Cutting slots in steel

Looking for ideas.
I have to cut slots in 4 pieces of 1/4". They are 3" x 7/16"

How would you do it? Would you just have them milled?

I'm thinking just drill the ends and cut the slot with either the grinder, air cutoff or maybe even a Dremel but worry about keeping the tolerances. I know Jeremy could do it in his sleep but he doesn't count 

Hey, depending on how much time you have and where you live, I might be able to help you out. I work for my father in law and here we have a plasma cutter and a nice double vertical mill Bridgeport, and other useful things in the machine shop we have here and shipping and recieving dept. I've been copying Howe 4 link suspension mounts for my rig. Which is mostly band saw work, but it's been saving me money doing it myself.   What do you need the slots in? What are you trying to do?

It's the bracket to the right. It's the upper link, frame side bracket, I came up with. I can cut the shape on my bandsaw it's just the slot. I might mess around with it this week if I get a chance.

personally i would use a mill... but thats because i have easy access to one...
a grinder would definitely do it, but yea.. tolerances...

Changed my mind...haha
Just going to use a 3 holed bracket.

haha... well it's still a good idea for the purpose of indexing your geometry settings, but I guess using the old fashioned tape measure is reliable too.

Changed my mind again....lol
I'll try drilling a few holes and use the cut off wheels.

I have a new question. For the adjuster plates I would like to use stainless. Was thinking 1/8 but don't know what grade. They shouldn't see much, if any, load. They are mainly to index the pivot bolt. Corrosion resistance is a priority and I think paint would chip out of the adjustment holes.

Thoughts or recommendations?

304 Stainless should be the most common and most affordable grade of stainless available to you. 316 will prolly be the 2nd most common choice but a little more expensive due to the higher nickel content. Both are plenty corrosion resistant for your application.

304 is all we use. dont ask me why.
I know i read something in carol smith's book, but i forgot what.
I dont have a copy with me at the moment so i cant look it up sorry

What do you guys think about 6061 aluminum? Would 1/8" be safe? Maybe 1/4"? Having a hard time finding the stainless without buying way more then I need.

How exactly does that set-up work? I read that the right bracket is going to be welded onto the frame and it will have 2 pins on the top and bottom. How does the left piece play into it?

I'd just keep my eyes on bolt holes in the aluminum plates and make sure no cracking occurs, as well as monitor the bolts' torque. You're using these plates on both sides of the bushing, right? If these plates are being used the way I "think" they are, you could prolly get away w/ using 16 ga stainless if there are plates on each side of the bushing. 16 gauge is a much more common thickness than the thicker plate varieties.
If I'm not mistaken, these plates are just ensuring that the bolt stays located in the slot, correct (?)

What do you guys think about 6061 aluminum? Would 1/8" be safe? Maybe 1/4"? Having a hard time finding the stainless without buying way more then I need.

no, even aircraft grade aluminum is pretty weak. unless you do the calculations on it i wouldnt blindly try aluminum.
and anything that has adjustment personally i wouldnt use aluminum unless you plan on inspect/replace at pretty close intervals.

How exactly does that set-up work? I read that the right bracket is going to be welded onto the frame and it will have 2 pins on the top and bottom. How does the left piece play into it?

The right piece is mounted to the frame with two pins. The left piece is used to adjust. Those pieces will only have one pin pass through them at a time. The reason for the two pins is so the adjuster can be smaller. Have it mount to the top pin for the higher adjustments and the lower for the bottom adjustments. I did change it around some so now it's only 2" of adjustment and in 1/8" increments.

I'd just keep my eyes on bolt holes in the aluminum plates and make sure no cracking occurs, as well as monitor the bolts' torque. You're using these plates on both sides of the bushing, right? If these plates are being used the way I "think" they are, you could prolly get away w/ using 16 ga stainless if there are plates on each side of the bushing. 16 gauge is a much more common thickness than the thicker plate varieties.
If I'm not mistaken, these plates are just ensuring that the bolt stays located in the slot, correct (?)

Yes, one on each side of the bushing. All the adjuster does is locate the bolt. This will mostly rely on clamping force of the bolt.

no, even aircraft grade aluminum is pretty weak. unless you do the calculations on it i wouldnt blindly try aluminum.
and anything that has adjustment personally i wouldnt use aluminum unless you plan on inspect/replace at pretty close intervals.

You make a good point. Don't know what forces the adjuster itself will see other then clamping forces. The one thing that slipped my mind was the way aluminum and steel react. Don't think I would want to run anti seize and rely on clamping force so much.

I may have some 16ga SS laying around. If not I'll keep an eye open on egay.

Thanks for the input.

Did a little work before a neighbor came over and asked me a bunch of stupid questions about putting up fences. Completly demotivated me.
One side is done. Weld looks like shit but these were too much work to remake them. At least no one will see it...lol

The adjuster is from a panhard mount from the old truck. It won't work for this but it should give a better idea what's going on.

I tacked all four pieces together to drill the holes and shape them.

(click for larger.)





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Oh, did find some .063" stainless in the shed. It's magnetic but that's all I know about it. Pretty stiff though.

Very nice.
FYI- So you probably have some 400 series stainless steel, as 300 series cannot be magnetized to any great extent. Nothing wrong w/ that mat'l. Just thought I'd let ya know.

Thanks bud. I have to PM you about a non related SS question.