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Mandrel bends?
coozer - 22/1/14 at 05:02 PM

Further on with my inlet..

Found the 1.75" bend a bit too big and think 1 5/8" would be better..

HOWEVER... I cant find 60 degree bends (42mm) this side of the pond..

Anyone point me to where I can get exhaust pipe in 42mm with a 60 bend? I need 8 pieces, although one to start with just to check would be ok...

v8kid - 22/1/14 at 05:22 PM

I just cut 90 bends to suit - just make sure you cut at right angles and its OK

coozer - 22/1/14 at 05:23 PM

quote:
Originally posted by v8kid
I just cut 90 bends to suit - just make sure you cut at right angles and its OK


have you made an inlet manifold?

907 - 22/1/14 at 06:06 PM

quote:
Originally posted by v8kid
I just cut 90 bends to suit - just make sure you cut at right angles and its OK




Nooooooooooo.

Buy 180's and cut into three.

Didn't anyone teach you not to waste stuff ?


Paul G

ste - 22/1/14 at 10:05 PM

quote:
Originally posted by 907
quote:
Originally posted by v8kid
I just cut 90 bends to suit - just make sure you cut at right angles and its OK




Nooooooooooo.

Buy 180's and cut into three.

Didn't anyone teach you not to waste stuff ?


Paul G



NNNNOOOOOOOOOOOOOO

Buy 360s and cut into six!!

ste - 22/1/14 at 10:05 PM

quote:
Originally posted by 907
quote:
Originally posted by v8kid
I just cut 90 bends to suit - just make sure you cut at right angles and its OK




Nooooooooooo.

Buy 180's and cut into three.

Didn't anyone teach you not to waste stuff ?


Paul G



NNNNOOOOOOOOOOOOOO

Buy 360s and cut into six!!

adithorp - 22/1/14 at 10:28 PM

Out of interest, what do you use to cut them and how do you ensure it's straight (radial).

mark chandler - 22/1/14 at 11:40 PM

Just a hacksaw with 24tpi blade, tried a cutting disc, lots of dust and mess, also reciprocating saw and jig saw but it overheats the blades and snatches badly. The best tool would be a bandsaw but do not have one.

I just lay on the floor and lay a straight edge to where the centre of the circle would have been and draw a line across. Push a tight fitting socket into the end you clamp in the vice to stop the work collapsing as you cut.

907 - 23/1/14 at 10:12 AM

quote:
Originally posted by ste
quote:
Originally posted by 907
quote:
Originally posted by v8kid
I just cut 90 bends to suit - just make sure you cut at right angles and its OK




Nooooooooooo.

Buy 180's and cut into three.

Didn't anyone teach you not to waste stuff ?


Paul G



NNNNOOOOOOOOOOOOOO

Buy 360s and cut into six!!





Never done it with pipe, but I've made 360's in 25mm box section and cut into four.

90 deg bends in 25mm box
90 deg bends in 25mm box



Also, Mark is spot on. The band saw is the ideal tool.

The bed of a band saw has a gap, with the blade running in line with the middle of this gap, and if the bend
is placed in the vice open ends facing up, the back of the bend sits on the edges of the gap. Mounted thus the
blade will always runs through the bend radius point and so the cut will always be square with the bore.
Using a Wixey digi angle gauge I can cut any angle I wish from a bend.

I can see no reason why the jaws of a band saw couldn't be replicated along the lines of a carpenters mitre block
and be used as a cutting guide for a conventional hacksaw.


Cheers,
Paul G

matt_gsxr - 23/1/14 at 10:33 AM

quote:
Originally posted by ste
quote:
Originally posted by 907
quote:
Originally posted by v8kid
I just cut 90 bends to suit - just make sure you cut at right angles and its OK




Nooooooooooo.

Buy 180's and cut into three.

Didn't anyone teach you not to waste stuff ?


Paul G



NNNNOOOOOOOOOOOOOO

Buy 360s and cut into six!!


I have made a manifold and I found that 135deg bends are the most cost effective when you cut them up.

adithorp - 23/1/14 at 01:04 PM

quote:
Originally posted by matt_gsxr


I have made a manifold and I found that 135deg bends are the most cost effective when you cut them up.


Is that because it allows 15' for a bit of fettling/adjustment/...cocking-up?

matt_gsxr - 24/1/14 at 11:37 AM

quote:
Originally posted by adithorp
quote:
Originally posted by matt_gsxr


I have made a manifold and I found that 135deg bends are the most cost effective when you cut them up.


Is that because it allows 15' for a bit of fettling/adjustment/...cocking-up?


Thanks for your confidence in my mechanical bodgery (well placed sadly).

For some reason a 135 wasn't much more than a 90 pricewise, but it gives you much more flexibility.
It is also useful having the straight sections.