Cutting a groove in Aluminum

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I've got a piece of 1/4" 6061 aluminum for amp frontplate. I need to cut a 3/8" deep and 4" wide slot down the front of it. Does anyone know a easy way to do this? I've got a decent table saw but do not relish the idea of making 50 passes to get a 4" wide groove. Any ideas would be greatly appreciated.

BTW, I'm new here. My name is Jason, I'm an EE student at the U of Washington. I've been reading the posts for a couple of months and have probably learned more than I have in 2 years of school. Thanks.
 
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Jason_N said:
I've got a piece of 1/4" 6061 aluminum for amp frontplate. I need to cut a 3/8" deep and 4" wide slot down the front of it. Does anyone know a easy way to do this? I've got a decent table saw but do not relish the idea of making 50 passes to get a 4" wide groove. Any ideas would be greatly appreciated.

I am a little confused here, it is 1/4" thick and you want to cut a 3/8" deep slot?

--
Brian
 
I have a quick answer and then a total thread jack. I have heard that a router can work with aluminum if you go slow and use plenty of lubricant, ie. tons of wd40, cutting oil, even salad oil will work. You could set up a table and only have to reset it maybe 8 times depending on the bit width. Also make sure the bit isnt heating up too much periodically.

And for the thread jacking,

I am planning to go for the same major at the same college as you in a couple years (I am in 10th grade at the moment) and everybody I have talked to has told me something different about the acceptance standards for UW. What were your grades and sat score like? I really would like to know how much time I need to put to grades and how much to put into electronics.

Thanks!
-Chris
 
Hi Chris,

I don't know what the standards are for getting into the U these days, but if you get an AA degree at some comm coll in this state, you are guaranteed admission into the U. The harder part is getting into the EE department. SAT's won't matter much, and a 3.5 is considered a "safe" GPA for admission. Last quarter the lowest GPA to get in was a 3.2. Writing a good personal statement will go a long way as well. If you have a lot of electronics experience as a hobby or what not, that is really good as well. My wife is pulling on my arm to go to the christmas party, so if you want more info or help or anything, email me at jlnordwall@msn.com.

Later,
Jason
 
you can take it to a machine shop and have them mill it or bench grind it. The bench grind will leave a smooth finish. You can then polish it for smoothness or shotblast, your choice. Milled will leave swirls in the material. if they make full passes beyond the material the swirls may be appealing to you. Tell the machine shop the finish you want and they can do what you want.
 
I have used many of the above methods with varying success. I prefer using a table saw with a melamine/plastic dado blade. It is the most stable and reliable (read safest). If you want to fine finish the groove, use a wooden block slightly smaller than the slot and wrap it with wet/dry sandpaper. If you use a router, pick a plunge style bit with a good quality aluminum cutting fluid. It's pretty cheap and give the smoothest finish (no galling or burning). The plunge bit has more cutting surface for an easier cut. This will extend the life of the bit. Use cutting guide on both side of the router and cut in passes of 1/8" depth or less. Lastly, WEAR LONG SLEEVES. The router is going to throw hot chips everywhere and they smart when the hit the soft skin of your forearm . :eek:

Keld,
Shot blasting is much like sand blasting but uses a different media (tiny glass balls usually). This is where high pressure air is force through a "gun" with a media added in before it leaves the "barrel". The process effectively workhardeneds the surface and gives it a nice even surface. The different medias produce different finishes. The media can be walnut shells or silica sand all the way up to silicon carbide or small ballbearings it all depends on the desired result. I see high pressure water being used quite frequently nowadays, both to finish or cut the metal..
 
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Peter Daniel said:
Whatever you do, it will allways look rough. The easiest way is to get a piece of 1/8" aluminum and attach 2 pieces of 3/8" aluminum strips separated 4" apart. Saves you a lot of work, aggravation and possible failure.;)
This is the way I would do it. Just take a look at Peter's work. It's hard to argue with the master.
Keld said:
Sorry about my "noknowledge" but what does shotblast mean.
shotblast like shotgun fired at close range???
Shot Blasting is a process where small steel pellets, similar to shotgun pellets, are blown through a nozzle by compressed air as is done in sand blasting.

Rodd Yamashita
 
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That is a tough one. There are a few things you can do that will keep the face free of bolt heads.

1.) You can blind drill and tap into the back of the 3/8” plates. It can be tricky because you’ll have to be careful not to break through the face of the plate with the tip of the tap-drill. You will also need to have a good bottoming tap (a little hard to find in the smaller thread sizes). A bottoming tap, or bottom tap will have threat cutting edges right to the tip of the tap.
2.) You can have threaded studs welded into the back of the 3/8” plates.
3.) You can have a reverse bevel grove cut into the back of the 3/8” plates that you can slide heads of flat head machine screws into.
4.) You can weld the plates together along the edges. Tricky, and you’d better have a good welder that not going leave holes or warp the hell out of everything.
5.) You can glue it ( as Christer suggest). I’m not sure what glue to use.
6.) If you were to put handle on the front, you could trap the plates between the handles and the 1/8” plate.

I think I would use 5 and 6.

Rodd Yamashita
 
Jason_N said:



Where can I get this glue?

It is quite common here in Sweden, and I am sure it is in the US
too. I suppose you can find it in harware stores and paint stores
and basically anywhere you cand find various types of glues.
I don't know which brands you have there, but you may look for
Loctite Super Attak, for instance, or just ask for cyanoacrylate
glue.

Just be careful, it will stick to almost anything. Don't glue your
fingers together (happens easily) and under no circumstances
get it into your eyes.
 
roddyama said:

I think that this is "Super Glue" or one of the many variations of it.

Rodd Yamashita

Yes, it used to be called "super glue" when it was first introduced,
but I think that was one particular brand. I didn't write that name
for the risk that there may perhaps be other glues sold as super
glue. Just make sure that the content label states cyanoacrylate.
 
Glues

Yes, cyanoacrylate is Crazy Glue, super glue, or whatever you want to call it.

I would probably try Epoxy instead. I know that some swear by cyanoacrylate, but I haven't had success using it for permanently attaching things, and I don't know of its use in any industrial applications.

Probably the best one for use with metal that's readily available to individuals (in the US) is "J-B Weld." They sell it at Home Depot, and any decent hardware store. For a couple of bucks you can make a test. You should abrade the surfaces of the Al where you plan to glue them. Use something like 60-80 grit and scuff them both up. Epoxy will give you some time to work with the things to get them aligned the way you want, and then you can put it in the oven at its lowest possible setting, and in an hour you can use the thing.

This method will save you many hours over trying to machine it somehow.
 
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