bending aluminium

8/11/2019 Bending Aluminium

1/11

How to bend a l um i n ium the ea sy wa y (Ea sym ode )

Koog ar 2010

I f yo u have eve r been i n t o e l ec t ron i cs in a ny p a r ti cu l a r way t he p rob l em o f ten a ri ses a t the e nd o f a p ro j ec t Wha t the

he l l am i go ing to put a l l th i s in ! to m ak e i t in to a fi n i she d i tem .

Som e p eo p l e s st anda rds a re d i ffe r en t to o t he rs and some are qu i t e hap py pu t ti ng t he i r p ro j ec t s in a ny t ype o f box and

be l ieve me I' ve seen som e th i ngs on l ine ve rg i ng f rom a pc i n a c a rdbo a rd b ox t o am p l ifi e rs i n c i ga r box es .

Now d on ' t ge t me wrong t h i s c an be we l l imp l em en t ed a t times you on l y have t o loo k a t the Cmo y M in t Am pshoused

i n an A l to i ds Ti n to see a g oo d im p l em en t a t ion .

The re a re qu i t e a few n i ce o f f the she l f co mm erc i a l ch assi s' s ava i lab l e suc h a s Ham mo nd

Mfg e x t rude d a l um i n ium se ri es bu t they a re ve r y he i gh t l im i t ed you a ren ' t go i ng t o f i t any t ype o f l a r ge t rans fo rme r in

there .There a re m an y o thers som e f rom EBa y, som e o f the Chinese c ha ssi s are g rea t but fa c to r in sh ipp ing an d tax a nd

you r soon rack i ng up 100 + on l y t o have t o mo d i f y it and t hi s i s whe re m y j ou rney b eg i ns. .. ... .

Fo r many yea rs i have wan ted to m ake a m y own PC c ase bu t th i s in v o lv ed b end i ng me ta l and i have t o say i won tb o the r star ti ng a pro jec t i f the e nd resu l t doe sn 't loo k p ro fessiona l .

You have on l y to l o o k a t CygnusX1 a wor k o f bend i ng a rt t o see a de si red end resu l t.

Ea rl ie r th i s ye a r i de c ided to s ta r t a n ew D.I .Y Audio pro jec t , i wan ted a sm al l yet p ow e r fu l am pl i fi e r fo r the PC to run

s ome Q Acoustics 1010i book she l f spea ke r s. I de c i de d a Ga i nc l one w as the w ay t o g o a nd d ec i ded on a LM3875

Cla ssi c k i t f ro m Audiosector.Pe te r is a g rea t f o rce i n t he D IY Aud i o wo rl d a nd i s a m as te r a t m ak i ng simp l e ye t be au t if ul

c ha ssis s a s wel l a s the bi ts inside : )

So t he k i t was bu i lt and t he p ro t o t ype ch assi s wa s ma de t o ho use and tweak t he l ayou t a f te r a w ee k o r so i had t he

l ayou t do wn an d i knew the d imens ions o f t he cha ssi s t ha t i req u i red . I a l rea dy h ad dec i ded t ha t i wou l d nee d t o m ake

m y own c hassi s and t he p rospec t o f bend i ng a l um i n ium arose ye t aga i n .

One t h i ng i knew was tha t i wan t ed pe r fec t bends and b end i ng 3m m a l um i n ium wasn 't go i ng t o be e asy no t on l y tha t

bu t ac t ua l l y ge t ti ng p rec i se b end s and kee p i ng e ve r y th i ng squa re wo u l d a l so no t be e asy you ha ve t o f ac t o r in how

mu ch ma te ri a l the ben d w i ll use and whe re i t w i ll end up . I t houg h t ab ou t t h is fo r a few da ys i eve n l ooke d a round fo r

a b rake p ress bu t they were e i the r too e xpe nsi ve o r fee b l e even som e o f t he l a r ge r one s co u ld o n l y bend t hi n gaug e

m e ta l s .

