Repurposing an FDM Printer to an SLA Printer finding a suitable laser source

[werto165]

Basically my 3rd year uni project is to change an existing FDM printer gantry to an SLA printer. I would use a galvanometer based system however the requirements permit that a standard XY gantry to be used. I was researching online to try and find a suitable laser diode, basically it's unanimous that a 405nm laser will work fine, I'm not entirely sure on the power, but I assumed the higher the power the faster the cure time = better in every way.https://www.ebay.com/itm/Focusable-405nm-100mW-Violet-Blue-Laser-Diode-Module-12V-w-TTL-450nm-Goggles-/322440424229 I've come across this and wondering if it's suitable for control with a RAMPS 1.4 board? Also, I'm trying to find a laser with the smallest possible spot size, however I can rarely find information about the spot size, I assume it's to do with the lens rather than the laser itself but if you could find something with a spot size smaller than 300um that would be really useful. 

 

I was also wondering if something like this would be possible like the guy outlined in this post: 

 

https://laserpointerforums.com/f49/even-smaller-spot-size-using-mask-89357.html

 

Cheers. 

[Hackentosher]

I mean anything is possible le if you throw enough money and arduino at a problem. Keep in mind that you need a dark chamber that keeps the resin safe from uv light, sooo can you do that with an i3 base?

[Pixel5]

this is not as easy as it may look like and no higher power is not better in every way because more power also means the reflections and unfocused light at the borders of the beam will harden the resin so you decrease your resolution unless you have a very good focus system in the laser.

 

so what exactly is your plan here? you gonna user X and Y to position the laser where it needs to be and the Z axis? you gonna build something on the z axis that slowly submerges the printing part in the resin and cures the upper layer or how do you wan to do this?

 

 

[werto165]

16 hours ago, Pixel5 said:

this is not as easy as it may look like and no higher power is not better in every way because more power also means the reflections and unfocused light at the borders of the beam will harden the resin so you decrease your resolution unless you have a very good focus system in the laser.

 

so what exactly is your plan here? you gonna user X and Y to position the laser where it needs to be and the Z axis? you gonna build something on the z axis that slowly submerges the printing part in the resin and cures the upper layer or how do you wan to do this?

 

 

Haven't decided whether it's going to be top down or bottom up yet. But ideally I think that top down would be easier but there's a possiblity that I might be using a galvanometer to compare so I think that a bottom up would be better. Essentially I need to design the mount that attaches the probe to the XY and then I'll have a stage attached to the Z axis perhaps design the vat too, haven't really looked that deeply into as the project doesn't officially kick off until 29th Jan.