Pete B Posted March 19, 2010 Share Posted March 19, 2010 I thought I'd better post this here as I'll probably get stoned out of the gliding section.........particularly after the electrifying slope debate recently! A while back I bought a Super Grone 236 sailplane on the 'Bay: Full description is here, but suffice to say it seems to me a bit of a porker at 1630g or 3lb 9oz bare, rising to an estimated 2000g or 4lb 6oz with a planned 3s electric setup. First of all, having found virtually no information regarding this model on the Web, does anyone have any knowledge or experience of it, please? Is it a sledge or just a donkey? I get the impression it has been around for a few years. Secondly, as mentioned above, and not having a nearby slope, I'm thinking of a swift circumcision of the nose and installing a folding prop setup. This will allow me to use it on my normal site and on any slopes I can reach (with or without the prop!). Wing area is about 4.5sq/ft, so will have a wing loading of about 16oz/sq ft. As I'm looking more for a power-assist rather than drag it around on the motor like a hotliner, I reckon 50-75 watts/lb will be plenty, so I'll need 220-330 watts. Typically, my motor stock is just off each end of that range! I've a 2217-9T 200W 15A 950Kv which may get it off the ground, suitably propped, and a XYH 4240-10T 900kv, which rated at 540w is probably a bit too much. It's a pity as I was rather hoping I wouldn't have to buy another! I expect to use a 10 or 11" folding prop and I've found a couple of motors on GC that should suit, this 1100Kv or this 1000Kv. I'd be looking to prop the motor for about 30A maximum so they seem to me to fit the bill. Comments would be welcome! Pete Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted March 19, 2010 Share Posted March 19, 2010 I would use the 900kv 500watt m'self. Use a nice big 11 or even12" prop to get the power up to around 350 - 400 watts, I think you will find 50 -75 a bit low. Use decent high capacity 3s and you should be good to go.Oh and when ready to try it, Andy E says you can use his slope with pleasure Quote Link to comment Share on other sites More sharing options...
Pete B Posted March 19, 2010 Author Share Posted March 19, 2010 Ta, Timbo, that helps - but I'll have to order a 5mm shaft prop spinner now! How is it that I always have the wrong permutation of everything? I've got a couple of suitable 4mm shaft spinners and blades in 10 x 8, 11 x 6 and 11 x 8. Just received my last order from GC as well! Probably easier to order one of everything next time............. Tell Andy I'm thinking of fitting a clothes peg and card behind the prop to give it a nice roarty sound............ Pete Quote Link to comment Share on other sites More sharing options...
flytilbroke Posted March 19, 2010 Share Posted March 19, 2010 I shall be following this closely. I got one second hand too, at a club auction (Ross-shire mfc) years ago. I added the power pod and an SC .15. Not knowing any better I test chucked it off a twenty foot high hill on a calm day without the motor running. It is still waiting to be rebuilt Quote Link to comment Share on other sites More sharing options...
Pete B Posted March 19, 2010 Author Share Posted March 19, 2010 Certainly seems as if it has the gliding potential of a well-aimed shovel, ftb! Pete Quote Link to comment Share on other sites More sharing options...
Pete B Posted April 7, 2010 Author Share Posted April 7, 2010 Well, there're good days and there're bad days, but more of that later...... The problem I had with this beastie was to squeeze a lecky setup into a relatively compact space. The servos are mounted double-decker fashion with rudder/elevator down below: The XYH4240 900Kv motor, much as Timbo would have liked me to use it (he does like BIG motors and BIG props, doesn't he), was just too much to squeeze into the nose area, so I settled for the XYH3542 1000Kv from GC. I've been pleased with the reliability of these motors which I believe are Turnigy's without a label. Not having an endoscope, I could only photograph inside the nose with the aid of a mirror and (modestly) some fine photographic skills! A busy little cockpit as you can see. The second photo shows the aileron servo to torque rod connection. It's rather fiddly to assemble with my sausage-like fingers........... Back at the business end, I needed to make provision for the motor so the nose (which had 130g of lead moulded-in!) was despatched with the Dremel and a ply motor mount fabricated and epoxied in place. I also cut a ventilation slot each side of the nose: A battery tray of 1/8 ply was fitted and the Hobbywing Pentium 40A ESC servo-taped to the inside of the nose: It's a bit cosy.......... And this is the finished product: Weight has been my main concern all along. The moulded tail assembly isn't exactly light and nowhere in the product documentation are there any specs for weight, C of G measurements, etc. All I had to go on with the reduced-scale drawing was the C of G symbol just behind the wing joiner. Not being too familiar with swept wings, even if it's just the leading edge, I added about 4 oz total of lead to the nose either side of the battery tray and this seemed to put the balance point in roughly the right place. The motor, with a 12 x 7 folding prop and a Zippy 3S1P 2200mah 20C, produces 412W at 37 - a little close to the 40A ESC but I'm not planning to use it as a rocket. A heavy-feeling 4lb 9oz means something close to 100W/lb at full chat. Having looked at it, and the weather, for the past couple of days, today was just right. Overcast and no wind, so there was no more to do than have a warm up with