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I need suggestions on how to machine this item
- Thread starter blibecap
- Start date
Is the shape a circular one or an oval once its roled? I.e. when its in place and looking down on it e profile appears to be a circle.
If its a circle maybe you could use a rotory table to mill the edge off.
big lenses by the way
are they very wide angle hence not going with a simpler hood design? The only lens i have with that design of shade is about 170degree field of view (horizontal)
Stuart
If its a circle maybe you could use a rotory table to mill the edge off.
big lenses by the way
are they very wide angle hence not going with a simpler hood design? The only lens i have with that design of shade is about 170degree field of view (horizontal) Stuart
I guess the answer is how much do you want to spend, how accurate it has to be and do you want smooth milled surfaces or sawed and filed.
I can see having it rolled and machined on a 4TH Axis CNC Horizontal Rotary Table on a VMC or a Live tooling CNC Lathe to get it accurate and great finish. You could also buy a tube, I checked Speedy metals and they have one with a bigger ID by .25, but you could bore it out on your lathe and not pay to have it rolled and welded. In the long run it might be cheaper.
Otherwise what the other guys have said here sound good too. The biggest expense I can see is writing the program and set up...Plus once you make the program, store it can be used again and again, next time you make more. Many small shops are hurting and you might be able to get it made cheaper then you think.
Call a local shop with a VMC with 4 th axis and have them send you a quote. Cant hurt.
I can see having it rolled and machined on a 4TH Axis CNC Horizontal Rotary Table on a VMC or a Live tooling CNC Lathe to get it accurate and great finish. You could also buy a tube, I checked Speedy metals and they have one with a bigger ID by .25, but you could bore it out on your lathe and not pay to have it rolled and welded. In the long run it might be cheaper.
Otherwise what the other guys have said here sound good too. The biggest expense I can see is writing the program and set up...Plus once you make the program, store it can be used again and again, next time you make more. Many small shops are hurting and you might be able to get it made cheaper then you think.
Call a local shop with a VMC with 4 th axis and have them send you a quote. Cant hurt.
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If I had to do that job for a quantity of five (not many) I think I would go "old school". As suggested above, make a paper template and glue it to the tube with rubber cement. Drill four holes at the transition of the two curves. They look to be around 5/8". This will finish that part of the cutting. Mount the tube in a vise or clamp firmly to your bench and make roughing cuts slightly outboard of the lines on the paper with a saber saw. Work to keep the saw upright relative to the surface of the tube. After the cuts are made, file to the line. When filing aluminum it REALLY helps a lot to rub the file surface on a old candle or block of wax. This helps to keep the file from clogging, but you should still clean it often to get a smooth finish. There are lots of fancier ways to do this, but they will tend to have fancier prices which are hard to amortize over just five parts.
Next time I think I would cut the parts in the flat (band saw, waterjet, laser) and take the part and the off cut to the roller guy and have him roll them as one.
Good luck!
Next time I think I would cut the parts in the flat (band saw, waterjet, laser) and take the part and the off cut to the roller guy and have him roll them as one.
Good luck!
Here is what I'd try if I only had to make a few.
Get a cylinder rolled and welded together. Cut some appropriate length chunks off the tube. Then cut that profile you want out of real heavy cardboard. Wrap the cardboard around the tube and use it as a guide for a hand held plasma cutter. Clean up cut edges with your favorite tools.
if you are lucky you might get two of them cut out before you need to make a new cardboard pattern so make a couple of patterns to start. Or you could make the pattern/guide out of 1/4" diameter metal tubing, thinking copper tubing here, or just about any metal material the torch tip could guide against. That way you could use it over and over.
The problem I see trying to roll them after cutting is they are going to bend where there is little material left because the material isn't consistent in the force required to roll it.
Get a cylinder rolled and welded together. Cut some appropriate length chunks off the tube. Then cut that profile you want out of real heavy cardboard. Wrap the cardboard around the tube and use it as a guide for a hand held plasma cutter. Clean up cut edges with your favorite tools.
if you are lucky you might get two of them cut out before you need to make a new cardboard pattern so make a couple of patterns to start. Or you could make the pattern/guide out of 1/4" diameter metal tubing, thinking copper tubing here, or just about any metal material the torch tip could guide against. That way you could use it over and over.
The problem I see trying to roll them after cutting is they are going to bend where there is little material left because the material isn't consistent in the force required to roll it.
