+ Reply to Thread
Page 3 of 10 FirstFirst 1 2 3 4 5 6 7 8 9 10 LastLast
Results 21 to 30 of 94

Thread: The Under $50 Cell Checker

  1. #21
    RBW Member omech will become famous soon enough omech will become famous soon enough omech will become famous soon enough omech will become famous soon enough omech's Avatar
    Join Date
    May 2007
    Location
    Vancouver, BC
    Posts
    62
    Copis Megalodon

    Re: The Under $50 Cell Checker

    Quote Originally Posted by tony13  View Original Post
    Been looking into making one for myself. I'm having trouble finding molex connectors in both male and female, any leads? Plenty of places with females but no males.. Also any good places to get cable, 3 pair or more. I'm assuming some type that is solid as to not let pressure drop thru it, or is this unfounded.

    Tony
    I've been dealing with the same problems you mention above, so here's my solutions.

    The Molex connectors on cells are the KK series and the male version is only available in a various configurations of PCB-type connector - so no male crimp direct to wire available. I combined a male PCB-type connector with a non-locking female connector to create a male connector on the end of a wire. The part numbers are:

    Molex KK header, right-angle, friction lock, gold 22-12-2034 $0.38each
    Molex KK crimp terminal housing, without locking ramp or ribs 22-01-2031 $0.021each

    The cheapest source was Arrow Electronics www dot arrow dot com.

    To assemble, push the PCB end of the pins thru the plastic block a bit so that when mated to the plug the 2 plastic bits are tight together, then add a dab of epoxy to prevent loosing the male connector.

    Alternatively I guess the simple solution is to just solder a male connector onto the end of the wires and cover it with some heat shrink (see photos on Narked@90's fischer connector page). But I thought the crimp-on connector provided a little better strain relief and gave more to hold onto while plugging and unplugging.

    As for wiring, I too had great aspirations of finding gas-tight cable but ended up going cheap and dirty from McMaster-Carr.

    71335K53 Audio Cable 22/6 Awg, 0.16" OD, 300 VAC, Gray $0.22/ft
    6907K9 Nickel-Plated Brass Liquid-Tight Cord Grip Straight, 1/4NPT, 0.11"-0.26" Cord Dia $5.34each (note these are compatible with 1/4NPT but actually have straight thread and use an oring to seal, so the thread length isn't too long and the seal will be better if the initial part of the female thread has a nice smooth chamfer)

    I cut off the cable's outer sheath as soon as it emerged thru the pressure side of the cord grip and spread out the conductors a little so I could fill around the wires inside the cord grip with epoxy. While the glue was still fluid I sealed up the pressure pot and let about 2psi push the glue into place. However I found that gas will still leak down each individual conductor between the insulation and the copper strands so I ended up putting a little dab of epoxy on the end of each wire inside the pressure pot where they attach to the crimp terminals. Took a few extra minutes but it holds 30psi indefinitely.

    Here's a couple of pics.

    owen
    Attached Images

  2. #22
    rEvo Shearwater tony13 has a spectacular aura about tony13 has a spectacular aura about tony13 has a spectacular aura about tony13 has a spectacular aura about tony13 has a spectacular aura about tony13's Avatar
    Join Date
    Jul 2007
    Location
    NJ
    Posts
    342
    rEvo

    Re: The Under $50 Cell Checker

    Owen thanks for the info. Alot of good ideas. The only thing I've found and was thinking would work for the molex connectors is this.3Pin ATX Y Cable-FAN-CABLE-Y at Cables4computer
    I was thinking to either try and open the crimps on the pins and reuse them(not sure it's doable) or just cut them of and butt splice them to my cable with some heat shrink to make it pretty.
    Also was thinking along the same lines with the OPV. Which one did you get?
    Do you feel the 30psi gauge is adequate? I want the low scale but am worried about blowing the gauge by accidently over pressurizing. What the OPV set at?
    Tony

  3. #23
    RBW Member omech will become famous soon enough omech will become famous soon enough omech will become famous soon enough omech will become famous soon enough omech's Avatar
    Join Date
    May 2007
    Location
    Vancouver, BC
    Posts
    62
    Copis Megalodon

    Re: The Under $50 Cell Checker

    I got the OPV from Mcmaster as well.
    48435K72 Brass Soft Seal ASME Pop-Safety Valve 1/4" NPT Male $6.78 45PSI

    It not adjustable but they are available in 5psi increments. I picked 45psi as I don't know what aluminum grade the pot is made of. that pressure gives me a bit of safety factor even at low material strengths. And I can still test to 4ATA (albeit with limited accuracy) without mucking up the gauge as I can isolate the gauge by installing a plug from inside the pot.

    apparently the rule of thumb is to select a gauge that has 2x the system pressure. I plan on doing most testing at 15psi max so this works and it gives twice the needle movement per psi of a 60psi gauge, so that should reduce the eye-induced error.

    I put the OPV on mostly to stop reduce the chance of sending chunks of aluminum off in random directions - i was less worried about the bargain basement gauge.

