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Misc Forums => NON LSR Posting => Topic started by: Jonny Hotnuts on May 09, 2012, 01:02:23 AM

Title: production machining question.....need help!!!!
Post by: Jonny Hotnuts on May 09, 2012, 01:02:23 AM

I need to cut a 'v' notch (15ish degree) in the long side of 1.5X.75" (.083) steel rectangle.

This is so I can bend the tube and then weld the seam, essentially having the bar make a sharp bend without buckling. 

The problem is I need to do this a few thousand times.......

I have been doing limited production by using an angle grinder with very thin cut off wheel and guide bar and hand cutting the notches in a series of tubes lined up.
This is quite cumbersome....notches are inconsistent and its time consuming.

I dont want to buy a something like horizontal mill and end up spending thousands of $$$ on a solution.

Any suggestions?????


~JH
Title: Re: production machining question.....need help!!!!
Post by: Tman on May 09, 2012, 01:09:35 AM
Chop saw, end stop for the tube and go. Needs to not really be a true V notch, a good welder can get nice penetration regardless. You are overthinking this unless it goes on teh space shuttle............oh snap! The brains killed THAT program! DOH!
Title: Re: production machining question.....need help!!!!
Post by: RichFox on May 09, 2012, 09:33:27 AM
Be a nice job for somebody with a shaper. You could put a cutoff wheel in a radial arm saw. Set a vise and stops to locate the tube and cut something that will be welded anyway.
Title: Re: production machining question.....need help!!!!
Post by: Dean Los Angeles on May 09, 2012, 10:16:21 AM
Build a fixture and stop for a band saw. We did something similar at work and it went pretty quick, but only 40 pieces.

The 15 degree angle dictates a thin blade.

Any reason you can't cut completely through and weld it in a jig?
Title: Re: production machining question.....need help!!!!
Post by: Vinsky on May 09, 2012, 01:30:30 PM
 Haas makes friction cutting circular blades that I used in my double bevel compound slide saw. It worked great. The only problem was, the hot steel chips ruined the plastic blade guard. Other than that, it makes very quick and accurate cuts.
A quicker but more expensive way would be to sub it out for robotic laser cutting.
Title: Re: production machining question.....need help!!!!
Post by: McRat on May 09, 2012, 03:59:18 PM
If I understand?

Fastest, strongest:

Cut on horz bandsaw, fine tooth blade (thickness unimportant), use coolant, low RPM.  Harbor Freight has cheap models ($200), so do many of your buddies.  You can set the 7.5° (per side) at the saw vice which is built-in.  

Blow off, clean on wire wheel.  Weld 100% around, using a jig (c-clamps to blocks OK).  Bending steel near a saw cut isn't optimal.  It's weaker, and can start cracks, and you aren't saving any time or money anyhow.
Title: Re: production machining question.....need help!!!!
Post by: Glen on May 09, 2012, 05:21:24 PM
Find a shop that can bend the tubing. A lot of fab and welding shops have benders for almost any shape.
Title: Re: production machining question.....need help!!!!
Post by: SteveM on May 11, 2012, 03:22:21 PM
How long are the pieces?  For thousands of them, pay someone to make the cuts at a local steel service center.  They should be set up for that kind of work.

In our machine shop here at work, we have a horizontal band saw with auto feed, coolant, and a head that can cut any angle.  I would set up on a stack of 20' long tubes, set the saw for 7.5 degrees on one cut, square for the second cut, and whatever length needed,  then have someone put the cut pieces in a box as they came off the saw.  Maybe 30 seconds per cut on a stack of 5 or 6 tubes.

Steve.
Title: Re: production machining question.....need help!!!!
Post by: Jonny Hotnuts on May 12, 2012, 05:52:08 PM
(http://sphotos.xx.fbcdn.net/hphotos-snc7/577057_3694796324547_1114496579_33430714_1775461970_n.jpg)

Thanks for the suggestions.....

THis is what the bars look like.

I like the look of the weld on 3 sides....and have to weight the tradeoff of time welding 4 sides, vs. time to cut the notches by hand to gain consistency of angle.
Title: Re: production machining question.....need help!!!!
Post by: johnneilson on May 13, 2012, 11:57:19 AM
If I am following you on this, it could be done via cnc mill. It would require machining from 3 sides (1ea. side and final open end).
If you have thousands to do, it would probably be cost effective. I see a couple benefits, consistancy, radius in corner for bend and probably not require a fixture to weld two pieces.

Just another way to skin the proverbial cat.

John
Title: Re: production machining question.....need help!!!!
Post by: Glen on May 13, 2012, 12:11:28 PM
Hotnuts what are you trying to build?????
Title: Re: production machining question.....need help!!!!
Post by: Peter Jack on May 13, 2012, 12:34:26 PM
Jonny, why not weld them all the way round and then give the back side a quick rub on a belt sander with a fairly coarse belt? That will give you both the ease of fabrication and the appearance you're looking for.

Pete
Title: Re: production machining question.....need help!!!!
Post by: Captthundarr on May 13, 2012, 12:39:22 PM
Hotnuts what are you trying to build?????

Yea, whats up wid dat?
Title: Re: production machining question.....need help!!!!
Post by: Jonny Hotnuts on May 14, 2012, 11:03:43 AM
Quote
Hotnuts what are you trying to build

These are extension handles that have become a mandatory safety methods standard for a large shipping company (long haul division) that rhymes with 'UPS'.

I am going to try the full cut and weld method. The more I think about it, it will solve some probs.

~JH