Tony Bennett Posted April 28, 2014 Share Posted April 28, 2014 looking smart now sir. cant wait to see it flying. Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 29, 2014 Share Posted April 29, 2014 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted May 5, 2014 Author Share Posted May 5, 2014 Thanks Lads - I am giving some thought to the ventilation Tom - as you imply there is no problem getting the air in,...its getting it out that's the challenge! OK, well this has been sitting on the bench for the last week or so - while I've been enjoying the better weather and getting plenty of flying in! But - windy today, so back to it. I've mainly been working to finish the hatch - which has proved to be a bit of a pain! I originally intended to use two small dowels as the front locators and a sliding catch at the rear. The dowels - easy. The catch, well I couldn't quite see how I was going to fix it to the cowl - but thought "hey this can't be that big an issue, just go ahead fix it to the hatch and cross the locating hole bridge when you come to it" - big mistake! I built up the hatch - dowels in front, catch at the back - only to find there was just no way I could find something "meaty" enough to put a hole in! After much head scratching I gave up - and went for a nylon screw into a captive bolt! The only down side of this is I still have the remnants of the slot for the sliding catch - never mind. So, here is the hatch way in the cowl,... And here is the hatch,... And the inside of the hatch,... The hatch is on a double curve - that's why the edging pieces are not continuous - by doing them in sections I don't have to bend the wood! Here is the mounting plate for the rear fixing nylon screw - M4,... And I've let in some hardwood dowels into the front to give a more secure fixing for the cowl screws,... Here's the cowl fixed in place,... And finally here's the view of the hatch in place on the underneath,... The only M4 nylon screws I have at the moment are white! I'll get a couple of black ones with "thumb tabs" on them - I need one for the Dawn Flyer as well. OK, so that's progress so far. I think all the messy and fiddly stuff is more or less done except for providing a way of fixing the battery in place - but I have some ideas for that. BEB Edited By Biggles' Elder Brother - Moderator on 05/05/2014 23:01:58 Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted May 5, 2014 Share Posted May 5, 2014 Worked out very neat BEB Nice job Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted May 6, 2014 Share Posted May 6, 2014 BEB - I've just started using 5S Zippy Compacts ilo Turnigy Blue (basic). The Zippy's are significantly smaller and lighter for the same C rating and capacity. Just looked up a 6S 5000 mah Zippy Compact and it's quoted as 703 gms, £35.54 plus postage. Just a thought! Quote Link to comment Share on other sites More sharing options...
Tony F Posted May 6, 2014 Share Posted May 6, 2014 Lovely work BEB you've given me some great ideas for the Airsail build and electric conversion. That is if its OK to borrow some of your ideas ? Tony Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted May 6, 2014 Author Share Posted May 6, 2014 Tony - I nick ideas all the time! That's what forums are for, its why we post this stuff. If someone finds a good way of doing something then the idea is to spread that around. Indeed - while the detail design is mine, the basic idea here was nicked by me from a guy on another forum as I stated near the beginning! Peter - thanks for the "heads up" on the Zipp - I'll certainly take a look. The opening will take the Loong Max - but just. This means I can't do what I'd really like to do which is lay a Velcro carpet for the battery to sit on - it would just snag as I try to slide it in. Now - as I posted on page one - I can get round this. But a smaller, lighter, battery is always welcome! BEB Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted May 6, 2014 Author Share Posted May 6, 2014 Those batteries do look interesting, and lots of positive feedback on other forums - but they are out of stock BEB Quote Link to comment Share on other sites More sharing options...
IanR Posted May 6, 2014 Share Posted May 6, 2014 BEB, instead of laying a carpet of Velcro, have you considered using a carpet of anti-slip mat - the rubbery, pimply stuff. A full bed of this with a Velcro strap to hold the battery down in close contact will, I am sure, prove to be very sticky. And battery removal is no problem, unlike separating two strips of Velcro from each other. I have done this in my Parkzone T28. Granted, its only a 3S battery but, in moving it forward to get the CoG right, the Velcro hold-down strap is only just in contact with the rear of the battery and yet the anti-slip mat still grips really firmly. I'm sure that, even a heavy battery, held down only at one end, but with a full length of anti-slip mat in the battery tray, will still do you a good job. Ian Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted May 6, 2014 Author Share Posted May 6, 2014 Sounds interesting - where did you get it from? BEB Quote Link to comment Share on other sites More sharing options...
Martyn K Posted May 6, 2014 Share Posted May 6, 2014 Various places BEB. Try places like Wilco or camping shops, it is sold to be placed in drawers to stop stuff sliding around. We use it a lot in the motorhome to keep stuff in place (on top of worktops) while we are driving around. It will definitely stop the LiPo sliding, but it will still need to be held down. Its like a very soft neoprene rubber with dimples. Regards Martyn Quote Link to comment Share on other sites More sharing options...
IanR Posted May 6, 2014 Share Posted May 6, 2014 B&Q - and can be ordered on-line, it seems. **LINK** Norm Abrams uses this stuff to hold flat pieces to his worktop whilst he uses his router on them in The New Yankee Workshop so it must be good! Looking at B&Q's photo, in close-up, it looks slightly different from mine which has round bobbles on it as opposed to square but the description seems the same. Anyway, at only 4 odd quid it must be worth a punt. Ian Edited By IanR on 06/05/2014 14:24:26 Quote Link to comment Share on other sites More sharing options...
