# Trim Aluminum



## kolias (Dec 26, 2008)

I need to purchase 6 aluminum pieces each approx. 1/2" x 6" wide x 48" long and both edges of these pieces must be perfectly straight. The choice I have is either aluminum flat bar which is an extrusion and the edges are not always perfectly straight or aluminum plate which is cut to size with some kind of a band saw and the edges definitely are not straight.

A local machine shop will charge me about $50 per piece to make the edges straight + one time setup cost of $75 + tax. I find this cost very high and therefore I have to do it myself.

I did use my router before to cut 2 slots on 1/2" thick aluminum each 3/8"x8" long and it did a good job so I was thinking to make a jig as per attached picture and trim the edges myself

On the picture, the vertical left piece of MDF / plywood will be the guide for the router. Do you see any problem with my jig? Suggestions?


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## Cherryville Chuck (Sep 28, 2010)

Yes, I see a problem. There is nothing preventing the router from digging into the aluminum. Any chatter will be transferred into the edge because the router is free to move that direction but not the other.You should be using a guide that will prevent the router from going deeper into the material than you want.

You could just clamp the piece to a sheet of mdf and use a flush cut (with the aluminum on top) or pattern bit (with the aluminum on the bottom) run along the edge of the mdf. That's a little bit simpler than what you are suggesting. Watch your router feed speed and listen to the motor to make sure you aren't dragging the rpm down to much.

What is going to be difficult, if it matters, is getting the 2 edges to be perfectly parallel.


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## Stick486 (Jan 4, 2013)

kolias said:


> I need to purchase 6 aluminum pieces each approx. 1/2" x 6" wide x 48" long and both edges of these pieces must be perfectly straight. The choice I have is either aluminum flat bar which is an extrusion and the edges are not always perfectly straight or aluminum plate which is cut to size with some kind of a band saw and the edges definitely are not straight.
> 
> A local machine shop will charge me about $50 per piece to make the edges straight + one time setup cost of $75 + tax. I find this cost very high and therefore I have to do it myself.
> 
> ...


instead get this saw blade...

Freud Tools - Thick Non-Ferrous Metal<br /> 

and use your tablesaw...
lube often...


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## kolias (Dec 26, 2008)

Good points Charles

I can see the problem of getting the 2 edges parallel and right now I don’t know how to achieve that but I'm sure I will find a way. However I don’t see any problem for the router digging into the aluminum because on the 2 slots I did previously I never noticed anything like that. If I hold the router tight, use low RPM and only take about 1/32" per pass I think all should be fine.

Thanks Stick, the Freud blade looks good but I will never use my table saw to rip aluminum. But I do use a similar blade for cross cut aluminum and works good. That is if I have an aluminum piece 1/2"x6"x48" and want to make it shorter, I put it on my chop saw and does a beautiful job


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## mgmine (Jan 16, 2012)

Stick and Charles are both right. If you don't want to use your table saw then you should use a table mounted router with fence. You will not be able to make a free hand cut on aluminum or even wood. The best you could hope for would be a routed edge created by running the stock against a bearing but then it wouldn't be the complete edge.


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## kolias (Dec 26, 2008)

Thanks Art for the help

I do have a table mounted router but thought was not very safe to use it for this purpose.

From the attached pic, which setup is the best?

I prefer the "B" setup because it will be easier to shave the edge in 1/32" or 1/64" steps


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## Quillman (Aug 16, 2010)

"Do you see any problem with my jig? "
************************************
Not necessarily, but routing aluminum without priors is full of surprises.
It's something I do and with ordinary routers but semi-special fixturing.
I size it to length and width and to ~.001".
But I'm successful because I know where it wants to go under duress.
And it has 12 ways to react. L/R, Up/Down, In/Out and CC & CCW with respect to its 3 rotational axes = 12!
I think you'd be better off having the machinist do your work. Taking a .032" cut in one shot, as you intend, will be met with adversity; I would not do it.
Example of the light stage cuttings I take, here I'm taking ~.003"/pass.
Modest, yes, but my fixturing allows me do it in a second or 2. So 10 passes will take less than a minute.


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## kolias (Dec 26, 2008)

Thank you Pat for the insight, your picture shows a very nice setup

I'm not an expert cutting aluminum but as you can see on the attached pictures this was my 1st cut last summer with a primitive setup and an ordinary router and did a beautiful job, cutting 2 slots on 1/2" thick aluminum

My limited experience tells me "take it easy" so I may start with .015" or less and push the router slow and using some lubricant also helps a lot

The main problem I see, as it was mentioned earlier, is making sure that both edges are perfectly parallel but when I get my setup going I think I will find a way


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## Danman1957 (Mar 14, 2009)

Hi Kolias,
What region of Canada are you located? I sell steel for a living and therefore have apretty good idea where you can buy aluminium from and if it is cut with a plasma or laser cutting table you won't have to worry about it. The tolerances are quite good especially with laser.
The size of plates you require could probably be considered offcuts for most production shops and you might get a deal from a local fab shop that's well equipped to cut or a cutting company that has these pieces on a shelf just waiting for a hobbyist like you.
Good luck,
Dan


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## OPG3 (Jan 9, 2011)

I cut aluminum every day with all of my tools, but as Pat (Quillman) mentioned; it can be troublesome. It looks like you've done it before - just don't try to rush the process. One strong word of caution, "WEAR EAR PROTECTION - HOT, FLYING METAL PARTICLES WILL MAKE YOU DO AN UGLY DANCE ROUTINE!"


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## greenacres2 (Dec 23, 2011)

And remember...like magnesium, burning aluminum does not play nicely with water. Spectacular to watch, but not from a close proximity!!


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## kolias (Dec 26, 2008)

Thanks Dan, I'm in Montreal and buy my aluminum from Rapido Metals. Rapido is a top notch place for people like me who buy aluminum in small quantities and delivers the same day. I can order a $10 piece in the morning and by the end of the day I have it and he is approx 60km away. He also sells in large quantities any non ferrous metals and his price is excellent. The only disadvantage is that he cuts plate / flat bar with a saw and the tolerance is +1/8".

I visited other places in my area and they all sell in quantities only. I'm just guessing but a place which can cut with a laser or plasma must be an expensive place and out of reach for a hobby person like me

Thanks Otis for the warnings, I will never touch aluminum without protective gear


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## mgmine (Jan 16, 2012)

kolias said:


> Thanks Art for the help
> 
> I do have a table mounted router but thought was not very safe to use it for this purpose.
> 
> ...


The A set up is what you want, the B setup should never be used because you are trapping the material between the bit and fence.


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## kolias (Dec 26, 2008)

Thank you Art


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## samurai (Aug 14, 2011)

may i ask you for what purpose you want to use it? there must be some aluminum extrusion profile like this 6 Series Profiles | Mechanical Components for Assembly Automation - Misumi eCatalog
btw here in japan we can buy any kind of cutom cut metal @ 0.5mm tolerance and you can give order for single piece.there are different kind of grade for the aluminium.like A7075 grade is very strong and little heavier than other but 1100 grade is lighter.A7075 grade cost 1300 japanese yen per kg and 1100 grade cost 800 yen per kg and you don't need to pay for any cut fee.they have very nice quality circular saw with DRO feed(digital read out) and pneumatic clamp.


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## kolias (Dec 26, 2008)

The purpose is to make a table base for a hobby cnc. I can also get aluminum here at any tolerance I want but as mentioned have to order in quantities and it will be much more expensive. Also I can order on line with my tolerance but then the shipping cost will make it very expensive


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