Grahamd

Posted by Terry Whiting 1 on 07/06/2010 11:53:56: No   I was at  NLMFC's  (Baldock) open day, being the 6th June they put on WW2 model D-Day. same absolutely fantastic models, but sadly not one Lysander.           So was I (2 miles from my house) and next year there will be

Here's where I am at the moment (only had the plans a few days, long story). Stab done Elevators and stab skinned/sanded  Fin and rudder done  And tonight the fuz/crutch (firewall not glued)  Should have the formers on tomorrow.

Before this excellent thread gets forgotten about, I'd like to ask a few questions to those who went the electric route? 1/ Where did you put your batteries in the end, and did it balance near the point without too much additional lead up front?  2/ What motor did you end up using (seen several on here using different setups, perhaps we could get a list) I have one in mind, but always open to discusion (GC XYH50-55 580kv is top of my list) ?  3/ based on your motor choice, did you (what size/make) user a 3-bladed prop (I've always used Graupner) ?  

I've also just taken the plunge and ordered the plan, but it will have to wait till I finish the Lysander

One deletion ? Model Images in Letchworth (Herts) is sadly no more.  One addition ?  Model Workshop Road FarmWendy BassingbournHerts (01223 208873) Best news yet, is he is open Sundays

Very interesting Ton, any more details ? Sheldon, they are not yet fitted, it was just an fyi of what they will look like when completed.

I now have all the wing ribs, braces etc cut and ready to go, but I'm off on me hols for a week, so building the wing will follow;

Whahay fin and rudder now almost complete (just need to add some small sheeting to the front of the rudder, ala full size rudder), the fin was sheeted in 1/16" and the rudder open (will be covering in Solartex).  The rudder is over 18" long    

Ok, if anyones still around? I said I would talk about my electric setup; I've spent many weeks browsing the  net and reading and asking to try and understand what seems to be a black art of understanding what electrics are about, and the following is what I have gleamed and understood, and I hope understandable to anyone else in a similar position.  POWER = WATTS Volts = abbreviated as V. Amps = abbreviated as A. Watts = V x A (This is a measure of power ie the work of turning a propeller to move the plane. (746 watts equals 1 horsepower)) I found the following guideline on-line and is an indication of watts per pound for different types of flying 25 W/lb = minimum for level flight 50 W/lb = Trainer/Casual/scale flying 75 W/lb = Sport flying and sport aerobatics 100 W/lb = aggressive aerobatics and mild 3D, effortless loops from level flight. 150 W/lb = all out performance (or reasonable 3D). 200 W/lb = Unlimited highspeed vertical flight. Assuming the Starlet comes out at 12lbs (original design weight was 11lbs, the then LMA limit) so 100 watts x 12lb = 1200 watts required.  Now working out the current required, if we use a 3 cell lipo, we have 11.1volts, so 1200 watts divided by 11.1v (Current = power divided by volts)ending up with 108.1 Amps !!!! so I increased the voltage to 4 cells (14.8v) now calculate 1200watts / 14.8v = 81 Amps, still too many, so 5 cells1200watts / 18.5volts = 64.8 Amps, a more realistic amount.  So if I could get a lipo that could supply 18.5volts and 65Amps for an hour I could fly full wack for an hour! But I can't, however I can get a 5 cell lipo (18.5volts) rated at 5000mah (5Amps) with a "c" rating (amount that can be obtained) of 20, that means 5amps x 20c = 100Amps but only for 3 minutes (60 minutes / 20). Now if I double up on the lipos (series) then I have 37volts (18.5v x 2), now 1200watts / 37volts = 32.4 amps, so 2 X 5 cell packs of lipos rated at 5000mah and a capacity of 20c will provide 37volts and 100amps still for only 3 minutes, BUT I now only need 32.4amps so 33amps/100amps = 3 times as long, ie 9 minutes of flying at full wack. The reality is the model should be lighter not heavier and no one flys at full throttle for the whole flight (do they?). So I need to order two 5000mAh 5S1P 20C (where 5000mah is 5amps, 5S = 5 cells (18.5volts), and 20C is the amount (AxC)).  After some help I found an XYH63-64 230KV 55A Outrunner motor  Kv : 230 rpm/V (the k or kv figure on a motor represents the speed of the motor) efficiency current : 42A Current capacity : 55A/60s Input Voltage : 4-10 Lipo (or 14.8volts to 37volt) Recommended prop size : 20x10 / 20x13 / 22x8  Because I could potentialy have 100amps I need to use a speedcontroller (esc) rated at a minimum of 100amps.  Hobbywing Pentium-100A-HV Speed controller esc 1.1 Output: Continuous 100A, Burst 120A up to 10 Secs. 1.2 Input Voltage: 2-12 cells lithium battery or 5-36 cells NiCd/NIMh battery. 1.3 BEC: None. (no bec means I will still need a battery for the reciever) Well thats the theory, now I have the motor and the esc  Hope I haven't driven anyone away?  

