How do I make a right angle block

[Shotgun]

My uncle gifted me a 12" length of 1/2"x8"x8" angle. That is each side is 8" long and the material is 1/2" thick. I saw someone post a thread on how they made an angle block out of such a beast, and I'd like to make one with my limited home shop tooling.

I have a Rong-Fu, round column clone and an Atlas 12x36 to work with. I'm willing to mount the grinding cup in the mill spindle to get each side perfectly flat.

What I'm looking for is order of operations and mounting/clamping suggestions. I think I have a handle on the first steps.

1 - Drill mounting and strain relief holes in both sides.
2- Bake and cool for several cycles up to 400F (max my shop toaster oven will reach), to relieve as much stress as possible.
3- With the mill trammed as close to perfect as I can get it, face off one side and use the grinding cup to remove the tooling marks and get it perfectly flat using an indicator to verify.
4- . . .???

That's where I fall apart. How do I get the second side to be a right angles to the first? How would I test it to verify as much?

Yeah, I could buy a block for less than I would get from the chunk of steel as scrap. It's not even the best steel to use. It's construction scrap, so it is a little gummy to work with. But, if I can do this, I'll be AWESOME (at least in my own mind).

 

[DavidR8]

I watched this a while back as I was thinking about making an angle block.

 

[homebrewed]

My uncle gifted me a 12" length of 1/2"x8"x8" angle. That is each side is 8" long and the material is 1/2" thick. I saw someone post a thread on how they made an angle block out of such a beast, and I'd like to make one with my limited home shop tooling.

I have a Rong-Fu, round column clone and an Atlas 12x36 to work with. I'm willing to mount the grinding cup in the mill spindle to get each side perfectly flat.

What I'm looking for is order of operations and mounting/clamping suggestions. I think I have a handle on the first steps.

1 - Drill mounting and strain relief holes in both sides.
2- Bake and cool for several cycles up to 400F (max my shop toaster oven will reach), to relieve as much stress as possible.
3- With the mill trammed as close to perfect as I can get it, face off one side and use the grinding cup to remove the tooling marks and get it perfectly flat using an indicator to verify.
4- . . .???

That's where I fall apart. How do I get the second side to be a right angles to the first? How would I test it to verify as much?

Yeah, I could buy a block for less than I would get from the chunk of steel as scrap. It's not even the best steel to use. It's construction scrap, so it is a little gummy to work with. But, if I can do this, I'll be AWESOME (at least in my own mind).

I'm assuming you don't have a surface grinder or have the tools/knowledge to scrape. Given that, you can get pretty close to a 90 degree angle by using a dial test indicator. Mill one of the sides of your piece so it's smooth and flat, then flip it around in your vise so the smooth side is vertical, and the rough side is parallel to the table. Mount the DTI on your spindle so you can move its finger up and down that vertical face. Shim your workpiece so you don't see any change on the dial as you move the DTI up and down. That face now is very close to perpendicular to the spindle. If you mill the top side, it will be very close to perpendicular to the side face -- i.e., at 90 degrees. A .0005" DTI is OK, a .0001" is better yet for this.

 

[Mitch Alsup]

I'm assuming you don't have a surface grinder or have the tools/knowledge to scrape. Given that, you can get pretty close to a 90 degree angle by using a dial test indicator. Mill one of the sides of your piece so it's smooth and flat, then flip it around in your vise so the smooth side is vertical, and the rough side is parallel to the table. Mount the DTI on your spindle so you can move its finger up and down that vertical face. Shim your workpiece so you don't see any change on the dial as you move the DTI up and down. That face now is very close to perpendicular to the spindle. If you mill the top side, it will be very close to perpendicular to the side face -- i.e., at 90 degrees. A .0005" DTI is OK, a .0001" is better yet for this.

This, but add some machinist jacks to support the top corners and keep the flat from bending under machining pressure.

 

[f350ca]

I made a couple of them from some 6 inch angle. Use them in the shaper.
I'd recommend welding gussets on the back, as the chap did in the video. 1/2 inch may seam thick but they will flex and vibrate quite a bit.

Greg

 

[Shotgun]

So much good information, in such a short time. You guys are the best. The updated order of operations:


1 - Mill mounting and strain relief slots in both sides.
2 - Weld in stiffening gussets
3 - Bake and cool for several cycles up to 400F (max my shop toaster oven will reach), to relieve as much stress as possible.
4 - With the mill trammed as close to perfect as I can get it, face off one side and use the grinding cup to remove the tooling marks and get it perfectly flat using an indicator to verify. Use jacks to stiffen the far corners.
5 - While it is still in the vice, mill the top and sides then grind them perfect.
6 - Flip it in the vice, and use a dial indicator to get it all square. The machined top (now on the bottom), will indicate on the bottom of the vice, which I verified to be flat.
7 - Repeat steps 4 and 5.

 

[graham-xrf]

Shim your workpiece so you don't see any change on the dial as you move the DTI up and down. That face now is very close to perpendicular to the spindle. If you mill the top side, it will be very close to perpendicular to the side face -- i.e., at 90 degrees.

Did you not mean the face is then very close to parallel to the spindle - or do I misunderstand?

 

[mattthemuppet2]

I think this is a lot more challenging than it first appears - I made a couple of new vise jaws for my 4x6 bandsaw out of angle (4" I think, maybe 3") and did the same, welding in gussets on the back. I first tried cutting both faces in the same set up, top face with the end of the end mill and the side face with the side (with jacks supporting the angle) - chatter was crazy with that much end mill stick out. Then I tried cutting one face, then rotating the work 90deg and indicating off the cut face with a DTI, adjusting the angle with the jacks until it showed no change. That worked better but it didn't come out perfectly square. Close enough for a bandsaw, but not for precision work.

 

[Shotgun]

I think this is a lot more challenging than it first appears -. . .

Hold my beer?

 

[mattthemuppet2]

more "how long are your teeth still?" for grinding them in frustration I think it's doable, but the milling part is best considered the "roughing in" part, with subsequent steps getting it both flat and square. Seriously, once you get into metrology type stuff it's an impressive rabbit hole!