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...........................
8)
JO

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.
8)
JO

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.
8)
JO

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!
8)
JO

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:

8)
JO

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!

8)
JO