Cutting a shape through a flat and curved face?

[pren]

Hi.

I'm designing a bed for a friend of mine. So far I've come up with the design below

One of the main features is the heart shape cut out of the head and foot boards. The head-board one is straight forward as it's flat. The issue is with the foot board. It's curved on one face and flat on the other.

I intend to join the edges of both cut-outs with some form of flexible timber, so they would both need to be exactly the same. The head and foot boards will be of a hollow, ribbed construction from 6 or 9mm MDF.

Any ideas how to cut the curved face so that it matches the flat one with out distorting around the curve? Or would it not be an issue? :?

I have a router at my disposal if that helps. I'll make a template to cut out the flat faces.

Trust me to make things difficult! :roll: :lol:

Thanks in advance.

Bryn

 

[jasonB]

cut it over length so it sticks out teh front then trim/sand it flush, probably al lot easier than developing the true shape, not done that since technical drawing at school.

Jason

 

[joiner_sim]

I don't see why you can't just put your template on the flat side of the foot board (once made, made with a block in the middle where the cut-out is to be, so you don't have to infill any gaps) and then router it out.

 

[jasonB]

I don't see why you can't just put your template on the flat side of the foot board (once made, made with a block in the middle where the cut-out is to be, so you don't have to infill any gaps) and then router it out.

If the drawing is to scale then it will need a 6" long router bit!!

Jason

 

[joiner_sim]

Well, I did wonder how thick the whole thing is going to be, but without sizes, you can't tell.

 

[dennis]

Pren

Mount your template on two battens running downwards parallel to the centre of the heart and clamp onto the curved side.

Dennis

 

[norman]

Hi Prin

scroll/jig saw from flat side with fine blade. Or by hand with frame saw again with a fine blade.
Make sure that the bed end is well supported and square.

have fun
Norman

 

[DeanN]

I'm with Dennis - but I was thinking of making a full size template (the width of the panel), and using this to clamp onto the material and router out the shape on both sides - supported on the curved side with battens. A smaller template would obviously save timber.

 

[joiner_sim]

I was trying to think of how to cramp some support on the curved side, but yes that sounds about right!

 

[Chris Knight]

The problem is that eg circular holes on the flat side should be slightly elliptical to match on the curved side, Dunno what you call an elliptical heart.

I think you'll need to guess a bit and fill in any gaps with a bit of inlay of some kind.

 

[DeanN]

Agreed, but if the same template is used on both sides (supported on the curved side), the resulting cut will follow the curve. Maybe a diagram is called for.

 

[pren]

Hi guys.

Thanks for all the suggestions.

The biggest issue I have is avoiding distortion on the curved face. If I use the same template from the flat face on the curved face, then looking through the resulting opening from the flat side, the heart in the curved face would be narrower.

Does that make sense, because I'm loosing myself! :lol:

A flat sheet of A4 paper is 21cm across. Now curve the same sheet and it becomes narrower as viewed from above. If this happened with the 'heart' opening, I couldn't link the two faces with board.


HANG ON!!!! I think I've just understood the batten idea that Dennis and DeanN were on about!!!

You mean: mount battens to the same template as the flat face in such a way as to allow the template to remain flat with the centre in contact with the center of the heart location? either end of the template would be, say, 50mm above the curved panel? Then rout with a cutter long enough to clear the distance + MDF?

Why that's .... that's brilliant!! :shock: :lol:

I really couldn't see where the battens came into it!

I get pretty thick when it's late.

That'll do nicely, gents! Thanks very much!

Bryn

 

[DeanN]

Bang on - the template stays flat on both sides, with the battens used to support it on the curve. This should guarantee the 2 sides meeting up, but depends on the having a router bit long enough to span the gap. A picture would have helped explain it.

 

[Chris Knight]

Dean,

You are quite correct and I guess that the gap shouldn't be more than a 2 inch long, half inch diameter bit could reach. Next trick is to assure alignment of the two holes...

 

[pren]

Next trick is to assure alignment of the two holes...

Exactly what I was pondering. Easiest way, perhaps, would be to drill two holes through the entire frame, above and below the opening, that correspond to two holes in the template?

Cheers.
Bryn

 

[dennis]

Providing that the tops of the head and footboards are perfectly straight and flat, you can square the centre lines of the hearts from the flat face and down the curved face, and measure equal distances down both faces to set the templates.

Dennis

 

[CNC Paul]

Bryn,

How about making up the bed end then slip a jig over it, then router the heart from both sides with a top bearing cutter.

Paul