Sasha I've got a question on the shield boss rig.

Mad Matt · Post by **Mad Matt** » Wed Jan 03, 2001 2:19 pm

Ok well here's my plan. I usually make bosses from 14ga 8" dia disks cause I get em free. The most common flange size request is 1".

So I'm gonna get some pipe with a 6"-6.5" inner diameter. Sorry about the imperial. That'll leave a flange of 1"-3/4".

I'm planning to get the bottom piece of pipe 6-8" long so there's plenty leftover depth for anything odd I might do in the future. That's roughly 165-203 mm. And for the cap piece of pipe I was planning on approx 1" or 25mm.

Now what do you think I should have for minimum wall thickness? I plan to try and avoid any kind of cast pipe if I can.

Next step. Weld some 1"x1" angle iron onto the top and bottom of the big pipe and just one set on the short one. Probably 4 of em dividing the pipe into quarters. Yes this is on the outside. And yes I'll use fairly heavy angle. Now with a 6" id on the pipe and 1" angle that'll only leave me with the pipe wall thickness around the outside edge of the pipe. What I was thinking is that the angle on the bottom would have holes drilled through it so I can screw it down to a stump. The angle that is used to clamp the short pipe on to the top wouldn't have holes and I could just use 4 pairs of vice grips to hold the piece that clamps the boss in down.

Do you think that the vice-grip idea is at all feasable. Or would they vibrate loose easily. I'm thinking of using the vicegrips because they'll make it fast and easy to clamp the top piece in place. If you don't think it'll work then I'll probably go with inch and a half angle which will give me the clearance necessary to put the disk in if I bolt the top on. But I would then need to either trim one side of the angle on the top or get the top piece of pipe 1-1/2" long which is pretty deep for a hammer to go into.

Also do you think 1" or 25.4mm is big enough for the top piece of pipe.

I know this is pretty demanding. Feel completely free to give no answer. I'm just hoping to have a little less trial and error then I would probably have on my own.

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The budding mid 14th century German Transitional guy.
Mad Matt's Armory

Sasha · Post by **Sasha** » Wed Jan 03, 2001 3:39 pm

I will be glad to help.
First coffee, then answer.

Be back in a bit.

Sasha

Mad Matt · Post by **Mad Matt** » Wed Jan 03, 2001 3:40 pm

Good idea a coffee and a smoke for me too.

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The budding mid 14th century German Transitional guy.
Mad Matt's Armory

Mad Matt · Post by **Mad Matt** » Thu Jan 04, 2001 1:22 pm

Bump.

Sasha I think you're the slowest coffee drinker in the world.

Just teasin and bumpin in case you forgot.

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The budding mid 14th century German Transitional guy.
Mad Matt's Armory

Sasha · Post by **Sasha** » Thu Jan 04, 2001 9:45 pm

Okay. Finally here.

Firstly, Do not make the pipe too long. The metal really will not go much past a hemisphere before it start trying to tear and and pipe much in excess of that is just going to make it less comfortable to hammer and also introduce another problem.

Regardless of wall thickness, I have found that over-long pipe-sinks tend to start neding at the bottom edge where it rests on the anvil bed.
I shortened the pipe and the problem went away. Less leverage and less shear, I think.

I cheated on making the shelf for the top of the pipe-sink. I welded on a loop of 6mm barstock and then smoothed it all down. I could have stuck it in the forge and then flared and flanged it...but this is much quicker and lasts just as well.

The walls of the pipe I use now are 5mm. Idealy I would go for 7-8mm in future.

Using vice grips on bits of angle iron sounds like it might be asking to have the blank vibrate itself out form under the vise-grips.

I like the high-tensile nuts and bolts I use. It is alos less bulky and less likely to get in the way of hammer blows. If you do want to use the angle iron approach, then consider drilling holes in the tops to the angle iron brackets. That way you can choose to use nuts and bolts or at least have an axtra corner for the vise-grips to grab onto.

I normall do this circular walk around the anvil as I hammer these with the big sledge. Basically introducing force from all 360degrees. This might look like a monty python version of a religuos ceremony...but it produces good results.
So it goes. BANG...step slightly to the right. BANG...same again. BANG....and step right one more, keep circling that anvil.

By the time you are doing the last cleanup blows with a smaller hammer....you can stop the circledance.

I didn't understand a couple of your questions. What "top peice of pipe"?

I will take some pics of the process as I do it...and then you can take some pics of the way you do it once you have built your version and we can compare notes.

I'll take some shots when I get home.

Sasha
....it takes a while to drink your way out of a jaccuzzi full of coffee
Riverforge

Mad Matt · Post by **Mad Matt** » Fri Jan 05, 2001 9:26 am

LOL at your jaccuzi comment.

The top piece of pipe would be a very short piece of the same pipe as the bottom. This is what I'd clamp or bolt onto the top to hold the shield boss in place. Angleiron goes around the outside of the pipe. I'll do a little sketch later today.

Thanks for the advice on making the bottom pipe too long. I'll go with 3" and maybe 1/2"

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The budding mid 14th century German Transitional guy.
Mad Matt's Armory