Michael P Clark Posted July 19, 2012 Report Share Posted July 19, 2012 Bash, I am doing the same LED lighting idea you had. Unfortunately, my follow cart is still in the design phase, so no pics. But that LED lighting idea now has more merit since you pulled it off. great looking cart. Quote Link to comment Share on other sites More sharing options...
Bash Posted July 21, 2012 Author Report Share Posted July 21, 2012 Here is a look at the back of the minirack. Stuart has been workingon te PowerPost, which will distro the power and also provide a few easy to get at IPs for mics, and OPs to video etc... Note also the regulator that Stuart has managed to mount in the base of the minirack. This should protect any kit powered frm the rack against overvoltage. We are slightly concerned that when we look into the LiFe PO batteries (we think that we can squeeze one in behind the RK3 radio mic racks) there may be a problem with respect to float charging, and high voltages. So - regulator has been fitted to the bottom of the minirack. The PowerPost is not yet fully wired up - Stuart offered one socket up to it, then thought it looked rather smart, so he just popped the rest in to photograph it. I am loving the rate of progress though. Have a good weekend folks, Simon B Quote Link to comment Share on other sites More sharing options...
Jan McL Posted July 21, 2012 Report Share Posted July 21, 2012 I hate it when I drool and type...but love this cart. It makes my knees weak. There. I've said it. Quote Link to comment Share on other sites More sharing options...
Jeff Wexler Posted July 21, 2012 Report Share Posted July 21, 2012 Mechanically and aesthetically your power distribution is beautiful! Power regulation is important, I agree, but use of a DC to DC converter for your main power distribution could cause problems of its own. Most of the devices we use have their own power supplies internally, often with DC to DC converters, and each of these devices interact with each other (and now will interact with your "master power" regulator). This interaction frequently causes noise for audio components. I understand your concern for over-voltage and such but there are other ways of addressing this. What I have done (and your probably already know this) is to use a very high quality low-noise regulated DC power supply (connected to mains) that floats across the LiFe battery. This supplies a constant regulated 13.8 volts dc to the gear. So, when connected to mains, the gear never sees more than 13.8 vdc (and each piece of equipment is good with that) and when on battery alone the gear will see only less, not more, than the 13.8 vdc. This has worked very well for me for the last 15 years or more. Quote Link to comment Share on other sites More sharing options...
jason porter Posted July 21, 2012 Report Share Posted July 21, 2012 Beautiful setup! I am planning a similar design, but with a traditional base/bike wheels. hijack alert- Jeff, does your AC/DC converter charge your LiFePo battery? Or do you need a charge circuit in there in-somewhere? Or, does it not charge your battery at all? What I have done (and your probably already know this) is to use a very high quality low-noise regulated DC power supply (connected to mains) that floats across the LiFe battery. This supplies a constant regulated 13.8 volts dc to the gear. So, when connected to mains, the gear never sees more than 13.8 vdc (and each piece of equipment is good with that) and when on battery alone the gear will see only less, not more, than the 13.8 vdc. This has worked very well for me for the last 15 years or more. Quote Link to comment Share on other sites More sharing options...
Jeff Wexler Posted July 21, 2012 Report Share Posted July 21, 2012 Jeff, does your AC/DC converter charge your LiFePo battery? Or do you need a charge circuit in there in-somewhere? Or, does it not charge your battery at all? The regulated power supply is not a charger, there is no "charging" circuitry per se, but the constant 13.8 vdc does serve to charge the battery (or more correctly, keep it "topped off"). The battery needs to be fully charged before putting into service (which I do with a charger specifically designed for LiFe batteries I am using), but once in service the battery rarely gets discharged to a point that requires conventional charging. Quote Link to comment Share on other sites More sharing options...
