Case for DMMCheck - Page 1
Forum section: electronics / projects

author: Spawn
author_rank: Frequent Contributor
timestamp: March 03, 2013, 03:54:50 am
content: I wanted a case for my DMMCheck to protect it, so I ordered a case from Conrad and worked out the face plate. The original case had a metal plate which wouldn’t work so I made one with Plexiglas but that shattered when I was putting the panel temperature meter in there.This time I used porous PVC because it is easy to work with. Some people are interested in such a case so I made also a video while I was making the face plate.Anyways if someone has neat ideas for a case share with us, this is how mine look like:Here is the video how I made it:

author: quarks
author_rank: Frequent Contributor
timestamp: March 03, 2013, 07:02:53 am
content: Nice job, thanks for sharing.

author: Spawn
author_rank: Frequent Contributor
timestamp: March 03, 2013, 02:14:14 pm
content: Thanks quarksI am glad you liked it.One thing I forgot to mention where I got the temperature meter, because it is battery powered it won’t affect the DMMCheck’s accuracy, I asked this with a mail to maker of DMMCheck (Doug) he replied with I shouldn’t use anything powered with switching power supply and a linear power supply would be okay, which is obvious of course.But I already had one panel meter battery powered so it was even better, I check its accuracy with a calibrated Vaisala temperature meter and it was only 0.4 Celsius off at 21 Celsius.If someone needs such a temperature meter, these are widely sold on ebay just like this one here:http://www.ebay.com/itm/New-Mini-LCD-Digital-Panel-Thermometer-Temperature-Meter-/190794471656

author: iloveelectronics
author_rank: Frequent Contributor
timestamp: March 03, 2013, 02:23:09 pm
content: Very nice video indeed!I am in the process of setting up a new warehouse/lab/office space and I'll be certain to get some of those heavy tools like the drill press and perhaps that mini table saw as well!Funny you mentioned the little thermometer too as first thing after I watched your video was to see if I could source some of those...LOL! Did you cut that really long lead on that meter short or did you just tuck it in the case?

author: SeanB
author_rank: Super Contributor
timestamp: March 03, 2013, 02:55:54 pm
content: I have used a few of those ( one is sitting in front of me now) and the calibration on them is optimistic at best. They can vary up to 5C at room temperature, and worse still they use the battery voltage as a reference, so as the battery ages the readings drift higher. I looked at the whole box of them and selected those that read close to each other, as a hope that the average would be room temp. They can be calibrated, though to do so you will have to power them from a reference of 1.4-1.6V and adjust a few of the resistors on the board to get them to read better.There is a 2C difference between the one and a cheap Craplins one that sit next to each other with no moving air or heat sources near them. The Craplins one at least is more accurate after having compared it to known temperatures in a cabinet.

author: Spawn
author_rank: Frequent Contributor
timestamp: March 03, 2013, 05:17:01 pm
content: Quote from: iloveelectronics on March 03, 2013, 02:23:09 pmThanks FrankyMost people think those Proxxon’s are expensive, but in Europe the price is okay. The saw is around 100 euro’s which is not expensive if you ask me. With another blade it is great for PBC cutting, but if you plan to cut PCB’s all the time than I would recommend a higher table top model from Proxxon from what I read those are better for PCB.My debate with myself is right now, shall I get a Proxxen milling machine or a Digital oscilloscopeAs for the temperature meter, I didn’t cut the wire, didn’t even take out that small wire which came with it to keep together.Quote from: SeanB on March 03, 2013, 02:55:54 pmSean, I am not sure if this one reads bad after voltage drop, time will learn. I got couple of these 2 or 3 years ago, I could only find one back I don’t know what happen to other ones. I put 2 batteries in and compared the reading after two hours with a calibrated Vaisala meter after both where settled. Funny you mentioned about the battery, because I was think to add a AAA battery in the box for the meter if the battery dies quickly.

author: SeanB
author_rank: Super Contributor
timestamp: March 03, 2013, 05:26:28 pm
content: The LR44 in them easily does 2 years or more, it normally dies from old age, as the power used is less than the self discharge of the cell.

author: RobB
author_rank: Contributor
timestamp: March 03, 2013, 06:31:22 pm
content: I like your work, very neat. These units are just begging for a suitable case as they seem vulnerable when naked.As these DMM check units are not something you would use every day unless your name is MartinI think some sort of dust cover would be an advantage. Looking at your design perhaps a second top case could be hinged from the bottom clam shell style and sealed with some door sealing foam or a rubber seal.As for the double sided tape, I would be wary. I may be talking out my arse here but in the long term the adhesives may degrade the PCB.It's a pity the maker does not provide mounting holes at the PCB corners. One solution might be to make two frames from PCB material. the first with a window just large enough to fit over the DMMcheck pcb and the second top frame with a window just smaller so it retains the DMMcheck. fasten the sandwich to the cover plate with four small screws and nuts and you are done.