my Cub and then commit the Super Grone to the air............. As I said at the beginning, there're good days and there're bad days................and today was a good day! She flew beautifully. Plenty of power to spare - she climbs at 45+deg full throttle - and maintains height on less than half-throttle. That's fine for me. Very graceful in the air, she lets out a very satisfying whoooosh on a low pass..........and has a very respectable glide angle too. Co-ordinated turns looked nice and flat. The C of G wasn't an issue and I feel I can lose perhaps a couple of ounces I have set it up with spoilerons as I am concerned about the approach glide but didn't use them today. At my site the only possibility for a long flat approach is from south-west to west, the remainder being obstructed with trees etc, so the calm conditions today gave me the chance for a greaser, which she did without any fuss. I suspect that despite her weight, she is very efficient and some thermal activity should prove interesting later on. Meanwhile, I must find a slope..................with or without the prop< Quote Link to comment Share on other sites More sharing options... Tim Mackey Posted April 7, 2010 Share Posted April 7, 2010 Excellent result there Pete - youve done a nice job Quote Link to comment Share on other sites More sharing options... 1 year later... Mike Richards Posted February 16, 2012 Share Posted February 16, 2012 Hi Pete, I have just got hold of one of these but dont have the instructions, I dont suppose you have a set do you? Regards Mike Quote Link to comment Share on other sites More sharing options... Pete B Posted February 16, 2012 Author Share Posted February 16, 2012 Hi Mike, Welcome to the forum. You'll find plenty of help here, I'm sure! As a starter, I have dug out the instructions for the SG. They come in the form of a reduced-size plan with instructions in Italian and English. I haven't the facility to copy the whole plan but I've taken a piccie to show you the whole and I shall scan the detail parts that you need. If you can PM me with an email address I'll get the scanning done in the next couple of hours and send it to you Pete Quote Link to comment Share on other sites More sharing options... 12 years later... Danitegue Posted November 20 Share Posted November 20 (edited) Hello Pete. I have just inherited a model like this one, and I would like to add a motor. Unfortunately all images of this thread are not visible anymore.... "Photobucket, image is currently unavailable". Your images/setup would be really helpful to me, as an starting point. Would it be possible to re-upload them? Thanks in advance. Edited November 20 by Danitegue Added image Quote Link to comment Share on other sites More sharing options... Martin Harris - Moderator Posted November 20 Share Posted November 20 Welcome to the forum. Pete isn't as regular a visitor as he used to be - perhaps a PM might help get an answer more quickly? Quote Link to comment Share on other sites More sharing options... Danitegue Posted November 20 Share Posted November 20 4 minutes ago, Martin Harris - Moderator said: Welcome to the forum. Pete isn't as regular a visitor as he used to be - perhaps a PM might help get an answer more quickly? Will try! Thanks Quote Link to comment Share on other sites More sharing options... Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply Share More sharing options... Followers 1 Go to topic listing Latest Posts Home ELECTRIC FLIGHT Motor Discussion Aviomodelli Super Grone 236
Tim Mackey Posted April 7, 2010 Share Posted April 7, 2010 Excellent result there Pete - youve done a nice job Quote Link to comment Share on other sites More sharing options...
Mike Richards Posted February 16, 2012 Share Posted February 16, 2012 Hi Pete, I have just got hold of one of these but dont have the instructions, I dont suppose you have a set do you? Regards Mike Quote Link to comment Share on other sites More sharing options...
Pete B Posted February 16, 2012 Author Share Posted February 16, 2012 Hi Mike, Welcome to the forum. You'll find plenty of help here, I'm sure! As a starter, I have dug out the instructions for the SG. They come in the form of a reduced-size plan with instructions in Italian and English. I haven't the facility to copy the whole plan but I've taken a piccie to show you the whole and I shall scan the detail parts that you need. If you can PM me with an email address I'll get the scanning done in the next couple of hours and send it to you Pete Quote Link to comment Share on other sites More sharing options...
Danitegue Posted November 20 Share Posted November 20 (edited) Hello Pete. I have just inherited a model like this one, and I would like to add a motor. Unfortunately all images of this thread are not visible anymore.... "Photobucket, image is currently unavailable". Your images/setup would be really helpful to me, as an starting point. Would it be possible to re-upload them? Thanks in advance. Edited November 20 by Danitegue Added image Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted November 20 Share Posted November 20 Welcome to the forum. Pete isn't as regular a visitor as he used to be - perhaps a PM might help get an answer more quickly? Quote Link to comment Share on other sites More sharing options...
Danitegue Posted November 20 Share Posted November 20 4 minutes ago, Martin Harris - Moderator said: Welcome to the forum. Pete isn't as regular a visitor as he used to be - perhaps a PM might help get an answer more quickly? Will try! Thanks Quote Link to comment Share on other sites More sharing options...
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