all the way down .
I couldnt understand why i was getting a blank sreen untill i looked closely at it.
I just used a paperclip and fished it out but i havent let my son do that again cuz it was kind of a pain fishing it out.

Scott

#3 Tjoppen OFFLINE  

Tjoppen

    Chopper Commander

  • Topic Starter
  • 197 posts

Posted Tue Mar 27, 2012 6:47 AM

Sliding some cardboard in there seems to have worked fine.

Attached Thumbnails

  • harmony_cardboard.jpg


#4 Thomas Jentzsch OFFLINE  

Thomas Jentzsch

    Thrust, Jammed, SWOOPS!, Boulder Dash

  • 18,575 posts
  • Always left from right here!
  • Location:Düsseldorf, Germany

Posted Tue Mar 27, 2012 8:46 AM

I am using a cardboard there too. Even colored it black to look better.

#5 20ohm20 OFFLINE  

20ohm20

    Moonsweeper

  • 480 posts
  • Location:Rochester, NY/Temecula, CA

Posted Tue Mar 27, 2012 11:16 AM

I was actually thinking about this the other day, but I so rarely remove the SD card from my Harmony cart, I don't think I'm going to bother doing anything to it. The cardboard idea is a good one tho'.

#6 iesposta ONLINE  

iesposta

    Stargunner

  • 1,439 posts
  • Retro-gaming w/my VCS
  • Location:Pennsylvania

Posted Tue Mar 27, 2012 11:52 AM

Thanks for pointing this out. I never thought about that happening.
Kind of like how I stuck my SD card into the DVD slot which is millimeters above the SD card slot on the right side of the iMac...

#7 batari OFFLINE  

batari

    )66]U('=I;B$*

  • 6,454 posts
  • begin 644 contest

Posted Fri Mar 30, 2012 7:53 PM

Yes, it's happened to me before. However, the fix is not trivial. It's not just a matter of cutting a smaller hole.

Harmony is contructed of two boards soldered together. The reason this was done was for ecomony of scale for Melody boards and the Harmony cart (they share a common board) so I could have a large quantity of this one board professionally assembled to keep costs down.

Now, although I have a jig to attach these two boards, there is considerable tolerance as to how these boards fit together, and the shells are not all made equally (some have the screw mast in a slightly different place, some shells are made of harder plastic, some hold the main board better than others) and that coupled with the card insertion, the board actually can move inside the shell. All this together means the hole must be wider than it seems like it needs to me.

Furthermore, some clearance is needed above the card slot because you need to guide the screw mast into the hole in the board while putting the shell together. Some shells simply will not close unless you insert a thin tool in while the shell is snapped together to help slide the screw mast into the hole.

Engineering is often not just elegant with exact solutions, as sometimes you are minimizing a bunch of less-than-ideal solutions.

Someday I plan to produce a new Harmony with just a single board and a new, custom shell. This will be available as a special edition, and will cost more due to the smaller quantity and increased material cost, but this will not have any of the issues with fitment or anything else that some regular Harmony carts have.

#8 RevEng ONLINE  

RevEng

    River Patroller

  • 3,135 posts
  • bit player
  • Location:Canada

Posted Fri Mar 30, 2012 8:05 PM

How about putting a square of black foam tape on the sd slot casing, prior to assembly?

#9 batari OFFLINE  

batari

    )66]U('=I;B$*

  • 6,454 posts
  • begin 644 contest

Posted Fri Mar 30, 2012 8:17 PM

How about putting a square of black foam tape on the sd slot casing, prior to assembly?

If I could still get the tool in without damaging the foam, that could work, but perhaps it could be done after assembly. If that is the case, those who already own a Harmony could try it as well.

#10 Omegamatrix OFFLINE  

Omegamatrix

    Quadrunner

  • 5,460 posts
  • Location:Canada

Posted Sun Apr 1, 2012 11:51 AM

Just don't use the Activision type of foam that disintegrates after a few years. I've also gotten my card stuck in that slot as well!

#11 KevinMos3 OFFLINE  

KevinMos3

    Stargunner

  • 1,153 posts
  • Founder of the Timothy Dalton as Bond fan club
  • Location:Behind YOU!

Posted Tue Apr 3, 2012 11:34 AM

When I first got my harmony cart, I was a little surprised and disappointed with how large that hole was, but I understood why. I figured it was just so much faster and easier to cut to those points than to try to be exact. If you're dealing with just a couple of carts, it wouldn't be a big issue, but when you're producing a lot, I supposed he needed to go the faster/easier route. I didn't even know about the other reasons stated by batari above.

Here was my solution:
Harmony Slots.jpg

You can see from this pic, there is absolutely no excess clearance. I cut a new shell to fit exactly. :)

#12 snstay OFFLINE  

snstay

    Moonsweeper

  • 302 posts
  • "I know what willis is talkin about"
  • Location:midland, MI.

Posted Tue Apr 3, 2012 5:12 PM

Hmmmm i wonder if theres anyway to get an end lable on there and look decent with the 2 holes there.
Where did you get the new label from when you made the cart?

Scott

#13 KevinMos3 OFFLINE  

KevinMos3

    Stargunner

  • 1,153 posts
  • Founder of the Timothy Dalton as Bond fan club
  • Location:Behind YOU!

Posted Tue Apr 3, 2012 6:56 PM

I plan to put an end label on it. I just haven't decided on a design yet.

I put the original label back on. I just warmed it with a blow dryer on low setting, lifted a corner with a hobby knife, carefully peeled it off, and set it on wax paper until I was ready to stick it back on. The glue on those labels is really good btw. I'd really like to know what brand of sticker paper was used cause the ones I had in the past were no good.

#14 Harbinger OFFLINE  

Harbinger

    Combat Commando

  • 6 posts

Posted Sun Apr 29, 2012 8:55 AM

Simple solution--go to a hobby store and get a piece of thin styrene stock. Measure and cut a piece to fit in the depression where the end label would be, then measure and cut two holes--one for the SD slot and one for the USB connector. You could paint it with Krylon Fusion to match the cartridge case's color or use a marker to darken the styrene. Attach with contact cement and you're done.




0 user(s) are browsing this forum

0 members, 0 guests, 0 anonymous users