peter030371
|
| posted on 18/5/16 at 07:35 PM |
|
|
Marking up before cutting
I have been scratching my head for a few days now and I haven't a clue how to solve this one.
I need to cut a hole in my Striker bonnet for the air filter to poke through but how do I mark it?
It needs to be something like this one here.
 
RAW demo
Any wonderful tricks to mark it all up before I start cutting?
|
|
|
|
|
big_wasa
|
| posted on 18/5/16 at 07:59 PM |
|
|
Cardboard and masking tape.
|
|
|
peter030371
|
| posted on 18/5/16 at 08:20 PM |
|
|
quote:
Originally posted by big_wasa
Cardboard and masking tape.
I am very good with cardboard (half the car has been mocked up with it) but trying to mimic the compound curves of a Striker bonnet is not easy!
|
|
|
matt_claydon
|
| posted on 18/5/16 at 08:28 PM |
|
|
Cut a small hole and keep removing, making it bigger, and refitting. Once it actually fits over completely, mark an even distance all around and
finish with one more enlargement.
[Edited on 18/5/16 by matt_claydon]
|
|
|
adithorp
|
| posted on 18/5/16 at 08:44 PM |
|
|
I'd start with lots of measuring... then give up on that and do as Matt says. Start small and work up.
Is this a burst of enthusiasm, post Llandow?
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
|
|
|
peter030371
|
| posted on 18/5/16 at 08:51 PM |
|
|
quote:
Originally posted by adithorp
Is this a burst of enthusiasm, post Llandow?
Yes  don't put me off. Do you want to come and help? I can supply unlimited Java Cakes if it fits?
|
|
|
adithorp
|
| posted on 18/5/16 at 10:01 PM |
|
|
Taking the Dremmel to my own car is one thing... doing it to yours is a different matter entirely. I'm on a diet anyway.
[Edited on 18/5/16 by adithorp]
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
|
|
|
907
|
| posted on 19/5/16 at 05:01 AM |
|
|
Buy a very large box of corn flakes and extra milk. Eat corn flakes.
Cut the front off the box plus 25mm of the side. L_________________ like this.
Clamp the 25mm edge to the top chassis rail a suitable set distance from the scuttle, ( scuttle to edge of box 500mm ? )
You now have a sort of hinged flap that you can offer up to the filter. Start cutting the hole, offering it up to check progress,
until it passes over the filter. Bend and curve the cardboard to shape and check it still passes over the filter.
It doesn't matter if the hole is a bit tight. You can always make a hole bigger, but not smaller. ( As Matt says. )
Un-clamp and stick it on your bonnet using the "scuttle to edge of box" (500 ? ) dimension.
Mark and cut. Trim and round edges & corners with a flap wheel.
Paul G
|
|
|
peter030371
|
| posted on 19/5/16 at 07:39 AM |
|
|
Thanks for all the suggestions 
I have loads of cardboard (so no need to feed my family on cornflakes for every meal just yet) its just getting it to bend over the bonnet that is
curving in two directions at once is difficult.....however its the best option I have. Will start cutting (card) this lunch time and see how I get
on!
I am sure I have seen a write up on how to do this somewhere but I can't find it now and I just want to get on with it 
|
|
|
Fred W B
|
| posted on 19/5/16 at 08:27 AM |
|
|
You can make a pattern of a curved surface by applying multiple strips of wide masking tape over it, put some wax on it first to reduce the tack of
the tape and alternate the directions you put the tape down till you have a good thickness. Take the tape "patch" all the way down over
the chassis rail to give you a reference once you peel it off the bonnet. Then fit the filter and stick the tape back on the chassis rail and cut it
to suit as described by 907. Then put bonnet back and mark out
Cheers
Fred W B
[Edited on 19/5/16 by Fred W B]
You can do it quickly. You can do it cheap. You can do it right. – Pick any two.
|
|
|
peter030371
|
| posted on 19/5/16 at 09:39 AM |
|
|
quote:
Originally posted by Fred W B
You can make a pattern of a curved surface by applying multiple strips of wide masking tape over it, put some wax on it first to reduce the tack of
the tape and alternate the directions you put the tape down till you have a good thickness. Take the tape "patch" all the way down over
the chassis rail to give you a reference once you peel it off the bonnet. Then fit the filter and stick the tape back on the chassis rail and cut it
to suit as described by 907. Then put bonnet back and mark out
Cheers
Fred W B
[Edited on 19/5/16 by Fred W B]
That makes some sense and I had been scratching my head about using tape....I may try something along these line with some cardboard too
|
|
|
nick205
|
| posted on 19/5/16 at 09:57 AM |
|
|
Cutting the exhaust aperture in my MK Indy bonnet I started small and got bigger until I had the shape I needed - time and patience are the key to
this IMHO.
|
|
|
mcerd1
|
| posted on 19/5/16 at 10:10 AM |
|
|
You could just make a complete cardboard bonnet so you know it'll line up...
But however good a pattern you make, when it comes time to cut the real thing, make sure you cut it undersized to start with so you'll have room
to make adjustments
Silly things like a different thickness of cardboard compared to the real bonnet could make several mm of difference to the size and position of the
hole....
-
|
|
|
David Jenkins
|
| posted on 19/5/16 at 02:24 PM |
|
|
quote:
Originally posted by mcerd1
You could just make a complete cardboard bonnet so you know it'll line up...
That's what I did, roughly - I cut an over-sized hole in the cardboard so that it was an easy fit (i.e. inches over-sized), made a close-fitting
hole in another piece of cardboard, placed the big bit over the engine compartment and shuffled the smaller bit around until it fitted neatly. I then
taped down the smaller bit temporarily, and glued it afterwards.
Make sure that you put marks on the cardboard (centre-line, and where the real bonnet is folded under on the sides) so that you can line up the card
on the aluminium.
Cutting the eventual hole in the aluminium a bit under-sized is a good plan.
[Edited on 19/5/16 by David Jenkins]
|
|
|