I ha ve a b i t o f a m o t t o i f you c an t buy i t o r bo rr ow it then m ake i t ! and t hi s i s when i thoug h t i wou l d m ake my own

ben de r . I rang m y f rie nd M i c k a s i reme m be r ed he had som e a ng le i ro n flo a t in g a round bu t a s i t tu rned ou t he had

used i t .As i cou l dn ' t wa i t and had a l ook a round fo r ma te ri a l s i had l y i ng a round when i no t ice d i had qu i t e a b i t o f

38mm ba m boo wor k top o f f cu t s , so i dec i ded t hi s m i gh t j ust fi t t he b i ll as i wasn ' t ben d i ng s tee l t he im pa c t on t he

ed ge o f the b ac k stop wou l d be a l o t le ss


2/11

Heres the re sult of a n a f te rno ons wo rk. . .. . .. .

I 'm no t go i ng t o ge t i nt o t he co nst ruc t ion o f t he ben de r as it s p re t t y se l f exp l an a t o r y and t he l eng t hs w il l

d i f fe r dep end i ng on w ha t t he s ize o f shee t you need t o be nd .

One o f the mo st im po rt an t pa rt s a re t he h i nges these w i ll t ake a l lo t o f fo r ce du ri ng t he b end and i ts p re t t y

c ri ti ca l tha t the re i s as l it tl e p lay a s p ossib le a s th i s w i ll i n fl uenc e the q ua l it y a nd t ig h tness of the be nd . I

used som e 4 i nch he avy du t y st a i nl ess hi nges bec ause t hey were t he be st i ha d a roun d .One o f the

bo nuses o f t he 38mm p l ywoo d wa s t he fac t tha t t he h i nge s c ou l d be sc rewe d i n p l ac e i d idn ' t need t o

bo l t them th rough t he ba se a nd sw ing a rm .

The o t he r b it o f adv i ce i s t o r un the f ac e ed ge o f the b ac kst op t h roug h a t ab l e saw i used a ang l e o f 5


3/11

The two M10 bo l t s i n the t op a re t o c l am p t he shee t b e twee n t he b ac kst op an d t he b ase , The b ac kst ops

bo l tho l es have a s lo t c u t in t hem to a l low t he b ac kst op t o b e sl id ba c k t o a l l ow f o r the t h i ckne ss o f t he

m a te ri a l to be ben d .

See ho w the f ac e o f t he ba c kst op sl ope s bac kwa rd sl igh t l y

Time to be nd o r ne ar l y .

So we h ave t he ben de r bu t we a ren ' t fi n ished as the re i s ano t he r t ri c k t o ge t t ing t he pe r fec t bend and t h is

i nvo lves mak i ng a sco re o r cu t l ine on t he shee t whe re you w an t the be nd t o st a r t you w i ll nee d a t a b l e

saw for th i s w i th a b lad e w i th as m an y teeth a s yo u po ssib le an d p re fe ra b l y sharp :P .A lum in ium c uts

su rp r i si ng l y easy w i t h a d ec en t t ab l e saw bu t r eme mb er i f i t g rab s i t won t be a s fo r g i v ing as woo d t o you

o r the saw ,ma ke sure yo u take p rec au t ion s w i th gu a rd s and safe ty g lasses ! !

He re we c an see t ha t t he b l ad e i t se t a t abo u t 1 / 3 rd o f the t h i ckness o f a l um i n ium th is fi gu re w i ll dep end

on t he t hi ckne ss o f t he m a te r ia l t o b e b en t .

He res a p i ec e o f a l um i ni um 3mm thi ck . ( I t s a goo d i de a i s to p rac t ice on som e sc rap fi rst .. ..


4/11

So w e ha ve t he de p t h se t on t he t ab l e saw and t he li nes ma rked on t he m a te ri a l to bend . .. .. .. .. .

