Adrian Day Posted January 9, 2012 Share Posted January 9, 2012 Well here goes, Starting the Pix-E Major sent to me from RCM&E looking forward to this one, better that i got the cnc kit, wood pack and plan as a prize, again thanks to Ken Anderson and David Ashby But in keeping with the scratch building side i have been busy copying most of the parts so far, reason being that then i can make even more as really like this model, and take my hat off to Tim Hooper for this design. the ones with a green dots have been copied but doing well so far having test fitting of parts on wings looking like its going together pretty well, pictures will follow shortly CNC Kit Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 9, 2012 Author Share Posted January 9, 2012 All the parts cut so far just the stick work to do next Above the test fit of the wing ribsEdited By Adrian Day on 09/01/2012 09:58:56 Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 9, 2012 Share Posted January 9, 2012 Just adding a post so I can follow along Adrian....Pix E is on my list to build in about one & a half models time. I will be using my CNC scalpel & fretsaw to cut my bits out however...... Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 9, 2012 Author Share Posted January 9, 2012 Welcome Steve nice to have you following hope that some where along the line what i put may be of some help not great with words but will put things best that i can , wish i had a CNC machine would be in my element dont think i would ever stop building its a sweet model small have like the look for about a year when it first came out in the mag, you say your going to make it in 1 .5 models time what you building at present? Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 9, 2012 Share Posted January 9, 2012 I have only built one CNC kit & was amazed by the quality & accuracy of the cutting & the fit of the parts....I had to keep reminding myself that it was actually balsa wood I was dealing with & not T066 Aluminium!!!! Certainly very different from the old "die crushed" kits we used to have.... My half finished model is the Luton Minor from Dave Royds' RCM&E plan a while ago & which has been on the bench far too long now (it got moved so I could build a big Wot 4 & then a Midget Mustang from the Tony Nijhuis design in RCM&E ages ago) & then the next one will be a Mini Panic which is designed for electric but will have a 32 glow up the sharp end when I've finished with it........this has been maturing nicely under the bench for just over 16 months now so it should be just about ready to build..... Pix E should come next although I might be forced to sneak a Sharkface in there too....a 22" 1/2A design that Big Bandit Chris has inspired me to build. Mind you he seemed to put his together in less time than it takes me to change a scalpel blade....sigh!!! In between I need to work, decorate the house, the washing machine sounds a bit dodgy too, re-lay the patio, build up my little boys train set onto a folding bench, keep his & his brothers R/C buggies going, put a new 2.4GHz radio in both their boats, fettle my foamie slope soarer so I can chuck it off a big hill.... & I might get the odd days flying in if I'm lucky.....so a start date around.. oooh this time next year is a possibility....but don't count on it..... Am I complaining though?? Nope not a bit of it....I love it all...... Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 9, 2012 Author Share Posted January 9, 2012 Wow Steve sounds like your not going to sleep between now n 2013 lol but keeps you thinking and thats never a bad thing i guesssounds like you have been busy with all the builds you have been doing,, cant go wrong with Tony Nijus plans they are fantastic same as Tim's the best part its the build blogs they help out bigtime, been watching a TN build thats really good four hurricans built at same time Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 9, 2012 Author Share Posted January 9, 2012 been on a busy one today so far got most of the wings made! just waiting for the leading edge to dry before i fit the wing tips other than that fingers crossed its all going in the right direction think while they are drying may cut all parts for the tailplane n fin should take to long .... i dont think. Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted January 9, 2012 Share Posted January 9, 2012 Adrian, Good luck with the Pix-E! BRC Hobbies no longer list the motor that I used in the prototype, but this looks to be a very suitable alternative package; 2822 motor/ESC Given the light weight of the model, I'd stick to a 2S 1300 li-po or similar, with a 9x4.7 or 9x6 slo-fly prop. Shouldn't go far wrong.... tim Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 9, 2012 Share Posted January 9, 2012 This is the motor I have in mind for my Pix E......using a 2S as Tim suggests on an 8 or 9 " slow fly prop.....Lovely.... Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 9, 2012 Author Share Posted January 9, 2012 TY Tim, May just need luck not dont open frame planes before so this will take a little learning but looking at you threads giving me good hints how to do things, some that not seen in the mag Still kind of learning so this should be fun little model to work with Thank you also for the link i looked at that one but didnt know if it was going to be good enought but as you know 10000x better than me will take your word and invest in that one good price to we all like that regards Adrian Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 9, 2012 Author Share Posted January 9, 2012 TY Steve, now thats given me food for thought price is good power looks good wonder what price ESC would cost to go with that one? If it would work out less or more regard Adrian Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 9, 2012 Share Posted January 9, 2012 Ah...the eternal problem of choice!!!! It's Tims model so he will be best placed to advise..... For ESCs I've got a unit "in stock" so to speak....I think its a 25A unit but I'm not sure. If you are going to use a 2S Lipo then thats around 8 volts & I reckon you will need about 80 watts or so to fly the Pix E; so you will need 10A max out of your Lipo (8V x 10A = 80 watts) so go for a 12A or 18A ESC to be safe.....these are around the £10 mark...see 12A & 