author: Spawn
author_rank: Frequent Contributor
timestamp: March 03, 2013, 07:13:25 pm
content: Thanks RobMy name is not Martin, but I like his videosI got more than 30 multimeters myself till I got the DMMCheck I was comparing the meters with each other. I will sure make use of it more than a common user, my mistake was not getting the DMMCheck Plus, my next order will be that one. Unlike most other forum members here I use the AC part of the meters a lot more.About the dust part, after my video I decided not to use a double sided tape indeed, the Plexiglas protection can be push back little and I can take out the DMMCheck out than put it in a antistatic bag.Agree on the mounting holes on the PCB, I think the maker want to keep it small as possible.Because of the positioning of the on/off switch and the test outputs I couldn’t cover the top part permanent, I really wished I had a milling machine so I could put the PCB flat in the face plate and make it flat with it.

author: robrenz
author_rank: Super Contributor
timestamp: March 03, 2013, 07:32:54 pm
content: Nice job and nice video

author: Spawn
author_rank: Frequent Contributor
timestamp: March 03, 2013, 09:44:06 pm
content: Thanks robenzNice to hear from a real machinist, I am sure you can make a real nice one with the equipment you got there

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: March 03, 2013, 10:38:35 pm
content: Quote from: RobB on March 03, 2013, 06:31:22 pmI don't think you are talking out of your arse but worrying about the adhesive is misplaced in that these reference boards are sensitive to physical strain and compression. Any mechanical mount is likely to be inferior to a free float style of containment if the mount compresses the board. I don't have a DMM check but was looking to get one, if I recall correctly the actual ref element is at the edge of the board. These things are a bit fussy. I like the dust cover idea.

author: Spawn
author_rank: Frequent Contributor
timestamp: March 11, 2013, 12:32:26 pm
content: About the clamshell idea mentioned by Rob, I found a case looking close to what I used but then with a cover. The case is bigger and has a aluminum face plate again, but it could be good case for DMMCheck Plus.Here is it:http://www.ebay.com/itm/250788469929chickenHeadKnob sorry, but somehow I didn’t notice your post. I didn’t use the double sided tape as I mentioned and the DMMCheck is easily get out like that, it is sitting in a anti static bag now. Indeed the voltage reference chip is at the edge between the voltage measurement points, that’s why I decided to put the Plexiglas protection over that chip and the highest point on the PCB.As my own debate about getting DSO or a Proxxon milling machine, milling machine won, I am proud owner of a Proxxon MF70 and it is sitting on my bench last 3 days now

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: March 11, 2013, 06:26:10 pm
content: Quote from: Spawn on March 11, 2013, 12:32:26 pmWell,Hi Spawn Stop teasing us will you and post that new babies photo here to .What are you ideas about this case

author: RobB
author_rank: Contributor
timestamp: March 12, 2013, 06:22:22 pm
content: Quote from: Spawn on March 11, 2013, 12:32:26 pmOh dear another money sink.As a professional CNC machinist I know just what it can cost to get even a basic tooling setup for a mill. CNC or manual ?Should be very handy for chassis bashing. If you need any hints or tips just holler.CheersRob

author: Spawn
author_rank: Frequent Contributor
timestamp: March 12, 2013, 07:29:09 pm
content: Quote from: RobB on March 12, 2013, 06:22:22 pmIt is manual right now, bleave me nothing like you use at your work LOL it is way smaller. Great for making small parts like the face plate I had to make at start post.Later stadium I am going to start a project to make it CNC. I did use big milling machines before but never a CNC so it is a nice learning project for me.Before someone asks, I am not going to mill PCB with it.Quote from: Amarbir[Lynx-India] on March 11, 2013, 06:26:10 pmCase looks good for things with display on it, we need one with cover.If I have to show off, I will show off with all my ProxxonsIt fits perfect there, had to expand my bench for it:

author: RobB
author_rank: Contributor
timestamp: April 10, 2013, 10:25:44 am
content: I think I saw you mention something about a V2 case in the works. Any progress/pics ?Cheers

author: Spawn
author_rank: Frequent Contributor
timestamp: April 10, 2013, 05:01:12 pm
content: v2? I was talking about a case for DMMCheck Plus I guess, but I don’t have a Plus yet, I am busy with another project at the moment.