Fun with 3D printing - Printing Surface

Just a brief one to update everyone on what we have been up to. Basically we have been heavily focused on the printing side of the business recently so haven't had time for any fun projects. We did, however, get to go to a seminar on 3D printing and the The National Museum of Computing (FYI well worth a visit, especially if you get to have a guided tour). The equipment on display was excellent and is on our wish list (thank you Triformica for the invite) but is a LITTLE out of our budget just at the moment. But... it did get us thinking about how useful 3D printing would be in house, just for prototyping and component repair so after having a look around we decided to buy a Printrbot Simple kit to cut out teeth on. We now have 3D printing capabilities! No, we cannot produce commercial grade pieces but it is a lot of fun.

I would warn anyone planning to purchase one of these who isn't in to tinkering that at this price range you WILL need to fettle and tweak it to get even basic prints out. That's not a failing of the machine as such but this is emerging technology and is not very refined.

We have had the machine 3 weeks and have already made a few changes which I will go in to detail later.

As a quick summary we have so far:

Home etched a heated bed.
Re-Designed the bed to take a heated bed and glass surface.
Made a new power supply from a PC ATX supply.
Built a spool holder 2 spool holders a spool platter.

The first thing I will discuss however is the printing surface for PLA filament. If you don't already know getting the filament to stick to the bed on the first layer is a right pain in the backside. We tried acrylic (too stuck down, bed was scrap), ply (sometimes worked), hairspray on glass (worked 50% of the time), masking film (worked 50% of the time), plain paper (worked too well) and pretty much anything else we could stick in there. In summary the prints were lifting, lumping or generally being a pain most of the time.

Our Solution:

Glass bed heated to an indicated 55°C, layer of masking film (Perfect Tear Main Tape) and a solution of 50% water, 50% PVA glue on top of the tape. So far we have not had any problems with this at all. We can run the head a little higher, splurge (technical term) the filament a little less, run faster, and remove the part by lifting the tape off the bed. We have to re-coat each time but it takes moments (our working area is only 95x100x100mm) and costs practically nothing (we even have the tape in 100mm width by the box load). The only issue we have is a little tape gets glued to the bottom of the piece but we can easily remove this with water. When putting on the PVA the tape wrinkles a little but soon flattens out when it drys.

Hopefully someone will find this useful and not have the headaches we have!

Other mods to follow soon :)

Round Peg, Square Hole

Today I had to purchase a cheap tap and die (this one) set to repair a heat press. It worked perfectly well on steel so I thought I would try acrylic.

After tapping a few holes for no reason whatsoever I thought I would try threading a slot as a replacement for a capture nut. 

As it turns out it is practically impossible to do and keep the tap anywhere near central!

20 minutes later I knocked up a jig (with tapped holes of course) to hold everything in alignment. You can download the plans here.

Its similar to a doweling jog but a lot less complicated. Surprisingly it works like a charm! The tap cuts easily (although if you go too deep and reach the end of the slot the whole thing binds up completely and will not undo) and the final joint is surprisingly strong. Probably not as strong as the captured nut but it does the job.

Specs if anyone wants to try this:

Acrylic - Cast 5mm Clear (Perspex) 

Tap - M4 x 0.7

Hole for thread - 3mm

(3.2 is quoted for M4 but with laser kerf 3mm seems better)

Slot - 3mm

DHT Sensor for Gary

Gary the gecko gets a bit funny about his environment so we have to keep an eye on his temperature and humidity. We could have gone a purchased one but that would have been too easy! One ATMega328, home brewed PCB, LCD screen, DHT11 sensor and a laser cut case and we are away!

Not many notes on this one as the PCB creation was experimental and I will be writing it up fully later.

Anyway, here are some pictures.

More pics:

Ebay Listing

We have finally got round to starting to add some products to ebay, all laser cut of course. Ebay shop. So far we have quite a few home decor items which are great but the most interesting item is a Breadboard Component Holder.

More after the break

Pumpkin Toast!

Laser engraved (Toasted?) Pumpkin Toast!

Why?

Why not! It's Halloweeeeeeeeen!

Gecko Lid

We were given a large fish tank and instantly went on a hunt to find something to put in it (fish being dismissed as "boring"). In the end we decided on a Crested Gecko because of the habitat requirements mainly. He has no tail (we are suckers for disadvantaged) and we call him Gary!

Anyhoo...

Laser Pin Table

Being attached to a print facility we cut a lot of paper and board and are always looking for ways to improve the cuts, reduce ashing etc. We have tried honeycomb, frames backings etc and decided to try a DIY pin table. 

Custom USB Cases

We have been asked to make a short run of custom USB Flash Drives so we needed a proof of concept. 

Boarduino ATTiny Programmer

We have been doing a lot of ATTiny programming recently and decided to simplify the process by making a board to plug everything in to rather than breadboarding it every time.

