First DNA 30D build, questions!

[Red Leader]

Hello! I have been attempting to make a dna 30d mod and i have a few custom things i want to do with it. I am trying to make a dual 18650 dna 30 with passthrough charging and an output usb. Now i have almost all the materials i need except for the dna 30 which is coming in the mail soon. Currently i have:

*hammond 1591B Aluminum enclosure
*24 guage wire, black and white
*20 guage wire, black red and green
*fatdaddy floating 510 connection
*100g tactile switches (2)
*keystone dual 18650 battery holder
*stainless steel push switch for firing button
*micro usb charging chip
*SC-0202 0.8A DIY Mobile Power Bank PCB Module
*DNA 30 is coming in the mail soon...

now im wondering, am i missing anything to make this mod complete? soldering everything together is probably going to be the most difficult part for me and I just want to make sure i don't need any extra resistors or something for this powerbank to work. i have seen them built into a dna before but the build instructions seem pretty vaug. When this is finished I want to make a build instruction and possibly make a video on how i made this so i can get the word out. Im very determined and willing to do anything to make this work so help would be very much appreciated

 

[jayme396]

Do you have experience soldering?

 

[Red Leader]

slight. i have been practicing on cheap boards and working my way up. I have a friend who took a soldering class who will also be helping me

 

[caddimike]

If you don't have any electrical tape or heat shrink wrap for your solder points, you might want to buy some. Some people also use kapton tape inside the box to prevent shorts from happening. Common sense but I'm just posting this as a reminder!

 

[NealBJr]

Hello! I have been attempting to make a dna 30d mod and i have a few custom things i want to do with it. I am trying to make a dual 18650 dna 30 with passthrough charging and an output usb. Now i have almost all the materials i need except for the dna 30 which is coming in the mail soon. Currently i have:

*hammond 1591B Aluminum enclosure
*24 guage wire, black and white
*20 guage wire, black red and green
*fatdaddy floating 510 connection
*100g tactile switches (2)
*keystone dual 18650 battery holder
*stainless steel push switch for firing button
*micro usb charging chip
*SC-0202 0.8A DIY Mobile Power Bank PCB Module
*DNA 30 is coming in the mail soon...

now im wondering, am i missing anything to make this mod complete? soldering everything together is probably going to be the most difficult part for me and I just want to make sure i don't need any extra resistors or something for this powerbank to work. i have seen them built into a dna before but the build instructions seem pretty vaug. When this is finished I want to make a build instruction and possibly make a video on how i made this so i can get the word out. Im very determined and willing to do anything to make this work so help would be very much appreciated

Nothing was mentioned about what you need to mount it all inside.

 

[mikepetro]

Hello! I have been attempting to make a dna 30d mod and i have a few custom things i want to do with it. I am trying to make a dual 18650 dna 30 with passthrough charging and an output usb. Now i have almost all the materials i need except for the dna 30 which is coming in the mail soon. Currently i have:

*hammond 1591B Aluminum enclosure
*24 guage wire, black and white
*20 guage wire, black red and green
*fatdaddy floating 510 connection
*100g tactile switches (2)
*keystone dual 18650 battery holder
*stainless steel push switch for firing button
*micro usb charging chip
*SC-0202 0.8A DIY Mobile Power Bank PCB Module
*DNA 30 is coming in the mail soon...

now im wondering, am i missing anything to make this mod complete? soldering everything together is probably going to be the most difficult part for me and I just want to make sure i don't need any extra resistors or something for this powerbank to work. i have seen them built into a dna before but the build instructions seem pretty vaug. When this is finished I want to make a build instruction and possibly make a video on how i made this so i can get the word out. Im very determined and willing to do anything to make this work so help would be very much appreciated

Are you using the Powerbank board to charge cell phones etc? I have that function on several mods, like the E-Mech etc, and to be honest I have never used it even once. But thats just me, seems I always have a micro USB charger handy wherever I am. Anyway, simply hooking it to the +/- of the battery legs would work,with microswitch in series on the positive leg to give you the option of turning it on/off, otherwise it will slowly drain your battery (it is constantly trying to keep the USB port at 5v which will use some juice, thats why you want to turn it off while not in use). Dont see an on/off microswitch in your list.

Also I didnt see any mention of a PTC Fuse. Fusing is highly recommended, especially you are using the USB out port. While the DNA will protect itself (except for reverse polarity), fuses protect the battery against other malfunctions, like a direct short to ground.

Have you thought about a screen bezel to make mounting the screen easier. Several people like Bap and jonniemac offer them on Shapeways. I used them on a couple of my builds and it sure made mounting the screen a LOT easier.

 

[PinkPanter]

I have a dna20/30 schedule in my album

You need 2x 3A fuse for a DNA30.

 

[Red Leader]

I have shrink tubing and epoxy, got a little lazy when it came to writing down all the materials i guess haha. but i do NOT have any ptc fuse or switch... im thinking about how you never used your usb port though and i'm wondering even though i don't have any fuses, would i still be able to make a relatively safe build if i ditched the usb port and just wired to dna together as planned?

 

[mikepetro]

I have shrink tubing and epoxy, got a little lazy when it came to writing down all the materials i guess haha. but i do NOT have any ptc fuse or switch... im thinking about how you never used your usb port though and i'm wondering even though i don't have any fuses, would i still be able to make a relatively safe build if i ditched the usb port and just wired to dna together as planned?

In my opinion, no.

If the battery is not fuse protected, and a wire comes loose inside the Mod (or any other of a number of failure modes) and causes a direct short you will get the "magic smoke". How dramatic the magic smoke will be is dependent on the particular battery and the failure, but batteries were not designed to be shorted. Granted, it is less dangerous with 18650s than a Lipo flat pack, but it is still best practice to fuse your battery.

It isnt the DNA so much, the DNA has built in safety circuits to protect itself, but there are many more failure modes beyond the DNA board.

Of course, this is just my own personal opinion as a Electronics Engineer, you will also notice that Mamu, Bap, and most other accomplished Modders will all use fuses. Things happen, especially while you are just starting out, but the more experienced realize this even more ( most of us have smoked something along the way), hence why it is "best practice" to design a mod with fuse protection.

Safety should be by design.

 

[Red Leader]

OK! well i ordered the fuse and the microswitch and it should be here by tuesday. for now im going to finish the holes in the box then paint! will post pictures soon

 

[rawr]

Excellent tutorial for building your own dna mod!