metal boat project

[Thunderhead19]

This boat is now available for demonstration and sale. Demonstrations can be arranged through Dave Garrington at our headquarters in Esquimalt, British Columbia; home of Canada's Pacific Naval Fleet.
(250) 386 8244

[joshman]

As for the cutting problems, Im quite suprised to hear of mis-shapen parts. I used to run a plasma table full time and the only problem we ever had was that the machine itself would start cutting out of square on large items, (less than 1 degree though). This was due to high speed cutting (1000 IPM) and servo slippage adding up over time. Aside from that the only cutting issues that even ordinary plasma cuts could have are thicker or thiner cuts than what the plotting computer/person had allowed for. This would only contribute to 1/16" difference in cut at the most.

By the way how much $$$$$$$ did you pay for a water jet table? Last time I looked they were $150,000+, plasma is a easy $50,000. Anyway this was off the subject but the plasma table subject excited me.

[Pavel]

Originally Posted by boltonprofiles

Thunder -

Our high definition plasmas need little or no de - burring, obviously depending on the plate thickness, and certainly none up to 12.5mm, so this angle surprises me.
Paul.

since this thread got alive again, this statement really surprised me. I would love to see a plasma aluminium cut which does not need de-burring if it is to be welded afterwards (i.e. to hull specs. quality welds). Did I sleep over the progress in plasma cutting or is it just a wishful thinking Thunder? I would believe that even laser-cut would need de-burring as opposed to water-jet which in addition to no-deburring cut also leaves no HAZ whatsoever. To me water jet is superior for to be welded aluminium cuts, but I would be only happy to learn otherwise.

Thanks

Pavel

[Thunderhead19]

The table ran us bout $150 CDN. The High def plasma cut plates needed the edges cleaned up a bit, but didn't show a bad amount of "dross". It was similar to what you'd get from a band saw cut, I suppose. There is a miniscule bur on the back side of a waterjet cut plate, its tiny and razor sharp.

[Pavel]

I think the issue is not the dross but the Al2O3 which is necessary formed during plasma cutting as opposed to water jet or skill saw cutting. This can cause major problem (with in-weld inclusions) with the high quality welds and thus a priory requires de-burring. Or does the new high definition plasma avoid oxidation problem with alu? I wonder...

[Thunderhead19]

Originally Posted by Pavel

I think the issue is not the dross but the Al2O3 which is necessary formed during plasma cutting as opposed to water jet or skill saw cutting. This can cause major problem (with in-weld inclusions) with the high quality welds and thus a priory requires de-burring. Or does the new high definition plasma avoid oxidation problem with alu? I wonder...

Never experienced any problems with Al2O3 on this project, or any of the previous 8 patrol boats (also plasma). We had to have our welds x-rayed on the patrol boats-no problems. Many edges were beveled for welding, that may have eliminated the problem.

Hello guys, MMBS has done projects of all sizes of metal buildings like insulation of pre-engineered metal buildings, workshops metal buildings, erected metal buildings, monarch pre-engineered metal buildings, tin or metal buildings, steel frame metal buildings, commercial metal buildings, church metal buildings, gymnasium construction, storage or warehouse metal buildings, cold storage facilities, manufacturing and office metal buildings, auto body repair shops and grocery stores metal buildings, and a multitude of other uses.

Web site - http://www.mmbsinfo.com

[winters]

Originally Posted by Thunderhead19

The entire boat was developed using Rhino3D and most parts were water-jet cut. Everything fit perfectly. It was actually quite spooky considering I felt there would be issues arising from the different plate thicknesses which ranged from 1/4" bottom to 3/16 sides and 5/32 frames (in addition to all the complex forming).

I'm also considered about this issue. Did you use any margins and/or settings in Rhino to compensate ? I don't know if i have to but just wondering about the complex parts & different plate thicknesses as you say..

[Thunderhead19]

Actually I broke the hull bottom plate into segments, but unequally. By unequally, I mean that I tried to find the true tangents to the surface in a few reasonable places.

Because of this, the hull bottom plate did not come out fair, but I created frames from them anyway, and faired them out manually. The idea behind doing this was that the plate had to come out to the real surface area and be constrained by as many real boundaries as possible. The frames weren't changed enough by my manipulation to make them fit badly, and it actually compensated quite well for minor welding distortion.

I made no allowances for plate thickness except for the internal framing.