When I lent my services to a collegue who was working on a film about 12 years ago, I was introduced to the world of cnc. I remember watching this huge machining centre milling out a slab of mdf and turning it into a fantastic set of gears. I knew that it would have taken me hours to achieve the same thing with traditional power tools. I decided then that I would invest in a cnc router for my own business Oxenham Design. At that time I could turn on a computer, but even to check email seemed like a crazy set of operations. I persevered and learned every piece of relevant software I could get my hands on. I am now fortunate enough to be using Vectric's ASPIRE software, and Techno cnc routers, which has helped us to create some amazing projects, both in part, or in full. I thought that this blog would be a great place to share "behind the scenes" adventures with the software, materials and equipment we use, as well as the projects we build.

Monday, 26 March 2012

Cutting Texture

I was able to get the files for the spinning texture display cut on Sunday. It was really nice to 'build' something physical and not digital. Although both have their place!
The spinning text portion came out great! Exactly as I drew it. Before I cut them from the sheet of HDU, I had the router mark the centre axis. I then marked the parts in pencil so I would have a dead-centre for the the pole they'll mount to.
 The rocks portion came out just as nice, although I did bump the stepover up a bit to reduce the machining time a little. I ran these at 360 IPM and the 'ROCKS' only took 28 minutes with a 1/16" tapered ball nose.

While waiting for the files to cut, I hacked the rock form out of some leftover Ripley's Shark styrofoam. This piece is around 6" deep. Not to big, it won't take up much room as it sits on the front counter.

I glued the "ROCKS" portion to the flat on the styrofoam form and coated it with fiberglass reinforced autobody filler. Despite what you might hear, you can actually coat styrofoam with Bondo. It does eat the foam a tiny bit, but not nearly like fiberglass resin does. This has given me a very strong shell to work with. I will remove all the foam when I have finished all the cleanup on the filler. I'm thinking I will glass in some mesh on the inside to give it even more strength, but it might be a little redundant. I'll have to see how thick the shell actually is when the foam comes out.
Sadly, I have to wait to finish this piece further until next week. Time right now is a little tight on other stuff. But at least I got it this far!

Saturday, 24 March 2012

This texture rocks!

I didn't get to the shop today as some other things had come up pretty last minute. But I did get to model the 'ROCKS!" section of the display. I thought I would walk you through this portion as well. There isn't much that is different from the "Texture" portion. The process is identical:
I imported the vectors from Corel, although I could have just as easily done this part all in Aspire. I also want this to be kind of curvy as well. So I drew up the 3 vectors that I will use for the 2 rail sweep.
This wavy bend will make the word far more interesting to look at. It's the small details that add to the overall finished piece. A very small step to do, but well worth the pre-thought in the end.
Selecting the outside edge of the text boundary, I raised it up a little. And as I selected the "add" function when I was creating this component, it will get "added' to the base relief I created with the 2 rail sweep.
I selected the final text vectors and chose to slightly dome the tops of them. Not a lot, just enough so they're not so blah looking.
Back to my textured bitmap that I used on the word "TEXTURE". Might as well keep it consistent! I kept the height of the texture to around the same height as before. Around .180".

The final step is to trim it all up! I selected the outermost vectors and deleted any of the model outside of this.
Voila! Done. All in all, these steps only took a total of 3 minutes to do. That's what makes Aspire so great. And it was fun too!
I might go in on Sunday and cut these pieces on our Techno cnc. I am looking forward to figuring out the gearing to spin the upper portion.

Friday, 23 March 2012

Bringin on the Texture!

O.K. I'll admit it. Sometimes I get distracted. I snuck in some time to work on a project that I have been wanting to make for a while. As I have been infront of the computer lately, I decided to draw it up, with the intention of running it on our Techno cnc.

This will be a motorized piece that will live at the shop, but I will take to various training seminars I get to teach at.

