big bore recessed DNA 20 box

[d9mel]

What do you use to bore a hole of that diameter in the cast aluminum? A stepped bit?

I thought about using a stepped bit, but was worried that it would wander off center since there is only one cutting tooth.

Wound up using a 22mm hole saw to get a consistent cutting pattern, and there was some box hardware that had to be cut too.

The tricky part was that the internal depth of the box is 21mm, so i had to cut out +0.5mm on each side and the wall thickness is only 1.5mm

 

[d9mel]

D9....will the resin stick to glass? I was wondering if you could clamp a piece of glass to the face and fill from the back.

Thats a really good question Bap. I've gotta set another window and have tons of resin so ill give it a shot, I thought about using a releasing agent (I normally use cooking spray for epoxy ) to see if that would help smooth it out.

the poured side has a super smooth surface, but unless it is completely leveled can have slight waves to it

 

[d9mel]

Here it is all finished up (got a GCR and have been using an XL carto tank), along with its big brother thats still waiting for batteries

 

[tmassey]

so what batts is the big brother getting? dual 18650's? ever since doing the 1590a with 1 18650 ive been thinkin u could squeeze 2 into a 1590g

 

[d9mel]

you could use 18650s, just have to move the board up some. I'm going to use Li-Po cells like this old pack (2x1100mah).

I've been really impressed by the performance and run time of Li-Po cells, and am planning on using this one (3400 mah) for the next build.

 

[westy78]

Wound up using a 22mm hole saw to get a consistent cutting pattern, and there was some box hardware that had to be cut too.

Cool, I was wondering how a hole saw would work in aluminum--now I know. Thanks for sharing!

 

[tmassey]

I was thinking more along the lines of this AW 18650 Protected 3400 mAh Rechargeable Lithium Battery Would give way more batt life and are still rated at 25c if I read it right which would be plenty over kill. I have the 2600 version in my 1590a and it will run the dna all the way to 20w. Although quite A bit more expensive

 

[d9mel]

Spring break is officially over for me... I think I'm more bummed than my 9th grader.

That cell is rated at 2c (6.8a) @25° Celsius. They've been coming out with a lot of high capacity low discharge 18650's lately.

I tested that board with an efest 18650(~50 cycles) and that old Li-Po pack(~100 cycles) and the efest read weak battery @15 watts and up but the lipo fired no problem up to 20 watts, that's just my experience.

That's why I solder in the Li-Po cells, but used a battery holder for easy swaps with the 18650

Off to chemistry, have a good day all!

 

[westy78]

I tested that board with an efest 18650(~50 cycles) and that old Li-Po pack(~100 cycles) and the efest read weak battery @15 watts and up but the lipo fired no problem up to 20 watts, that's just my experience.

Interesting. The efset was the 10c IMR Li-Mn variety? Did it do this when new, and then the performance degraded after 50 cycles? I wonder if this is an efset issue, or whether Li-Po packs just perform better long-term than IMRs. Anybody else finding this to be the case?

 

[bapgood]

Interesting. The efset was the 10c IMR Li-Mn variety? Did it do this when new, and then the performance degraded after 50 cycles? I wonder if this is an efset issue, or whether Li-Po packs just perform better long-term than IMRs. Anybody else finding this to be the case?

Yes I agree 100%....Lipo's seem to outperform the round cells hands down. It's hard for me to say that since the lipo's I have used have all been larger capacity, but it seems to be the case. Someone running a Nivel mod could easily quantify this. It may have something to do with the protection circuit in the round cells, or they are just over spec'd??? Typically lipo packs don't have any protection (so add a fuse if you use one!!!)

 

[d9mel]

Dont take me wrong the Efest cells are great and my new panasonic can operate @ 20W , but the only downfall for applications like this is that the Efest are only 5c cells (2000mAh or 2.0Ah@5c =10A max discharge) while the Li-Po cells used (3.7V 1100mAh 12C Lipo li-po RC Battery 5G4Q3 5#10 5G4Q3 5#10 4G1 RC Helicopter) are 12c (1100mAhx2 parallel for 2200mAH or 2.2Ah@12c = 26.4A max discharge).

when I tested the board the charge on both cells was ~3.8v. and I was using a 2.2ohm carto.

this shouldnt be used as a reference for grading cells because these are just simple observations, the total discharge cycles are an estimate and these batteries have been pretty heavily abused( Efest was used in a Zmax and charged on a cheap charger).

In all reality I was just testing the functionality of the board, and have no need to vape at 20W, rarely go over 9W



If any of my info is incorrect, please speak up. I know a little bit about batteries but there are alot of folks on here that have much more experience with them

 

[d9mel]

I was thinking more along the lines of this AW 18650 Protected 3400 mAh Rechargeable Lithium Battery Would give way more batt life and are still rated at 25c if I read it right which would be plenty over kill. I have the 2600 version in my 1590a and it will run the DNA all the way to 20w. Although quite A bit more expensive

this is a similar OEM cell Test/Review of Keeppower 18650 3400mAh (Black). I found the flashlight forums to be a great resource

 

[d9mel]

I want to point out that there was a gap between the aluminum angle and door of the box just big enough for a dime, paper clip or any variety of thin metal objects to fit through that could potentially turn a good day into a really bad day, so I made a seal out of double sided foam tape that i used to secure the screen and board.

 

[stubb]

Can u post a pic of the back and how the alum piece is mounted. Constructed?

 

[stubb]

Alum angle piece that is

 

[d9mel]

Here's the inside, I cut a slit and bent the angle then trimmed the excess for clearance for the 18650 holder. Used SS flathead screws and nylon locknuts.

Counter sunk the screws, but had to drill one a little lower than the other( didn't have as much clearance as I thought)

 

[westy78]

...used silicone jacketed wire...

What are the advantages of silicone jacketed wire as opposed to PVC? I was planning to use "continuous-flex miniature wire" (stranded, PVC insulation) from McMaster. Should I reconsider?

 

[d9mel]

The silicone jacketed wire I used is extremely flexible, easy to work with and the insulation doesnt distort with (reasonable) heat. Believe its from hobby king (bapgood has more experience with it it) and I would definitely recommend it.

The mcmaster wire looks good too, but I've never used it.

I was checking out your design last night and had an idea, gonna hop over there now

 

[stubb]

Here's the inside, I cut a slit and bent the angle then trimmed the excess for clearance for the 18650 holder. Used SS flathead screws and nylon locknuts.

Counter sunk the screws, but had to drill one a little lower than the other( didn't have as much clearance as I thought)

Cool thanks. Where did u get the micro switches and buttons at

 

[stubb]

And the 18650 battery holder. Lol.