What follows below is the construction of a basic vacuum table for use in thermal vacuum forming of poly styrene. In the first photo you see the basic supplies used to create a simple vac box, or table. You need to plan ahead and decide what size box you need, make measurements and compensate for the thickness of your material. In the display below I used 2" X 6" studs left over from a construction project.
Photo 2 shows the basic box form. Always have a flat, level place to work and keep your form square.
Photo 3, measure and cut a piece of pegboard to your frame.
Photo 4, measure and cut plant stakes, or 1" X 2" framing in place to support the pegboard.
Photo 5, Use a hole saw to cut the appropriate sized hole for your vacuum hose and fitting. At this point you may want to epoxy a PVC fitting in place to get a good fit. Nail a piece of plywood, or MDF to the back (Not Shown) and make sure to caulk around every crack, or seam.
Easy peasy, you've made a simple vac table. See the links for video.
http://www.youtube.com/watch?v=e5CGfoxnKaQ&feature=related
Here's a nice little video that always makes me laugh. You've got to love it, it's really so simple.... ;)
http://www.youtube.com/watch?v=yhajk_IDTUo&feature=related
There are literally dozens of videos on YouTube showing this process from the simple to the sublime.
http://www.youtube.com/watch?v=BVVE5EHzRnk&feature=related
Monday, June 14, 2010
Tuesday, May 4, 2010
temp
Monday, March 29, 2010
Day 17 "Compare Contrast Construct."
While finishing up the actual blueprints for the TOS Enterprise I want to shift the focus of this blog toward the actual construction of the new model and a few ancillary topics relative to construction. Additionally, I'll be comparing some of the existing prints with what I've been working on as well as comparing some of the differences between the physical models. After studying the screen captures, photos of the physical model, the Smithsonian dimensions etc... I came up with a profile the I feel confident is wholly accurate to the engineering hull, I then went back and compared that profile to the Sinclair and Casimiro profiles. I overlayed a section of Sinclair's cutaway to highlight the differences. I sized that profile up to the scale I'm working in and used it in the last post to come up with a conical form to create the primary section of the engineering hull using the same methods that I developed to create the 1/350th scale ship. This time around I used a finer, more flexible, higher quality mesh to begin construction. Using the simple compass that I discussed in the last post I cut out a flat for building up the upper and lower halves of the primary hull, this too is the same method I used to build the 1/350th, but again with higher quality, more substantial materials. When I built my first scratch built project I wanted to use the cheapest, easily affordable materials available to virtually anyone. I wanted to show that you don't have to have an entire facility full of high dollar, precision equipment to be able to come up with a reasonable representation of the Enterprise. The last time I used paper, tape, glue, fiberglass and Bondo. I'm essentially using the very same method with only slightly higher quality materials, this is in part due to time constraints and the size of the project involved. "Insanity: doing the same thing over and over again and expecting different results." Albert Einstein. I feel the opposite is also true, if something works the first time then there's no reason not to do it the same way, with the caveat that you learn from your mistakes and refine your process.
I'll come back and show more of this process later, however I will have to refer back to the construction of the original 1/350th ship. Unfortunately I was making progress and didn't have the time to take stage by stage photos.
I want to move into construction of a basic vacuum table and some basic electronics in the next couple of posts. In the mean time I've uploaded some more reference shots of the various incarnations of the ship.
Sunday, March 28, 2010
Day 16 "Phasors on Maximum."
I should note that the Day 1-16 designation only represents days of actual work and do not reflect running days on a calender.
Before I move onto to a basic explanation of phasors and how they applicable to this discussion I need to take the time to make a couple of corrections. In a previous post I stated that there were 16 ribs on the *exhaust vents" on the sides of each nacelle. In fact there are 17 ribs on these vents and the pattern is actually a corrugated pattern, this same pattern is reflected on the "S-Curve" at the rear of each nacelle. See applicable photos. I also stated earlier that I had not seen anyone correctly represent the lower sensor dome. I stand corrected. After looking over the Casimiro blueprints I find that he did indeed present an accurate profile for this parts. My apologies to Charles.
