Frank Skilbeck
-
Posts
6,257 -
Joined
-
Last visited
-
Days Won
1
Content Type
Profiles
Forums
Blogs
Gallery
Calendar
Downloads
Posts posted by Frank Skilbeck
-
-
9 hours ago, Peter Jenkins said:
Hi Frank
Please explain what you mean by extended time. My message was that it's OK to charge up LiPos a day or 2 days early since they will not lose any charge over that period. It's the same with LiFe and Enelope NiMH but not other NiMHs.
I don't make a habit of it but if I don't use all my packs then I'll leave them fully charged for up to 2 weeks. If it's going to be longer, then I'll stick then kn my charger and didchafge to storage voltage.
I've run 5S 5000 mAh 25C packs for the past 14 years and, as I'm sure you've found, some packs swell up early while others soldier on for ages even from the same label. I don't use high C packs as my flying rarely demands more than 80-85 A - that is in 10S configuration - and then only demand that for around 6 - 7 secs at any one time. That equates to around 2,800 W max demand although in my current setup the max power I've seen was 3,600 W at 98 A. That was a test early on to check with the manufacturers figure of a max 99A draw on a 23 x20 props. It did what it said on the tin! I should emphasise these readings were taken with telemetry while airborne with max/min figures stored for inspection. I no longer check max power while the aircraft is tethered on the ground as my testing showed that you can pull 25% more power out of electric motors in such circumstances.
I aim for a minimum of 100 cycles per pack but have had cheap Turnigy ones reach 200 and expensive packs die at 60 cycles.
The articles I've read have noted that the cells degrade more quickly if stored at 100% charge and elevated temperature, if you charge them up at lower temperatures and then they warm up there is some minor degradation which accumulates over time. But yes there are lots of reasons why lipos die early so it is probably me being a bit over cautious.
-
10 hours ago, Peter Jenkins said:
Toto, LiPos hold charge for weeks. So, charging a day or so earlier is no problem.
They do, but it's not a good idea to leave them at 100% for an extended time, especially if they see big temperature fluctuations.
I've had a few swell up that have been left fully charged, so no put them on a storage charge when I get back from flying and then top them up the day before, whem I know the weather is going to be conducive for flying.
-
1
-
-
9 hours ago, toto said:
Hi Grumpy,
I have the A test downloaded and in my flightfolder, it's just been a while since I've studied it. I'll need to revisit it ..... several times ...... before I book to sit it. Likewise with Article 16 to prepare for any questions asked.
I believe that if you take the theory test on line and can demonstrate to the examiner on the day that you have passed it, then any questions are restricted to you site specific safety protocols. I may of course have misunderstood that but I'll make sure that I have done the required swatting before hand anyway.
Toto
If you are a BMFA member you can do their registration competency certificate online, https://rcc.bmfa.uk/rcc and add it to your BMFA membership. Note you can keep redoing it until you pass, it's no problem.
-
I've run petrol engines on standard 10% ethanol, seem to run ok on it, but the problem maybe degradation of elastomers, e.g carb diaphram, perishing, not done enough running to determine if this is a problem. You can buy synthetic petrol, no ethanol, but it's about 3x the cost.
-
Shout out for 3DRX, not used them before but they had some aeronaut props I wanted, ordered yesterday afternoon arrived in post at lunchtime today. 👍
Also bought some bits (glow switch and magneto cutout) from Mike at Model Radio Workshop on Monday afternoon, arrived Wednesday.👍
-
18 hours ago, FlyinFlynn said:
Yikes.....nearly as expensive as playing with toy planes.
But not as addictive........🤪
-
1
-
-
-
I have a 1/5 th scale T21 with scale spoilers, they are quite effective.
These have a servo on each spoiler with a simple linkage, they are top mounted and hinged with solartex (wing is covered in solartex). If you can put them on separate rx channels as it makes setting them up easier.
I have an ASK11 motor glider with similar spoilers and they do make landing on our tight strip much easier. One thing to note is that I much prefer to have the spoilers on a proportional control, in my case the "throttle" stick.
Years ago I had top mounted spoilers on a Chris Foss Hi Phase, these had a pull cord to pull them open and fridge magnets to keep them shut, single servo in the fus and when wings were plugged in it was a simple case of hooking the spoiler cord loops to a ball link on the servo arm, it worked very well.
