Lightobject.com Support Forum

Hi, I've been having great success with cutting mountboard, now I've managed to get it to cut cleanly using 35% power and 12 speed, so I thought I'd havea go at mdf again. Before the original went belly up, and before the conversion to dsp, I managed to cut through 3mm mdf without too much trouble, with basic air assist. Now though, with the new tube and the dsp I can't get through 3mm and can barely cut through 2mm, and thats at 3 speed and 75% power, which produces 20ma, which I'm sure its not advisable to go over. I've also got an improved air assist, which feeds the air right at the cut in a more focussed jet than previously.

Does anyone have any ideas? 3 speed is seriously slow, and really does char quite badly, and as yet hasn't produced a clean cut in 2mm. I've got good alignment but I'm wondering how you can tell if the lens needs replacing. I'll admit it was the original that came with the moshi. Could that affect it and if so does anyone know ofa good place to get quality lenses in the UK?

Cheers, Tim.

Hi tim
did you check for the sweet spot with a ramp??? means you take a strip of the material ( 3mm) lay it down and on the right end put a about 10mm thick piece under then cut a line . then turn it around and look where it cuts thru with the thinnest cut . measure the distance from the bottom of the laser head to the material on this point this is the focal distance for cutting.
you should clean the lens before and check the lens if it is clear whipe it of with denature alcohol dont push to much.
yes the lens can go bad what diameter has your lens? there are different seller for the best different diameter.
another part is did you check the laser settings in the manufacturer settings the frequency should be between 15000 to 25000 .
I can regularly cut 3mm bamboo ( the herdest wood) with 6 speed and 55 % power (17mA), but on mdf you have to be carefull because it depends on the manufacturer what kind of glue they use some are very hard and bad for laser cutting you can see this if it smokes like hell real black.
another point is what I just experienced that the new tube was a piece of crap and did not bring anythings was worth then my old one.
I send them back and wait for another new one from a different seller ( CNC cooltech)

twosoc wrote:Hi, I've been having great success with cutting mountboard, now I've managed to get it to cut cleanly using 35% power and 12 speed, so I thought I'd havea go at mdf again. Before the original went belly up, and before the conversion to dsp, I managed to cut through 3mm mdf without too much trouble, with basic air assist. Now though, with the new tube and the dsp I can't get through 3mm and can barely cut through 2mm, and thats at 3 speed and 75% power, which produces 20ma, which I'm sure its not advisable to go over. I've also got an improved air assist, which feeds the air right at the cut in a more focussed jet than previously.

Does anyone have any ideas? 3 speed is seriously slow, and really does char quite badly, and as yet hasn't produced a clean cut in 2mm. I've got good alignment but I'm wondering how you can tell if the lens needs replacing. I'll admit it was the original that came with the moshi. Could that affect it and if so does anyone know ofa good place to get quality lenses in the UK?

Cheers, Tim.

Hi walt, I forgot to do the strip thing so I'll try that, its currently disassembled as I've persuaded my dad to turn me a new air assist head out of ali, as the delrin one caught fire when the air assist tube kinked and the fine detail bit produced a large flame. Whoops. So as soon as I have it all together I'll try to find the sweet spot. I think its an 18mm lens. The mdf is laser df from hobarts and to be honest I wasn't impressed the sheets were seriously warped, I've had to cut them to size and weigh them down to try to force them flat. Plus they haven't bothered to reply to the email I sent.

I'm pretty sure the settings are within that but I recently reinstalled the lasercad and maybe I missed that. If the sweet spot doesn't make much difference I'm tempted to invest in a new lens, then run it for a while until I can make some money back then maybe get a new tube from a trusted supplier, the one I got was a replacement from the machine manufacturers. TO be fair it does a really good job of cutting mountboard, so for this project its fine, I'd just like to not be limited to thick card.

Had a quick play about with it today, five mins before tea, turns out I was 3mm too low. Handily I had some 3mm mdf lying around, and was but a moments work to pop a sheet under the cutting bed to bring it up to height, now the lines much thinner and hopefully I won't have to use as much power. I managed to get one piece through 2mm mdf at 35% power 12 speed, but I can't get the rest to go through, maybe that bit ran twice and the rest didn't? Who knows but if its nearly through at 35% and the max I can do is 75% I should have plenty of settings between them to get it right.
Dad brought me the new air assist head today, its pretty snazzy I must admit, needs a bit of fine tuning to get it to work properly, but its much better than my emergency mountboard and gaffer tape stopgap.

hopefully I'll have more time tomorrow to get a good cut going.
cheers Walt, once again you've saved the day, you need a costume or something.

glad I could help
greetings
walt

twosoc wrote:Had a quick play about with it today, five mins before tea, turns out I was 3mm too low. Handily I had some 3mm mdf lying around, and was but a moments work to pop a sheet under the cutting bed to bring it up to height, now the lines much thinner and hopefully I won't have to use as much power. I managed to get one piece through 2mm mdf at 35% power 12 speed, but I can't get the rest to go through, maybe that bit ran twice and the rest didn't? Who knows but if its nearly through at 35% and the max I can do is 75% I should have plenty of settings between them to get it right.
Dad brought me the new air assist head today, its pretty snazzy I must admit, needs a bit of fine tuning to get it to work properly, but its much better than my emergency mountboard and gaffer tape stopgap.

hopefully I'll have more time tomorrow to get a good cut going.
cheers Walt, once again you've saved the day, you need a costume or something.