Grinding heavy duty structurals 1

[Honorio]

We are a manufacturer of large ship tankers to carry crude oil. These large ships have thousand of wide-flange beams that make up the tanks in the ship. The engineering specifications as well as the customer requirements call for all squared edges of the beams to have a radious of either 2mm or 3mm. Currently, we manually grind off those squared edges to specified size. This task has proven to be costly, time consuming and tedious.
I am looking into retrofitting a mechanical chain conveyor with several power grinders so arrange that as the beam runs securely in the conveyor, the 8 grinders would grind the edges of the web as the beams pass through.
We have the capacity of making a device like that work.
My questions are:
1-Are we re-inventing the wheel?( I haven't found any thing
similar)
2-Is this the best way to go or is it better to make a hand
held device which grinds off both edges on a single
stroke?
3-Are there any heavy duty or very robust power grinders
that we may not know about?

Thank you for your comments!

PS. Purchasing rounded edges wide flanges and/or outsourcing the grinding has been considered already.

 

[JayMaechtlen]

Aren't there some hand/power tools for similar work- I think Trumph (sic?) makes this kind of equipment?

Also, some companies make power tools for repairing equipment in place- might work for your application?

 

[Honorio]

We currently use power tools, that's what the problem is, long beams and several to grind.

 

In my opinion, the most efficient and economical way is to mill the edges.
There are several different types of equipment that could be installed in a carriage to perform the work.
Look for field equipment to mill keyways in shafts and work in structurals.
Sincerely,
Antonio Reis

 

how about "scarfing" them? This is a tool, sort of like a lathe tool/form tool, and the motion of the beam would be what cut the radius. This is like a "shaper" bit too, or a bit like external broaching.

The advantages over milling are many, including much lower cutting tool or "insert" costs. The flange edge itself could stabilize the cut, much like some sort of a super-tough version of a wood-plane. This assumes that you don't need to straighten the edge, just radius it.

I'm also assuming that you are doing this prior to forming... At least I HOPE so, for the oceans sake...

This radius could also be cut with several inserts "ganged" along the way, lowering the cutting force compared to one full-radius forming tool.

You could get production rates of around 200 edge feet per minute! Machine design would require a lot of rigidity, yet specific degrees of freedom, but non of those degrees of freedom would require anything high-speed.

 

[Honorio]

I am not too familiar with that equipment to do "scarfing". Can you provide me with more information on this equipment. Where do I find it? This approach may be what I need to solve my problem, I want to look into it.

 

try the carbide insert manufacturers. "Skiveing" is another term. I am TOTALLY UNSURE OF THE SPELLING...

This method is used in steel/metal forming mills to remove scale from plate.

Good luck - you'll likely be building your own machine. Make it BEEFY!!!