Martin McIntosh Posted May 30, 2015 Share Posted May 30, 2015 Question for Richard or anyone who can help. Just finished balancing and covering a set of AJ blades to try. They are 460x42mm. Looking at Rich`s JPEG it would seem that the bolt hole is 11mm from the LE and the shim 10mm behind this. Before I drill them, is this correct because the CG of these is way behind the 11mm mark? Also, from looking at Rich`s, the shim was only about 4mm from the bolt hole centre. What do you use which works? Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted May 30, 2015 Share Posted May 30, 2015 Posted by Martin McIntosh on 30/05/2015 16:31:38: Question for Richard or anyone who can help. Just finished balancing and covering a set of AJ blades to try. They are 460x42mm. Looking at Rich`s JPEG it would seem that the bolt hole is 11mm from the LE and the shim 10mm behind this. Before I drill them, is this correct because the CG of these is way behind the 11mm mark? Also, from looking at Rich`s, the shim was only about 4mm from the bolt hole centre. What do you use which works? Martin the bolt hole should be 1 mm behind the chordwise cog, which is usually at the back of the spruce le section on those blades. Then 10mm from the blade root, and the shim should be 9mm behind the bolt all measurements from the bolt hole centre Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted May 30, 2015 Author Share Posted May 30, 2015 Steve, The Panther went into fail safe last weekend at about 50 feet, not sure why as it was pretty early on in the flight and the battery was relatively fresh. Checked it all over at the crash site and all seemed to be ok, will rip the gear out and give it a good testing before I commit to any repair work. As you know, the sharp lower leading edge on the blade brings the aerofoil cord line down, like wise, a thicker trailing edge pushes the cord line upwards as the cord line runs at its centre. All helps spin up as the cord line is in a negative attitude. Martin, I will take some measurements for you tomorrow unless anyone can do so this evening? Rich Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted May 30, 2015 Share Posted May 30, 2015 Thanks for the replies guys. The chord wise CG on mine is 15mm from the LE which seems rather far back. The blades feel rather light at 17.5 gm. ready to go and the LE, which is 11mm, does not feel or look like spruce. I would have to cut off and reposition the top reinforcing plate to fit the bolt as suggested, which would look wrong to me since the model has already flown with home made CFL blades and a 1.2mm shim 4mm behind the bolt which is at 1/3rd chord. No rush to get these wrong. Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted May 30, 2015 Share Posted May 30, 2015 That makes sense to me Martin my bolt hole is 15.5mm from the LE trust me those AJ blades do have a spruce LE well mine do, and I have a 0.4mm shim as described 10mm behind the bolt hole centre and spin up is good though possibly could be better Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted May 30, 2015 Share Posted May 30, 2015 Thanks Phil, pending other replies I shall probably do similar. If you are contemplating going to Greenacres in July, please be aware that the date has changed to 11-12 July. Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted May 30, 2015 Share Posted May 30, 2015 That's OK Martin I would add I'm seriously considering a 0.8mm shim once my current repairs are done and having seen what Richard had to say about a thinner TE decreasing the negative incidence Re green acres , yes I'd seen the date change and must be one of the few it actually helps as my club attend and display at wood spring wings on the weekend it was planned for and I provide the marquee transport. So now I'll have an empty trailer for my camping kit and more room in the van for models Quote Link to comment Share on other sites More sharing options...
Richard Elliot Posted May 30, 2015 Share Posted May 30, 2015 Hi Phil If you go from 0.4 to 0.8mm shim then you will increase spin up but loose lift. When I flew yours at the trimming day it seemed to have a good balance of the two. Cheers Rich Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted May 30, 2015 Share Posted May 30, 2015 Thanks Rich it was a thought as I felt she took a little longer run than most to achieve full spin however I will of course bow to your greater experience and not try to fix what ain't broke Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted May 30, 2015 Share Posted May 30, 2015 I am going to move the top plates rearwards and drill the holes at 16.5mm, then fit 0.8mm shims. The AJ blades have about a 1/16th TE and had not thought about my thinner ones causing any problems. See you there Phil, I need a hand to erect my larger tent! Quote Link to comment Share on other sites More sharing options...
Richard Elliot Posted May 30, 2015 Share Posted May 30, 2015 Phil Don't stop experimenting, that's all part of the fun, it can take a bit of twiddling to hit your own sweet spot and you learn a b it each time. Twenty flights on my latest model and I'm still dialling myself in! Hope to see you all at green acres Cheers Rich Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted May 31, 2015 Share Posted May 31, 2015 No problems Martin all being well I'll be there on the Fri evening looking forward to seeing you all there Quote Link to comment Share on other sites More sharing options...
