Re: Source for brass channel

Bill Lugg
 

Yes, I've experienced a similar issue on an unrelated part.  It was a verrrrry long time ago in a college shop class I took related to my ME degree.  We were tasked with fabricating a small C clamp from 0.5 inch steel plate among other things.  The shop teacher pointed out to us that when we cut the block out of the cold rolled steel plate, we'd be relieving the stress on that side of the material and the C would tend to pull together a bit.  IF it was a precision part, we'd have to take it to the mill to true it up (we cut it on a band saw), but for our purposes, it was simply important to drill the hole through the leg AFTER cutting so it would be straight and not affected by the warpage.

The moral of the story seemed to be there's no way to prevent this problem.  Especially when you're working on something as small as a piece of brass bar stock for an HOn3 loco.

Bill Lugg

On 10/7/19 3:58 AM, Dale Buxton wrote:
Long ago (about 25 plus years now) I was working on the same type of project, channel iron for a tender frame. I made some very small channels out of brass bar stock. Using first a slotting saw in my lathe and then a milling machine. Along the way,  I encountered a problem that I still don't know how to overcome. It has to do with longitudinal stress relief. When Brass bar stock is extruded, it develops (so I am told) an annealing stress along its length. I my case, the bar stock I was working kept warping away from the slotting saw or milling head as I worked down its length. Every time I finished a cut and I went to reposition the stock in the vise to continue the slot. The stock had developed a springy warp in it that curved away from the cut in it. I tried several times to eliminate warping effect but I never figured it out.

I realized some time later that I was annealing the brass and adding hardness to one side but not the other. I thought about heating the brass to relieve the new annealing that I had created, But I didn't want to soften the brass too much and make it useless. I was really on unsure ground here and had no one to ask what to do to fix the problem. (I still don't) At the time, I had to resort to bending it back the the other way from the warpage. This of coarse made the brass even harder! I eventually got enough channel to complete the the tender frame members so I never investigated how to eliminate the warping that I got. After that I discovered "Special Shapes"  and never attempted to make my own channels again. With Special Shapes gone, I will either have to find a new vender or workout the stress relief problem.

D Buxton

On Sun, Oct 6, 2019 at 5:08 PM Mike Van Hove <vanhovem22@... <mailto:vanhovem22@...>> wrote:

If I understand the problem, I would say this is not for a saw,
but for a small milling machine.

Now, you have an excuse for buying one of those.

Mike Van Hove
Columbia, MO

> On Oct 6, 2019, at 11:06 AM, Bill Lugg <@luggw1
<mailto:@luggw1>> wrote:
>
> Yes, I was wondering that too, I've got one of those Microlux
table saws, but I'm not sure I've got the right blade for this
task.  I'll have to look.  It would take just the right plate
around the blade too to prevent the material from slipping into
the machinery.
>
> Bill Lugg
>
>
> On 10/6/19 9:52 AM, Brian Kopp wrote:
>> Bill for ripping tube like that I wonder if there is a smallish
table saw out there in the hobby market.....
>>
>> That might be nice for other ripping tasks too like wood or
brass sheet stock.....
>>
>> Its always a good time to buy tools.... =)
>>
>> Brian
>>
>> --
>> Brian Kopp
>> Jacksonville, FL
>
>
>




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