Steven Brown Posted June 15, 2008 Share Posted June 15, 2008 My brother just purchased a spektrum dx6i full range tx that runs on 4 AA cells, i.e 4.8volts we have no concerns about the minimal voltage required to power the tranny as it is 2.4 gig and much more efficient than 35mhz. The problem is that some of the older members of our local club say that a welded nicad pack would be much safer than single cells plugged in on to metal contacts. What is the real deal with these metal to metal contacts? has metalurgy changed in the last two decades? and most importantly where does the B.M.F.A stand on this subject? views and arguments wanted........... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 15, 2008 Share Posted June 15, 2008 I would personally never use sprung contact connections in ANY R/C air models - rcvr or tr.Thats my view - now.... bring on the argument Quote Link to comment Share on other sites More sharing options...
Former Member Posted June 15, 2008 Share Posted June 15, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 15, 2008 Share Posted June 15, 2008 tak a tak a tak a tak Quote Link to comment Share on other sites More sharing options...
260 Flyer Posted June 16, 2008 Share Posted June 16, 2008 How many times have you removed the back of your TV remote and "twiddled" the batteries to get it working? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 16, 2008 Share Posted June 16, 2008 Yo - my point demonstrated rather nicely Rob - apart from the extra weight of the carrier too Quote Link to comment Share on other sites More sharing options...
Former Member Posted June 16, 2008 Share Posted June 16, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted June 26, 2008 Share Posted June 26, 2008 Note the batteries in question are in the Tx not the Rx. Lots of RTF which include the TX use individual cells. Quote Link to comment Share on other sites More sharing options...
Former Member Posted June 27, 2008 Share Posted June 27, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Steve Mortimer Posted July 5, 2008 Share Posted July 5, 2008 i have used loose cells in my old R/C car TXs and never had a problem, and i have put them through a lot of rough use, knocking them off toolboxes, dropping them, running over the rough field and throguh teh woods with them, never even so much as a glitch.i had to use a cell holder and 4 NiMh cells on my trainer when i first got it because the bloke i bought it off had "supposedly" put the pack and the electric engine starter that came with it in the post (never turned up, never heard from the guy again) i guess aslong as you do the normal wrapping in foam with an elastic band around them you should have no problems (well, i didnt anyway) Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 5, 2008 Share Posted July 5, 2008 I stand by my original opinion - land based stuff, and little indoor type helis do not pose the same potential dangers. The BMFA have a firm policy / recommendation on this point and you may well find your Insurance is voided if you fail to follow the "rules" - see page 20 of the BMFA Handbook. Quote Link to comment Share on other sites More sharing options...
Former Member Posted July 5, 2008 Share Posted July 5, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 5, 2008 Share Posted July 5, 2008 Well a potential problem exists, more so than with a hard wired battery - that potential is problem is one that is easly and cheaply avoided Quote Link to comment Share on other sites More sharing options...