James Mark Posted June 1, 2015 Share Posted June 1, 2015 Hello Martin You can add another Atom to the completed list, it has still to fly, just waiting for calm weather! Would like to add a photo but it is beyond my computer skills to move the image from my desktop to the Forum! Cheers James Mark Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted June 1, 2015 Share Posted June 1, 2015 Well after an argument with a tree , I broke my Coolwind supplied fibreboard rotor plate, I've made a new one but this is from 1mm fibreboard vs the 0.8mm Coolwind one, so isn't quite as flexible, anybody see any problems Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted June 1, 2015 Author Share Posted June 1, 2015 James, Nice one, look forward to seeing a photo if you can work things out Frank, 1mm thick FG sheet should be fine but to be on the safe side it wont hurt to increase the size of the triangle slightly. Here is another Atom completed, its Dani Ellison's 2nd ever build and number 2 Atom for him! bit of teenage bling going on with the colour scheme It is getting close to 50 built Atoms Rich Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted June 1, 2015 Share Posted June 1, 2015 That's one cool looking Atom Dani's built there. My rebuild of Diesels ride is done, paint drying as I type its back at home waiting to be put together so pictures can be expected when I get back of holiday on Saturday. I'm not sure its better than the Mk1 but it is subtly different, using some of the mods others have come up with and some of my own, mostly in materials and hardware layout. Edited By Phil Winks on 01/06/2015 23:07:54 Quote Link to comment Share on other sites More sharing options...
Bob Bertram Posted June 1, 2015 Share Posted June 1, 2015 Nice paint job on Dani's Atom. Have finished the rebuild of mine, all it needs are the head/servos adjusted but the forecast looks pretty naff so I guess there is no hurry. Will have to read all through the thread again to glean all the info on setting up the head unless there is an easier way! Quote Link to comment Share on other sites More sharing options...
James Mark Posted June 2, 2015 Share Posted June 2, 2015 Finally manage to figure out how to upload photos! Here is my latest creation. Quote Link to comment Share on other sites More sharing options...
Terry Whiting 1 Posted June 3, 2015 Share Posted June 3, 2015 Mark , A nice visual looking model Quote Link to comment Share on other sites More sharing options...
Ozgur Sar Posted June 6, 2015 Share Posted June 6, 2015 Hello everyone, I would like to share the results of my latest modifications. My atom got heavier due to reinforcements to several parts of the body and blades. So blades were flexing more than before. This caused blade strike a few times and even broke the triangular head plate once. So I cut two new head plates and placed them over each other (doubled them). This has solved the extra flexing problem and made the head stable. Other problem was the vertical CG being so high that caused the gyro unstable both on take offs and during flight. So I cut the mast approx 1 cm to lower the head towards the body. This has dramatically improved flight characteristics during my test flights today. This also fixed the gyro to roll to left during take offs. Rudders were also not effective as I wanted to be so I cut new bigger rudders which improved my tail control in low speed flights. I hope my modification results may help some of you that may have faced the problems I specified above. Edited By Ozgur Sar on 06/06/2015 20:10:10 Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted June 6, 2015 Share Posted June 6, 2015 Post over confident flight rebuild is complete along with some minor mods More details in this post on my build blog Quote Link to comment Share on other sites More sharing options...
Ozgur Sar Posted June 8, 2015 Share Posted June 8, 2015 One of my friends captured my atom landing this weekend Edited By Ozgur Sar on 08/06/2015 07:41:15 Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted June 9, 2015 Author Share Posted June 9, 2015 James, Thanks for posting a photo of your finished Atom, I do like the colour scheme Phil, Nice work, have you flown it with your new mods? Ozgur, Glad to hear you have your Atom dialled in now, thanks for taking the time to post a video! Keep up the good work gents Rich Quote Link to comment Share on other sites More sharing options...
Mark Stringer Posted June 9, 2015 Share Posted June 9, 2015 Not a great video but the only one I have so far .. my Atom as flown by Rich H on Sunday. It was too nose heavy still having the lead in the nose from the very windy trimming session .. you can see it drop in the turns (1:28 for example) ... when I had a go at finally flying it I did the same circuit but my lack of experience caught me out and she came down to fast and wouldn't pull up .. straight at us .. we all dived for cover it is made a fast landing but it did clip my sons shoulder with the tip of the blade. Son and Atom are fine but once I have removed some lead I will go somewhere quiet to practice so that I can get the feel for it. Will edit this when the video is the right way around!! Edited By Mark Stringer on 09/06/2015 15:58:29 Quote Link to comment Share on other sites More sharing options...
Mark Stringer Posted June 9, 2015 Share Posted June 9, 2015 I don't seem to be able to edit my own post for some reason .. so here is the video Quote Link to comment Share on other sites More sharing options...
Recommended Posts
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.