Charles Lee Posted May 6, 2014 Share Posted May 6, 2014 Ian gave me this tip for the anti slip mat as he watched me nearly rip my P.A. biplane apart trying to remove the lipo. I now use this method on both planes & helis with no problems at all. Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted May 6, 2014 Share Posted May 6, 2014 BEB - HK Global Warehouse is showing stock - but they'll take around 2 weeks to get here. The Euro Warehouse is out of stock as well. They seem to be popular batteries! Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted May 6, 2014 Share Posted May 6, 2014 BEB & peter if you chose the SCS delivery option from the HK global Warehouse the lead time is usually pretty quick, the courier basically fetches consignments over as personal luggage and hands it over at heathrow to parcel force or similar this speeds things through customs and frequently I've had stuff faster than getting it from the UK warehouse, you do pay a little more for it though. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted May 6, 2014 Author Share Posted May 6, 2014 I shall investigate that Phil. OK I've weighed it - 7.8lb, that's with just about everything, a Loong max 6s 5000mAh battery, battery compartment, motor, mount, ESC, cowl with fixing screws and a pretty heavy IC 14x7 prop to make up for the fact that I haven't got the spinner on board. The only thing missing is the Rx. That's not bad at all - the BlackHorse spec says 7.26lb - I suspect that with the OS90FS and two flap servo slowers I have removed, my original was a bit more than that, maybe around 7.5lb Anyway, the upshot is that it's probably about the same weight as it was before - give or take a couple of ounces. If I use a lighter, or slightly lower, battery it might even come in below the IC weight. BEB Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted May 6, 2014 Author Share Posted May 6, 2014 I've been doing a few calculations - and I don't think that the case for Zippy Compacts quite stacks up after all. The 6s 5000mAh Zippy Compact is: L=161mm, Height=46mm, Width=45mm - Weight=703g, Volume=333,270mm3 The Loong Max 6s 5000mAh I have is: L=140mm, Height=49mm. Width=48mm - Weight=780g, Volume=329,280mm3 So they are not really "compact" at all! True they have a slightly smaller cross-section, but only by 3mm in each direction, while they are actually significantly longer - by 20mm. And length is an issue for this model as I have to be able to lift the front of the battery sufficiently to clear the chin of the cowl and I'm far from sure that 3mm off the height will compensate for 20mm on the length. I've had a look at the possibility of going 5s - but that doesn't really work either: At 6s, with a 14x7 prop, it would draw 47A, giving 1.18kW and deliver a thrust of 4.8Kg. At 5s, with a 15x10 prop, it would draw 57A, giving 1.2kW and deliver a thrust of 5.2Kg So the 5s gives me a 25% increase in max current (with an associated decrease in flight duration), for basically the same power. The extra 0.4Kg of thrust is academic really because the model only weighs 3.5Kg - so both promise somewhat unscale like, unlimited verticals! Conclusion - stick with the 6s Loong Max I think. BEB Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted May 6, 2014 Share Posted May 6, 2014 Hmm good analysis BEB. Guess it depends on what you are comparing the Zippy Compact with. I use Turnigy standard 5 S cells and the Zippy is definitely smaller and lighter then them. Looks like Loong Max is a close in size but heavier by 77 gms. As I use 2 5S batts that is an additional 2 x 77 = 157 gms! So for me they are worth it! Be intersting to hear how the beast performs in flight. Quote Link to comment Share on other sites More sharing options...
Redex Posted May 7, 2014 Share Posted May 7, 2014 Just wondered if you had considered the Dynamic range - 6S4500 (bit less on capacity) L=130 H=42 W=49 and weight is 601gms !! Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted May 7, 2014 Author Share Posted May 7, 2014 That's smaller than both of them Redex! And lighter. But tonight's result means I'll be staying with the Loong Max! Do you ever get the feeling that things are going uncharacteristically well? Tonight I decided to balance her and fix the battery position. To be honest I was not looking forward to this as what was I going to do if I found out that the battery had to go further back than the length of chute? Or so far forward I couldn't get the hatch on? So, with some trepidation I put the battery in - I decided to start off with it level with the front edge of the chute - this would be an ideal position in some ways as it would mean I could get a Velcro strap around the front easily, the battery would be easy to get hold of to take out and the hatch would close nicely. OK, I carefully positioned my home made balancing stands underneath the inverted model, fiddled until she balanced,....and.....they are smack on the main spar! Just where they should be! How's that for luck! Here is a picture of the battery in the magic place,... Couldn't be better if I'd designed it to that - which I didn't, it is just good luck! The eagle-eyed amongst you will observe that the plate that was holding the captive nut to fasten the hatch down has gone - it was a bit awkward getting the battery passed it, you could do it - but not easily. So I've gone back to the string catch having sorted it out. BEB Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted May 7, 2014 Share Posted May 7, 2014 Nice one BEB, don't you just love days when all things go right? Shame they don't seem to balance the....er days when things don't Cheers Danny Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted May 7, 2014 Share Posted May 7, 2014 BEB - well done! Are you going to use a spark arrestor to avoid the darn great flash and crack when you connect up the drive battery? I swear by them and I have to connect a 10S and it all happens as if there are no volts present! Very easy on the nerves. Quote Link to comment Share on other sites More sharing options...
Simon B Posted May 8, 2014 Share Posted May 8, 2014 I've never found it necessary on 5 or 6S, personally. Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted May 8, 2014 Share Posted May 8, 2014 Simon, you're clearly made of sterner stuff than me! Quote Link to comment Share on other sites More sharing options...
Simon B Posted May 8, 2014 Share Posted May 8, 2014 With XT60s you tend to not see it really, as it's all contained. If I used bullet connectors I might not be so brave... Quote Link to comment Share on other sites More sharing options...
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