Bad Experiences with Laser Cutting.

by Phillip Powell
(UK)

Hi I ordered a set of Laser cut parts from a well known company here in the UK called Belair. It was a complete waste of time and money (£80+)the nub of the problem for me was that the plans drawn by a well known designer (Philip Kent) were wrong so when they were scanned and converted to a format usable by the CNC laser cutter it produced very accurate useless parts that didn't line up or fit the required stock size wood for assembly. In fact it would be true to say that the amount of time and effort modifying the wing ribs to make the wing equal to that of cutting them myself.


I should point out at this point that I had little or no problems with the fuselage.

My request to companies that produce CNC cut parts is quite simple make sure they fit the together and if a slot is called for that is a given size then check that it is. Inaccuracies because of the width of the drawn line are commonplace when they are scanned for conversion and just because the designer is a well known good bloke doesn't make them infallible.

Just in case you think I am nit picking I had to change eleven ribs out of fifteen adding varying amounts to increase their length from five to ten millimetres and adjust every slot and cutout for the ribs.

Yes I would have produced ribs that didn't fit as well as the drawing was wrong but I would have seen this as I went along and it wouldn't have cost me anywhere near £80. We must remember these laser cutting machines are computer controlled which means rubbish in rubbish out very accurate rubbish.

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Mar 21, 2011
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starstarstarstarstar 		Dont blame the laser
by: Anonymous

I'm a bit shocked about the comment, it seems like the laser is being blamed for the bad plans or even some blame to the laser opperator. I have never cut plans for a plane but I do own a large laser and I get perfection from the laser every time, I do lots of work for people and normally I do the design so there is no problem but if someone brought be a design and it was wrong , I would not be responsible for it,you bring it and ask me to cut it and I cut it. The operator is not responsible to assemble or test fit the peaces, his job is to cut it.
I'm thinking I'm going to give this rc plane cutting thing a try, just for fun, I hope I don't disappoint anyone.
Feb 07, 2011
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starstarstarstarstar 		Check the Plans.
by: Bob Bishop

I am sorry to here of your bad experiences with laser cutting. Your comment re: rubbish in equals rubbish out is well taken.
We can learn a few things from this-
1. If the original plans were CAD drawn, then scanning the drawing may be avoided and a step removed from the process.
2. If you know that your particular plans have been laser cut before, find out if the process was successful and if possible talk to a previous customer.
3. If this will be the first time that laser or indeed ANY form of cutting parts,is used, it is smart to check the drawing for parts accuracy. Check the rib chord and ensure it is the same for the plan and individual wing ribs. Check the fuselage, width and height and compare to the fuselage former drawing.
Remember that the designer/draftsman, who drew the plan is human and does make mistakes! If you find errors, then please inform the designer. He should be grateful and should correct the plans.

Many thanks Phillip for the information. I wish your experience had been more positive!

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