|
|
Post by john66 on Jan 16, 2012 21:45:46 GMT 1
Its a weird one as like it or not I guess to a degree, we're all sheep, I came to this site and for the best part only read about much more powerful upgrades when going brushless. I simply went along with the recommendations of others......Baaaaaaaaa!
Had I have come along to the forum and the talk had of been about the most efficient scale type slow fly brushless motor, I too would have probably gone that way Im afraid to say......Baaaaaaaaa!
Im now looking for a compromise between slow fly characteristics with enough oomph to power some modification weight!
Sorry for the minor hijack.
John
|
|
|
|
Post by renard80 on Jan 17, 2012 0:51:45 GMT 1
Im now looking for a compromise between slow fly characteristics with enough oomph to power some modification weight! Me too, John! Having taken on board flydiver's wisdom, I intend stripping back my SC to absolute lightweight basics. Now I need to know what LIGHTWEIGHT brushless motor and motor mount, obtainable in the UK, are suitable for a stock HZ SC. I don't want to set the world on fire. I just want to wander around the sky and have fun. In my innocence, I assumed finding such a motor would be a simple matter. But whenever it is raised on here, I get baffled and bewildered by the high-tech responses. As a dumb-dumb technically, am I asking too much? In words of one syllable, without blinding me with science, PLEASE, you lovely people - what lightweight motor and mount (UK available) are suitable for the HZ SC? (Yeah, sorry, I too have hijacked this thread . . . but at least it's all to do with reducing weight.) |
|
|
|
Post by flydiver on Jan 17, 2012 1:36:00 GMT 1
|
|
Gohmer
Squadron leader
Posts: 113
|
Post by Gohmer on Jan 17, 2012 3:03:56 GMT 1
|
|
|
|
Post by john66 on Jan 17, 2012 12:11:25 GMT 1
Thanks Fly & Ghomer for the very useful info!
John
|
|
|
|
Post by ginginho on Jan 18, 2012 10:19:00 GMT 1
Nice build Gohmer, cramming the ESC and Rx in the cowl should help with the balance. I have a couple of observations/questions: I'm intrigued by the cable nearest the camera that is connected to the Rx and goes into the fuse (by the looks of it). It looks like a 5 wire (black, red, yellow, red, black). I'm pretty sure it's not servos as I can see a couple of orange,red, black cables also in the Ex which is a fairly standard servo wiring colour scheme. So what is it or am I just not seeing this too well? Secondly, it looks like the EFlite mount is connected to another piece of black plastic (sort of half moon/kidney shaped) that is then bolted to the firewall. Am I seeing this correctly? If this is the case I'd assume the Eflite mount is attached to this by screws/bolts. Did you use the ones supplied with the Eflite mount (as in the picture displayed from the link)? If so have you considered using nylon bolts instead? I replaced steel bolts with nylon on my MPX Fox R/C conversion to help keep the weight down and also on the landing gear add I did to my Twinstar. It's not a massive saving, but every gramme/ounce helps!  John and Renard: Rob at Giant Cod used to do various Blue Wonders, he may well still do them. I know this as I've got one that I bought to put in a depron Fokker DR1 I was going to make. EDIT: I suspect this is the one fly is referring to: www.giantcod.co.uk/blue-wonder-1300kv-micro-brushless-outrunner-motor-p-402398.htmlThere are also 1500Kv and 1700Kv variants if 2 cells flight is being considered. |
|
Gohmer
Squadron leader
Posts: 113
|
Post by Gohmer on Jan 18, 2012 16:20:06 GMT 1
Thanks ginginho. This is my third one. I try to improve a little each time. Cable is a servo extension from the RX bat. slot so I can bind the airplane to different TX's without removing the cowl. Eflite mount is attached to the black half moon (black sharpied 1/8" ply) with upper RH gear box mounting screw and one screw thru ply only. Total of four servo screws holding the whole thing, including a small one to keep the nylon stick in the eflite mount. This is the piece between the eflite mount and motor: www.rcplanebuilder.com/index.php?main_page=product_info&products_id=119 weighs 4g including the tiny bolt and nut that holds the motor bearing housing to it. A better system for someone that bounces theirs on its nose sometimes is another eflite mount on the motor and a short piece of balsa between them. |
|
|
|
Post by flydiver on Jan 18, 2012 17:31:10 GMT 1
|
|
|
|
Post by john66 on Jan 19, 2012 12:23:30 GMT 1
Cheers for the link fly!
