Re: [diy_3d_printing_and_fabrication] Polygon mirror scanning based 3D printer
- I'm not sure I understand your idea, you want to move a mirror to correct the focal length? Your mirror scanner would have to be synced with the moving mirror and so your speed would probably end up the same as if you just mechanically scan the laser.Changing an optical path length while maintaining it's direction also normally needs 4 mirrors.GrahamOn Sat, Jun 2, 2012 at 6:47 PM, Paolo Velcich <pavel@...> wrote:
I may be completely wrong and my idea could be not practical, but :
what about adding a moving mirror coupled with a collimating lens, just like on the laser cutting machiones ?
Sync to the prismatic mirror from the printer ?
This way you would be sure 100% about the planarity and focusing of each pixel.
Such a light assembly, driven by a belt, could have decent speeds.
- Hi Mark,
Solarez resin for 3d printing is $254/gallon which one are you using?
--- In firstname.lastname@example.org, vrsculptor@... wrote:
> I see a couple of big advantages to this over DLP.
> 1. Resin is cheaper. You can tune LED to be compatible with cheap (Solarez @ $51 gallon) epoxy resin. This is probably a factor of 4 cheaper than DLP resins.
> 2. Size. Legal size (8.5x14) models are within capability of print engines.
> As you pointed out it is slower but I'm not sure that is an issue for a lot of us.
> > I also think we need to be careful not to forget that DLP style printing is
> > exceptionally fast compared to just about all other forms. The layer time
> > our uprint if you did the whole build area is: go for lunch. And lets face
> > it if we get it to work at all we could have a homemade 3D printer with an
> > A4 work area and high resolution for very little money making parts that
> > could not be made without a 3D printer.
> > 0.1mm is quite a thick layer compared to the 20um we have talked about, so
> > really that might be considered the time for 5 layers?
> > I have a question John, how on earth do we measure the
> > layer thickness's when we test? Build a tiny 3D printer that just prints
> > blocks (let laser shine through a mask on the vat bottom) then look at the
> > block. I've been quizzing Michael about similar issues on his kick starter.
> > All I know is I won't be using my callipers to measure 20um.