Ramblin' Dan's

3D Print Design Studio

Search

Blog Posts

3D Printing - "It's all about design and quality output. Not how fast the printer can run."

UV Cure Box

The camera doesn’t know how to manage an exposure using a lot of UV ligDSC08062ht. It’s close to what it looks like with the human eye. Some colors fluoresce under UV light. This is one of two 10 watt UV lights I am using.

Most of the resin I intend to use with my WD7 printer requires a UV after cure process. The parts could be set out in the sunshine, if the sun is shining. The more controllable process is to use a UV cure box and put the parts inside the box with UV lights to cure. Faster and more controllable.

I like building most of my machines and building a UV cure box is not much of a challenge and is fun to do. It doesn’t need to be very big for the size of the prints that the WD7 can produce. This box is only eight inches square.

I have my homemade HB2 CNC router and this is a good project for using it to make the parts. I am using low cost 5/8 inch wood fiber board. This is not the high quality MDF. It’s the coarser material that Lowes stocks in 1/8 sheets. (2’x2’), 33% more material than is required for this project.

I used my table saw to cut all the parts to exact size. It’s far less waste than using the router to do all the cuts to size. I have a nice 8” x 24” board left over. Then the router is programmed for the top and bottom edge recess and the recess for the turntable on the bottom center. Two of the sides are cut through for mounting the UV lights. The base of the lights get warm so with the fixture totally outside the box, the box will be cooler. Heat is not required or desired to cure the resin.

I use Vectric Aspire to create the CNC path files. The computer pictures (below) of the parts are produced by Aspire

Bottom Top
This is the bottom with a recess to center the turntable This is the top. Note the inside corners are rounded for an easier fit.
sides with Lights DSC08063
Two sides are made like this for mounting the lights Here are all the box parts "kitted" and dry assembled sitting on the HB2 CNC OH Router I built from scratch.
DSC08065 DSC08066
Closer look. The lights will be mounted on opposite sides. I think 20 watts (2 -10 watt fixtures) are enough. Parts separated. The lights will be slightly off center because of the corner design. The inside of the box will be covered with glued on aluminum foil.
DSC08067 DSC08068
The light is a perfect fit into the machined recess. This is what it looks like on the insde. The walls will be covered with aluminum foil. (Next step.)
DSC08069  DSC08070
The recess is made the same size as the solar powered turntable. The turntable can be seen in the lead picture. I was testing to see if UV light would work. It does a fine job powering the turntable. The box is assembled and operating. Not much indication of the intense UV radiation going on inside.
DSC08071 DSC08072
I proped the top open and took a picture letting the camera exposure sensor only look at the ambient lighting in the shop. Note the box is lined in aluminum foil. Same shoot with the camers sensing the UV inside the box. I note the kind of UV "haze" coming from inside... A trick of the camera?
DSC08074 DSC08075
Active inside shot. The turntable runs well on UV lighr. There are no batteries, just the solar cells. I am wondering how the plastic in the turntable will hold up in all the UV radiatioj. It only costs about $5 so not a big concern.
DSC08076 DSC08077
Looking at the other side. Each lamp is ten watts. The lamp case gets a little warm, but most of the power must be going into the ilumination. Here is another shot adjust for ambient exposure. The light inside the box certainly looks intense!
DSC08080  The "wall wart" power supplies I am using are 12 volt DC rated at 2 amps each. That 24 VA or watts with a resistive load. Each lamp draws 10 watts so I have a safety margin over 100 percent.
The electrical. These are low voltage lights. 12 or 24 Volts AC/DC. Some sort of auto switching I presume. Same watts either voltage. (Less amps at 24 volts)  
UV Handle v1 DSC08081
This is a handle for the lid I drew up in Fusion 360.  Handle FDM printed in white PETG and screwed to the lid. If yer gonna build a handle, make one ya' can grab!

The proof is with the next print job when I will have some objects to cure. I think it certainly more UV than sunshine. I picked these lamps as they emit UV at the correct wavelength for resin curing, 395nm - 400nm. Energy is not wasted at the wrong wavelength.

DSC08082"Holy poker chips batman!" I poured about 3/16 inch of raw resin into a small plastic cup. Then I placed it into my curebox. I filpped on the UV lamps and checked the small cup about 60 seconds later. The resin and the bottom of the cup were so hot I couldn't touch them. The top of the cup and the rest of the box was cold. There was a good wiff of cured resin.

The resin had completly hardened through in less than 60 seconds. The reaction is certainly exothermic because of the heat in the material. I would call it an extreamly rapid reaction. I certainly have enough UV power available. I left it in another four minutes, just to be sure. The picture shows the poker chip I made. 20 Watts is probably overkill. I have a real part printing and will test agin. I think I have a very good cure box.

The Author

Ramblin' Dan Kautz

dankautzThere is no doubt one of my hobbies is writing about my hobbies. I read somewhere a long time ago, the best things to write about are the things you know very well. I have been writing and publishing long before the personal computer became the tool of choice.  My first printed and published club newsletter was created in the late 60's.

Read more ...

Our Mission

The intention of this web site and “Ramblin’ Dan’s 3D Print Design Studio” is to promote creative design thinking and demonstrate how ideas can be changed to tangible creations through the proper application and use of Three-Dimensional Printing systems.

Read more ...

Copyright © 2018 TEDatum Publishing . All Rights Reserved.