Former Member Posted July 5, 2008 Share Posted July 5, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Yorkman Posted July 5, 2008 Share Posted July 5, 2008 well,is it possible to fit a soldered 'block' of 4x AAs into the spektrum transmitter?I have a DX6i set on my shopping list........ Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 5, 2008 Share Posted July 5, 2008 yes - but not the easiest of jobs....and would probably - ironically - invalidate the guarantee ! Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted July 5, 2008 Share Posted July 5, 2008 Timbo but the BMFA handbook says that it's OK to use dry cells in the TX and these don't usually come in welded packs. The Spektrum manual says it's OK to replace the dry cells with NiCd's of NiMh's.Will using the Tx set with non-welded NiMh's invalidate the BMFA insurance, will Horizon Hobbies be responsible in that event as it's included in their manual?Should RCME be issuing a warning advising people not to fit loose rechargable cells in the DX6i's but continue to use dry cells as advocated by the BMFA? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 5, 2008 Share Posted July 5, 2008 The BMFA clearly state that spring loaded battery boxes should not be used.Perhaps they mean in the actual model rather than the tr?However, it was not my intention to get into the BMFA standpoint ( there are many things about the BMFA that I dont agree with anyway ) but I merely stated and stressed, that it was just my personal opinion that using spring loaded battery holders in airborne RC modelling equipment was neither good practice or necessary these days.I for one am somewhat surprised that the DX6i uses such a battery box - but as this is the standard setup for this model of tr then I expect there will be no problem with Insurance etc Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted July 6, 2008 Share Posted July 6, 2008 Timbo, thanks I'd rather use some high quality rechargables than poundshop dry cells. I would be quite happy fitting a welded pack into the Tx but I'm not sure how that would affect the warranty of the equipment.I must admit that the battery box supplied seems of good quality and the batteries are very secure.In the instructions Spetrum state that the DX6i sold separately is normally supplied with rechargable NiMH batteries and overnight charger but when sold as part of a RTF set will come with dry cells. It looks like in the UK they decided not to ship with rechargables and charger (maybe to meet the magic < £100 mark).They state in the manual that optional NiCd or NiMH 1.2 volt AA cells can also be used and then go to great lengths to warn you of the polarity of the charging jack which is different to say futaba. There are no instructions on fitting a welded pack into the Tx, maybe that could be a technical article in RCME in conjunction with Spektrum.Ironically I'm only using this set in my small electrics at present and I'm using my 35 set in my larger glow and electric planes. Quote Link to comment Share on other sites More sharing options...
260 Flyer Posted July 6, 2008 Share Posted July 6, 2008 In my job as an equipment engineer, the majority of electrical/electronic problems I have to deal with are caused by bad contacts on connectors. Your goal on any system should be to reduce the number of connections to the absolute minimum. In using 4 loose cells in a battery box you will have 5 critical contacts as opposed to 2 for a hard wired pack. If you use 8 cells you then have 9 chances for a spec of dust or spot of corrosion to spoil your day. Safe flying and happy landings! Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted July 6, 2008 Share Posted July 6, 2008 Nobody heard of WD 40 & I dont mean spraying the battery box & melting it .I dont normally use "quick fix " products but one molecule thick of the afforementioned product works for me & folks involved in space technology I would never ever use a battery box - only in 'er indoors's boats Grumpy Quote Link to comment Share on other sites More sharing options...
Garry Pollard Posted July 6, 2008 Share Posted July 6, 2008 HiDont know if you know this obscure fact, that GB is the only country in the civilised world that takes the cover off a unit to get it going again by spinning batteries. The rest of the world does the logical thing and take out the old ones and throw them away. Surley the Speky shows you the voltage available and wlii bleep when to low [Tx only] unless your ears are good. Where is the problem Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted July 6, 2008 Share Posted July 6, 2008 This is one of the prime reasons i don't like the "toy" trannies that come with rtf's point in case the twister range of contra helis and the belt cp not only do std 800mah dry cells discharge to quickly not only are there to many contacts to fail but both these units have poorly fitting back plates that eject there cargo at the drop of a hat. disastrous if your mid air at the time just try refitting 8 dry cells before your pride and joy beats itself to death on terra firma or worse still some poor innocent passer by. Just an unfortunate incident early in my ownership of my twister bell 47 has I'm afraid coloured my judgement on these. How can these manufacturers get away with. and I quote "proffesional fm transmitter Included" plastered across the box when I've seen better units in a fisher price box.Climbs carefully down off the soap box Must just add I'm not commenting on the DX6i as I've not laid my hands on one yet Quote Link to comment Share on other sites More sharing options...
Former Member Posted July 7, 2008 Share Posted July 7, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted July 7, 2008 Share Posted July 7, 2008 The battery box in my DX6i seems very secure, I think if I was to take it out and fit a welded pack I'd have more concerns over my modifications than the original battery box. Quote Link to comment Share on other sites More sharing options...
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