Author Topic: Square holes on aluminum.... how do you do it?  (Read 19859 times)

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Offline beanflying

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Re: Square holes on aluminum.... how do you do it?
« Reply #50 on: October 16, 2019, 11:58:00 am »
The issue becomes the blades on most coping saws and in particular electric scroll saws. I have owned an electric one for over 30 years and I don't use it on Aluminium ever. Balsa, Ply and some plastics is about it. You will do much better with the hardened teeth on a jigsaw blade than a scroll saw on Aluminum.
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Offline soldar

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Re: Square holes on aluminum.... how do you do it?
« Reply #51 on: October 16, 2019, 04:21:01 pm »
The issue becomes the blades on most coping saws and in particular electric scroll saws.

I am having trouble parsing and understanding this. What's the issue?

Obviously you need to choose the right blade. I have used a fret saw on aluminum without problem since forever. It allows cutting of all sorts of shapes without problem.
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Offline drussell

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Re: Square holes on aluminum.... how do you do it?
« Reply #52 on: October 16, 2019, 04:22:38 pm »
The issue becomes the blades on most coping saws and in particular electric scroll saws. I have owned an electric one for over 30 years and I don't use it on Aluminium ever. Balsa, Ply and some plastics is about it. You will do much better with the hardened teeth on a jigsaw blade than a scroll saw on Aluminum.

Have you tried the abrasive blades? 

They are usually called things like "Carbide Blade" or "360° Cutting Saw Blade".

A manual coping saw version with carbide or diamond grit is usually available inexpensively in the tile cutting section of your local hardware hut. 

You can also usually easily find a thicker model blade intended for use on a standard hacksaw handle for a few dollars if your panel is small enough to be able to use the typical hacksaw's limited reach.  Eg. $3.73 Canadian available at Home Depot here, but online order only, apparently, but they do free "ship-to-store-for-pickup":

https://www.homedepot.ca/product/qep-10-in-rod-carbide-saw-blade/1000164562

 

Offline Bassman59

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Re: Square holes on aluminum.... how do you do it?
« Reply #53 on: October 16, 2019, 04:30:53 pm »
I have a suggestion for the front and the back panels if you are doing prototypes. Instead of cutting on the metal plates or 3D printing, you could use black acrylic sheets (2mm thick) and cut the shaped into them using a laser cutter. I have a low power laser CNC and use that to cut the acrylic panels. They come out very well and it is much faster to cut.

I don't have access to a laser cutter!
 

Offline Bassman59

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Re: Square holes on aluminum.... how do you do it?
« Reply #54 on: October 16, 2019, 04:35:56 pm »
I like to use a manual scroll saw.

I have a coping saw and I used it for a panel with only a few largish (1.5 cm) square holes, and it worked well. I also used it on plastic.

My latest thing has a couple of long slots for a bargraph LED meter, and cutting that by hand in 1.5 mm aluminum doesn't seem like that much fun.
 

Offline Bassman59

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Re: Square holes on aluminum.... how do you do it?
« Reply #55 on: October 16, 2019, 04:55:51 pm »
Well, I suppose the right adhesive to use also depends on the type of plastics you used. Is that PLA or ABS?

It's PLA.

I did some searching and most of the results for "best adhesive for PLA" return things that assumes you want to glue two pieces of 3D-printed plastic together, not put a decal on a large-ish piece. There are various cyanoacrylate suggestions. Applying the glue to the panel could be annoying.

To experiment, I took a piece of the printed plastic and sprayed it with two coats of primer paint, let it cure, then sprayed it with the E6000 adhesive and stuck my decal on that. Then I put some weight on the thing and let it sit for a day, and the sticker seems well stuck on.
 

Offline Bassman59

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Re: Square holes on aluminum.... how do you do it?
« Reply #56 on: October 16, 2019, 05:00:32 pm »
As soon as you have to include any of your own time as a "cost" then just farming the whole thing out to your local Laser/Waterjet cutter suddenly looks like very good value indeed, especially if you value accuracy and repeatability...

They tend to have minimum order quantities, but once over that value the cost is trivial.

For a one-off prototype that's kinda expensive, but for making, say, 25, it's a no-brainer!

I checked and Front Panel Express will make my panels for $32 each in qty 1, which is now sounding better and better. But I'd like to get my design correct before I spend real money, so 3D printing to at least get the holes in the right places is reasonable.

I should revisit the idea of using aluminum printed circuit boards with black soldermask as panels.
 

Offline dom0

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Re: Square holes on aluminum.... how do you do it?
« Reply #57 on: October 16, 2019, 05:04:24 pm »
The issue becomes the blades on most coping saws and in particular electric scroll saws. I have owned an electric one for over 30 years and I don't use it on Aluminium ever. Balsa, Ply and some plastics is about it. You will do much better with the hardened teeth on a jigsaw blade than a scroll saw on Aluminum.

