Nees help - Non flame cut hole in 2.5" plate

   / Nees help - Non flame cut hole in 2.5" plate #1  

Inkomodius

Bronze Member
Joined
Sep 11, 2008
Messages
78
Location
Grovedale, Alberta
Tractor
Massey 275, JD 6715
Hey friends, Haven't been on here in forever however your the first people that I thought of haha. I need to put a non flame cut 3" hole in 2.5 inch of plate. Its 1" plate on either side of a 1/2" web on wide flange. So as long as the holes are accurate I can do each plate individually.

So far I have flame cut a smaller hole and cone stoned it to finish diameter (takes forever), had a tool built for a mag drill that mills to final diameter this too takes forever and breaks bits mainly do to the web of the wideflange being bowed, and as soon as the carbide bit hits the gap it breaks.

So any ideas?
 
   / Nees help - Non flame cut hole in 2.5" plate #2  
There was a thread on annular cutters that may help.
 
   / Nees help - Non flame cut hole in 2.5" plate
  • Thread Starter
#3  
Unfortunately my mag drills will only work up to 1.5" annular cutters. I was hoping someone would be familiar with line boaring for pins on heavy equipment. It also has to be portable as I do this in others shops.
 
   / Nees help - Non flame cut hole in 2.5" plate #4  
You'll have to wait until some of the more experienced guys get on in the morning for more ideas then.
 
   / Nees help - Non flame cut hole in 2.5" plate #6  
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   / Nees help - Non flame cut hole in 2.5" plate
  • Thread Starter
#7  
Hmmmm that boaring head looks cost effective but have no experience with them. Can you get them to fit a mag press? Or would I need a press with a MT spindle? I will have to do some research.

And Shield, I would Love one of those Hougens, I cant justify the cost. Or even the cost of the 3" annular cutter! HAHA. I Honestly do not know how many holes I have to drill. Every set or prints calls for either a 45mm or a 76mm hole. And since we have 18 welders in the shop I never know which print I get given. I want to make my life easier, the quality better all while being cost effective.
 
   / Nees help - Non flame cut hole in 2.5" plate #8  
Since the maximum depth of cut is an inch a good quality hole saw would work (I like Lennox brand myself). Mark the center of where you want the hole, use a compass to scribe the circumference of your hole and then drill a few holes (3 or 4 at least) whose outside just touches the inside of your scribed circle. These give a space for the chips from the hole saw to go so you don't fill the teeth gullets up. Once that's done, drill the proper sized pilot hole and have at it with the piloted hole saw. Use lots of cutting oil. If you need a more accurate sized hole than the hole saw gives (you haven't told us what your tolerance requirements are), you might try to clean up the outside of the teeth on a belt sander to reduce the cutting diameter, much akin to how the set on the teeth on a wood saw will affect the kerf width. The outside of the teeth can never be less than the diameter of the hole saw body of course. If that isn't accurate enough, then you probably need to use an annular cutter. Hougen Rotabroach Industrial Cutters

(I've been a little pedantic for the benefit of any newbies.)
 
   / Nees help - Non flame cut hole in 2.5" plate #9  
The slowest speed on my 17" Jet floor mounted drill press is 200RPM, and when I used a 3" Milwaukee hole saw in 1/4" mild steel, it was a time consuming and delicate process to get the hole saw to make the hole. Although I didn't use the chip escape holes, I did raise the hole saw off the work, used a toothbrush to remove stuck chips, and flooded the workpiece with cutting oil. I also had on hearing protection due to the noise. I doubt I would have much luck cutting 1" plate with a 3" hole saw.
 
   / Nees help - Non flame cut hole in 2.5" plate #10  
It sounds like you are cutting on a weldment? Is it attached to something larger or is it transportable? Water Jet cutting is capable of more than acceptable accuracy with no HAZ and if it is just a circular bore that you are after it should be relatively inexpensive. Trick being it has to be something they can put on their water jet table. Just my 2 cents.

Chris.
 
 
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