Had a few hours to kill whilst it rained , so I completed the second elevator. Now the whole thing is taped together so I can sand it as a complete item.   

I've been absent from modeling for over 2 years, and the best way I know of getting back into something is to throw yourself into it big time, and the Starlet suits that object fine. First lets see what a Starlet looks like, yep its a small homebuild plane that is built the same way we build our models.    The original plans (Traplet) were drawn by Dennis Tapsfield (now deceased), and are a bit aged in there design, so hope to make a few small changes as we go, the biggest being the use of a Large Brushless Motor, instead of the suggested 20cc petrol engine (or 1.20 4s), but more on that latter.  The first thing I like to do with plans is either get a copy, or in my case take them to pront-a-print and get them to scan them to uncompressed .tif on a cdrom. This has two advantages, one you can view the plans on your pc (at home or WORK) and second using software such as IsIplot you can print all or some of the area to standard A4 pages. The Tailplane on the plan only shows one side (saving paper) but using IsIplot you can print both sides (I do this using the "mirror" optin on my printer) and stick them together using tape.  I also print out the parts I want to cut and using baking paper (from Wilkos) I trace and cut the parts I need.  Then its of we go with the tailplane construction (using lite balsa where possible to keep the weight down).  Then I sheeted the surface with 1/16" using small pvc bags (I got her indoors to make these) with lead shot inside to hold the balsa in place.  This is a photo of the full size, which looks like a large model....  So I looked at the above and made a few changes to the elevators, 1/ I only used the 4 ribs as per the full size, and 2/ I added some 1/2" strips front and back that I then scalped to shape.  Then using G10 I made some elevator horns (still got to drill them), one on each elevator.  If your still reading, next post I'll describe the electrics I'm going to use.        

Erfolg, I know your pain, and if only I had a penny for every model covered with poly-c

Posted by Erfolg on 08/04/2010 14:31:11: Graham   The history is very interesting.   It does beg the question though what is the fundamental difference between "Ronseal Floorseal" and the other water based varnishes for floor finishing.   Is it the hardness? or something else.     Ronseal Floor XL was developed for shopping mall wooden floors, where traffic is VERY heavy and the wood needs to take shoes, buggies, walking sticks and every thing else you can imagine, or would rather not Ronseal Diamond is a home use varnish, the real test I found was over time, although a quick test showed you could rip the covering off the wood, as it was not designed to bond into the wood like floorseal XL does. Hence Poly-c can warp wood, varnish is more fogiving as it does not penetrate to the same level (molecular). The real problem now is the silly EU rules over chemicals, hence everything is becoming harder to get and more expensive, and more and more chemicals are being banned in the UK.

Posted by Erfolg on 04/06/2009 09:15:02: Phil   It seems I am wrong in that Wickes and Poly C is essentially the same stuff.   I am still unable to find the original artical, that a reference was made to Poly C. Yet a conversation on the telephone with a mate, who is a floor fitter revealed that approx. 2 years ago, I was after a sample of a product made by Ronseal.   The product at that time cost approx £55 per 5l plastic container. Apparently it was called "Contractor Quick Cure". At that time he had not used. So there was no left overs available. He says that the range has widened now, For heavy traffic areas you can buy an hardener, or a high traffic version. It is still dear.     Hmm, as the author of the original article in Model World (wish I'd called it something else) maybe I should clarify a few facts? The original driving force for me was to find something similar to epoxy/G-cloth covering that was clean and easy to apply (Poly-c fits this well). I experimented with dozens of varnishes and epoxies etc before trawling the then rather limited internet, and in desperation called Ronseal (uk). After many calls I was put through to their techy dept, who (lucky for me), knew an ex employee who had done similar to a model glider, many years earlier. Some days later the same techy guys called me back to tell me they had discovered which of their products was used and why. The product was called "Ronseal Floorseal XL", and a 1 gallon sample was sent to me foc (still got most of it).   I then spent almost a year testing its adhesive and strength properties against dozens of other "Similar" off the shelf products, but never found one that came even close.   I wrote the artical for MW and almost a year past before the article was published. The article was a great hit with everyone wanting to get hold of the stuff I jokingly called poly-c. When I made some calls to Ronseal, due to the elapse in time, the product was now only available via pallet drops of 100 x 1 gallon botles , and Ronseal complained to me about the number of phone calls they were now geting asking for 250mls or less...   Not being in a situation where I wanted to purchase a 100 gallons of the stuff, I passed the details to Rc World, who did buy a pallet load, and decant it into smaller bottles. (oh and by the way I got NOTHING, NADA from Rc World for this, and even had to write the instructions on their web site   Do I regret any of it, no, this hobby is about sharing (I hope) and thats what I have done, and the reward is reading how many people have used it over the last few years (too many, tooo quick).   Grahamd  Edited By Grahamd on 08/04/2010 13:25:26

