Geoff Bradley

I've got a model 4000 kit which included a flexidrive attachment (model225) Didn't fancy a battery job. http://www.amazon.co.uk/Dremel-4000-Rotary-Tool-4000-1/dp/B0033UWLXI/ref=sr_1_6?s=diy&ie=UTF8&qid=1359543976&sr=1-6 I've found it very usefull for all sorts of jobs both modelling and around the house - a sturdy bit of kit which is more than can be said about the attachments available ( drill stand etc) which seem a bit cheep and nasty to me !!! I also bought a rotary tool set from Aldi which complements it well. I consider it a very good buy.

That's a little advanced for me at the moment !! I'm just trying to find a method of working out a safe power train that everyone is in agreement with. People seem to atack it from different angles and I'm finding it very confusing as to which method is correct.

Welcome to the - erm - discussion Martin !! Do you include thrust in your method of calculating a power train ?

Thanks again Pat - It must have taken some time to type that out so I'm pleased to say I like it At last a calculation that includes the prop power to revs relationship in the calculation. I'm not one to stir things up but I wonder if others think this is the 'definitive' method of calculating the power train ? I do hope so !!!!!

Pat - that is just what I was after - I'll study it carefully and inwardly digest, I want to understant everything that is happening with my set up and it looks as if this will educate me !!! If I don't understand I will return !!!!! Thanks

i've had a good read and followed it OK until he picked 9000rpm out of thin air !!! Just had a discussion with a friend who says I should calculate the stall speed from the wing loading - then multiply it by 2.5 and 3 to give the speed I should fly at in order to have a stable flight - then pick the biggest prop that will go on my plane which is as close to 1/4 the wingspan - then work out the revs required for different pitch props ..... then work out the kv ...... he didn't get to the end - we will discuss it next week when I see him! At first I thought - he's pulling my leg - but thinking about it he could be right !!!!!

Thanks Christian - I'll have a read and then return !!!! Just a thought - if the prop provides our thrust surely our calculations should start with deciding on a prop that will provide what is required and work from there !!!!

Thanks for all the replies - Alwyns method seems to be , from what I've read on the net, to be as I thought but leaves me unsure of a few things .. Should the motor efficiency be included somewhere in the calculations? Not all motor manufacturers give recomended prop sizes ! How does the Kv of a motor affect the set up ?

I'm a beginner Pat but I would .. Decide on the required Wattage ( ie 150 W per lb for a basic aerobatic) Convert the Watage to HP ( 1HP = 746 W ) Look at the IC engine specs and pick one with the required HP output. The prop size for the engine will be given in the engine spec. No battrey req'd - just a supply of the correct fuel for the engine. No esc required - just a servo to opperate the throttle.

Thanks Martin and Frank - those are two of the many that I have allready come across. Do they give the same results and how do you know they give the correct set ups ??? Also you have to be in front of a computer to use them. I would rather work things out myself so that I know how the calculations are done.

I've spent literally hours searching the internet and have come across various methods of calculating 'power trains'. Similar results are often obtained by using these methods but sometimes there can be differences ie. 3S or 4S liopos ?? Also if you look through the different threads - when people ask for help with a particular set up - disagreement is rife !!!! So isn't it about time the situation was sorted with a definitive method ? Personally I don't understand why the calculations don't start with the prop ? Perhaps an article in the mag would be a good idea ! HELP !!!!!!

I am almost sure it has Rentman - good point

Thanks chaps - time for a search ont internet !!!

Some brilliant flying and quality movies. I'm currently looking for a camera to try and match the quality displayed - will anyone post the equipment they are using ?

I've had a good search on t internet with regard to 'bridge' cameras and have come up with four possible choices ... Fujifilm Finepix HS30 EXR, Canon Powershot SX40 HS, Nikon Coolpix P510 and Panasonic Lumax DMC - FZ150. Has anyone got experience with any of these - especially in movie mode. At the moment the Lumex is ahead by a nose !!!!!!

Good advice Pete. Devon I've now done it that way - works fine with just a small piece of foam under the hatch to stop the lipo moving about.

All good advice - thanks chaps. I'm not in a hurry so they search goes on - HS30EXR still in front at the moment .

Velcro and foam it is - thanks chaps

So I've got the plane - assembled no problem but what is the best way to position the esc and lipo to help air flow and be secure !!! It would be easy just to pack with foam but I'm concerned about overheating. can anyone pass on their solutions ? Pretty please

Brilliant build CS - keep up the good work It's good to see someone so young building - and showing such a good knowledge of our hobby .

Thanks Simon but tooooo many digits for me !!!! Bill - that looks good - top of my list at the moment

The camcorders with viewfinder are a bit pricey for me so I may have to struggle with a screen view jobbie !!! Can anyone advise me how much 'optical zoom' is required for decent model flying photography ???

MMmmmmm - a fair bit more than I am thinking of paying !! That's interesting about the viewfinder - time for a look on tinternet !!

Just realise - showing my age I meant a 'camcorder' !!!!

I've decided to buy a cine camera but have no idea what to go for. I want something that will give decent quality and don't want the planes to look like a fly in the distance !!! Can anyone point me in the right diection please ?