soundslikejustin Posted July 22, 2012 Report Share Posted July 22, 2012 Here is a look at the back of the minirack. Stuart has been workingon te PowerPost, which will distro the power and also provide a few easy to get at IPs for mics, and OPs to video etc... Note also the regulator that Stuart has managed to mount in the base of the minirack. This should protect any kit powered frm the rack against overvoltage. We are slightly concerned that when we look into the LiFe PO batteries (we think that we can squeeze one in behind the RK3 radio mic racks) there may be a problem with respect to float charging, and high voltages. You have no need to be worried about over-voltage with a lifepo4. At full charge, they have a lower output voltage than a traditional li-ion battery (Np-1, v-lock etc) Jeff's idea is a good one, getting a regulator that floats over the Lifepo4 battery. At 13.8v, the battery will never see a full charge after the initial charge Jeff does (14.4v is the full-charge voltage of a 4-cell lifepo4) but that shouldn't do any harm to the battery. The other option would be to install a battery with a charge management board, which means you can charge and discharge the battery at the same time - essentially floating, but controlled via microprocessor. Quote Link to comment Share on other sites More sharing options...
Bash Posted July 22, 2012 Author Report Share Posted July 22, 2012 Am interested to know other people's views on the float charging thing with LiFEPOs. Our research suggested that some charging voltages could be well beyond 17v, which could get a bit edgy with some of the kit. There seems to be so little real world knowledge out rhere re LiFE PO voltages..... It would or could e easy to bypass the regulator, so if we get into trouble we will do just that!! Kindest regards, Simon B Quote Link to comment Share on other sites More sharing options...
soundslikejustin Posted July 22, 2012 Report Share Posted July 22, 2012 Am interested to know other people's views on the float charging thing with LiFEPOs. Our research suggested that some charging voltages could be well beyond 17v, which could get a bit edgy with some of the kit. There seems to be so little real world knowledge out rhere re LiFE PO voltages..... It would or could e easy to bypass the regulator, so if we get into trouble we will do just that!! Kindest regards, Simon B Charging voltage for a LifePO4 pack with a nominal voltage of 13.2v (or 12.8v - depends on if the cells are rated at 3.3 or 3.2v each) will NEVER reach 17v. If it did, the battery would likely be damaged, but at least would not combust as a typical li-ion or lipoly would... I'm sure you're probably aware, but lithium batteries are charged via a CC/CV process. In the first stage, a constant voltage equal to that of the full charge of the battery is applied - in the case of a 4 cell lifepo4 pack, that would be 14.4v. This voltage is supplied at a constant amount of amps, until the battery actually REACHES this charge voltage (usually at around 85% SoC). In the second stage, the voltage is kept constant, while the amps taper off until the battery is full (delta-v) or the amps drop to a pre-defined value (usually .1 of the initial charge rate) The hardiness of the lifepo4 cell allows it to be dropped into (and replace) SLA batteries as the chemistry is very stable, and can handle over voltage, over charge and over discharge in a much safer way than li-ion (read: smoking and fire). Quote Link to comment Share on other sites More sharing options...
Geoff Maxwell Posted July 23, 2012 Report Share Posted July 23, 2012 That is some really beautiful work. Way beyond my ability. I did built a mini cart on the Zuca platform last year and posted a lot of detail. I noticed the link had been removed so I'll post again as images. Its been a progression of trial and error. For those of you wishing to use the Zuca I can offer some insight and cautions after using it for 8 months. Look for a new thread "Maxwell Zuca cart" Quote Link to comment Share on other sites More sharing options...
Bash Posted July 23, 2012 Author Report Share Posted July 23, 2012 Hi Geoff, and thanks for your post here and the new thread. It was, amongst others, your Zuca cart that simewhat inspired me to go and twist Stuart's arm and see if I could get him fired up to work with me and make the minirack (which I somehow wonder if it ought to be being called the midicart!!). We are aware of the lack of width on the Zuca, and see that as a very lightweight option indeed, to be rarely used. Stuart and I are currently working on a load of ideas for our own base. We have not yet arrived at the same conclusions, but it will certainly be small enough to go through even quite narrow household doors. Kindst regards to all, sb Quote Link to comment Share on other sites More sharing options...