There are scoll saw and coping saw blades that work for aluminium, but most blades are only meant for wood and plastics.
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Offline soldar

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Re: Square holes on aluminum.... how do you do it?
« Reply #58 on: October 16, 2019, 05:17:44 pm »
There are scoll saw and coping saw blades that work for aluminium, but most blades are only meant for wood and plastics.

I guess I have the right ones because I have never had a problem sawing aluminum.

Also, for straight longer cuts I have used a regular hacksaw blade.

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Offline Gyro

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Re: Square holes on aluminum.... how do you do it?
« Reply #59 on: October 16, 2019, 06:25:11 pm »
Likewise. You need a finer pitch blade than you use for (soft)wood but that's about all. Jewellers use very similar blades to cut Sterling Silver.
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Offline tkamiyaTopic starter

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Re: Square holes on aluminum.... how do you do it?
« Reply #60 on: October 16, 2019, 06:45:09 pm »
I wonder if there are any high speed dremel type tool that will withstand heavy-duty usage?  I used a regular type for this particular time.  Well...  it got awfully hot.  Also locking mechanism jammed so I had to take it apart and fix it.  Maybe something like dentists use? 

 

Offline soldar

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Re: Square holes on aluminum.... how do you do it?
« Reply #61 on: October 16, 2019, 07:09:41 pm »
I wonder if there are any high speed dremel type tool that will withstand heavy-duty usage?  I used a regular type for this particular time.  Well...  it got awfully hot.  Also locking mechanism jammed so I had to take it apart and fix it.  Maybe something like dentists use?

I am thinking a compressed air "Dremel" would be tougher and last forever. Have you been to a dentist lately?
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Online langwadt

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Re: Square holes on aluminum.... how do you do it?
« Reply #62 on: October 16, 2019, 07:10:18 pm »
Likewise. You need a finer pitch blade than you use for (soft)wood but that's about all. Jewellers use very similar blades to cut Sterling Silver.

https://youtu.be/Xo2GM2urd5I
 
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Offline tkamiyaTopic starter

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Re: Square holes on aluminum.... how do you do it?
« Reply #63 on: October 16, 2019, 07:46:13 pm »
I am thinking a compressed air "Dremel" would be tougher and last forever. Have you been to a dentist lately?

Wooohooo!  Great idea!  I already have a smallish compressor.  Thanks!
 

Offline soldar

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Re: Square holes on aluminum.... how do you do it?
« Reply #64 on: October 16, 2019, 07:50:25 pm »
https://youtu.be/Xo2GM2urd5I

Yes, in Spanish I have always called those saw blades "hair blades" because they are so thin. That arc is smaller and gives the user much better control. Mine has a wider arc with longer blade and more reach. It allows reach into deeper places but is also more cumbersome to use. Maybe I sould get a smaller one for finer work. In fact, I could use broken blades from the bigger one. 
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Offline soldar

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Re: Square holes on aluminum.... how do you do it?
« Reply #65 on: October 16, 2019, 07:54:03 pm »
Wooohooo!  Great idea!  I already have a smallish compressor.  Thanks!


I have a broken refrigerator and the intention of using the compressor to build myself a shop compressor. It'll be any year now. :)

Compressed air tools have the advantage of being powerful and refrigerated by the expanding air.
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Offline dom0

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Re: Square holes on aluminum.... how do you do it?
« Reply #66 on: October 16, 2019, 08:02:22 pm »
And being rather loud.
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Offline KL27x

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Re: Square holes on aluminum.... how do you do it?
« Reply #67 on: October 16, 2019, 08:10:57 pm »
Quote
I wonder if there are any high speed dremel type tool that will withstand heavy-duty usage?  I used a regular type for this particular time.  Well...  it got awfully hot.  Also locking mechanism jammed so I had to take it apart and fix it.  Maybe something like dentists use?
My only Dremel is probably over 10 years old and still works like new.

I use several Proxxon rotary tools, and the only one I killed was after a year or two of heavy use. Big side-loads in a router table, doing tasks that call for a real router. I've learned how to prevent even this. When the bearing starts to make funny noises, you have to stop using it and replace it right away before the commutators on the motor get worn out of whack. The Proxxon tools have their thin, slender neck at the cost of a stupidly thin ball bearing at that end. McMaster Carr sells them. They have only one model in this size, which is telling on how extreme a compromise it is.

Quote
Quote from: tkamiya on Today at 07:46:13 pm
Wooohooo!  Great idea!  I already have a smallish compressor.  Thanks!


