Neat quad design

[sausageroll]

http://diydrones.com/photo/my-new-handmad-quadcopter-vortex?context=latest

[Gav]

not bad!  This goes to show there';s always ';another way'; to build your quad.  A bunch of ally square tubes some right angle brackets and a rivet gun lol. like it!

[sausageroll]

Gotta be careful not to end up with a flying swastikia hahahah.

[XH558]

What a brilliant idea for a design that is .... would never have though of that - and SO simple 

If only that could be adapted to hex somehow 

[sausageroll]

Just cut the ends off at 60 degree angle and weld together.

[Gaza07]

Have you guys seen the pvc hex that was posted on here some time ago ?
Have a look here http://www.multi-rotor.co.uk/index.php/topic,228.0.html
And how about this one  http://www.multi-rotor.co.uk/index.php/topic,212.msg1153.html#msg1153 

[XH558]

Just cut the ends off at 60 degree angle and weld together.

Brilliant .... I don';t ';do'; maths .... failed the ';O'; level 3 times 

[sausageroll]

I was ****** at school but ive found more and more that I need to know certain stuff, angles, ratios, triangles etc, and ive learnt it all using caluclators on google, I can do a lot of it myself now, its great. lol

[XH558]

Funny you should say that - recently my son (who';s autistic) was scratch building a scale Tardis model and we needed to know the dimensions of the pieces for the sloping roof .... we knew 2 dimensions but needed to know the third .....well I just knew what we had to do.... out came Mr Pythagoras and lo and behold he was right - the pieces fitted perfectly   

I';ve learned more about maths building models than I ever did at school - out of necessity I suppose  ::)

[sausageroll]

Yeh its far more useful to learn the maths you need later in life when you can see a real world use for it. When i was 12 i had no interest in any of this stuff but now I need to use it and see a real use it takes me 20 seconds to learn it.

Shame really, it makes me feel like other than learning to read and write, all my time at school was a waste, i could have started doing what im doing now 10 years sooner lol.

[XH558]

Looking at your hex design there with the 60 degree cut - wonderfully simple - how would you join those together if you have no access to welding??

I suppose you could lay them over a centre board and perhaps glue gun them ....

Is aluminium welding difficult?  Does it need specialist equipment?

[XH558]

Aha - I';ve answered my own question ... 

http://durafix.co.uk/product_info.php?cPath=7&products_id=19

So it';s quite doable for a modest DIYer  .... I think I might have a go at this design - thanks sausageroll 

A cool winter project - all I have to do now is now is get the angle cutting right 
That';s after I';ve sourced a reasonably priced propane torch head for the propane cylinder I already have 

[Gaza07]

So are you guys welding aliminium with a blow torch like the one below, the reason I ask is I already have one most plumbers do, also the gas is very expensive from the site most plumbers merchants stock it much cheaper 

[attachimg=1]

[XH558]

Well I haven';t done it yet  but it seems feasible with these Durafix rods I linked to  ....

Easyweld will work with propane, butane, mapp, oxyacetylene or any fuel source as long as the material is brought up to 389';C ( 732';F ) before applying the rod.

So I need that very torch 

[sausageroll]

I weld a lot with those durafix rods. They work but ive learnt a lot using them,

You need to use MAP gas. butane is not hot enough. You need to get the whole thing to 750 degrees and a butane blowtorch wont do that with a big bit of metal, it acts as a heatsink and sucks the heat away from the join.

Second thing is, the metal has to be really clean. They supply a little stainless brush, but id go and find a big stainless brush to do the first clean up with then scrub with the included brush. It must be stainless brush and you cannot use the brush for anything but aluminium. Sounds stupid, but as soon as you taint the brush with steel or anything else, it wont work.

It works best if you file a chamfer on all edges your welding, so there is a V shaped grove to lay the filler material into. Heat the material up first then take the flame away and drag the filler rod in the groove. Dont put the rod in the flame caus big chunks will fall off and you wont getr anywhere. Get the metal hot then melt the fillter on the surface.

The main problem you will have with this type of frame will be getting the welds to all stick. With tig welding, the heat is very concentrated, but with this as you are heating with a map torch, the whole bit of metal gets hot. This means it expands, and with thinner bits of ally, it can expand unevenly and warp and end up looking like a pringle. The other issue is you do a nice, weld on one join then move to the next and the first one heats up and the filler dribbles out and together with the expansion of the metal it pulls the joint apart.

Also you need to clamp the parts together, lightly. if you do it too tight, when the metal gets hot all the preloaded tension from the clamps bends the metal. The way ive been doing box section rencetly is to drill a hole in the part, then put a long bit of threaded rod through and hang a weight off it. This way when the metal expands and shifts, the weight holds the clamp force up.

This will be hard to do with the square that you see here.

let me know if you need any help with it, the durafix rods do work but they are difficult to get the hang of some things they are not suited to, and unfortunatly, id say that welding this type of shape and material are not really best suited to durafix welding.

When done right its strong though. My whole NEX5 gimbal is held together with it.

[sausageroll]

Oh also make sure your wearing shoes, if you drop the very hot filler rod like I did the other day, your ability to wear shoes for a few weeks after may be severely effected.

[XH558]

That was really useful info - thanks ...

I was wondering about heat sink as I';ve sometimes had trouble even with solder when the heat is dragged away ....

I may have a rethink - or may have a go - yet to decide - but nevertheless that was brilliant input.

[sausageroll]

If you had the torch to hand, id say its worth the 20 quid to play with it. Its very useful stuff, I drilled a hole in the wrong place on the nex gyro head and i filled it over pretty nicely. Its not pretty but its strong.

If you need to get the torch too, the gas is about 15 quid a can, whereas a same sized can of butane is about 3 pounds, so its significantly more.

The torch head is a special one too, about 30-40 quid. They were trying to ban map at one point and b and q stopped selling it. you may have to go to a proper plumbers merchant, i get my map gas from graham the plumbers merchant.

[Gaza07]

Excellent info Pete thanks