18A Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted January 9, 2012 Share Posted January 9, 2012 Steve, That motor looks a bit hot with a Kv of 1650 rpm/volt. Perhaps suited to a faster flying model using a 7" prop? How about this one? Looks a bit gentler for a 9" prop...... GF 2210 tim Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 9, 2012 Author Share Posted January 9, 2012 Steve I have just looked at the links ty they are very useful have added them to a basket but not getting them yet, as for the motor i think I will go with Tim on that one as you say he knows this model and power set up (not saying you dont) sorry.. but as far as i know he would know what this model could or couldnt handle i dont really want to mess this up before i start very gratefull for both your inputs as really need as much as i can get right now. as for the 2s li-po is there any particular pack either of you would suggest, kind of from same site as MOTOR and ESC would be good thinking of getting 2 of this 9G SERVO thinking of getting this LI-PO Dont know if its right or wrong just doing this on a low budget Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 10, 2012 Share Posted January 10, 2012 Hi Tim....yes its a fairly high kv but I based it on the bell motor you suggested originally.....these have a fairly high kv too of around 1700 if my memory serves me & running a 2S set up I thought the lower kv motor this one at kv1200 might not be suitable.... I have one of the kv1200 motors also, destined for 3S use, so I can swap if I need to!!! @Adrian.....Tim would certainly be the man to advise you here.....he designed the thing after all..... IMHO the servos would be fine....I'll be using similar & the Lipo will be OK too although I might be tempted by a slightly larger battery at say 1300mAh..... Tim, might the smaller (900mAh) battery be a tad too light & cause possible cofg isues do you think? Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted January 10, 2012 Share Posted January 10, 2012 Gents, The li-po size probably isn't too critical. It sits just forward of the CG, and my model balances perfectly with it on board. If you use a smaller cell-pack then you might need to add a couple of grammes of noseweight as well. Steve, You're quite right about the Kv of the bell motor. I've just checked the specs on the GC website. I'd forgotten it was that high! As you were, gents......tim Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 10, 2012 Author Share Posted January 10, 2012 Hi tim thanks for all your help on the power side think i will go for the one i see and i have seen a 1300 on an american site but not sure on the cost of pnp, but it works out £3.80 for the li-po, also if i put the LiPo more to the rear is it pos to put the servos inside the model with a fine metal push rod as in the size wire used to hold the wing rods to the hing????well i have the wings finished today will take some pictures let me know if you think they look ok or not please ??? Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted January 10, 2012 Share Posted January 10, 2012 Adrian, Looks like you're getting your head around the power systems available! I'm a regular user of Giant Cod and they offer this 1300 cell pack; 2S 1300 Yup, you can put the battery and servos wherever you like! Putting the battery rearwards will certainly let you move the servo forward, although I would use thin steel wire as a pushrod - it's great under tension, but bows under compression. Use a length of 1/8 BBQ skewer with wire ends bound and glued on. A traditional pusrod, in fact!tim Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 10, 2012 Author Share Posted January 10, 2012 cheers Tim trying to get used to the maths never really known all the info on kv / w so on , only working in the idea of 1lb to 100w but never know how to work out the power set amps or battery, thats something i will need to work on in the future, thanks for the link that looks a perfect size for this model size and power and would go well with the motor u suggested ? must have known as today i bought 100BBQ skewers for 99p cant go wrong on that note i was thinking of running the wire inside a tube, such as a internal rod of a standard push rod if that makes sence, dont know if that would work but i know the idea your saying, even more food for thought??? what way would you think best Tim? Adrian Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 10, 2012 Author Share Posted January 10, 2012 WINGS COMPLETED Nearly finished wings took this before I finished adding the last 2 gussets But have now fitted them so all done now onto the tail !! think they look ok??? Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 11, 2012 Share Posted January 11, 2012 Those look great Adrian.......top drawer..... Don't forget to fit the mounting pins to the main spar before you cover it now will you..... Regarding the Lipo from the US then you will almost certainly get hit with import charges, VAT & probably a £12 handling charge from the carrier for almost anything bought from the USA.....that £4 Lipo could work out very expensive by the time it hits your bench......that is my experience anyway. Buy the one from Giantcod & you will be supporting a UK supplier......you'll miss 'em if they go..... The wire in a tube is the method I use on these small light weight models.....1mm wire in a thin plastic tube from my LMS....make sure the tube is supported at both ends & in the middle.....a good tip is to wrap the tube in a layer of masking tape where you intend to fix it to the airframe.....helps the glue bond to the tube..... Final point....100watts/lb is often way to much for these "vintage" type models...75-80w/lb is better & even 50-60w/lb can be enough. That said you do have a throttle so can reduce power & its always good to have a slight excess for windy conditions so the model will power its way forward. Beware of the classic aerodynamic spiral of more power adding more weight which needs more power & so on......add lightness wherever possible...... Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 11, 2012 Author Share Posted January 11, 2012 Steve tyGreat to get feedback from you and good information is hard to come by, trying my best to make it look like the real design, and do Tim's model justice, being a pain Steve would you happen to have a link for the tubing just so i can see what type you use, The one i was thinking is the orange one in the centre of this one from slecuk snake with yes the 1mm inside dont know if the snake intended would be any good as there would be 1 mm play,like the idea on the masking tape never thought of that, great tipon the li-po front was thinking the same thing as you have been told by some one who ordered from hobbyking that they had same problem, low price tilll they had to collect . I do try to get a lot from my main model shop in my town but not always possible (colin bliss models) then there isnt any postage or anything on to the lb watts n kv) thanks for the info there i guess that the 100w is really only good for sports models then but say 55 - 75w ish plb for the vintage type would be more the norm depending its application????? am i getting that right? how do you change the kv into whats any Idea??regards Adrian Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 11, 2012 Share Posted January 11, 2012 HobbyKing are not usually a problem re import charges......I've never been "had" so to speak. USA is a different matter in my experience.....I used to work for an American company & any samples they sent I got hit with import duties..... The tube isn't on my LMS web site so I can't post a link.....I can get some for you if you like......or take a look in your LMS or even Hobbycraft have it......white plastic tube about 2.5mm in diameter with a 1.5mm hole..... Watts/lb is a great way of working out how much power you need.....it goes something like this... Vintage...75-80w/lb Sports...100w/lb Aerobatic...150-200w/lb EDF...250w/lb There are loonies who put even more than that in....our very own Tim Mackey put about 750watts in a 2lb EDF model....what a hooligan...... Basically anything over 150w/lb will have good vertical performance.....remember it is always better to have too much power than not enough as you do have a throttle... kv is not related to watts at all....its the theoretical spped of the motor per volt thus a 1000kv motor will spin at 1000 rpm for every volt applied so at 10 volts it doing 10,000 rpm. Obviously these are theortical figures & the drag of a prop will slow the motor down so applying 10 volts to a 1000kv motor with a prop on it will not result in 10,000 rpm...more like 8,500 to 9,000 rpm with a significant current draw.....replace the prop with a bigger one & the revs will drop again & the motor will draw more current in an attempt to reach its designed speed.....this continues until something melts & releases the magic smoke. So from this we can see what an effect the prop has.....basically you take a guess at what you need & then test it & tweak the prop size to suit......too little power? Increase the prop size.....too much power....fit a smaller prop. This is why & how you can use the same motor to power a vintage floater on a 2S battery & a pylon racer on a 5S battery.... So how do you know what prop to choose in the first place.....ah...Grasshopper...that is the eternal mystery & has much to do with experience!!! From my own experiences based around mid size models on 3S batteries I always look for a 1000 to 1200 kv motor as this gives me around 10,000-ish rpm which suits the models I fly..... At the end of the day there are many variables in electric flight & a certain amount of experimentation is required to get the best from any set up......this makes it a) challenging & interesting ot b) a complete pain in the backside depending on your point of view.... We do have a database of some models on the site just here.....might be of use to you... Hope this helps....let me know about the tube....I'm going to get some for my next model on Friday so will happily get some for you........Edited By Steve Hargreaves on 11/01/2012 13:24:14 Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 11, 2012 Author Share Posted January 11, 2012 Steve Ty for the offer but i dont like to take advantage of anyones good nature,, will have a look in the model shop near me see how i get on , then if not and your going at all i may take you up on the offer, ty again. have you tried hobbyking at all are they anygood if so? have seen somethings on there i wouldnt mind trying outreally looking for a simple and very cheap rc for test flying a little park style even second hand would do motor front..so if my maths works well then .. if i get the motor Tim said about and the 2s li-po too then i guess it would work out 8100rpm with say a 10% loss for prop = 7326 rpm does that sound about right,?? i guess with anything electrical there is gains and drops all over the show, that and working out how to get the amps right for the esc thats another mathematicial matter to work on will take a look at that link you have put in see whats on there , have saved it so can go there any time then. thanks you AdrianEdited By Adrian Day on 11/01/2012 14:52:19 Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 11, 2012 Share Posted January 11, 2012 The revs themselves don't really matter that much Adrian....I've no idea what most of my models rev at but I do know that I like the way they fly...if I didn't I'd change......something... The kv is generally an indicator of the type of motor & hence the type of model its likely to suit......your Pix E with a tiny prop screaming away might make only 80 watts but wouldn't be very nice to fly......similarly you could put an enormous prop on a pylon racer & turn it at 6,000 rpm & still consume over 1 KW...but again it wouldn't seem right to fly. So don't get hung up on the revs per se.....think.... low kv....big prop...slow flight. High kv....small prop.....fast flight. Obviously there are many shades of grey within this picture but you get the idea. ESCs are easy...you get the ESC to suit the amps.....you know the watts you want from the watts/lb rule.....divide it by the battery voltage under load (thats about 10v on a 3S & 7.5 volts on a 2S) & thats yer max current. Choose an ESC the next size up.....so in your case I think you were looking for 100 watts (still think thats a bit much but we can tame it down with a smaller prop) off a 2s so 100 divided by 7.5 equals 13A so go for an 18A ESC.... Quote Link to comment Share on other sites More sharing options...
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