 I just rendered it quickly for the blog, as I know what it will look like when it's finished. The bare vectors I drew up in Corel. I did it this way to allow me to use some of the shaping tools available to quickly shape the wonky edges. The main rock heap won't be cut on our Techno cnc as it will be faster to sculpt by hand. And because it needs to be hollow. I'm hollowing it out to allow me to put in a gear motor that will slowly spin the word 'texture' at the top of the sign.
Getting it to look awesome was done in Aspire.
I first created a shallow bend with the 2 rail sweep function. This will allow the relief to kinda bulge in the middle.
 I selected the outside vector of my design and raised it up to give it some additional thickness. Then I picked the two vectors that create the border for the text, and raised them up as a new component.
I just kept on moving along and raised the outline of the text base plate up as well. This will help define the text a bit more, and give it a more polished look.
And finally, the actual text. I decided to make the top of the text angular for a bit more interest. I don't generally go with an angle greater than 30 degrees, as Aspire keeps the exact angle all around each letter, which can look silly with too steep of an angle. True ISO form letters would have the angle increase, or decrease, depending on the width of the text. As this isn't a feature yet, I just keep the angle low, so it's less noticeable!
Finally, to add the magic of texture. I created a bitmap image in Photoshop awhile ago that I use for most of my bumpy textures. I imported this in, and coverted it to a component, with a bump height of around .180".

This I wanted to cover the whole block, so I don't need to do any trimming at all. I could use the text vectors to trim the texture away, leaving the letters clean and texture free...........but that would look poopy. After all, it does say texture!

 Using the very outside vector, I trimmed the texture away, leaving the final model ready to cut.
I will mirror this whole model, less the text, and apply them back to back. This way, the word 'texture' will always appear while it is slowly rotating. I'm quite happy so far. I am going to cut this with my trusty 1/16" tapered ball nose cutter on Saturday. I will post about modelling the other portions as I progress.
It's funny how goofing off from 'work' still leads to running our Techno cnc.

Thursday, 22 March 2012

Polygon understanding.

Keeping true to last nights post regarding using hexagon, or any other SDS modelling program, I am posting another video from Guerilla CG:

I am going to keep looking for more of these, as they would have helped me tremendously when I was starting

The Polygon from The Guerrilla CG Project on Vimeo.


Wednesday, 21 March 2012

Understanding Primitives.

I'm a slave to the computer this week. The shark was a ton of fun, but now I'm back in CG world creating some new models and signage. I really wish I could talk about all of our projects, but some places guard their stuff pretty ferociously!
I did find a good video on line last night that I thought I would embed in my blog. It's geared toward 3d modelling, as opposed to cnc. When I started 3d modeling, I had so many questions. The problem is I didn't actually know what my questions were!
This video is embedded from Guerrilla CG. The Guerrilla CG Project a non profit organization dedicated to teaching the fundamentals of computer graphics. It grows from the contributions of artists and technicians from around the world.
I will probably post a few more this week, as they are very explanatory, and most of them apply to any polygon-based modelling software.

Primitives from The Guerrilla CG Project on Vimeo.


Monday, 19 March 2012

Swim safely my lightweight friend

I worked on Saturday to get the teeth machined up for the shark dispenser. While they were cutting away, I used the time to draw up the 3" thick base that he would be mounted to.
The base was pretty straight forward, only a portion needed to be 3d machined. This was the tapered pocket that the foot pedal switch, to turn the machine on and off, will live in when it's not needed. I tapered it towards the outside edge, as well as put in a small trough to allow for water drainage if this guy gets caught out in the rain.

The underside of the base has a recess for the 3/4" plywood cut-out to sit into, and I added deeper pockets radiating inward so the machine can suck cool air in from around the base. Today I did the last little touch-ups and filling, he's now ready to ride the current out of our place. I'm hoping to be able to stop over at the hard-coaters shop and get some pictures of him all coated when he's done.

I need to send a thanks to both Bill Feasby, and Chris Kalian for getting us to work on this pretty fun job! This stuff really makes the difference between working and having fun!
I wonder what's next...........................

Friday, 16 March 2012

Gummy the shark!