Geoff Maxwell Posted July 24, 2012 Report Share Posted July 24, 2012 That's great to hear. I look forward to seeing your base solution because the top half is fantastic. Best of luck with it. Geoff Quote Link to comment Share on other sites More sharing options...
mikewest Posted July 24, 2012 Report Share Posted July 24, 2012 Love it Mr B!! mike New Zealand Quote Link to comment Share on other sites More sharing options...
bendybones Posted July 24, 2012 Report Share Posted July 24, 2012 This is the most beautiful thing i have ever seen and should be given full civil rights. Following this thread is like watching a beautiful baby grow into a strong child. One day she will be married... and we will all cry tears of joy!! They will go on to have their own children. And make this world a better, more beautiful place to live. They will bring us to peace! Quote Link to comment Share on other sites More sharing options...
Bash Posted August 12, 2012 Author Report Share Posted August 12, 2012 OK.... so Stuart is back from his family holiday, and back on the case with the Minirack.... This is the Minirack, fully wired up, and ready for my hardware.... it feels like a shame to mess it all up with real equipment, and I cant get to Stuarts for a week or two... but essentially we are rsdy to mount up, plug up, and fire it all up... This is where we are now..... Oh... note the two USB sockets bottom right... for charging mobile phones (cellphones)!!!! Kindest regards to all, Simon B Quote Link to comment Share on other sites More sharing options...
Bash Posted August 12, 2012 Author Report Share Posted August 12, 2012 Oh.... and this is the solution that Stuart used for cable hangers - I believe they hail from the sailing industry.... I think they are dead cool, and we will put a few of them around the minirack. Next on the agenda is to design a more substantial base, onto which wecan mount the minirack, Something more stable than the Zuca....... We are also working on a LiFEPo4 battery scenario that we can build into the base unit... more news later..... Kindest regards, Simon B Quote Link to comment Share on other sites More sharing options...
Richard Lightstone, CAS Posted August 12, 2012 Report Share Posted August 12, 2012 Bash, Lots of beautiful ideas and design - the nautical cable ties are brilliant! Quote Link to comment Share on other sites More sharing options...
al mcguire Posted August 12, 2012 Report Share Posted August 12, 2012 The sailing hardware is called a CLAMCLEAT http://www.clamcleat.com/home/default.asp Quote Link to comment Share on other sites More sharing options...
David Waelder Posted August 12, 2012 Report Share Posted August 12, 2012 CLAMCLEAT is a trade name for a particular brand. The generic name is jamcleat. David Quote Link to comment Share on other sites More sharing options...
Olle Sjostrom Posted August 12, 2012 Report Share Posted August 12, 2012 A jamcleat on a bag has been a wet dream of mine for a long time. If its possible on a bag... Thanks for that discovery, I was about to invent one myself one of these days Quote Link to comment Share on other sites More sharing options...
old school Posted August 12, 2012 Report Share Posted August 12, 2012 I really like the work you are doing on this cart. CrewC Quote Link to comment Share on other sites More sharing options...
Bash Posted August 12, 2012 Author Report Share Posted August 12, 2012 Most of the real work on this rack/cart is being done by Stuart Ebbs, who is a genius. Most of the work I am doing invlves emails and the telephone... and my chequebook ;-)) That is praise indeed from one such as you, Crew..... Kindest regards, Simon B Quote Link to comment Share on other sites More sharing options...
Nathaniel Robinson Posted August 13, 2012 Report Share Posted August 13, 2012 That looks fantastic! I'm working on my own modular mini-cart (not much room for ANYthing in my Corolla); definitely inspired by this build. Quote Link to comment Share on other sites More sharing options...
Phil Palmer Posted August 13, 2012 Report Share Posted August 13, 2012 I'm fascinated by this thread and can't wait for every post and picture. Really beautiful work. P Quote Link to comment Share on other sites More sharing options...
Scott Smith Posted August 13, 2012 Report Share Posted August 13, 2012 Simon: I'm very impressed by what you and Stuart have achieved! First "see through" design I have ever seen! I'm curious about the manufacturer and source for the "T slot" aluminum frame components you are using. It looks a little different from what I've been able to find here in the States. Best Regards, --Scott Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.