Biggles' Elder Brother - Moderator Posted April 25, 2014 Share Posted April 25, 2014 I was having a bit of a tidy up in the shed the other day when I uncovered two boxes at the back of a shelf - I nearly choked when I opened them,... Two brand new OS outrunners! Both 5020-490's - roughly equivalent to a good 40 2 stroke or 70 4 stroke. They really are a thing of beauty,... Now these aren't cheap - but what did I buy them for? And two of them? Blessed if I know! Quote Link to comment Share on other sites More sharing options...
Martyn K Posted April 25, 2014 Share Posted April 25, 2014 I am amazed that you forgot you had them... It must be an age related thing... errrr and what about the Black Horse Chippie? Martyn (Sorry - pre-empted your next post - it was an unusual start) Edited By Martyn K on 25/04/2014 16:18:22 Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted April 25, 2014 Author Share Posted April 25, 2014 So, having these motors I started to think "What can I use them in?" as you do. I then remembered a thread that was running about a week ago on converting IC models to electric. Now I have a very old BlackHorse Chipmunk with a OS90FS up front. Nice model, but I think I've flown it once in the last two years - I just don't take IC flight boxes etc to the field anymore - so it sits in the shed gathering dust - a lot of dust - mainly balsa dust,... So, how about converting it? As I say its a nice model, flies well, deserves to fly. Well the first job was to clean it up a bit, give it a good looking at and strip out the IC system. First I removed the tank and throttle servo,... And then removed the engine,... There was a lot of low level damage around the cowl-fixing screws. On strippoing back some covering it became apparent this damage was more severe than first thought,... Ouch! The fuse in this area is just sheeting - and frankly I should have known better than to just fit the cowl screws through that. I'll add some dowel inserts to toughen this up. For now though I started patching up with a mixture of new balsa let in and some micro-balloons and resin mixed sloppy,.. With some of the basics put right, its time to start thinking about how we are going to do this conversion. BEB Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted April 25, 2014 Share Posted April 25, 2014 looks simple enough to convert for an expert like yourself. stand off's or a wooden box for the motor to bolt too. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted April 25, 2014 Author Share Posted April 25, 2014 Ah - all will be revealed Tony! BTW - I don't know about the "expert" bit! The problem with any conversion like this is how are you going to get the battery in and out. The easy solution is via removing the wing - but that's a pain in the neck. I don't want anything that's going to give me an excuse not to fly it - I want a hack I can take to the field and not have to fiddle about. So I need a hatch somehow. I did think about making the whole cockpit section removable - but quickly dumped that ideas - too difficult! I had a look around the web and found that two guys had already done this conversion. Both of then had built the hatch into the cowl. One had put the battery in vertically up against the fire wall, the other had built a sort of chute. First i considered the "drop in in vertically" solution,... That opening could be expanded a little bit and the battery would fit - just! But the battery I want to use is a 6s 5000mAh - a big brute of a thing! Putting the battery there would put an enormous about of weight very far forward. Now if this model had one fault it was a tendency to nose heaviness and indeed the model has an ounce or two of lead on the tail - unusual but there you go. This size battery that far forward would be real problem. So, its going to be the chute solution. First step - hack away to create a big hole in the front,... Next make the floor of the chute from 2mm ply and fit it in position, then try the battery in place,... Looks OK - just room for the wing - I checked with a straight-edge! And from the front,... OK, it fits. But how do I hold it in position? A simple "velcro carpet" won't work because I need to be able to slide the battery in and there isn't a lot of clearance to do so whilst maintaining a gap between the battery and the floor of the chute. So, the idea is to add two longitudinal rails either side of the battery and some foam. Then use a backstop to stop it sliding backwards and front lip to stop it moving forwards. To hold it down against the floor I can use a velcro tie at the front and fix some foam to the top surface of the wing inside the fuselage - the gap between the top surface of the wing and the battery is only a few mm's. Ok, that'll all work - but it won't be very adjustable. So I'm going to have to work out fairly precisely exactly how far down the chute the battery will have to sit to balance the model. To do that I'll have to add the motor and everything next. BEB Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted April 25, 2014 Share Posted April 25, 2014 The other problem I find BEB is that the manufacturers change the size of the packs, so as you replace the LiPos they are a bit hit and miss to find ones to fit Looks like you have allowed a little wriggle room a 6S 5000 is a lot of pack for this, my 86" 1/5th and a bit, Chippy is on 5S2P 10,000mAh total on a 500kV motor. will enjoy following along Cheers Danny Quote Link to comment Share on other sites More sharing options...