Rather than perf board we decided to make up a Laser masked PCB board  to take a boarduino, ATTiny and reset overide capacitor. More after the break:

Laser Engraved PCB

I thought we were being really clever with this one but apparently it has been done before!

We needed a PCB making for a simple stepper motor driver and thought "why can't we use the laser?". A quick trip to maplins we had a copper clad board and some grey automotive primer.

The process itself is really simple:

Model Aircraft Parts

We have recently been asked to produce a number of model aircraft parts so we had to have a go ourselves! We are pretty pleased with the wing so far but have come up with a few ideas to make a more laser friendly version such as incorporating living hinges on the leading edge, decreasing part count and simplifying construction!

We even laser cut the main wing support from 4mm Ply. It is actually 2 pieces and has a glued finger joint in the centre. From the couple of test pieces we did this was stronger that the ply itself.


When we have finalised the laser cut wing design we will post it up here.


If you require any laser cut parts please let us know and we will provide a very competitive quote.

Robot Gripper

I have designed a robot gripper for a Turnigy mini TG9e servo. A paypal link for the laser cut acrylic components is at the bottom of the page. The gripper is laser cut from 3mm and 5mm acrylic and bolted together with M4 16mm machine screws.

The servo arm is used to drive the gripper.

The green acrylic under the servo is the 5mm section. Make the bolts finger tight and adding a blob of superglue to the nuts helps keep everything solid.

The servo hooked up to a boarduino.

You will also need a small servo such as the Turnigy TG9e (I believe the TG9 will fit as well), 7x M4 16mm machine screws, 7x M4 nuts,14x M4 washers and a teeny tiny screw to attach the servo arm to the gripper (the ones with the servo are ideal)

The "wrist" has 2x 4mm holes but if you require something different just let me know when ordering.

Servos can be sourced here .
M4 hardware is available from all good hardware stores ;)
Instructions can be downloaded here.

Bluetooth Headset

Simple mod from last Saturday night (I really need to get out more!).

I have a pair of bluetooth headphones but unfortunately the headband is broken and one of the speakers is a bit dodgy so I decided to mod it to have a 3.5mm socket.

More after the break.

Fire Detector 2

So I set up the Chipkit Uno32 with the temperature sensor TMP36 from oomlout.com, installed the serial port monitor on the laser pc and tested the system. All fine so far.

Fire Detector

After Martins fire, and have a near miss myself I am planning to build a fire detection system for my laser. I am already building an Axolotl temperature sensor system (which I am logging at the moment) so when that is complete I will have a look at using a similar system for fire detection. Whilst the temp sensor is being finished I am going to log the temperature in the laser to see what sort of range I am dealing with. For this I am going to use the chipkit / arduino prototype for the Axolotl system and write something simple to monitor the com port on the PC.

I will strip the LED and buzzer off and hook up the temp sensor directly.

More details and code will be published when I have it hooked up.

Bus!

Recent commission - card bus / coach. Really simple design that will be branded up and possible personalised per recipient. It will be supplied flat to be constructed by the person receiving it so it had to be a simple tab and slot design.

DTG

I have an old Epson D92 that we used for dye sub printing. This has now been superseded so I get to take it apart! the plan is for a simple Direct To Garment system which I plan to document and publish the laser files on Thingiverse.

So far we have torn down the printer and it is basically modular. There is the main beam which the heads run on and contains the control board, the power supply and a stepper motor to drive the paper, or in this case platen. the only issues I can foresee is the paper trigger timing and making sure the drive is powerful enough to pull the platen along. I plan to design with adjust-ability in mind so hopefully ironing out problems won't be too tricky.

The printer is an older model however the current Epson S21 is practically identical internally so modifying the design for this should not be too difficult.

Below is the first sketch, and this has already been replaced by a newer improved version! It is based on 4mm ply and has no consideration of joints, bracing and in places basic physics.

Fridge Parts

Another emergency fix - this time a bracket for a fridge tray.

The original was a really thin piece that has snapped and broken away over the years. We stuck all the bits we had back in to place and reinforced it with some cut acrylic. Holes have been cut in the acrylic in case we need to drill and bolt later. Just in case!

Victorian Gentleman's Travelling Electronics Case

I was fortunate enough to acquire a large wooden trunk to store some of my kit in. It was in a very sorry state so a tub of black paint and some laser cut corner pieces later and we have the Victorian Gentleman's Travelling Electronics Case, perfect for quick jaunts by steam ship or dirigible! Sorry for the lack of before pictures, I had nearly finished before I remembered!

my bloody valentines.... commission.

I am not very good at mushy, sentimental design so when commissioned to produce something for a valentines day promotion with the specification "something with hearts and cherubs and stuff, you know, like valentines cards" I was not thrilled. Below is what I came up with, which despite not being to my taste at all the client loves it. lol. I don't think I am going to win any design awards with it though!

On a side note I have set up my old record player in my office and have been dusting off the old vinyl. There is something really pleasing about a record as opposed to digital media, I think it may become a permanent feature. Now I have to resist the urge to take it apart!