News about building area, resin, curing time...

Hi Guys, few updates:

1) Building area

• I am still facing a lot of problems to find the right material for the bottom building area, so far I have tested glass (result: don't work as the resin stick to it), acrylic (result: resin stick to it as well) and polycarbonate (Result: resin does not stick but after some minutes the polycarbonate become opaque because of some chemical reaction and does not work anymore.
• The plan is to test some other materials within next 2 weeks.

2) Resin and curing time

• The resin works very well after adding some dyes and this solve completely the issue of curing more than the required layer. I manage to print a small object with amazing quality and no "shadow" on other layers.
• Now I am using 8 seconds for curing time and I am getting a amazing result.

Cheers,

Jr

New tests and new findings...

Hi Guys,

I was wrong, the curing time was not enough to cure the resin totally, the resin was yellow because was not cured. I put it for few hours in the sun and became crystal clear, and got very hard.

The problem now is that increasing the curing time also increased the stickiness, so the acrylic base does not work... I need to find another material for this.

Meanwhile I will finish some other parts of the printer that are still pending. The program is 95% ready and it's amazing. I will share it later on.

Another important thing, the resin is clear and the light pass through and cures more than the layer it suppose to cure... so, there is no way we will produce a crystal clear object... but I am fine with that...

Also I am checking with Dymax if they can provide the resin with color.

Regards,

Junior

First findings..... while printing... Now I will go out for a drink :)

1) I used curing time = 4 seconds, I think it was too much, the resin got too strong and start to stick on the acrylic. It became because of the over curing.

2) You need to wait few seconds after curing one layer so the resin can settle better and avoid bubbles

3) You need enough resin to cover at least the Tilt area. As it was my first test I used just 90ml of resin (economy mode.. hahahaha). It was big mistake, the bubbles start to appear and once they became big part of the layer the object broke because of the lack of the strength combined with over curing.

4) After finished...don't wash anything with detergent or soap... store the remaining resin in a anti-light recipient and leave the remaining one on the tank. Use the light to cure all the remaining resin in the thank, so you can remove it easily.

5) My thank is made by acrylic... works pretty fine and VERY cheap... comparing to the quartz I bought before (didn't work with quartz).

Many things that I will right later... but the method works and the resin is good for that.

Cheers,

Jr

IT WORKS!!!!! :)

Hi Guys,

INCREDIBLE!!!!!! I have just printed my first object on the 3d printer... still many things to adjust but the process works very well!!!

Please see the pictures.

Cheers,

Junior

Work in progress

Hi Guys,

Just want to put some new pictures of the work I am doing... I will explain later on how everything works.

Cheers,

Junior

Last post for today... initial plans and findings

My plan is to build a chemical 3d printer similar method of this one (http://www.youtube.com/watch?v=HbNl0CsB2xE). Using visible light and DLP chip to cure visible light resin.

The main advantages are: high resolution, very small waste and no powder mess... and most important low cost for building :) ... but high cost for the resin :(

But there are also some disadvantages: if you want a high resolution the
printing area must be small, because of high price of chemicals you will spend
a lot of money for big printing area.

I am not buying a DLP kit to build the machine as this would cost a fortune, so I am using a DLP projector that you can find anywhere.

Some of my findings so far:

1) The projector must use DLP chip www.dlp.com

2) Resolution: I am using a 1024 X 768 (0.55'' DLP chip) – I bought a used
projector on e-bay for less than 500USD. If you want a higher resolution you
will need a more expensive projector (over 1000 dollars). As I am planning to
have 100X80X130 mm building size which will give me a very good resolution, one
pixel will be thinner than a human hair (100 microns). My projector is Optoma
EP728. Projector lamp is cheap, I bought spare one...

3) The Z resolution is also important, I am using a microscope screw lead (140mm
- travel). This will give me a resolution around 0.01 mm on Z

4) As the projector lens are not for short throw distance, I did a small
modification to adjust the focus in short throw. (Removed some screws – my throw
distance 170mm)

5) The top-down building process has 2 main issues: bubbles and chemical level
as you introduce more solid material (elevator) the level goes up which could
give a small difference on Z axis. For this reason I am building a bottom-up
platform, this makes the project simple and also reduces the cost of chemicals
as you don't need to have a full Z deep building area.

6) Software: For slicing the solid I will use any commercial or non
commercial (Fogassa/Pov-ray). For printing I am building one which I can share
later on.

7) Chemicals: I have purchased one material from Dymax for keypad coating (very
hard (D80) and low viscosity that will arrive in 4 weeks, if it works it will be
best cost (around 200 USD per kg – must be cheaper in USA).


Cheers,

Junior

What do I need to think while planning to build a 3D printer?

Well there are many things you need to consider.

1) What is the purpose?
This will help you to decide which kind of material, build size, resolution, etc. The most important thing is that your choice will also define the costs :(

2) What skills I need?
Well, today you can learn basically everything on internet, you won't become an electronic engineer overnight but I am sure you can learn how to control a step motor (I did it :)). You can ask help to friends.

3) What about tools?

You will need many precision tools, it is not possible to build such machine with simple tools. You may need to use a CNC for precison parts. I will mention some tools used while building the printer.



4) Time and money..
Yes, you may spend sometime to do it and money too. I expect to spend around 1.5k to 2k USD to build one. But I already spent 2 times this amount just in tools last 2 years, but don't worry you can use your friends tools also.

Have fun

Jr