Ron Gray Posted August 7, 2023 Share Posted August 7, 2023 52 minutes ago, Nigel R said: Slow down I second that! Quote Link to comment Share on other sites More sharing options...
toto Posted August 7, 2023 Author Share Posted August 7, 2023 Ok no worries, just thought I'd let you jo what I had. I'll try the 12 x 8 later today. Cheers Toto Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted August 7, 2023 Share Posted August 7, 2023 I think what Kim, Nigel and Leccy have said is spot on and there is no need to panic, all is not lost! Quote Link to comment Share on other sites More sharing options...
Learner Posted August 7, 2023 Share Posted August 7, 2023 Although it will work, Stil think you were supplied the wrong combination. A 500 kv motor with a 15in prop for a trainer designed for a 46 what were they thinking! Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted August 7, 2023 Share Posted August 7, 2023 Most unusual for Steve to get it wrong but it’s not a major issue. 1 Quote Link to comment Share on other sites More sharing options...
Learner Posted August 7, 2023 Share Posted August 7, 2023 6 minutes ago, Ron Gray said: Most unusual for Steve to get it wrong but it’s not a major issue. I think the prop sticking in the ground an inch might of been😂 Quote Link to comment Share on other sites More sharing options...
toto Posted August 7, 2023 Author Share Posted August 7, 2023 The manufacturers can get it wrong too. VQ quoted for a Electrospeed 30A ESC and motor combo in their instructions for one of the twins that I bought. Steve informed me that it was under powered as highlighted by a freind of his and it should have been the 40A combo. In fairness to Steve I had bought a couple of models off him at the time so maybe I am the one who confused him. He is a great guy and I would not like to point the finger his way. It's no big deal just a bit frustrating for myself. Toto 1 Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted August 7, 2023 Share Posted August 7, 2023 A model of that size is well suited to a 40mm outrunner - I believe the manufacturer recommends the Rimfire 46, which is quite an expensive motor - over £100 retail - and budget alternatives to that from other manufacturers would be perfectly fine for a trainer. As Learner points out, you could likely fly the model at a lighter weight on 4s1p 5000mah packs, with a 40mm motor, around 800kv and a range of props from 10x7" to 12x8" - you already have the motor and your battery packs, so it is just a matter of selecting an appropriate prop. The thing with electric, as opposed to IC, is that you can finely tailor the prop/motor/battery combination to make a particular motor do what you need it to do, by changing the prop size. Armed with your Wattmeter you test the current drawn and the input watts of the set-up, until you get to something that you are happy with. Most electric flyers soon build up a large collection of propellors and those who are serious about efficiency will do quite a lot of testing to get the optimal prop size for the motor and cell count. Props are almost never wasted, they will always come in handy for some other model down the line. 2 Quote Link to comment Share on other sites More sharing options...
Learner Posted August 7, 2023 Share Posted August 7, 2023 49 minutes ago, Ron Gray said: Most unusual for Steve to get it wrong but it’s not a major issue. Yes sorry Steve, a lighthearted dig comes across different in the written word Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted August 7, 2023 Share Posted August 7, 2023 I'm sure Steve won't mind! to be fair to him, he did spec the motor up as per the Domino specs for a 45 IC - and they state the Rimfire 45 (46?). Based on that he supplied a very close match, but I would have gone for something a bit smaller possibly this - 4250/06 800KV TORNADO THUMPER V3. I would also look to use 4s rather than 6s batteries as they will be quite a bit lighter (capacity like for like there could be 200g saving!). Quote Link to comment Share on other sites More sharing options...
Nigel R Posted August 7, 2023 Share Posted August 7, 2023 Based on prior experience of 40 size electric, I'd have gone even lighter on the motor, a 3648 with a 4S 4000. 1 Quote Link to comment Share on other sites More sharing options...
toto Posted August 7, 2023 Author Share Posted August 7, 2023 Hi .... I tried the 12 x 8 and here it is ..... approximately an inch from the deck ..... I still have 3.5 inch wheels to go on instead of the 2.5 inch that are on at the moment. I had to bore out the prop slightly. it was wide enough at the back end but had a definite graduation in internal diameter towards the front end .... maybe 1mm or so. these small aluminium spinners ..... once you get them finger tight ... I assume you need to back this up with grips or something to get it tighter still ? toto Quote Link to comment Share on other sites More sharing options...
toto Posted August 7, 2023 Author Share Posted August 7, 2023 My 3.5 inch wheels from RC models will probably arrive tomorrow. Another 0.5 inches gained in height after they have been fitted. I need to solder connectors onto the Watt Meter which I will hopefully do tonight. Toto Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted August 7, 2023 Share Posted August 7, 2023 25 minutes ago, toto said: I assume you need to back this up with grips or something to get it tighter still No!, the hole through the spinner allows you to use a 'Tommy' bar (Philips screwdriver!) to tighten it up, do not use grips! Quote Link to comment Share on other sites More sharing options...
toto Posted August 7, 2023 Author Share Posted August 7, 2023 (edited) No worries .... it sits finger tight as we speak ..... I have not assaulted it in any way. Thanks for the warning. That was close ..... again. I think there are two minute holes on the spinner .... one either side. I did not look into it in detail. I'll look at that when I go back into the shed later. Many thanks Toto Edited August 7, 2023 by toto Quote Link to comment Share on other sites More sharing options...
toto Posted August 7, 2023 Author Share Posted August 7, 2023 I take it the Tommy bar is a similar idea to the T bar that is used to tighten a vice. You simply push the bar through the dome head and turn to tighten. Toto Quote Link to comment Share on other sites More sharing options...