Onc e you re h ap py w i th t he d ep t h now we se t the saw tab l e f enc e t o t he fi rst cu t . (A l it tl e no t e he re u si ng t h is me thod

o f c u tt ing t he l ine rem ov i ng a t hi rd / ha l f o f the ma te ri a l w i ll g i ve pe r fec t 90 deg ree sha rp i nsi de co rne r ) i f we j ust be n t

usi ng t he be nde r yo u wo u l d end up w i th a rad i us on t he i nsi de a s we l l the ou t si de .

He re you ca n see t he cha nne l l e f t by t he Saw b l ad e . .. ... .. ..

(A t i p he re i s i f you a re m ak i ng a U sha pe d c ove r/ l id fo r som e th ing you wou l d ha ve c u t 2 li nes in t he shee t so you

wou l d h ave a s ide / m i dd l e o r t op / si de sec t ions , i f you w an t the m idd l e ( t op ) sec t ion t o kee p t he same w i d t h as t he

m arks m ake t he cu t o n t he o t he r si de o f t he m arks tow ards the si des tha t w ay when you b end i t you w i ll ma i n ta i n t h is

me asu rem en t and any ex ce ss c an be cu t o f f t he si de l a t e r by p l ac i ng the be n t p iec e o n i ts si de i n the t ab l e

Saw.


5/11

)

Here i fl ipp ed the shee t ove r to d up l ica te the o ther side . . .. .. .. .. . .. .. .

Time to Ben d the shee t in to som eth ing usefu l

He re yo u ca n see t ha t the b ac kst op ha s be en sl id ba ck and t he bo l t s t igh t ened t o a l low f o r t he t hi ckne ss o f t he

m ater i a l .

The e dg e o f t he cu t i s exa c t l y li ned up w i t h the g ap be twe en t he ed ge o f t he ba c kst op b ase and t he sw i ng ing s i de . The

o t he r cu t e dge i s d i rec t ly i n li ne w i t h the bo t t om o f t he ba c kst op .


6/11

When we st a r t t o f o l d t he who l e cu t l ine w i ll ac t as a we ak po i n t and t he be nd w i ll fo l l ow t h is pa t h e xac t ly t il l ea ch c u t

ed ge m ee t t oge t he r p r oduc i n g a sm oo t h squa r e bend .

I f yo u didn t qui te ge t 90 de gree s t ry push the pie c e slight ly pa ssed 90 to a l low for sp ring ba c kNow i just turned the p iec e

round i n t he ba cks top re - c l amped and ben t aga i n.


7/11

We no w ha ve a Chassi s l id w i th p e r fec t be nds w i t h a n ice rad i us w i th pe rfec t 90 deg ree sha rp i n t e rna l c o rne r s!


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11/11

Ge t a p ai r of Digi ta l Ca l ipers

The finest pe rm ane nt m arker suc h a s Pente l NMF50 (my favo ur ite) wi l l draw 0.5mm l ines on anything

Finer the m arks the mo re a c cura te your bends and c uts w i ll be a 2mm line w i th me an yo u co u ld be o ut by 2mm on square

or that hole yo u dr i lled just wand ered o f f 2mm do esn t soun d l ike a lot but whe n yo ur dri ll ing four holes to m ate to a nother

pie c e i t wo nt !

A lumin ium Grad es

5251 H22:

(Me dium st reng th al loy, work harde ns rap idly. Resistant to m ar ine atm osphere

1050A:

(Ma l lea ble. Goo d c orrosion resistanc e. )

5083"O":

(Rea di ly weld ed , sui table for use in c ryo ge nic ap pl ic at ions e.g. storage & transpo rtat ion of liquid ga ses & in shipb ui ld ing .

Used in ge ne ral eng inee ring fo r too l ing , j igs & fixtures.)

6082 - T6:

(The rec om me nde d a l loy for st ruc tural purpo ses wi th go od st reng th & gen eral

Co rrosion resistanc e. Used for vehic les, br idge s & crane s, gen eral en gine er ing & too l ing plates.

Not rec om m end ed for fo ld ing / fo rming)

Ha ve Fun .. .

Koog ar 2010 rup e r thi rst@nt lwo rld.c om

bending aluminium

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