Part 7 - mirror mirror! Seven years bad luck?
Last night I sliced the rear dome in 3D Builder and added pin holes for alignment. Then I loaded up Lychee slicer and made a print file for the left side and set it printing.
This morning, I took the print off the print bed and found a problem. It had printed the right side.
Assuming I was just an idiot I rechecked the model and Lychee, both showed left-hand models, but the print icon showed (clearly) a 3D model that was the right side. It looks like a bug in Lychee that any model mirrored in the application is printed back in it's original orientation.
In the meantime I popped the rear-right half dome onto the rest of the helmet and just propped it up to see how it will look.
The front-right visor (I checked three times before hitting print) is now started. See you in 12 hours or so...
Amazon delivered the higher grit sandpaper, so I have got busy after supper this evening and it it looking reasonably clear. Obviously I haven't done the entire section and there are three other sections to sand and two that haven't printed yet. Lots to do!
Part 6 - Can you see?
Wednesday morning after feeding the kittens, I checked on the print. It looked awesome.
However once washed and cured, the visor had become a little cloudy. This is caused by oxygenation of the resin. Over exposure to UV also caused yellowing. So there are a number of problems to address. One suggestion is to add a little blue dye to the resin to prevent yellowing. The suggestion of curing the model under water to reduce oxygenation is impractical as the visor part is way too big for any container I have and none would fit in the curing station either.
Anyway, the (now proven) method is to repeat sand and polish the resin to a clear finish. I have ordered some various grade of sandpaper and some turtlewax polish compound, so that will be my next step. Currently it's a case of cloudy with chance of RemLok!
Part 5 - resin or vacuum forming?
The visor for the helmet is in a number of sections. All of these are twice the size of my print area. This means I have two options. One, I print a set of former pucks (as suggested by CMDR Antonia) and vacuum form some plastic over them to make the visor. Two, I print the visor model in translucent resin. This comes with several issues, the main one being size - I will have to half all the parts then weld them after printing. Another issue is resin is transparent, but a little cloudy; fine for "glass" statues, but not much use for an optically transparent visor. To fix this you need to sand and polish the resin to a clear finish.
To test this I first had to buy some translucent resin. I then chose a small "glass" model I could print and test to see how hard or easy it would be to get transparent. This was the result.
With some painted caps and little alcohol ink, the results were excellent.
Having proved the concept, I went on to halve the front visor model and add some pin holes for alignment, so it would be easier to assemble.
I set it printing and came back twelve hours later...
Part 4 - getting your paint on
I had done some sanding and smoothing on the helmet and felt the main assembly was complete enough to paint. I gave it a coat of black primer and then with some key areas masked off, applied a second coat of chrome.
The masking tape worked with mixed results, however it did serve to give the paint a "worn and scratched" look. I then added a coat of Plasticoat clear to finish.
Part 3 – welding with a jig
In order to ensure the ear muff, jaw pieces and rear top section all join act exactly the right angles, CMDR Antonia had modelled an alignment jig. I printed a left & right jig during the day and then in the evening put all the parts from one side into their respective jig and carefully welded them together with spots of resin and the UV torch. Once the parts were fixed, I removed them from the jig and added a thin application of resin in all the cracks and joins, effectively making the parts a single piece.
With that done, I printed the rear cross sections. Again I needed to print these in two halves and then weld them together. This was getting easy now, so having done that, I welded the rear cross section to the main helmet.
Part 2 – rear top side-pieces and the cross member
The rear left and rear right side pieces were printed next. One of the STL models from Thingiverse was corrupt, so I just mirrored the good model and printed them both.
The cross member which is the bar that goes over the top of the helmet was my first real problem. It was considerably larger than my print area. To resolve this, I used Windows 3D Builder to cut the cross member in half and then printed it in two halves. Once printed, washed & cured, I used resin welding again to join the two halves. I could then assemble the pieces then for the first time.
I have for some time liked the idea of making an Elite: Dangerous Remlok space helmet. One I could wear to LaveCon and go in cosplay.
The early concept art was quite basic, but the helmet in game is a thing of beauty. When I bought a 3D printer a few weeks ago, I started to look for a model I could print.
Low and behold, on Thingiverse, the talented CMDR Antonia [Bradley] had created a model for 3D printing a wearable RemLok on a filament printer. The printer I have is a resin printer which has a smaller print area and works very differently. Filament printers are like an icing syringe on a robot arm, while resin printers pull the model out of a vat of liquid a 5 micron layer at a time.
Part 1 – printing the small bits
Some of the models included a thin sheet; a “base” or raft, for filament printing. Before I could start, I needed to edit the models to remove the base or they wouldn’t be usable in the 3D printer slicer software. I did this using Windows 3D Builder.
First, I printed out the jaw which just fit on the build plate, then the ear muffs and their caps. The results were stellar, but I managed to chip a bit off the jaw getting the print-supports off. Note to self: be more careful!
I had hollowed out the prints, so I needed to seal the drain holes and did this with a light paint of resin and a UV Torch. This is a technique called resin welding.