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Texturing Brass Bars on a Swiss Lathe

Bendak

Aluminum
Joined
Aug 26, 2017
Hi all,
I work for a company that manufactures high-end cabinet hardware in C36000 brass and am looking for a solution to add decorative textures to our drawer pulls (ideally up to 30 inches in length). I have attached several images as examples of what kinds of textures were are trying to achieve. Apart from the hand-hammered textures, these were manually and meticulously done on either a rose engine lathe or staight-line machine. Are you aware of any tooling that would be able to achieve this on a swiss lathe? I have two thoughts on this:
  1. The first would be a set of tools that can essentially pot broach decorative textures on the OD of a round bar. It would consist of a number of turning tools facing inwards towards the OD of the bar with the ability to advance, retract, and rotate together as the bar stock is fed through the tooling apparatus (similar to tooling heads on escomatic machines).
  2. Another possibility is rolling the textures similar to how thread rolling is done on a swiss lathe.
So far I have not been able to find any tools like these on the market. We could use an engraving tool to make these textures, but this would take too long with all of the indexing involved. We have two Tsugami swiss lathes and a Haas ST-20Y with 12-foot automatic bar feeders. Any other ideas as to how we should go about making these kinds of parts?

Thanks,
Jack
 

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I would ass-u-me that the textures on much of the mass-produced hardware is rolled into the parts.

I wonder if you could achieve some of the desired patterns via some sort of custom knurling tool? They would probably be $$$ upfront but last a while considering the materials you will be working with.
 
G2 and 3 could possibly be put on in a Bar Marking machine, but that's likely how it's done now?

H2 could be done on a swiss, for whatever the length of the sub spindle axis has in Z. Just pull in Z2 with the main collet open and move up and down in Y as you go.

I have an old Tornos that has a lot of Z2 travel, but I can't say that I have seen anything offering that much daylight in decades.

As long as your mill goes off the bar at the apex, you could doo a "hitch" with the sub and go again. When done to length, shove it back in and index it, and go again - with a different start point. It could be done. Not overly quick, but it could be done.

You could find larger fixed head lathes that would have a long Sub/linear travel than a swiss. (longbed)*



Edit:

* But the fixed head wouldn't have the benefit of the guide bushing to hold the bar while being pulled, so that wouldn't work as well. But cimb milling while pulling, could still make it OK. (fear of chatter)



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Think Snow Eh!
Ox
 
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My immediate thought was custom knurl tools. You'd have to work with the manufacturer so you get a properly sized tool that will repeat on the diameters you want to run. As FamilyTradition said, it'll be some dollars up front (and probably a few weeks lead time at least) but if you're running brass one set should last you quite a long while.

For the straight line one (G3) I had a thought of putting it through a custom machined ring with "scratchers" sticking out to get the lines, perhaps attached to the gang just in front of the guide bushing? Push it through the ring a bit with the main, come grab it with the sub, travel as far as you can, rechuck, etc. You could even make a ring to hold custom inserts so you could have different styles of groove.

I haven't had occasion to make use of polygon turning but H2 *might* be a candidate? I'm not sure if it would be able to pick up the pattern, but might be worth looking into.
 
Not a Swiss solution, but G3 and G4 might be amenable to a laser engraver, especially since all the oxide is going to get cleaned off in preparation for the final high polish.
 
My immediate thought was custom knurl tools. You'd have to work with the manufacturer so you get a properly sized tool that will repeat on the diameters you want to run. As FamilyTradition said, it'll be some dollars up front (and probably a few weeks lead time at least) but if you're running brass one set should last you quite a long while.

For the straight line one (G3) I had a thought of putting it through a custom machined ring with "scratchers" sticking out to get the lines, perhaps attached to the gang just in front of the guide bushing? Push it through the ring a bit with the main, come grab it with the sub, travel as far as you can, rechuck, etc. You could even make a ring to hold custom inserts so you could have different styles of groove.

I haven't had occasion to make use of polygon turning but H2 *might* be a candidate? I'm not sure if it would be able to pick up the pattern, but might be worth looking into.
Hi SWYooper,
I contacted Accu Trak about this, but they said only G3 would be possible, though I am not sure why G2 could not be done as well.
 
Not a Swiss solution, but G3 and G4 might be amenable to a laser engraver, especially since all the oxide is going to get cleaned off in preparation for the final high polish.
We went down that route for a while but struggled to find a laser engraver that could engrave brass at a meaningful depth without taking an exorbitant amount of time. The problem with too a shallow a depth of cut is that it tends to look cheap (like a decal) and would be taken off rather easily by our buffing wheels. We were also hoping to find a laser-engraving/texturing system that can accommodate an automatic bar feeder.
 
Hi SWYooper,
I contacted Accu Trak about this, but they said only G3 would be possible, though I am not sure why G2 could not be done as well.

No, you need to talk to more like Sossner Steel Stamps, not knurls.
Similar in concept, but on a different level.


I'm not following the story given tho:
You work at a place that makes these, but you don't know how they are currently made?


---------------------

Think Snow Eh!
Ox
 
I'm not following the story given tho:
You work at a place that makes these, but you don't know how they are currently made?


---------------------

Think Snow Eh!
Ox
Starting to look like someone's homework assignment for junior college.
 
A chambusburg 1 would be nice for h1 and 2. A nazel or belche would also work.
So would a little giant 25 for h1, h2 might need something bigger.

Yang, Turkish, or glasser (German) hammer easiest option for both.

Why try and fake it when doing it right is not that hard?
 
Regardless, you are not going to stamp or knurl anything on a swiss and think that you are going to come back for a second pass on it. Even if using those type of tools, THAT won't be the machine it's ran on.

I only see H2 as a possibility.

You could run it w/o a guide bushing, but even at that, you are not going to want to re-clamp on an already formed surface.


------------------

Think Snow Eh!
Ox
 
We went down that route for a while but struggled to find a laser engraver that could engrave brass at a meaningful depth without taking an exorbitant amount of time. The problem with too a shallow a depth of cut is that it tends to look cheap (like a decal) and would be taken off rather easily by our buffing wheels. We were also hoping to find a laser-engraving/texturing system that can accommodate an automatic bar feeder.

You can buy a Citizen L220 with a Laser on the B Axis that could do it, and run 12ft bars. If you've got the cash, that is.
 
Starting to look like someone's homework assignment for junior college.
In my original post I said that the guilloche were made on a rose engine lathe and that the hammered were done by hand. None of these have been made by us, they were images taken from the internet.
 
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I used to use a Pullmax P7, with in house made texturing dies to do some similar patterns in tubing and bar stock cold, this was back when I did ornamental ironwork. Was more organic in that I was manually moving the material through the machine, but that could be automated.

When done carefully the material stayed fairly straight, I would then use shaped wood block and a rubber mallet to straighten and true it up.
 








 
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