Gummy due to the fact that the teeth won't be cut until tomorrow! Today was another 'just as planned' day. I really like these kind of days (aim low, and your never disapointed ;) I drew up the files for the cedar sign last night. We seem to have the only cnc router that isn't limited to 2d cutting. By this I just mean that we cut all the dimensional signage for about 5 local sign shops. This is very good for us! Sometimes I am just as happy to run the files, and let someone else do the finishing work. They needed the 2'X3' sign for today, so I let our Techno cnc buzz through that while I cleaned up all the seams on the shark dispenser. For a change, I really liked sanding this time. Normally it can be very boring, but I just kept moving forward.
He's looking stellar now. I got the bottom jaw all fitted and glued up, as well as the arms attached. I will finish the last of these seams on Saturday. He also has 2 small fins that pop out of his shirt sleeves. I'm going to leave these separate so they won't be a problem for spraying the hardcoat on. The only thing left for us on this is cutting the base plate, and adding the teeth. Because he's hollow from top to bottom for the machine to fit into, this whole thing only weighs in at 18 lbs!

I think he will make an awesome addition to the Ripley's Aquariums.

Thursday, 15 March 2012

I love it when a shark comes together!

Today, for the most part was very uneventful. I mean that in the best of ways. Sometimes I don't want any excitement on a short run job!
I finished all the cutting on the shark dispenser. Even the double-sided machining went exactly as planned. Increasing the step-over to 15% certainly helped with the run times, On average, I was getting a double sided file every 40 mins. There was a total of 28 files that needed running so I was happy to get it down to the 40 min mark.

He'll look a whole lot more awesomer with the tape removed tomorrow. I have been using clean clay as a filler on some of the seams so I dont have to deal with any shrinking, thus speeding up the time it will take to deliver him to the hardcoat stage. I'm getting more used to the size of him now, those sheets of styrofoam he's standing on are 4' X 4'.
Tomorrow I will fit the shoes to the body, clean up the seams, and get the arms glued on. I have a cedar sign to router first thing in the morning, so I was in a hurry to get all the parts done today. The sign can router away while I'm doing my best to finish him up. Which is good, because I'm running out of creative shark blog post titles.

Wednesday, 14 March 2012

Will it ever end!

All day was spent cutting pieces for the shark dispenser. Remember the final scene in Jaws where Roy Scheider shoots the dive tank in Jaws' mouth, causing the shark to explode into tons of pieces? That's kinda what it looked like today. Parts everywhere. Because I nested alot of the parts to get more yield, I wasn't able to assemble a lot of them due to the fact that they aren't being cut in any particular order. I managed to save all the double sided machining for last, so tomorrow will see that getting started. I did finish the head and neck section off today, but won't be able to finish the seams until the glue is dry tomorrow.

 The nice thing about building this in slices is that it allows us to make the head hollow. This is where the dispenser will be filled from. We will be cutting out a hatch that will have a lock installed to keep nosey parkers from getting into the machine.
 As per usual, the parts are now going to be coming of our Techno cnc faster than I can assemble them. I'm quite pumped about this job now, it's nice to see progress!

Tuesday, 13 March 2012

More Like Megalodon!

I knew the shark dispenser was big, but it wasn't until we started running the files on our Techno cnc that I came to grips with it. As I am the one who modeled this from scratch, I was very aware of the 74" height, but as pieces started to appear out of the foam, they did kinda take me by surprise! Enough to go back and check my measurements a few times.
This is the top of the lower jaw, you can see the 3/4" masking tape holding the slices together while the urethane glue dries.
I have decided to re-toolpath some of these files with a bigger step-over. I started at 9% in Aspire, but decided to jump it up to 15%. I have decided it will be faster to clean-up the steps with a sanding sponge than let the smaller stepover run for extended times.
I got the outer left and right sides of the head machined and assembled. I really like seeing something I've modeled in the computer, coming together in real life.
Tomorrow will be a long day, waiting for multiple sheets to be cut before I have enough pieces to start assembling.

Any way you slice it though, these are some big shoes to fill:


Monday, 12 March 2012

Slicing and Dicing Oxenham style!

