Unknown Domain

Water/laser/plasma cut 0.8mm black anodised aluminium quote

They people I spoke to about the cutting of the black anodised aluminium quoted £1 per flap which is reasonable but then you have to buy material too and the original devices used plastic, by the looks PP 0.5mm

Stanford University Graduate School of Business

I found this amazing project using what appears to be Krone units from looking but its absolutely beautiful to watch.

Monument to Change As It Changes - Zambrano Hall - Stanford University Graduate School of Business




From the artist:

Read more: LA Times

Materials update

So after a load of looking at other materials again I am here:

Styrene - Brittle and carcinogenic when burnt

Polypropylene - Same as the original flaps

ABS - Single sided

Acrylic - Brittle

PETG - Extremely melty

Rapidform said to use 4D Model Shop as a resource for finding out what materials are available but buy else where, I have however found engineering plastics, the plastic shop and eSheet so I think I am okay on that front.

Cut Laser Cut had two new suppliers to look at Arjowiggins (Priplak range) and Bayplastics Ltd. However I think its obvious that PP is the right material, I just need to get the right grade, definitely going to harrass that VitaSheet bloke, I also got another couple of names out of Cut Laser Cut...

One last thing to look into:

Black anodised aluminium - I spoke a long time ago to a company called ML Fabcuts but I never pursued it to a quote. I will contact them, VitaSheet man and possibly Arjowiggins tomorrow.

Cut Laser Cut

20120209-175358.jpg

I visited Cut Laser Cut today and spoke to a really helpful chap, who's name I neglected to ask. We had a good chat and came to the conclusion that PETG/Mylar which Rapidform suggested was very melty, he also said ABS might work but the samples all had a smooth/rough sides, however showed me the above sample of sign writers engravable ABS which if double sided would allow me to etch the characters directly onto the flaps.

I could imagine a process of putting the sheet of ABS in once and etching, then flipping it and etching again, with a cut immediately after. The problem is that laser etching is expensive as it is a very slow process, and the material only appears to come in 0.8mm which is single sided and he didn't know what it actually was branded as, however looking into it the material is supplied by Rowmark and is for sign-writers to do laser etched signs.

The material is essentially a white sheet laminated with black.

More plastic stuff

I received these samples from theplasticshop.co.uk today and I am very impressed with the speed with which they replied and the lengths they went to for just one small order. I am not happy with the material however, not their fault. It's just it has a gloss/satin like finish when I really just want a light grain both sides which is the same both sides.

I am going to harass the VitaSheet people again as they have not gotten back. I also spoke to a guy at RapidformRCA who advised agains styrene which Cut laser Cut recommended because of the carcinogenic fumes caused by laser cutting the styrene plastic.

Quick jot down of my ideas before bed

Polypropylene nightmares…

I looked into the eSheet company and they only sell the same BLACK9170 (aka BK9170) from VitaSheet Group, however I emailed to see if they can supply a G01 finish both sides or recommend someone. There minimum order quantity (MOQ) is £35 which is good for me so I asked them to quote how many sheets for that price but I am okay with buying it from Sea White at the moment for prototyping.

I also spoke to Cut Laser Cut in Vauxhall who said PP (Polypropylene) only comes in a two grain finish, which despite their great laser knowledge shows how much they know, but they said to look at styrene, but styrene is what Plasticard is, and although it's smooth it has a tendency to snap as I mentioned in my post about Twitter Display V2 however I may pop in to take a look.

I have also spoken to a few suppliers in China but they will only supply smooth black 0.8mm in 1 tonne MOQ while they will supply natural (milky white) in single sheet MOQ.

Very annoying, I can't use PVC in the laser cutter either so there is one less material. I need to find a solution as I am not happy with PP having two tone, I also need to investigate screen printing some PP at some point, I will speak with Rose Thomas about this, the screen printing tech at UCA where I work.

Research dump over, whats next?

I am still keen to build a unit and try to find a way to fund and fabricate my original idea. My skills in laser cutting are much better, I have had a chat with someone who is a bit of an engineering hobbiest and even spoken with a water jet cutting company who told me to make it in plastic not metal as I was thinking.

Drive system

I asked for a stepper motor for my birthday last year so I now have a nice 1.8º stepper motor from Cool Components. I also have an EasyDriver and coupler from FreeDay 2011.

I am keen to try a timing gear and belt assembly this time however I think it will turn out to be cost prohibitive. I also know I need to use spring loaded screws to stop the stepper from rattling free and I need to use opto-switches to detect flaps passing.

Structure

I also know that 3mm acrylic is plenty strong enough and that I should buy Tensol to glue it rather than superglue like last time.

Flaps

I am still looking for a supplier of polypropylene sheets for the flaps, I spoke to Sea White who provided the original material and they told me that it is VitaSheet BLACK9170 which is sold by the VitaSheet Group, I contacted Jed Brutes who has promised to contact a supplier who can provide a G01 (smooth) finish to both sides in low volume as they can't deal with me directly, pending a call still, will follow up next week.

I have also contacted The Plastic Shop who are working with their supplier to get me a sample of 1mm natural finish and a 3mm black so I can see what the 1mm thickness is like, however the Sea White was perfect at 800 micron (0.8mm) thick. I also just remembered I had some samples sent from a site called eSheet and I am going to pursue buying some from them again as it was actually a really good finish.

Laser cutter

I've gone from no laser cutter to having access to two, one at UCA where I work which is on campus not far from where I live and one at RCA which is large format where I am a student until the end of the year, however the UCA one is better and I can use it myself now I am a laser trained staff member there and want to keep the project bubbling over until summer when I will go for it rather than distracting me too much during my last term at RCA.

Next steps are to continue sourcing the materials and especially the timing belt and gears.

Split-flap pixel array

Not much info about this but looks like another split-flap prototyper at ITP...

http://itp.nyu.edu/shows/thesis2011/sean-fitzgerald/

Wikipedia: Split-flap display

The wikipedia article was the most useful resource in the V1 design as it has a patent drawing which explains how it works.

http://en.wikipedia.org/wiki/Split-flap_display

It also links to the patent on Google Patents which gives you a closer look, and it appears to be barrel timed (for lack of an engineering vocabulary).

http://www.google.com/patents?vid=3501761