Advice needed: Material and weld process type for this assembly.

[MwTech Inc]

You may not have to use filler rod, but, even with perfect square ends the metal will still need to "fill" the space.
So "technically" you will get a tiny drop in the surface.
But after a few practice runs getting the settings right I doubt you will notice.
pin is ok but if you make a shaft with a collar at the bottom you have an easy cheap jig and less machining on the tube.
Plus, if your pin is loose and the cap falls down in, just tolerance stack ups here, now you could erode the tube wall .
You will need to watch your heat as you have a solid plug vs thin wall tubing. Just keep your heat directed in towards the plug


I would use a split collar on the bottom of the shaft so you could adjust the tube/plug position. The shaft/ collar thing will only work if you have tight tolerances on the tube and plug. if not, then I would make the plug a "loose press fit" and just insert them. Still could use the shaft for a welding jig. No need to ground clamp the actual tube , just grab the shaft, slide tube/plug on, weld, slide off, repeat 200 times

OR just a thought, make the plugs a tight press fit and don't weld at all. Chuck in lathe, faceoff the end give it a chamfer and you are done.
Would be really clean looking.

 

[Vancbiker]

Brazing has its benefits too. Especially for larger quantities. Put a “j” root on the end of the plug and stick a ring of braze on it, press it into the tube. Then put a ring of braze on the joint between the block and the end of the tube. Stand them up and slip them into a kiln. Turns it into a batch process requiring minimal skill and produces very consistent results

You do have to be very consistent on the prep work, like cleanliness and flux application, before the fit up to get consistent results from furnace brazing. If the OP has big quantities it would be an excellent process choice.

 

[Herding Cats]

I would be very cautious of autogeneous welding (no filler wire) on material that is prone to cracking.

 

[MwTech Inc]

Have we had settled on the material yet??
still thinkin the press fit plug may be the way to go........
but we don't know the application

 

[Freedommachine]

I would use a split collar on the bottom of the shaft so you could adjust the tube/plug position. The shaft/ collar thing will only work if you have tight tolerances on the tube and plug. if not, then I would make the plug a "loose press fit" and just insert them. Still could use the shaft for a welding jig. No need to ground clamp the actual tube , just grab the shaft, slide tube/plug on, weld, slide off, repeat 200 times

Ahh, ok. I'm smellin what you're steppin in. This is a 10x better idea than locating off a pin. It will also provide a quick and easy way to load and unload parts from the rotary positioner.

Speaking of which, it would appear China has cornered the market on small weld positioners. There seems to be two flavors:

Small: https://www.ebay.com/itm/225357902000

And not as small:

VEVOR 50KG Rotary Welding Positioner Turntable Timing w/ 200mm Chuck 80W Motor | eBay

It is mainly used to tilt and rotate workpieces and keep them in a horizontal or vertical position for further welding. This welding positioner can also be connected to an automatic welding machine to ensure an auto welding process.

www.ebay.com

Have we had settled on the material yet??
still thinkin the press fit plug may be the way to go........
but we don't know the application

I haven't ordered material yet. I was thinking about 1215.

A press fit would probably work but I don't know the tolerance on the tube. There will be a spring in the tube pressing against the plug. I think welding will be a safer way to approach it.

 

[MwTech Inc]

Spring in the tube....ok
Yea...... i would have a bit of doubt in the back of my mind too, "will the plug ever fall out" ...lol Probably never would but you don't want to look stupid in the future...understand.
Depending on spring pressure, two welds opposite , basically a real good tack. with a tight plug would work. Would cut a lot of time.
Guess that will all come down once you get material....

 

[Goff]

If the plug does nothing more than seal the tube, would Loctite work? It would be faster than welding.

 

[Freedommachine]

If the plug does nothing more than seal the tube, would Loctite work? It would be faster than welding.

It probably could but like MWTech mentioned, the risk of it falling out and having my customers lose confidence in the quality of my work -as well as their customers doubting the quality of their work - is a risk I cannot take.

I will show you guys what this thing goes to in a few months. It's pretty cool, I think you'll like it

 

[Garwood]

If I was designing that thing, if there was any way possible, I would design it for zero welding.

Tube holds a spring! That's all it does? Use a spring pin to hold a plug and a spring pin to hold the other end to the block if you can.

Takes seconds to press a spring pin into a Drilled hole. Takes way more time to fixture and Weld or braze stuff.

Other options- very simple tool can swage one end down or create an external flange. Or you can have the tube laser guys make some "c" cuts in the ends allowing tabs to be formed which lock into an od groove in the plug and an ID groove in the bore.

 

[Freedommachine]

If I was designing that thing, if there was any way possible, I would design it for zero welding.

Tube holds a spring! That's all it does? Use a spring pin to hold a plug and a spring pin to hold the other end to the block if you can.

Takes seconds to press a spring pin into a Drilled hole. Takes way more time to fixture and Weld or braze stuff.

