Jump to content
Please be aware of scammers when using the Sale/Wanted forum areas

Chris Bott - Moderator

Members
 View Profile  See their activity

  • Posts

    8,533

  • Joined

  • Last visited

  • Days Won

    4

 Content Type 

Everything posted by Chris Bott - Moderator

  1. Chris Bott - Moderator
    For the LVC setting go as low as you can set it.  The volts stay so constant till empty LVC does not help in any way shape or form. Except if it cuts off while you still have charge left, because you are using so much current that the volts go that low.  By the way, I accidentally took my first pack (yes pack) to zero volts (yes zero) accidentally twice (yse twice) by leaving it on a fat test resistor and fogetting. What an absolute numpty I know!  However I am still flying with that pack two years later and am still noticing very little difference. This of course is not something anyone would recommend, It just shows that  worrying about where to set LVC really isn't an issue. If you feel power dropping off at all, you are pretty much deadstick. It is almost like a fuel tank running out.
  2. Chris Bott - Moderator
    Hi Timbo I've finally got myself the A8 charger too (a proper charger) after charging A123's with various home made concoctions. Including a £15 laptop psu that gives 10A into 6S. Proper round can A123's should not be taken higher than 3.6V  As you go above that voltage the volts rise quite quickly but you don't put any "useable" charge in. Its almost like charging a small capacitor. A123 say they can be taken to 4.2V but also state that this can reduce life expectancey. (LiFe expectancy? lol).  It's important to know that they are in balance, as the cell going high volts "deprives" the lowest cell from getting to 3.6V if you see what I mean? It seems that once current has dropped off at 3.6V then all the active ingredient is used up. Overcharging cannot take place and is not useful,.This is a key reason that they are safe. I'm really keen to see how the square (rectangular) ones perform so keep us informed. By the way, on my A8, on fastest charge, 7A, into 6S, the charge is ended with a message "connection break" and I dont get the info telling me how much has been put in. This always happens so I guess its a software fault. Does yours do this at all?
  3. Chris Bott - Moderator
    I love the look of the motor mounts - is that a service you will be offering to the rest of us Think I'd use 4 rather than just the one
  4. Chris Bott - Moderator
    Dont forget A123's are down on voltage compared to lipos.  You will be disappointed with comparative performance if you don't/cant fit a bigger prop.
  5. Chris Bott - Moderator
    It excites me Timbo!I think the A123's will excite you Mind you when we did Dannys Wot4 (watt4?) we put 6 A123's in. This was to keep current down and duration up. Oh and to be balistic
  6. Chris Bott - Moderator
    Shaun, I'm afraid you'll have to wait a little longer for the verdict that we are all so keen to know. We did go to fly this morning, Danny with the Fury and me with my Ripmax DH88 on a cheap setup. Due to the recent weather, the clubs new mower was taking the opportunity for its second outing and we couldn't fly within the time we'd allowed. It was also very cold and windy so we had to give it up as a bad job. Plan is to go again one evening.So watch this space... The good news is that the mower is doing a great job and the stip for the funflys should be superb.
  7. Chris Bott - Moderator
    I think Danny likes his lightweight, but with the ability to shock It's the electric personality that counts
  8. Chris Bott - Moderator
    I think I've settled on a solution for mine. Theres not much in it between adding one extra connection and this to be honest. For me this leaves my batteries in my standard stick of 3 for use in other models. Just need to find a 10A connector for charging. Or use Timbo's method, which makes it impossible to charge with ESC connected.
  9. Chris Bott - Moderator
    Looking good Danny I need to speed up to catch you with finnishing the DH88 for the same flying session.. Bring the vid camera and we'll see what we can get. I'm trying to work out an external Deans arming solution with charging. I currently arm by having cells in 2 lots of 3 in each nacelle. Each "3" is connected to the ESC, and I arm by connecting the 2 "3"'s together at the back. This would be a great place to charge. But to do that I need to short accross the ESC ends while charging. This setup then has the potential of a short at both ends so I've given up on that idea...  and I'd still have to get to the ESC end. So a new setup. To charge at the front, where I arm with a shorted Deans, I need one more connection for the other side of the battery. Do I put in another deans just for charging? That has the potential of connecting the arming plug accross the battery so thats a no no. I could put in one 4mm round and make a charge lead which supplies the battery side of the arming socket and the 4mm (or even a 2mm). Anyone have a neater solution???  Maybe just a different style 2 pin socket for charging is after all the simplest solution?? Tell you what - I'll also buy ice creams (or maybe even a beer) for the first person who can show me a decent solution, live in the flesh, at our funfly.  Danny I hope the ice cream man comes, otherwise its a trip out to the shop
  10. Chris Bott - Moderator