I've been reading all the help answers you are getting on this project and it seems you have a lot of choices--one thing I can add to theirs is in the final finishing of the scallops--if you have a vertical reciprocating drum sander you can use it to smooth your scallops--different size drums and coarse to smooth will do the job. I would start with a rolled piece and stand it on its side and cut the scallop shapes first and then finish them smooth with the drum sander. on my drum sander I make my different sizes of drums approx 6" long and then glue good cloth backed sand paper on them. I make mine from 1/2" to 3" diameter--I glue them on by wrapping them on in a spiral.--you could also use a small finger belt sander to finish them after cutting them. --Dave
How about using an eletric nibbler: http://www.youtube.com/watch?v=YmfgS-konzc
I would avoid a plasma cutter and just use a jigsaw or a fretsaw / scrollsaw;
http://www.hegner.eu/multicut.html
Get your aluminium sheet and either contact cement it to a piece of ply or double sided tape it down. Then just cut it out. Once you have cut it out and sanded the edges smooth, then use a heat gun to soften the glue or tape and lift away. With the pieces already to shape, then just roll the pieces.You can then weld them with this:
http://www.alumiweld.com/
I have cut thin thrust washes using my Hegner scrollsaw using this method, and I have used those welding rods to repair aluminium items in the past. If you have any woodworking friends I would assume at least one will have a scrollsaw. Standard blades work fine for aluminium and all you need is a little WD40 or alcohol to cool and lubricate the blade. This means the only thing you will need to buy is the aluminium and the welding rods.
Paul.
And just a quck side note, due to thermal expansion properties of aluminium, measure the aluminium when it is the same temperature as your camera. When welding it, it would help to have a tube or cylinder the size of your lens to mark everything out and hold it in place where you will be welding. Allow the rest to move freely to expand as necessary so you don't warp your piece.
http://www.hegner.eu/multicut.html
Get your aluminium sheet and either contact cement it to a piece of ply or double sided tape it down. Then just cut it out. Once you have cut it out and sanded the edges smooth, then use a heat gun to soften the glue or tape and lift away. With the pieces already to shape, then just roll the pieces.You can then weld them with this:
http://www.alumiweld.com/
I have cut thin thrust washes using my Hegner scrollsaw using this method, and I have used those welding rods to repair aluminium items in the past. If you have any woodworking friends I would assume at least one will have a scrollsaw. Standard blades work fine for aluminium and all you need is a little WD40 or alcohol to cool and lubricate the blade. This means the only thing you will need to buy is the aluminium and the welding rods.
Paul.
And just a quck side note, due to thermal expansion properties of aluminium, measure the aluminium when it is the same temperature as your camera. When welding it, it would help to have a tube or cylinder the size of your lens to mark everything out and hold it in place where you will be welding. Allow the rest to move freely to expand as necessary so you don't warp your piece.
I don't think a nibbler can handle 1/4 aluminium its for sheet metal. I don't think a sawzall will make the scallop radius cleanly. i have cut a lot of 1/4 and 3/16 with saber saws lots of lube, lots of frustration and lots of time t still requires dressing the cut i don't think the scroll saw would serve any better especially since the piece must be rolled first clamping would be a bear.
A plasma cutter of the right capacity (not a hobby machine) will cut it quickly and cleanly like butter the piece will need some clean up after.
I also see you can get 9" od aluminium tube with 1/4 wall http://www.vitaneedle.com/aluminum-tube.htm The initial cost of the material would be far offset by the reduction in cost of forming. With the layout done i don't think it would take an hour for a good operator to cut the 5 pieces with a plasma cutter. The drum sander would make short work of the clean up.
"It doesn't have to be too accurate as it's job is to provide shade and some protection to the dome. I do have to make 5 of these tho." The straight cuts can be made very nicely with a cheap wood cutting carbide tipped circular saw blade.
Bob
A plasma cutter of the right capacity (not a hobby machine) will cut it quickly and cleanly like butter the piece will need some clean up after.
I also see you can get 9" od aluminium tube with 1/4 wall http://www.vitaneedle.com/aluminum-tube.htm The initial cost of the material would be far offset by the reduction in cost of forming. With the layout done i don't think it would take an hour for a good operator to cut the 5 pieces with a plasma cutter. The drum sander would make short work of the clean up.
"It doesn't have to be too accurate as it's job is to provide shade and some protection to the dome. I do have to make 5 of these tho." The straight cuts can be made very nicely with a cheap wood cutting carbide tipped circular saw blade.
Bob