1. The cost of a laser galvo is below $100 and the cost of a HD DLP is above $550. The preformance and reliability are very different. We are telling that with the same price range we are using a much more sophisticated part to generate light patterns.
2. Consumable is not part of the maintenance for the printer. Number of layers to print depends on many variables, such as exposed area, exposed pattern geometry, lifting speed, resin adhesion to the film and silicone hardness. We have customers using a vat for over 500 hours printing tiny models.
3. Laser could be bottom up too. It is just a way to generate patterns. Some people use LCD to generate patterns too. By nature, the laser spot size is larger than the tunable DLP pixel size, laser galvo has more moving parts, laser diode is more sensitive to temperature. Degradation of a laser diode involves spot size and beam shape changing. In addition, if the calibration is gone, you need to send the whole printer back for beam calibration. Bottom up has less front investment and the machine is simpler.
4. Yes. Actually, there are 2K projectors available but the price is equivalent to 3 or more printers. Laser can not cover any area unless the galvo has a dynamic beam shape correction mechanism which is very expensive. Alternatively, you can put the laser far away from the vat to reduce the angle but the spot size increases. The more angle away from the vertical, the more elliptical the laser spot becomes. Therefore, outer region has less resolution than the central region of the vat.

Alan

These are great questions and here are the answers.

1) DLP is a very sophisticated projection system developed by Texus Instrument. It consists of a lamp, optics, a DMD chip and controlling circuits. DMD stands for “Digital Micromirror Device”. For a HD DMD chip, there are 1920 times 1080 (2073600) tiny mirrors (pixels) with a size about 10 um. All these tiny mirros can be switched on and off swiftly by the controlling circuits. DLP technology is widely used in commercial mass-produced DLP projectors so it is very reliable. Compared with LCD projectors, DLP projectors have a higher contrast ratio which is important for the SLA application. In a laser SLA system, a laser galvanometer system is used to create light patterns by drawing. It consists of two 405nm laser diodes, two focusing lens, two mirrors, two motors and a controlling circuit. The “cost to acquire” a DLP projector is about 3 times the cost to acquire a low cost laser galvanometer system. Kudo3D’s technical team had 12 years of experience in laser diodes and we decided to use the native 1920×1080 HD DLP because of higher resolution, higher printing speed, higher reliability and lower future cost to maintain. On the other hand, the galvo system is very small and can be fit into a small case. The advantage of galvo is simply cheaper and easy to design the looks of a small desktop 3D printer. Here are some reality for the cheap laser galvo system. The lifetime distribution of laser diodes is a broader bell curve compared with the light bulb of a projector. The laser diode lifetime is very sensitive to the laser chip temperature when emitting light.
The chip temperature depends on both how the heat is taken away from the chip and the ambient temperature. The lifetime also depends on the quality of the two cleaved cavity mirrors and the coating covering the cleavages. The chance of a premature failure is higher than a light bulb. If you search “laser failure” for those popular SLA printers, you will find many discussions. Other than the lifetime of the lasers, there are also moving parts that could fail in a galvo system. This system must be well calibrated before using. For a layman, replacing a part means that you have to send the printer back to the manufacturer for a sophisticated calibration. Otherwise, the laser beam may not be focused tightly or the beam shape may not be optimized. It is also difficult for a cheap laser galvo system to have a resolution comparable with the DLP because of the limitation imposed by the focusing distance between the lens and the vat and the quality of lens. People who want performance and reliability will find Titan1 more preferable than those little SLAs.

2) We did not mention the replacement of the PSP container under maintenance because PSP container is a consumable. This is true for all SLA printers. It is just like the cartridge of a 2D printer. If you are a DIYer, you can replace the Teflon film before it wears out. The number of layers that can be printed for a film depends on the cumulative separation force, the hardness of silicone and the model tolerance of the warpage. There is no absolute answer for the lifetime. Tiny models such as miniatures have small separation force and higher tolerance on the warpage. For this application, the vat can last above 500 hours with a small build platform. Estimated number of layers is 100000 on the same printing spot with few repeated patterns.
We encourage the users to understand the separation force explained in the “printing guide”. It will help increase the life time of the Teflon film. If the model needs a very flat surface, harder silicone tends to keep the film flat for a longer time. We will start producing v2 with harder silicone next week.

3) The desktop laser system usually has a bottom up configuration like Titan1. The resin price is about the same as that for DLP. However, the resins for laser SLAs are not formulated for very high resolution.

4) PSP is indeed scalable. We believe with DLP this is the only low cost high resolution scalable solution now. All we need is a 4K projector to increase the printing area. If the resolution is not a key concern for large models, we can also use a laser galvo to generate large patterns on a PSP.

Under “Maintenance” shouldn’t it mention replacement of the PSP container as the surface wears out? After how many layers of printing approximately will a given part of the container wear out?

It looks as though the laser system requires a deep bath of (expensive) Resin. Does that only impact up front investment or also running costs due to wastage?

Will the DLP with PSP solution be scaleable over time? For example do we expect more pixels? (I guess a laser can cover any area.)