Other options- very simple tool can swage one end down or create an external flange. Or you can have the tube laser guys make some "c" cuts in the ends allowing tabs to be formed which lock into an od groove in the plug and an ID groove in the bore.

The tube does a bit more than just holding a spring. The rectangle part will definitely need to be welded.

You are really onto something here with the plug end though! It can be anything so long as it keeps the spring seated square in the tube .

Maybe I could roll the end in so that the spring rests against it.

Or I could roll a bead into the tube, something like this except only 1 groove.


The bead roll will probably be the way to go since it doesn't have the axial force that would be created trying to roll the end of the tube in.

The tooling should be simple enough. 3 rollers cut to the bead profile - 2 fixed, 1 adjustable. 3 ball bearings, a few bolts and some bar stock.

I can use my old south bend 9" and 5c chuck to spin the tube. Bolt the bead roller to the compound and then tighten the adjustable roller to achieve proper bead depth.

What do you guy's think?

Reducing parts woohoo! Thanks Garwood!

 

[Garwood]

Hell, make a blunted wheel for a rigid pipe cutter. I bet two follow wheels and one forming wheel would work fine.

 

[Freedommachine]

Hell, make a blunted wheel for a rigid pipe cutter. I bet two follow wheels and one forming wheel would work fine.

That would be far easier if it works. Ok, I'll try the pipe cutter method first.

 

[MwTech Inc]

does the spring have flat ends or spring stock just cut and used?

And you have the ability to make it anyway you want to an extent?

Looks important?

 

[Freedommachine]

does the spring have flat ends or spring stock just cut and used?

And you have the ability to make it anyway you want to an extent?

Looks important?

The spring is a long coil, cut to length and then I heat and bend the ends closed.

Yep, I can make it anyway I want to the extent that it is easy to manufacture and does not impede it's intended function. The only part I cannot modify is tube i.d./o.d. and the geometry of the head.

Looks are somewhat important but only to the extent that it is clean and professional. They will get a black oxide coating when finished.

 

[MwTech Inc]

if you try the roll thing you may just be able to hand hold it??
Use the compound as a rest/anti-rotation?
Now I'm thinkin the pipe cutter size like is used on a Rigid 300

Could make a crimper, bit more complex though.....give Garwoods idea a try first..

 

[Freedommachine]

if you try the roll thing you may just be able to hand hold it??
Use the compound as a rest/anti-rotation?
Now I'm thinkin the pipe cutter size like is used on a Rigid 300

Could make a crimper, bit more complex though.....give Garwoods idea a try first..

Yeah the pipe cutter hadn't even crossed my mind. I only have small ones that I use for 1/2 copper or brake lines and such.

I started searching the Ebay 'recycled auction junk' pile and threw a bid on a half decent looking Ridgid 2A pipe cutter. (Similar to the one below) It looks to be about the size of a 6" C-clamp. It has a range of 1/8" - 2" diameter and uses replaceable cutting wheels so I figure; if a pipe cutter will do it, this one should suit the job.


If it doesn't work out, it won't be the worst thing I've wasted $50 on and I'll still have a man sized pipe cutter lol.

 

[Barbter]

I can use my old south bend 9" and 5c chuck to spin the tube. Bolt the bead roller to the compound and then tighten the adjustable roller to achieve proper bead depth.

Similar i was thinking....Can you put the tube in the 5C.
Then using a single or double head knurling tool (with the knurls ground off) - mount in compound slide cocked round at 45 degrees.
Run spindle at 100ish rpm and feed in?
That would roll/chamfer/collapse the end as it's only 35thou tube?

 

[Mud]

Could make a crimper, bit more complex though...

Maybe a Mastercool hydraulic flaring tool with a die made to only curl the end slightly closed. Would be super quick. Cost under $300 for the simple versions.

72475 UNIVERSAL HYDRAULIC FLARING TOOL SET - My Website

Tube and die set stabilizing arm for easy tube forming Magnetic adapter holder keeps adapters in place Equipped with an enlarged die set compression area for better grip of dies Create perfect production quality flares on annealed stainless steel tubing, terne plate steel tubing, soft aluminum...

www.mastercool.com

 

[Freedommachine]

Similar i was thinking....Can you put the tube in the 5C.
Then using a single or double head knurling tool (with the knurls ground off) - mount in compound slide cocked round at 45 degrees.
Run spindle at 100ish rpm and feed in?
That would roll/chamfer/collapse the end as it's only 35thou tube?

I bet that would work too. I ordered some material to experiment with while I'm waiting on the tubes. I'll try it with my standard knurling tool and see how it does rolling the end vs the pipe cutter bead roller.

The material is now 0.025" wall. The material I wanted was unobtainium so I had to go with metric. I spent all morning in SW checking clearances and trying to figure out where this change is going to bite me.

Everything looks like it will function fine but I am a little anxious about welding a 0.025" wall tube to the block. I'll cross that bridge when I get there though, no need to create problems that do not exist yet. Right?

 

[MwTech Inc]

Welding .025...jus got to have your game on...