    One thing I might add is the OPV does vent quite quickly - it's almost full bore of the 1/4NPT fitting - which is great for flushing the pot. But I added a 1/8NPT Schrader valve to allow fine venting control which makes it easy to set a fairly accurate pressure if so desired. I had it lying around so the price was right and the valve stem sticks up just the right amount to be finger actuated.

    owen
    Last edited by omech; 28th November 2009 at 01:31. Reason: feeling verbose

  4. #24
    I Make Stuff! sunkmail has a spectacular aura about sunkmail has a spectacular aura about sunkmail has a spectacular aura about sunkmail has a spectacular aura about sunkmail has a spectacular aura about sunkmail has a spectacular aura about sunkmail's Avatar
    Join Date
    Sep 2007
    Location
    North Vancouver, BC, Canada
    Posts
    184
    KISS Classic

    Re: The Under $50 Cell Checker

    Quote Originally Posted by tony13  View Original Post
    Been looking into making one for myself. I'm having trouble finding molex connectors in both male and female, any leads? Plenty of places with females but no males.. Also any good places to get cable, 3 pair or more. I'm assuming some type that is solid as to not let pressure drop thru it, or is this unfounded.

    Tony
    Owen's suggestions are great. Arrow is where I got my connectors from too.

    As for the cable, I used an old printer cable with one end clipped off. This gave me a sealed end, and was free, as I had it laying around. Using the D-Sub connector on the printer cable, I was able to solder the Molex mail pins directly into the solder cups. Total cost was about $4 in parts for the wiring.

    Going into the case, I used a enviromental chassis mount electrical gland. It's air tight and intended for hazerdous/wet environments. I managed to get it or free, as the electrical place I got it from didn't want to bother with the paperwork for a sale under $5.

    Owen - When are we diving again??

  5. #25
    RBW Member WD8CDH is an unknown quantity at this point WD8CDH's Avatar
    Join Date
    Dec 2007
    Location
    NY
    Posts
    112
    Homebuilt mCCRs, eSCR

    MK15, Electrolung, others

    Re: The Under $50 Cell Checker

    Quote Originally Posted by omech  View Original Post
    I was in Home depot tonight so I strolled down the plumbing isle. Here's the numbers you need:

    C5818CS - ABS DWV Plug w/o-ring
    and
    C5803-2-CS ABS DWV Adapter (SPIG x FIPT)
    or
    C5803 ABS DWV Adapter (Hub x FIPT)

    These are Nibco parts NIBCO.com - NIBCO® AHEAD OF THE FLOW® .

    all the best tracking down a source,
    owen
    Wow, this really must be a Canadian thing. I can find it on homedopot.ca but not at homedepot.com

    It's not on the Nibco web site either. Next, I will try to call the factory.

  6. #26
    rEvo Shearwater tony13 has a spectacular aura about tony13 has a spectacular aura about tony13 has a spectacular aura about tony13 has a spectacular aura about tony13 has a spectacular aura about tony13's Avatar
    Join Date
    Jul 2007
    Location
    NJ
    Posts
    342
    rEvo

    Re: The Under $50 Cell Checker

    Wow 3 Home Depots today and a Lowe's. Finally got 2 out of 3 at Lowe's. The HD's by me do not carry ABS pipe at all according to the salesmen. The plug I did pickup is just a threaded plug, no shoulder or o-ring. Do you all think using teflon tape on the threads would seal it enough? Would have to retape it ever time I use it but I don't see it happening that much anyways.

  7. #27
    RBW Member omech will become famous soon enough omech will become famous soon enough omech will become famous soon enough omech will become famous soon enough omech's Avatar
    Join Date
    May 2007
    Location
    Vancouver, BC
    Posts
    62
    Copis Megalodon

    Re: The Under $50 Cell Checker

    Good luck with the tapered thread. I'm sure it will seal but it would drive me around the bend to go thru that process every time. I tried to make mine as user friendly as possible, so cost and time spend building it was a lesser concern. My theory being that if it's pleasant and quick to use I should be more likely to test the cells frequently. Ideally my meg head would have a connector like the Hammerhead banana block - then i could just disconnect the whole sensor carriage and drop it in the pot. Then I'd probably test every time I calibrated.

    But back to the whole lack of non-tapered thread pipe fittings. Did you look at the 4" white pvc pipe fitting selection? There was a similar fitting in PVC that used a not-too-hard plastic gasket. I'm not sure it's compatible with the ABS fittings. But the associated PVC fittings had an addequate wall thickness to support holes drilled for bulkhead fittings.

  8. #28
    rEvo Shearwater tony13 has a spectacular aura about tony13 has a spectacular aura about tony13 has a spectacular aura about tony13 has a spectacular aura about tony13 has a spectacular aura about tony13's Avatar
    Join Date
    Jul 2007
    Location
    NJ
    Posts
    342
    rEvo

    Re: The Under $50 Cell Checker

    Yeah Owen I looked. Same crap.

    Sent pm.

  9. #29
    jeff addis swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver's Avatar
    Join Date
    May 2006
    Location
    southeast florida
    Posts
    1,076
    Revo

    Optima

    Re: The Under $50 Cell Checker

    what about the 4 inch test plug at Lowes? Wing nut expands gasket. seals tight supposedly to about 100 psi

  10. #30
    jeff addis swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver has a brilliant future swadiver's Avatar
    Join Date
    May 2006
    Location
    southeast florida
    Posts
    1,076
    Revo

    Optima

    Re: The Under $50 Cell Checker

    If anybody is still looking for a good, cheap pressure vessel to make a cell checker, i found one. Idea courtesy of my buddy Vince, the NEDU engineeer.

    He suggested the filter canister used in house drinking water applications. Rated to 125 psi, this model features 1/4 inch NPT in/out with a pressure release button on top and an O ring seal. At 10 inches long, a little bigger than what's required but no big deal.

    Available on line from Filtersfast.com all for $12.43 plus shipping.

    here is a pic of the completed unit.
    Attached Images

+ Reply to Thread
Page 3 of 10 FirstFirst 1 2 3 4 5 6 7 8 9 10 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts