Author Topic: Aluminum fabrication for Dummies  (Read 8316 times)

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Offline FunJimmy

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Aluminum fabrication for Dummies
« on: February 02, 2014, 06:05:36 pm »
You don't need expensive and technically challenging CNC machines to make impressive custom one-off parts!  Let me show you how to do it with simple shop tools.

I've received several "how-to" inquiries regarding some of the aluminum parts that I've fabricated for the Interceptor over the years that I thought I'd share my process with the collective.

Legal: The procedures depicted here are for reference purposes only. The author does not recommend the use of these methods and can not be held responcible for the health and safety of those that do.  Always operate tools in accordance with the manufactures recommendations and safety guides. Always wear approved safety googles, ear protection and gloves. 

Having recently purchased a Cone Engineering megaphone for the bike and I needed to fab up a muffler support hanger, so I thought this would be a good how to project.





First step is to figure out what you are trying to make, the materials (thickness & size), and a design concept before you start cutting hard materials.

Most of my design work is done with heavy gauge cardboard but in this example, I'm using 1/4" plastic. Soft materials like cardboard, plastic or wood are great cause they're easy to cut, shape and draw on.

If you toast a couple of designs along the way it isn't a big loss either.
As a matter of fact, it's so versatile I sometimes make a few variations in the design phase and select my favorite before the hard work begins.

Once you've nailed the design, it's time to replicate it in the final (1/4" aluminum plate) material.  The best way to mark your design details on aluminum is with layout fluid and a scribe. Layout fluid is the fast drying (blue) ink that I've brushed on my aluminum plate.





The next step is to confirm (once more) the fittment of your design before you start cutting. Adjust your template if required.





Start your fabrication with the hard mounts. These are the points that locate your part on the bike and need to be exact. In this example, I need to locate and drill the two mounting holes that align with the braze-on frame mounts.





Once my fixed mount points have been drilled I can overlay the template and scribe an outline.








Now the fun begins. Aluminum is a (relatively) soft metal to work with which makes it ideal for home fabricators.

There are several ways to cut aluminum. I often prefer a tablesaw for speed and straight line accuracy, but for this project I'm using a standard bandsaw fitted with a course wood blade.

You don't want fine tooth blades for cutting aluminum. They will plug up and become useless. Course (6 teeth/inch) are perfect.

Relax and cut as close to the scribe lines as possible. This will save some time later.





Rough cut and ready for final shaping.





This simple belt sander is perfect for shaping aluminum parts but it's a high friction method of shaping so remember to wear heavy leather gloves as aluminum gets really hot when shaped on a sander. The large flat belt table is great for straightening bandsaw cuts too.





It doesn't take long to get the final shape where you want it with the belt sander.




« Last Edit: February 10, 2014, 11:22:14 am by FunJimmy »
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Offline FunJimmy

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Re: Aluminum fabrication for Dummies
« Reply #1 on: February 03, 2014, 12:40:58 am »
One of the more difficult tasks when making custom aluminum parts is cutting out the centre of your work while maintaining accuracy with the outside dimensions. If you don't have to cut windows in your work the process is pretty easy but windows can greatly reduce the weight of a part and make the part look "Works" by comparison.

This support bracket will have the centre cut out but doing that is a bit tougher.

Scribing cut lines that run parallel to the outside can easily be made using vernier calipers. Simply open the vernier calipers to the desired gauge and scribe your guide line with one of the caliper's sharp tips while tracing the outside shape with the other. In this example I'm tracing 1/2" spars.





Once the outline has been determined it's time locate any inside radius corners. On this part there are four. Two 1/4" radius and two 3/16" radius corners. The 1/4" radius corners are managed by drilling a 1/2" hole while the two 3/16" radius corners are handled by drilling two 3/8" holes. The rest of the cut out can be made using a jigsaw or similar to produce straight cuts from hole to hole.








Because this part is quite small it was impracticable to cut it conventionally using a jigsaw so I flipped the jigsaw upside down and clamped it in the vice. Now it acts more like a reciprocating scroll saw but you REALLY have to hold your material with authority or the blade will toss it all over the place.

Cut slowly with a firm hand on your work and always respect safety protocols while wearing protective gear!








The difference between a home built product and one that you can truly be proud of is quality finishing. I spend most of my time here.

Quality of finishing starts with hand files and you should have a few good fine cut files, a couple of course ones and a file brush.

Wet & dry sand paper will also be necessarily, so pick some up next time you're at Home Depot. I usually keep 180 & 220 wet & dry on hand at all times. You won't need any finer for high quality aluminum work.





ALWAYS use soft jaws in your vice when working with aluminum.
If you don't have any, you can use aluminum angle as I have here.

File jigsaw marks and straighten the sides.





Back to the importance of high quality metal finishing. I use a piece of 3/8" glass from a display case for flat (wet) sanding. It works perfect for ensuring I get smooth flat surfaces. This level of surface finishing is essential for anodized or polished parts.

Note: if you plan to powder coat your part, there is no need to be so anal about the finish.





The angle and plumb line from frame tabs to muffler mount aren't straight so a little twist and bend is required to fit perfectly.
I clamp the piece firmly in the vice at the point I want the bend and they strike it with a firm block of wood or plastic.
Preferably something fairly solid and non-marking so you don't have to sand marks out later.




Look closely and you will see some minor marks from the edge of the soft jaws. If I had a metal break I could have bent the bracket with less marking.
After 220 grit wet sanding, I finish with Scotch Brite and SOS pad. Not perfect but pretty dam good.



 

Anodized black, this muffler support bracket will look great!






Thanks for following along
FJ
« Last Edit: February 03, 2014, 10:53:07 am by FunJimmy »
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Offline seanbarney41

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Re: Aluminum fabrication for Dummies
« Reply #2 on: February 03, 2014, 01:27:36 pm »
Lots of good tips here Jimmy.  Thanks a lot for posting.
If it works good, it looks good...

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Re: Aluminum fabrication for Dummies
« Reply #3 on: February 03, 2014, 02:17:16 pm »
Great thread, Jimmy, and great finished product.
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Offline Roach Carver

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Re: Aluminum fabrication for Dummies
« Reply #4 on: February 03, 2014, 05:23:40 pm »
Excellent. Thanks!

Offline FunJimmy

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Re: Aluminum fabrication for Dummies
« Reply #5 on: February 07, 2014, 06:31:06 pm »
Thanks guys.

I hope you find this helpful and give it a try some time.
It's not intimidating once you get into it and really rewarding to make your our stuff.

Here are some rear set brackets I made using this method.
The pegs & levers where purchased items.





Cheers
Jimmy
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Offline 754

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Re: Aluminum fabrication for Dummies
« Reply #6 on: February 07, 2014, 09:28:14 pm »
Did you break the corners with a router?.. Looks great..
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Offline papadapalis

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Re: Aluminum fabrication for Dummies
« Reply #7 on: February 07, 2014, 09:42:22 pm »
I've been wanting to make my own parts but dont have a mill or lathe and have been wondering if this was even possible, thank you for proving it is and sharing.

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Offline FunJimmy

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Re: Aluminum fabrication for Dummies
« Reply #8 on: February 07, 2014, 11:52:02 pm »
Did you break the corners with a router?.. Looks great..

Thanks Frank,

I thought about using the router but ended up hand filing the corner radius. 
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Offline FunJimmy

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Re: Aluminum fabrication for Dummies
« Reply #9 on: February 07, 2014, 11:59:59 pm »
I've been wanting to make my own parts but dont have a mill or lathe and have been wondering if this was even possible, thank you for proving it is and sharing.

Thank you.

A milling machine would be great but a lathe is better.
Frank has shown me how to use my lathe as a mill.
Still need to give that a try though.

I did a bit of milling on these rear set brackets using my drill press.
Not nearly as accurate as the lathe/milling option that Frank showed me, but better than nothing.



Both plates bolted together to ensure they're a match!



Shaping with a file but used the sander too.



Made a few discs on the lathe to use as radius gauges.



 
« Last Edit: February 08, 2014, 12:10:37 am by FunJimmy »
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Offline FunJimmy

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Re: Aluminum fabrication for Dummies
« Reply #10 on: February 08, 2014, 12:01:53 am »
Milling with a drill press!



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Offline FunJimmy

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Re: Aluminum fabrication for Dummies
« Reply #11 on: February 08, 2014, 12:03:11 am »
Turned out alright.



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Offline 754

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Re: Aluminum fabrication for Dummies
« Reply #12 on: February 08, 2014, 08:40:05 am »
I see you use the Hophead metal Treatment..good for you..
 Are you laying out the radius with dividers or using the discs?
 A long time ago, I used to use bottle caps, bar stock..whatever to draw the radius, but now I use dividers.
 One thing though, small cheap dividers suck, they just dont feel right in your hand... After you ever held a small round leg divider.. So I ordered a 2.5 or 3 inch and a 5 inch from Starrett.. These items were made by their factory in Jedburgh Scotland, and had to be ordered in..well worth it.. I smile every time I use them.
 You may find the roundlegs used on ebay, lufkin and other made them as well..

 I was going to mention as encouragement... That what Jimmy did..involves quite a bit of work.. But it is TREMENDOUSLY SATISFYING when you finish the piece..  And the more you have of you in your bike, the more you like/love it..(well done FJ)
 I really should do an article like this on the fork brace.. You can do the most of at home if you have a drill press and sander..
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Offline Roach Carver

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Re: Aluminum fabrication for Dummies
« Reply #13 on: February 08, 2014, 08:48:23 am »
Thanks to you both. In the day of Cnc and billet this and that it's good to see things made by hand with "basic" tools.I need to get my shop set up and vise mounted so I can try and make a few things.

Offline seanbarney41

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Re: Aluminum fabrication for Dummies
« Reply #14 on: February 08, 2014, 08:59:54 am »
I was going to mention as encouragement... That what Jimmy did..involves quite a bit of work.. But it is TREMENDOUSLY SATISFYING when you finish the piece..  And the more you have of you in your bike, the more you like/love it..(well done FJ)
 I really should do an article like this on the fork brace.. You can do the most of at home if you have a drill press and sander..
please do this article.  I am working on a tach mount right now, and a fork brace that is similar to what you have been hinting at for years, is my next project.
If it works good, it looks good...

Offline NobleHops

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Re: Aluminum fabrication for Dummies
« Reply #15 on: February 08, 2014, 05:35:06 pm »
Jimmy, that was an awesome how-to, super helpful and detailed. Thanks a ton.
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Offline brandEn

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Re: Aluminum fabrication for Dummies
« Reply #16 on: February 08, 2014, 07:30:46 pm »
Awesome post Jim. Thanks for the tips. You make it look easy!

Offline FunJimmy

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Re: Aluminum fabrication for Dummies
« Reply #17 on: February 08, 2014, 08:23:03 pm »
Awesome post Jim. Thanks for the tips. You make it look easy!

Thanks BrandEn,

I was thinking the same about your fantastic 750 builds.  :)
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Offline tweakin

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Re: Aluminum fabrication for Dummies
« Reply #18 on: February 09, 2014, 05:41:11 am »
Excellent write up Jim!  I am still in debt for the work you did on our F rearsets! ;)

Offline FunJimmy

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Re: Aluminum fabrication for Dummies
« Reply #19 on: February 09, 2014, 09:15:59 am »
Thanks Frank.

I see you use the Hophead metal Treatment..good for you..

That's one of the finest metal treatments I can find. Especially helpful when the going gets tough.

Are you laying out the radius with dividers or using the discs?
 A long time ago, I used to use bottle caps, bar stock..whatever to draw the radius, but now I use dividers.

I don't have dividers yet so chose the disc route on the rear-set brackets because they provide a solid (visual) guide to sand & file to.

I really should do an article like this on the fork brace.. You can do the most of at home if you have a drill press and sander..

I'd love to see you do this as well Frank. I've learned a lot from visiting your shop and I'm sure there are many more tips and tricks still to come.
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Offline FunJimmy

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Re: Aluminum fabrication for Dummies
« Reply #20 on: February 10, 2014, 01:22:02 pm »
My buddy stopped by to make some aluminum foot peg brackets and unfortunately the bandsaw blade broke while cutting his pieces. We could have called it a night and packed up until I purchased a replacement blade but we chose to cut the material on the tablesaw.

Course carbide tipped blades work great on aluminum. To minimize the risk of my work piece kicking back, I run the blade at maximum height so the teeth are as vertical as possible.




Here's a short video showing the cutting of 3/8" plate aluminum on a tablesaw.
Check out the volume of aluminum chips flying in my face. Eye protection is mandatory

http://youtu.be/lafjX6CbhGI

Here's another good video

http://youtu.be/tzVUfKslacY
« Last Edit: February 10, 2014, 02:08:01 pm by FunJimmy »
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Offline 754

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Re: Aluminum fabrication for Dummies
« Reply #21 on: February 10, 2014, 07:06:32 pm »
I would have left about 1/4 inch on the first cut, makes the next one easier to hold while cutting.
 Make sure to stop cutting if it clogs.
 It wont hurt to put a smear of oil along the cut line with your finger if sticking is a problem

Scary the first time I bet..
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Re: Aluminum fabrication for Dummies
« Reply #22 on: February 11, 2014, 04:14:29 pm »
 I've been using a 5" battery circular saw, it works well and doesn't have too much power. I saw through a stick of beeswax, it helps keep the blade from clogging up.
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Offline DavePhipps

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Re: Aluminum fabrication for Dummies
« Reply #23 on: June 10, 2014, 08:36:50 pm »
If you want to drill a 38mm hole in aluminum what would you use?
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Re: Aluminum fabrication for Dummies
« Reply #24 on: June 11, 2014, 12:08:27 am »
If you want to drill a 38mm hole in aluminum what would you use?

A hole saw... ;)
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