-
I was going to say what Martin said, but if you want to do cartwheel manoeuvres then having them spaced apart will help 😉
-
I've used a 4 cell sub C on mine, typically do 3-4 10-12 min flights per session and the battery (3300 mah) has plenty left.
BTW I fit a physical switch in series with the optical unit, to ensure complete isolation.
-
If you don't want to faff with extra ignition batteries and CDI unit then the Zenoah Magneto units are a good option, e.g. Zenoah G260PU 26cc, not the most powerful but good reliable engines.
I acquired an old Kalt 23cc (Rebadged Zenoah) in a Christian Eagle biplane, hadn't been run for years, I changed the carb diaphrams and it runs great, still as noisy as a DLE though.
Just engines do them https://www.justengines.co.uk/shop/petrol-two-strokes/zenoah-petrol-two-strokes/zenoah-g260pu-26cc-aero-engine/?v=79cba1185463
-
Just building a 1/6th scale Aeronca C3, would be an ideal candidate for electrictrickery, but I'm sticking with plan A of the Vega 50T. Lots of electric models though too.
Why can't the petrol engines be supplied with silencers, I refuse to call the standard item a silencer.
-
1
-
-
Yes, but the grid costs are more to do with connecting wind power to the grid, not charging electric vehicles. If anything as Vehicle to Grid is rolled out EVs will assist in balancing the grid, Octopus are currently trialling a scheme where they buy back electricity from your car and then recharge your car for free later, https://octopus.energy/power-pack/ But when we rolled out nuclear originally the power stations were all by the sea (for cooling water) and would have required distribution upgrades to connect them at the time.
BTW regarding range, one of the car magazines tested the new X Power MG4 against a Seat Cupra petrol, the MG4 was 17% down on it's official range and the Cupra 20% below the official mpg.
-
The DJI Minis, less than 200grams are full range, but obviously if they went behind somewhere and blocked the signal that would be different. If they hadn't programmed in a return to home it may have just auto landed.
-
If the lights were still flashing the owner can't have been too far away otherwise the batteries would be flat.
-
Pete, have a look at the Li-ion Molicels being offered, some EDF guys are using them, not quite the same punch as Lipos but mah per mah they are lighter. We've put 2 x 2s ones to power the Rx and servos in my mates FW190 to replace 2off 2200 mah 2s lipos, note model has all HV servos.
-
Spares might also be an issue, clubmate had an arrival that snapped the needle and housing off the carb, can't find anyone with spares, but I have a crate full of glow engines so might find something in there.
-
18 hours ago, toto said:
Hi Learner,
Watched the BMFA video again as its been a while. It is pretty useful both from a flying ele,ent point of view and the pre and post flight checks. I'm a bit away from that yet but it is my ultimate target. I'll also need to swat up on the potential theoretical questions that could be asked. It's been a while since I've looked at that.
A bit to go yet.
Toto
If you've done the BMFA online RCC test, then the questions on the day should only be about checking the model and club specific rules.
-
Just for info I have a Blade 300 with the ASX rx and it works fine on a DSM2 Dx6i.
Note also if the Align has a flight controller, maybe not as it has a flybar, then it may do the 120deg mixing and not the tx.
-
The blade holders are almost certainly not pushed on, if you remove the blade from the holder you'll probably see a screw on the inside that threads into the rod that goes across, see page 6 of this manual https://aligntrexhelis.com/images/manuals/Align/450/RH45E09AT.pdf
Also do be careful flying the heli, they can very quickly get out of control, so make sure you aren't in a confined space and any spectators are well out of the way,
-
Would depend on the size of the model, for larger models I prefer Sub C cells rather than AA for their ability to maintain voltage underload. Other than that I've used both Life and Nimhs for Rx/Servos and ignition. Don't leave Life cells on, if the voltage drops too low they are toast, so remember to make sure they are switched off after a days flying.
-
38 minutes ago, martin collins 1 said:
😅 I have plenty of ground running to do on the model before it goes airbourne so i can get a good idea if it is still useable or not. The charger has just finished, 1911 put in and showing 7.08 volts.
You might have got away with it, but do a discharge test at say 1 amp to check first, I did this with a 2s life and found under load it's voltage dropped dramatically.
-
1
-
-
Gravity, once the engine is running the carb will venturi effect will draw fuel in and the exhaust pressure will also push the fuel through as well.
-
INav and one of these and jobs a good un
Seagull PT19
in Scale and Semi-Scale kits
Posted
You say there is an extra firewall piece, could this be an adapter plate? Do you have a photo of the additional firewall.