Today I headed out to our styrofoam supplier to pick up all our sheets that we will be cutting the shark dispenser out of.  I actually had to do 2 runs, as I couldn't fit all 26 sheets into my Caravan at once. We ordered 3"- type 2 styrofoam. I went with type 2 for this job because it's going to get approx. 1/4" of urethane hardcoat sprayed all over it, and we may need hog out additional space inside to fit the dispenser unit it houses. Normally I would use the denser type 3, but that would just be adding useless weight considering the coating. By the time the order was ready, and I got back to the shop, it was already 5pm and I still had to cut out a small beer tap handle I modeled for a customer over the weekend. So the foam will fly first thing tomorrow. I did enjoy the time I spent last week, and weekend, working only in the computer, but the craving to make something real was gnawing away heavily by Sunday morning!
One of the most time consuming computer jobs was slicing the shark up into machinable slices. We have decent gantry clearance on our Techno cnc, but that's only one of the considerations when choosing the slice thickness. We are fairly limited on time for this job (story of my life!), so I'm going to use a modified 1/2" drill bit as a cutter. This will allow room for the cutter to rapid move above the material, as well as cut through the whole 3" in one pass, removing the time required for a roughing pass.
 Just a reminder of what the finished job will look like. The opening in the chest is for people to be able to see what's happening inside the dispenser. I do believe he gets a speaker installed into the roof of his mouth as well.

After most of Saturday, this is the shark exploded into the 3" sections, ready for bringing into ASPIRE!
As Aspire will fill in any undercuts when importing the pieces, it was very important to pay attention to how I was splitting it up. Some pieces will be split further in Aspire, and lots will have to be double sided machined to get all the detail.

This is an example of the arms and fins that I let Aspire slice up. One of the most usefull toolsets in Aspire, for this kind of work, is the "fit vectors to bitmap" feature. It  allows me to quickly, and very accurately, apply machining boundaries to the top and bottom of each piece, without killing myself by hand-drawing them in. Doing it this way drastically reduces machining times by having the cutter only cut the critical geometry of the part, not the whole thing. Anytime I can reduce unnecessary cutter movement, I reduce the time each part is on the machine.

On another note, I have been invited to teach some of my skills in Indiana in June. I am very excited!!! A fellow forum member, and Aspire user, by the name of Robert Jones will be holding a "sign camp" at his place and asked if I would be interested in showing some of our tricks methods. This is very flattering to say the least!
One of the neat things is that everyone who signed up for this camp will be receiving a 24"X24" HDU sign. I will be demonstrating some of the ways we finish our signs, and they will get to try out the techniques on their own custom pieces. So on Sunday I was able to finish up a design for Diane and Ernie Balch, They sent me some artwork, and mentioned they like to fish. So based on the information they sent, as well as knowing the finishing we will be exploring, I came up with this design that Robert will be cutting on his router for them.
 Simple and fun, I like it!


Wednesday, 7 March 2012

Shark dispenser

It's been a huge roller coaster ride at our place. The move was exhausting to say the least. I have been very lucky to be doing ALL computer work the last little bit. And by that I mean that as everything is still in a sort of chaos, sitting on a computer is just what I needed!
The Prana chair has been a game of start and stop with the files, so we haven't cut anything with that job. But there is 5 sheets of 2" HDU waiting patiently on the rack. We are moving a long waiting job to the front of the line. This is a 74" tall shark themed dispenser for a theme park. We are just doing the cutting and assembly, another local company will be spraying the hardcoat urethane. They get it in MASSIVE quantities, and have the industrial equipment to coat it with. This is a good mix for everyone.

 I'm going to cut it from 3" slabs of type2 EPS foam. I modelled this job a while ago, but he's only comming to fruition now. Sometimes things can move slooowly.

And as I love being in a creative work envelope, I always try and push my limits on what I'm doing. I was watching TV the other night and saw the Excel gum commercial. We didn't work on these, but the commercials are great.These are the ones with the little food guys that follow you around until you have a piece of gum. I've seen them before, but never really paid much attention to them. For some reason, last night they really stuck with me. So at 11 pm I decided I wanted to model a couple of them in Hexagon, and render them in a trial version of KEYSHOT rendering software. What a great, easy piece of software that is!

Long story short, I did some renders and was quite happy with both the models and the finals. Again, these are just personal projects to push some new skills, but they were fun!

Tonight I might comp them into some vacation photos. I'm having a blast!