John
|
|
|
|
Post by renard80 on Jan 19, 2012 13:22:16 GMT 1
Very many thanks to Ginginho, Gohmer and Flydiver for their invaluable information. Finally I am on track for a suitable lightweight motor, thanks to you guys! Just a few more questions from this technically-illiterate: 1) To confirm, please, that the Blue Wonder 1300kv in that link is OK for 3s batteries? 2) My ESC is 40A. OK with that motor? 3) And a 9x6 prop? 4) Giant Cod offer this motor mount "for the Blue Wonder". www.giantcod.co.uk/alloy-motor-mount-blue-wonder-p-406157.htmllAny thoughts please on whether it might be easier to fit on the Super Cub than the one Gohmer uses? (Sorry for what must be basic questions, guys! The technical side of RC flying leaves me confused, and anxious not to do the wrong thing.) |
|
|
|
Post by john66 on Jan 19, 2012 13:55:30 GMT 1
PS sorry Nick, I somehow missed your post, cheers for the input too!
John
|
|
|
|
Post by ginginho on Jan 19, 2012 14:23:38 GMT 1
Very many thanks to Ginginho, Gohmer and Flydiver for their invaluable information. Finally I am on track for a suitable lightweight motor, thanks to you guys! Just a few more questions from this technically-illiterate: 1) To confirm, please, that the Blue Wonder 1300kv in that link is OK for 3s batteries? 2) My ESC is 40A. OK with that motor? 3) And a 9x6 prop? 4) Giant Cod offer this motor mount "for the Blue Wonder". www.giantcod.co.uk/alloy-motor-mount-blue-wonder-p-406157.htmllAny thoughts please on whether it might be easier to fit on the Super Cub than the one Gohmer uses? (Sorry for what must be basic questions, guys! The technical side of RC flying leaves me confused, and anxious not to do the wrong thing.) Renard, in answer to your questions: 1) Yes but with the right prop. However you need to consider the size of the 3s pack too. Remember if you are trying to build light, you need to shed weight at every possible oportunity. Note that Gohmer states his latest build weighs 16.8oz with a 1000mAh pack. By my calculations thats sub 500g and has probably involved considerable effort to get it that low. This Blue wonder will work with that weight but will struggle with something much beefier. Bigger capacity packs equals more weight. 2) Again yes, but again you are trying to go light. I'm not sure what make of ESC you have, but for example a 10A HW (most GC reviewers of that motor seem to use a 10A) comes in at 9g, a 40A HW is around 40g. Quite a difference and a lot of extra weight that the little motor is going to have to try and pull along. The same applies to servos. For light builds you want the lightest that is capable of doing the job it's there for. 3) Probably not, likely you'll pull too much amperage and damage the motor. The GC reviewers all tend to go no bigger than a 8x4 on a 3S, but you are really in the realms of trying and measuring to get a viable combination that will work for you. You really need a wattmeter and a fist fulla props. If you are considering building light, I'd recommend reading some forums (RCGroups, RCUniverse and others) where people have made light versions of models and see what things can be done (a bit like the link Fly posted) before digging into the funds. It doesn't have to be a HZSC, but will give you some ideas of where you can start shedding ounces...RC conversion threads for MPX fox's have a wealth of weight saving ideas as the conversion has to be light else it just won't fly! Mine was a portly 106g and hence was the twitchiest plane I've flown with a fatal desire to stall into a spiral of death if airspeed wasn't sufficient. Things like ditching hinges for blenderm tape, replacing metal pushrods for carbon and replacing metal clevis' with shrink wrap all add up to an overall saving in the quest for light flight. |
|
|
|
Post by flydiver on Jan 19, 2012 17:30:33 GMT 1
When going light the details matter....ALL the details.
As indicated, ESC too heavy.
If you plan on using an old Cub lipo....WAY too heavy.
Prop too large for the motor, GWS 8x4 probably max.
The [2.5g 8mm Alloy Motor Mount for Blue Wonder] is suitable if you do the foam plug with a chunk of ply like Butch does in that link. But you may want the space up front for the ESC which gets more weight up front.
If you want to mount it like Gohmer then you want to use [10mm Electric motor mount]
If you are starting completely over you might consider the [Blue Wonder 1700kv 9.5A Micro Brushless Outrunner Motor] and going to 2S lipos, somewhat lighter and cheaper.
That's what those 'medium' KV motors are for. Use them with lower voltage but get similar performance to 3S.
Not a big deal, and either will work. Just match the KV to the voltage for suitable performance.
If this is all pretty overwhelming, maybe consider a Slow Stick with a light build. You'll get a nice, easy, floaty plane that is very easy to modify and mess with. The number of threads on it makes the Cub look like a plane barred from the hanger due to lack of popularity.
|
|
Gohmer
Squadron leader
Posts: 113
|
Post by Gohmer on Jan 19, 2012 20:18:28 GMT 1
Lightweight Cub would be a good idea for a topic, maybe even it's own a forum. We've solved the duct taped cowl question by now. More members should hear about the joy of flying "CubLite. I used one of these motors in Cub #2. Very quiet, plenty of power for a sub 20oz Cub. www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=5429I bet John66 could come up with a lightweight power system package that would help us out a lot on correct component selection. |
|
|
|
Post by flydiver on Jan 19, 2012 21:04:13 GMT 1
I agree, maybe this topic will have another useful spin.
|
|