Posted by ************ on 22/01/2009 18:27:30: Hi Graham,   What's happening with your Dauntless build?   I know its been a long, long time and NOTHING, but after the death of my father things got silly at home, with my mother not excepting his death, and expecting me to almost live in, just in case she needed anything? But I'm happy to say a corner has been turned, and if its of interest I would be happy to share the dauntless with you ans I now put the past behind me and get on with building her ?  Over to you

After what seems like an age, I hope I'm going to get back on with the Dauntless in the very near future. I made my first venture into the workshop last night for over 6 months, and it felt nice.  Currently I'm just about to start converting a Black Horse Decathlon from IC to Electric, so at least I'm now back in the building world. Thanks for all the kind thoughts Graham 

Thanks for all the kind words.  My father passed away 26th Nov, and was buried Friday. I'm trying to get enfussed about modeling but it aint happening, perhaps in the next few days ?

Thanks Geoff for the nice comments, the build is on hold for a few weeks as my father has just been given days, if not weeks to live, as a hospital infection of mrsi has now turned into a brain tumor.  Bare with me, I will return

Sorry no updates, I'm just finishing the flaps and then I should be in a position to sheet the wing up.

Got the first pair of flaps and dive breaks working

Wahay, months later and the damn retracts are now in and working. This pic shows me messing with the angles to get them correct for the axle. I also needed to space the wheels away from the retract leg (white bit), I'll probably make these from bar stock ally and drill them to match, but for the time being they are made from ?, wait for it. Toilet hinge rod , £3.15 from homebase, hollow heavy duty nylon rod, just the right diameter for my temp needs.

Flying from grass I'd rather have the slight extra weight in the ply and GF around the retracts than anywhere else  I'm sure I can save weight in other areas, for instance my flaps/dive breaks are probably half the weight of the original parts/concept. Graham 

when installing retracts, you always find you need to remove/modify some or all of the existing ribs and retract hard points supplied either in the kit or from plans, BUT nothing like what was waiting for me.  The Dauntless retracts when fully retracted do not use a gear door (another reason why I like them), instead the wheel center has a flat hub, and the tyres of the wheels are slightly proud of the underside of the wings. This produces another problem in that when they are deployed fully they need to be horizontal to the wing (center), CenturyJet (my retracts) have taken care of this by ofsetting the axle by about 8deg. So if you get the wheels sitting in the wing, then in the down position the legs look something like a FW190, but the axles are horizontal, problem is getting the two angles correct. Heres "as supplied" With the two pre-cut slots for the retracts (top), the angle is way out, I would end up with ALL of the wheel sitting on the wing. So out with the Dremmel. As you can see I needed the retracts as low as I could get them, but still slightly inclined in towards the wheel wells. This doesnt leave a lot to hold the retracts in !!! So I added some new 1/4" ply ribs (see red marks in picture), and rather than use barers to hold the retracts I'm using again 1/4" ply cross grained, each layer of ply has its grain running in opposite directions so the strain put on it by the retracts should be fine. I've also used captive "T" nuts with epoxy. Then "belt and braces", I've added GF sheeting around the retract/wheel well areas and over some of the ribs. My 1/4" retract plates are also epoxied to the front of the main spar webs and the rear of the front leading edge cyparis.

No problem with the pictures John, and thanks for sending the plans so fast in the first place, thats what got me started.

Had a few family problems this week (well thats an understatement) however hope I can now move on again.  Having manually played with the flaps etc, it was time to repaint the centre flap and drive it with the servo, disaster struck !!!, I could only get about 20%, 30% if I almost rip the servo out of the wing. Closer examination revealled my G-10 horns I made were too small (short), enabling the push rod to foul the trailing edge. I ripped the flap back off, and re-made the horns much bigger, so they JUST cleared the top sheeting when closed. Now that flap is just over 26" long, and when closed it actually goes "Snap" as it bangs closed (LOVE IT), and when the flaps are deployed Thats over 6o deg of flap, not far off vertical. Now I can use the template I made for the new horns and re-horn the other flaps and breaks, and get them installed and working via the servos. Must say its way cool watching the flap come down, and up.