Don Fry Posted August 7, 2023 Share Posted August 7, 2023 (edited) 18 minutes ago, toto said: I take it the Tommy bar is a similar idea to the T bar that is used to tighten a vice. You simply push the bar through the dome head and turn to tighten. Toto Yep. Regarding the prop. My guess that model will fly very happily on a six inch pitch prop. It just wastes power with an 8” pitch prop trying to drag the relatively slow airframe about. And I reckon it would be happy on 11” diameter. So more ground clearance, ok power, and longer flight times and less battery/ motor stress. Edited August 7, 2023 by Don Fry Quote Link to comment Share on other sites More sharing options...
Geoff S Posted August 7, 2023 Share Posted August 7, 2023 6 hours ago, Ron Gray said: I'm sure Steve won't mind! to be fair to him, he did spec the motor up as per the Domino specs for a 45 IC - and they state the Rimfire 45 (46?). Based on that he supplied a very close match, but I would have gone for something a bit smaller possibly this - 4250/06 800KV TORNADO THUMPER V3. I would also look to use 4s rather than 6s batteries as they will be quite a bit lighter (capacity like for like there could be 200g saving!). Not done the sums but I suspect watt-hour for watt-hour there'll be very little difference between 4s or 6s. The advantage of higher voltage packs is lower current for the same power. Certainly for a 40 size glow conversion, I'd go for 4S and a higher rpm/volt with smaller prop. 1 Quote Link to comment Share on other sites More sharing options...
Learner Posted August 7, 2023 Share Posted August 7, 2023 How smooth is the strip where you fly from? if its not good you may need a few spare props with that little clearance, although being a trike will help. Quote Link to comment Share on other sites More sharing options...
toto Posted August 7, 2023 Author Share Posted August 7, 2023 Hi Learner, In our club we have a tarmac strip which is pretty good but dependant on the wind, we can end up using the grass to an extent. Landings tend to be on grass. Toto Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted August 7, 2023 Share Posted August 7, 2023 36 minutes ago, Don Fry said: Yep. Regarding the prop. My guess that model will fly very happily on a six inch pitch prop. It just wastes power with an 8” pitch prop trying to drag the relatively slow airframe about. And I reckon it would be happy on 11” diameter. So more ground clearance, ok power, and longer flight times and less battery/ motor stress. I can run some numbers through eCalc for a 12x6 when I get home this evening. Quote Link to comment Share on other sites More sharing options...
Don Fry Posted August 7, 2023 Share Posted August 7, 2023 16 minutes ago, Shaun Walsh said: I can run some numbers through eCalc for a 12x6 when I get home this evening. Try an 11” prop. As well Shaun Quote Link to comment Share on other sites More sharing options...
Kim Taylor Posted August 7, 2023 Share Posted August 7, 2023 (edited) 1 hour ago, Geoff S said: Certainly for a 40 size glow conversion, I'd go for 4S and a higher rpm/volt with smaller prop. If starting from scratch, I'd agree. Toto already had some 6S packs, so I guess that's why he went that way. Way back on page 2 / 3 of this thread, I suggested motors for either a 4S or 6S setup (800 vs 500kV) in response to a way oversized suggestion from elsewhere. At the end of the day, the motor / esc / lipo he has now will fly it fine - he just needs to select an appropriate prop, which I would suggest will be a 12x6e. With the clearance he has now, plus the extra half inch from the bigger wheels, it'll be OK I'm sure. I've flown off grass with less than that with no issues at all, other than a green stain on the prop tips.🙂 Kim Edited August 7, 2023 by Kim Taylor 1 Quote Link to comment Share on other sites More sharing options...
toto Posted August 7, 2023 Author Share Posted August 7, 2023 ***************** HEADLINE NEWS ************* SOMETHING GOES ACCORDING TO PLAN ************** The time and the realisation was dawning that i would have to be able to press my Watt meter into service. Now given the issues with soldering on connections to my ESC's and the " were they dry joints or were they not ............. i was not looking forward to this one little bit. However, I had to bite the bullet and give it a go ........ It took two attempts with one of the wires as I managed to get solder on the outside of the brass connector which wouldn't allow the connector to " click " in. I thought ... you have to get it right this time ....... and now and behold ..... clicked in it did .... the proof would be in the connection though .... so .... and .... it would appear to have life. My soldering is not that bad after all. I also slid a " tommy " bar through the nose cone ( thanks Ron ) and tightened the prop. I'm now going to catch up with my mate John Smith for a minute and chill before working out the best way of using this. hopefully back on a positive footing .... about time as well. toto 1 Quote Link to comment Share on other sites More sharing options...
Geoff S Posted August 7, 2023 Share Posted August 7, 2023 1 hour ago, Kim Taylor said: If starting from scratch, I'd agree. Toto already had some 6S packs, so I guess that's why he went that way. Way back on page 2 / 3 of this thread, I suggested motors for either a 4S or 6S setup (800 vs 500kV) in response to a way oversized suggestion from elsewhere. At the end of the day, the motor / esc / lipo he has now will fly it fine - he just needs to select an appropriate prop, which I would suggest will be a 12x6e. With the clearance he has now, plus the extra half inch from the bigger wheels, it'll be OK I'm sure. I've flown off grass with less than that with no issues at all, other than a green stain on the prop tips.🙂 Kim I'm sure you're right. In middle-sized models (eg balsa Wot4 ARTF in my case) I seem to end up with 12x6 props quite often. Was it BEB some years back who suggested that the way to decide on a suitable glow to electric conversion was to start with the prop and rpm the glow engine used and work back? I find it works well. I haven't had a model with a trike undercarriage since my trainer so I'm always concerned about nose-overs breaking an over-long prop but that's not a problem in this case 1 Quote Link to comment Share on other sites More sharing options...
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