    Chris Bott - Moderator posted a gallery image in Member Albums

  11. Chris Bott - Moderator
    Looking good Danny. I see the weather seems to have noticed that you've nearly finnished the Fury. You've frightened it away
  12. Chris Bott - Moderator
    Went flying Sat and Sun. More club members turned out this weekend than have for a long time. Carried on with my experiment with a live webcam for our 3 funflys this year. Only caught the end of the morning session today after many had left. We also had an impromptu Club barbecue at the field. To checkout the webcam see http://greenacresmac.co.uk/May%20Barbeque.htm It did prove that I need a better camera...
  13. Chris Bott - Moderator
     you may have to get used to my spellling!
  14. Chris Bott - Moderator
    Danny, get that motor mounted and run some tests, I'm dieing to see some results.Timbo, not on your scale obviously, but I flew a DB Sprot and scale 56" Tiger Moth first flight yesterday on a 670KV Motor on 6M1's and a 12x6. (had the motor, cells esc spare and it made the cg spot on). Was so good I had 4 flights, last one must have been over 10 mins and I only put 1000mAh back in. I was very pleasantly surprised how slow and sedate the flying was. Having never ventured into scale or bipes before. Took more rudder than aileron to fly, but everyone had warned me about that.If you like the look of the field, I'm hoping to be there this afternoon with a live webcam. This is another practice for our funflys. Mind you on a day like today, I can't see anyone looking at a website this afternoon lol. If yr interested see greenacresmac.co.uk
  15. Chris Bott - Moderator
    Not sure if he'll thank me for this or not, but theres a video of todays flight at http://www.greenacresmac.com/Videos/Hurricane%202nd%20Flight.wmv  Sorry I didnt properly capture the huge grin afterwards Danny.
  16. Chris Bott - Moderator
    I guess proof will be in the pudding as they say. Thats why this is such an interesting experiment. At least with keeping the cost down, they are not expensive mistakes if an upgrade is necessary.
  17. Chris Bott - Moderator
    I recon Danny will prop for 50A but only use it very breifly. We've been doing a lot of eagle tree testing lately and its amazing how little power you use at straight and level cruise. So maybe 1200W just in case and probably less than half to cruise. 100W/lb was an old rule of thumb, generally applied to smaller models using inefficient brushed motors. With a bigger model and efficient brushless motors this can be relaxed substantially. With A123's we can prop for large currents, they will take it. Then maybe use this for takeoff only or the odd impressive vertical, and fly around scale fashion on much less power. Danny you'll be fine, especially on our nice new manicured lawn. You'll find out if the spec of that ESC is correct!
  18. Chris Bott - Moderator
    Pick entry 304 please!
  19. Chris Bott - Moderator
    Would have been mid 70s that I started. Keil Kraft free flight. A Jetex Javelin I remember for some reason, probably because I ignited the tissue and dope when I lit the motor, Still launched it and it went Ok for a while lol. Then onto profile C/L with diesel engines (oh the smell!) First radio was a McGregor single channel. It had crystals so was "advanced". Press once for left and twice for right if I remember correctly. In a Mercury Matador that you can still buy today. First Propo was Wiltron 4-5. It's still in the loft and the DEACs are OK. Things have come a long way since then, not so sure about my flying skills keeping up though.
  20. Chris Bott - Moderator
  21. Chris Bott - Moderator
    Well I am sorry!    But after constanly using these for 2 years, I really didnt think they would surprise me again! Theres nothing like a bit of banter to get me going, you've asked for it now! Great news (or is it rumour) is that hot on the heels of the 1000mAh A123's, there are very soon to be flat, rectacular ones in other useful sizes like 3300. By the way, A123 are also producing replacement batteries for the Toyota Prius which boost performance so much that Toyota are concerned about their motors!. This converts the car to a "plug in" that can charge at home and run on batteries. (its on bloomberg) They are power of choice now in many Robotwars robots and the power the record breaking killacycle (its on youtube) Argghh no.. I cant stop.. Oh yes - ""Repent - The end of the world is nigh...  " Oh and I must ring my broker...
  22. Chris Bott - Moderator
    Apologies before I start, I just have to make another comment about A123's. Tonight I got round to a job I've been thinking about for a while. Amongst other tweaks, I swapped out a battery in my MK Alliance pattern ship. Took out a 2 year old very abused battery and put in a brand new one. Then i did some power tests. I'd changed the prop too to give me a bit more speed. So comparisons aren't quite direct. The old battery has flown hundreds of flights, been crashed, and bent. Its been tested to 120A and flattened to 0V by leaving a test load on too long 3 times! It's still been flying the plane fine. The old battery tested as follows, with a 800KV motor, 12x6 Prop and 7S:-  Volts down to 19.7V while 43A was being drawn. This giving 840W. With the new battery in, I have fitted a 12x8 prop and as expected the current draw was increased:- Volts now down to 19.2V while 49A was being drawn. This giving over 950W. I'm putting the increase down to the change of prop. What I'm amazed about is how the old battery is standing up after all I've done to it!
  23. Chris Bott - Moderator
    Well if Dannys ordered it, then we are in for a heatwave.. Better book your camping pitch now
  24. Chris Bott - Moderator
    Sounds like a good plan to me. And maybe we'll get some decent weather this year??
  25. Chris Bott - Moderator
    Fantastic. Look forward to seeing you. Hope you can make it. Don't worry we won't be "preaching". I'm more than happy with anything that works these days. And I've just ordered some Lipo's for the summer too. Wednesbury is close, are you anywhere near these days?  Yes, its a shame Mark left for the hills, he's flown jets at our funflys a few times.
×
×
  • Create New...