I have a broken refrigerator and the intention of using the compressor to build myself a shop compressor. It'll be any year now. :)

Compressed air tools have the advantage of being powerful and refrigerated by the expanding air.

The problem with air grinders is air supply. They're hogs. They have much lower inertia and suck massive air even when up to speed. They get their torque from sucking massive power all the time. You probably need at least 20 gallon tank and a decent compressor to use one, even a pencil grinder. A fridge compressor is high pressure, low output; not at all right to run an air grinder.

I eventually upgraded my router table to take a trim router. And I bought a 1/8" collet for it, so I can still use all my rotary tool bits in it.

*edit: I also occasionally use a trim router like a big dremel tool, using both carbide burrs and stone/hard points. With a carbide burr, it will eat plastic and aluminum, but you need a big hand to hold it.

One curious thing I've found is that even the cheapest trim router you can find out of china runs true as any high money dremel or proxxon tool and will have a nicely balanced motor. Consumers seem to accept runout and buzz in cheap rotary tools, perhaps because they are still useful with a variety of tasks/bits. A router with any much runout would be fairly useless and perhaps even a safety issue. The balancing of the motor, which is the massive majority of the weight of the device, probably simply has to be done, and it seems that once that threshhold is crossed, it is perhaps not much more expensive to do the job, properly.
« Last Edit: October 16, 2019, 08:36:50 pm by KL27x »
 

Online coppercone2

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Re: Square holes on aluminum.... how do you do it?
« Reply #68 on: October 16, 2019, 09:49:12 pm »
don't you want a safety switch with 1/4 inch? I kind of feel like using a router free hand for metal is dangerous even if its overbuilt because of ergonomics. They are like a giant can
 

Online tautech

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Re: Square holes on aluminum.... how do you do it?
« Reply #69 on: October 16, 2019, 10:03:24 pm »
The English term is fret saw or coping saw. Great tools in skilled hands! The jewellers' tool of choice (used with a little V shaped bench plate).  :)

And I thought I could speak English! No wonder I could not find it. :)

Every day I learn something new. When I was younger I would remember and retain what I learned. Now I tend to forget it. Maybe I will put a label on my fret saw. :)
Note that a fret saw and coping saw are very similar but there's a distinct difference, fret saws have a very deep throat whereas coping saws have normally just ~120mm throats.
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Offline soldar

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Re: Square holes on aluminum.... how do you do it?
« Reply #70 on: October 16, 2019, 10:34:09 pm »
Note that a fret saw and coping saw are very similar but there's a distinct difference, fret saws have a very deep throat whereas coping saws have normally just ~120mm throats.

OK, so what I have been using all along is a fret saw. I always called it a scroll saw because I thought a scroll saw was just the mechanical version of the manual thing.

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Online tautech

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Re: Square holes on aluminum.... how do you do it?
« Reply #71 on: October 16, 2019, 10:42:12 pm »
Note that a fret saw and coping saw are very similar but there's a distinct difference, fret saws have a very deep throat whereas coping saws have normally just ~120mm throats.

OK, so what I have been using all along is a fret saw. I always called it a scroll saw because I thought a scroll saw was just the mechanical version of the manual thing.
:)
A fret saw is normally for shop and bench use whereas the much smaller coping saw is what carpenters had in their carry bags for finishing work onsite.
Typically coping saws used 14 tpi blades that are still too coarse for thin alloy and won't touch steel.  :(
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Offline beanflying

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Re: Square holes on aluminum.... how do you do it?
« Reply #72 on: October 16, 2019, 11:14:59 pm »
The issue becomes the blades on most coping saws and in particular electric scroll saws.

I am having trouble parsing and understanding this. What's the issue?

Obviously you need to choose the right blade. I have used a fret saw on aluminum without problem since forever. It allows cutting of all sorts of shapes without problem.

As per Tautechs posts blade pitch and hardness are the issue. My experience is the Coping saw blades and those found of the cheaper scroll saws are the issue. There are 'some' motorised saws that take a fret saw type blade that will be better but they are still not designed for working on 2-3mm Metal like we tend to use for fascias.
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Offline drussell

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Re: Square holes on aluminum.... how do you do it?
« Reply #73 on: October 17, 2019, 03:28:11 pm »
I wonder if there are any high speed dremel type tool that will withstand heavy-duty usage?

Absolutely.  They are called die grinders.
 

Offline Bassman59

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Re: Square holes on aluminum.... how do you do it?
« Reply #74 on: October 17, 2019, 05:11:17 pm »
I wonder if there are any high speed dremel type tool that will withstand heavy-duty usage?

Absolutely.  They are called die grinders.
A die grinder is a fairly blunt instrument, not something you'd want to (or even be able to) use for putting switch/button holes in aluminum.
 


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