Martyn K Posted April 25, 2014 Share Posted April 25, 2014 Hi BEB That is a similar approach that I used on my Flea-Fli. However, I allowed enough space to 'rock' the LiPo as I slid it in so that the rear of the LiPo is floating. I then used the Velcro Carpet to stop it moving forwards and backwards. You could probably manage with a similar approach but with the additional reinforcement of a strap - like they use on helis - to keep it in place. What is the difference in weight between the LiPo and Motor compared with the OS91F/S and half a tank of nitro.? Martyn Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted April 25, 2014 Author Share Posted April 25, 2014 So next I turned my attention to fitting the motor. The most important thing here of course is to keep the thrust line right. So a trip to BlackHorse's website found me a pdf manual which contains a cutout template to aid with fixing the original engine,... So, here it is in place. The white pin marks the position of the trust line. The four bolts are inserted into the original Tee Nuts used to hold the engine mount - I want to use them if at all possible. Next up transfer all that to a piece of 6mm ply and drill the holes - clearance for some M4 studding,... The corner holes are for the studding which will form the stand-off, whilst the ones at the mid-points of the sides are for the electric motor spider mount. All that installed on the model looks like this,... And from the side,... If you haven't tried this system of mounting a motor I can recommend it. I first came across it being used by some guys at Greenacres (Chris Bott and Danny Fenton among others). Despite the fact that it initially feels very sloppy, once you tighten up the nuts its actually very rigid. It also has the advantage of being finely adjustable - so you can get the right stand-off distance with spot on right and down thrust if required - by just adjusting the various nuts. OK, that's where I'm up to. next I need to add the speed controller, cowl, prop and spinner. Then with the wings on and the model inverted I can fiddle with the battery position until she balances at the right spot. BEB Quote Link to comment Share on other sites More sharing options...
Simon B Posted April 25, 2014 Share Posted April 25, 2014 I'll be watching this with interest. I've just inherited a Black Horse Super Air that was written off in front of the canopy. It gave me carte blanche to do a complete redesign of the nose, putting a hatch in etc. I've also converted the 61 P-51, which was a lot simpler, as it already had a removable top hatch... Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 25, 2014 Share Posted April 25, 2014 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted April 25, 2014 Author Share Posted April 25, 2014 Yes Tom I'm thinking in terms of an exit hole for the hot air back aft somewhere. One advantage is that the cowl has a nice big air inlet so that's handy and I'll try to get the ESC directly in the flow of that. But of course without an exit hole (potentially bigger!) the inlet is of limited value! BEB Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted April 25, 2014 Author Share Posted April 25, 2014 Sorry Danny - somehow missed your comment! Yes - I agree the 6s 5000 i s a big pack for this model. But it should keep the current down a bit and so with a 490Kv motor I should be able to prop a little bit higher whilst still getting a good flight duration. Well, that's the plan anyway! Quote Link to comment Share on other sites More sharing options...
Charles Lee Posted April 25, 2014 Share Posted April 25, 2014 Hi BEB Two motors!! what a find, I'm looking in all my less frequented cupboards but all i'll find is spiders. If you don't have a speed controller yet, I can recommend the Turnigy Plush 60A set to high timing rate. I have this setup in a YT International Bendix turning a 14 x 7 wood prop. Sounds fantastic, not normal electric sound. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted April 25, 2014 Share Posted April 25, 2014 Like the adjustable standoffs BEB Makes setting motor thrust up a lot easier Would like to know peoples opinions of the O.S. motors also? they certainly look good Quote Link to comment Share on other sites More sharing options...
