Richard Thornton 2

Thanks Mike for the info re the Ali. And thanks to both Ron and Mike regarding the warping effect. Sounds like I need to ensure anything is nice a dry before cutting and get the wood from a reputable supplier.

Hi Mike, where did you find these? Did you pop the 3D chocks up somewhere as you said?

I fully agree. I ran two sample cuts, one with kerf on all internal cut parts and one without. Both fitted together very well but the one with kerf made the joints ‘click’ into place with precision fit and absolutely no slop at all.

Apologies for not responding earlier. The wood is 3mm lite ply from a popular Hobby Store, ie Hobbycraft. These are just test runs at this moment, calibrating the machine etc. I will be getting the vast majority of my wood from SLEC as they have quite a choice, I must confess by being slightly overwhelmed by the variety of plywoods that they offer, have too chose wisely. Talking of calibration, after calibrating my S30, I seemed to have made things worse, dimension wise. It was as if I had mixed the x and y axis’s up. After the first test, the x was larger, the y smaller ie 150.2 and 149.8 respectively. After calibration, I did the run again but it made the x smaller by 0.4mm and the y larger by 0.3mm. So I recalibrated but used half values, and now it’s just under 0.1mm on both axis’s at 400mm which I am extremely pleased with. Then I discovered ‘KERF’ , everyday is a school day at the moment. 😳

This what I mean Ron. The piece has now taken a lovely bow to it. Do you need to ‘press’ the cutouts between something straight until they are ready to be used?

Any thoughts?

Well it’s been an afternoon of learning for me. The original 150mm x 150mm sheet was used initially to calibrate the machine however I noticed that the lines weren’t perfectly perpendicular to each other. DAMN. I initially thought the x and y legs weren’t square, but I couldn’t understand why as I had checked them all during assembly. It wasn’t but I did notice that although I thought the gantry was pushed right to the end of travel, there was a tiny misalignment between the two travellers. I adjusted the little grub screws on the cross travel and this seems to have done the trick. Really chuffed with the second set off cuts which I have used to calibrate the machine. Now I need to workout how to keep the bits that I have cut flat once cut. For some reason, both squares have taken a slight warp. One thing I have changed is the tool for setting the laser focus. There is a circular 50mm high aluminium setter which is awkward to use, well I think so anyway. I have made up a 50mm high aluminium plate that goes along the entire base of the laser which means when the knurled fixings are tightened, the whole head is level. The black lines are pen marks, thin lines are laser etched.

Right, S30 Pro assembled. Trying to fire up a Balsa Material Test run but everything seems to point towards using the rough guide based around the manufacturers material guide, which for an S30, I don’t seem to be able to find. Is there a basic library for 10w laser cutters that can be used for a starting point?

Well I am suitably impressed Mike. i am just waiting for the honeycomb’s to arrive before I can fire mine up. I have purchased an extender kit for the Y axis but after partly assembling it yesterday, thought it better to build it up initially as the standard size, get the little bits cut and learn from that before going for longer cuts initially. There may be many questions to follow Mike!

It’s arrived, complete with extension table and honeycomb beds x 2 Now the fun really begins

Ah ha. Thanks Leccyflyer and Ron, now it makes sense. I am ‘having to’ to draw in AutoCAD as the thing I want to build is a set of floats for my 1/4 scale Tiger Moth. I bought a laser cut kit from Blair and they are for a de Havilland Beaver which I thought would be fine. I have cocked them up completely by trying to make them sturdy enough and used polystyrene foam to get the desired curves. This created an issue when covering with glass cloth, which again I overcame but each compromise has led to additional ticks in the ‘putting on weight’ box. I have now created a further issue which is well known polystyrene, it breaths when exposed to sunlight. Eventually you have to stop, look at what you’re trying to achieve and take stock. Pros. I have spent hours getting them to where they are. Cons. To heavy. Not the correct shape. Pain to paint Breathing issues Waterproof issues. Post Pro If I get a laser cutter I can: I can use the laser to cut wood and engrave my scratch built parts for manufacture. Design the correct shape fitted to the full sized aircraft re the floats. Concentrate on making it light by using the model yacht techniques, use the filler/glue/covering polymer and paint that are compatible, and easy to use, rather than compatible with a compromise. Well above is the logic I have used anyway.

Hmm, now I am confused. I assumed that once you have drawn your design in AutoCAD or similar, you then have to redraw it in LightBurn? Going to have to finish drawing and start importing so I see what I get.

Many thanks Ron

Not had a response yet, any thoughts?

Evening Ron. Sorry you have felt the need to drop out of this conversation. THANK YOU for all your input and helpful conversation with regards to my original question. You have inspired me to take the plunge and buy a laser cutter. I know from reading others posts, you have got others to dust off their cutters and have a go. I am sure there are going to be more questions once my parcel arrives and I get it flashed up, neglecting to read the instructions as ever! Regards Richard

Just throwing another brick in the pond. When using a drawing imported into LightBurn or LaserGRBL, do you need the lines to be polylines or are ‘standard’ lines OK. I ask this after watching https://itat-forum.bmfa.uk/topicid/77 Which just like Ron’s zoom was extreamly informative and have already made use of 2 functions who’s icons have been sitting there all along just waiting to be used.

You lucky devil. They now charge £28 a year to keep it up-to date, that’s after you’ve bought the £90 version.

Can you elaborate please, difference between M4 and M3 ( and to avoid any abuse I appreciate it’s normally 1mm 🙈)

That’s a very good idea, thanks for the help. I wasn’t sure how that would be achieved. Going to take the plunge and order a Sculpfun S30 pro with air assist.

Ron, on your old Sculpfun cutter, can you ‘start’ a cut at a reasonably accurate position and is this done manually or by placing the object be cut in a position in relation to the bed. I realise it seems an odd question

If you import a drawing in DXF format, does it then cope with the curves?

Trying to sort out all the pitfalls before reaching for the credit card. (While the present Missus is in the garden!) Both the ATOMSTACK and SCULFUN models I am looking at or comparing, have extender kits. It seems that you can increase the cutter size from about 400 x 400mm to 800 x 400mm in the Y axis, there is a kit for the Sculfun that enlarges the X axis as well, BUT where do you get a honeycomb cutter bed that big without having to purchase 2 standard bed? Surely the cross over will cause issues. I see there is a 500 x 500mm but seems pointless extending the cutter without a matching bed, or am I being thick? Don’t all rush to reply, please 😈

Not meaning to ruffle feather at all. I like the way LightBurn works, ie the logic which is a preference only but also the fact that you have the ability to produce a “test cut” to sort of calibrate your cutter to the material your cutting. Finally, as I am yet to actually part with £90 when my free trail is up, I was particularly hoping that someone would point out that LightBurn and LaserGRBL are just as good as each other and what’s possible in the one program, is in fact, doable in the other.

Morning Basil. Interesting topic. I remember watching a tv documentary on the manufacture of the Spitfire Memorial located in Castle Brom and when the fabricated the support struts, instead of nice sweeping curves, the software that the drawing was initially drawn on, or just incase that’s libellous, the software operating the flame cutter, cut a series of straight lines to produce a curve. Funny how you remember stuff that at the time I thought ‘oh’ and now years later, wonder what draw that has been filed away in my head.

Thanks Ron. Following on from your BMFA ITAT zoom video, I noticed that you used that ‘template’ tester which at the time I hadn’t realised that it was bespoke to LightBurn and isn’t part of the cutters setup. So it looks like £90 extra spend on LightBurn, which does offer a 30 day trial period, BUT it seems a totally superior program when compared to LaserGRBL, but nothing in life is for free. 🙊🙉🙈