Charles Lee Posted April 25, 2014 Share Posted April 25, 2014 Posted by john stones 1 on 25/04/2014 19:30:13: Hi John I have two O S motors & would not use any other make. The setup in the Bendix is awesome & I have the larger 520 375 in the new ish Hangar 9 P47 Razor back 60 size. This model has the 100A O S esc & is a perfect match. The power is from 2 X 4500mah six cell packs in parallel. Using 6 cells I can turn an apc 17 x 10 with amps to spare. Any more info needed P M me. Would like to know peoples opinions of the O.S. motors also? they certainly look good Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted April 25, 2014 Share Posted April 25, 2014 Thanks Charles I may just power my Chipmunk with one. Sorry for the interruption BEB, its the first O.S motor I recall seeing on here, it looks superb Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted April 25, 2014 Author Share Posted April 25, 2014 No problem at all John. I'll be interested to see how it goes myself as while I am the proud possessor of two of them I've never actually run one! It certainly feels the business smoothness wise - but we will have to wait and see! Thanks for the "heads up" Charles, but I do have a ESC I plan to use in this - an EFlite job. OK well the next job has been to add the side rails to the chute floor,... Along with some foam on the side walls of the chute these will stop the battery sliding side-to-side once its fixed down/ "Side wall of the chute"? What side walls? Well they prooved a bit tricky to cut out! So I measured up with a pair of callipers then made a rough pattern from a bit of 1/32" balsa sheet. I could then try this in place and "fettle" it. This is the shape I ended up with,... I cut two of these from 1mm ply and fixed them to the chute floor and side rails like this,... Then that slots in place like this,.. This will be epoxied in eventually and I will add a cross bracing strip across the the top. The walls will be lined with high density foam and some lightening/ventilation holes added to the sides and floor. From the front,... The back,... As it is being glued in I'll pick up on those side lugs on the former and those remaining stubs at the side to make the whole thing integral with the fuselage. Finally from the 3/4 rear,... Now I need to root out a spinner and a prop, break out the cowl, fix everything in place with tape and try to balance it BEB Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted April 25, 2014 Share Posted April 25, 2014 looking good sir. going to be a nice flier when it is finished. Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted April 25, 2014 Share Posted April 25, 2014 Looks good. What are you doing with the original engine, another plane? CS Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted April 25, 2014 Author Share Posted April 25, 2014 Regarding the weight question Martyn; to be honest I don't know at the moment, but I suspect the electric is a fair bit heavier - that battery alone is very heavy. If its too heavy I'll have to cut down - but accommodating a smaller battery wouldn't be a structural problem. I'll be weighing everything tomorrow anyway - so I should be able to tell you then! BEB Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 26, 2014 Share Posted April 26, 2014 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Geoff Gardiner Posted April 26, 2014 Share Posted April 26, 2014 This is great.... I purchased one of these from the Southern Model Airshow a few years ago and it has been sitting in it's box, in a cupboard, ever since. Other builds keep getting in the way but I intend to convert to electric also. Will be keeping a close eye on proceedings. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted April 27, 2014 Share Posted April 27, 2014 I wouldn't be so sure the electric set-up is heavier than the glow. Last year I completed an Ezee Pzee trainer I picked up part-built at the Nats swap meet. It's big (84" ws ) and intended for a 60 glow but with a 5055 700 rpm/volt motor installed I had to fit 2 x 4S 3600 mAH just to get it to balance. They do, at least, give it an easy 15 minute duration of moderately aerobatic flight. I wish I could find a couple of unused OS electric motors tucked away in my workshop cupboard. A great find indeed and an interesting conversion. Geoff Edited By Geoff Sleath on 27/04/2014 18:19:16 Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted April 28, 2014 Author Share Posted April 28, 2014 Now when this model was in regular use - back in nineteen hundred and frozen to death! - the cowl was getting a bit battered - you saw the damaged cowl holes. I saw that Ripmax listed the cowl as a spare. So I connected the old LMS and asked them to get one. Which they did. And it lived in a corner of my shed ever since! When I started this conversion I thought "Oh must dig out that new cowl" - well finding it only took two days! But find it we have. So, time to cut a hole in it for a hatch. Now the odd thing here is that you don't normally want the bit you cut out of a cowl do you - so if you're like me you mark the cut-out and drill a series of holes inside the line, then join the holes up, out pops the bit you don't want - and you tidy up with a sanding attachment in the Dremel (being sure to wear a mask of course!) But we can't do that here - because we want the bit we cut out as a hatch cover. I thought about using the slitting disc in the Dremel - but decided that was a bit heavy handed. So, first put some tape where we are going to cut,... Next mark the cut lines - having measured carefully to see how much opening we need,... And then work it very patiently with a scalpel - three blades later - the GF really takes the edge of the blade very quickly! A nice big access hole. And from the side,... I'll be able to touch those white edges up with a spot of red paint at the end. And with the piece in place,... Next job is to make a wooden frame for this hatchway. BEB Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted April 28, 2014 Share Posted April 28, 2014 Looks great BEB, hope you have this done in time for Greenacres Cheers Danny Quote Link to comment Share on other sites More sharing options...
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