Onto to phasors... Essentially phasors are straight lines that follow along a center point of origin and point out to a point at highest amplitude of a sinusoidal waveform. This may not seem to be applicable to our discussion of transforming from 2 dimensions into three, but it is. Another way of thinking of phasors as one line in a right triangle. How we use phasors is really very simple. Earlier I said that we had to follow back down both angles on the engineering hull to a point of convergence. When these lines meet, or converge we establish the point of origin for our phasor. When we took our separate measurements for each section of the engineering hull cutaway and used the diameters to establish each circumference and finally used that as a linear measurement for each section we established the outer parameters for each conical, or tubular part. Now that we have our measurements we can use our phasor as a compass to get the arc for each conical. We don't need to do this for the tubular components.
Follow along with the pictures below and it will all become clear.
Since we are multiplying each diameter by pie (3.14), we're going to need a larger surface area than our original print profile. To keep things simple I used basic poster board available at any craft store. The first thing to do is to establish a center line mid way through the poster board. This gives us room to scale out our parts to whatever scale we choose to work with. After establishing our center line we over lay our profile and start plotting out straight lines to with reference to the original. As you can see I separated only the first three sections of the hull to keep things simple, the additional lines are referencing the pylon position. Upon establishing the points for each measurement on the rear most section of the hull use a rule to connect the points and draw a straight line, then us a compass from the point of origin following our phasor out to the next measurement and draw each arc. Now we have the shape of our cone that matches our profile and we've brought that section out into the 3rd dimension. In the following photo you can see that I created a simple compass using what I had at hand. Since I didn't have a large enough compass for the job at hand I took a 1"X2" strip of pine and used a drill bit and a drywall screw to plot out my arcs, this is the same compass that I used to create parts for the upper and lower saucer section. What you see is a piece of scrap poly styrene used to illustrate the method. The drywall screw made a nice scribe for cutting the styrene. There are a few that mock my methods, however, quoting Albert Einstein..... "Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction." ;)
Sunday, February 28, 2010
No posts for awhile.
I've got to get caught up on other things and have several projects in the works, so updates will be few, however I will pick up right where I laft off.
Keep on Trekkin! =/\=
Keep on Trekkin! =/\=
Day 15 "Constituent Parts"
Before we can get into explaining phasors and creating actual parts we have to break everything down into constituent components. Below is an example of breaking down parts of the whole into individual components. I've broken up the base engineering hull, into three separate parts, for the sake of this discussion. Note; though the center section is not a perfect cylinder it will suffice for this discussion. If we were going to machine this part we would use measurements directly from the profile.
We will come back later and add the addition cylinders inside the deflector cowl as referenced by Charles Casimiro's prints and other data.
We will come back later and add the addition cylinders inside the deflector cowl as referenced by Charles Casimiro's prints and other data.
Saturday, February 27, 2010
Day 14 "Revenge of the Arc Phasors"
.... Or, "Return of the 3rd Plane."
In a previous post I explained how to turn a two dimensional conical shape into a three dimensional cone, however, we have to build on that information and remember that we are no longer dealing with just a 2d object. when we are taking a 2d object and transferring it into a 3d object we have to consider the z axis and how that effects our shape. Since we are using the diameters of the different sections of the profile of the engineering section we have to think about how we are going to compensate for the additional dimension. In advanced mathematics, especially math that deal with expressing electrical sine waves we work with phasors. This discussion is not going to get into the depth of phasor math, but we can learn a simple lesson involving phasors and use them along with trig and a simple compass to modify our previous discussion, expand on it and create the entire engineering section. Don't get to bogged down with the terminology and don't let it intimidate you. I'll explain graphically what I mean here.
I've some up with a final engineering profile, see below. We are going to use this for the rest of this blog. I'm confident that it's accurate.
In the second photo below I've divided the engineering hull into additional sections so the we can recreate the entire hull. We'll be splitting the hull up into sections, building each section with card stock and assembling them into a whole. Before we move on to that part we need to follow along the top and bottom of the hull and take those lines back to the point of convergence. From the point of convergence we could use a really big compass to cut an arc between certain points after we do the math for each diameter from the previous post.
In the next post I'll show show what I mean graphically.
In a previous post I explained how to turn a two dimensional conical shape into a three dimensional cone, however, we have to build on that information and remember that we are no longer dealing with just a 2d object. when we are taking a 2d object and transferring it into a 3d object we have to consider the z axis and how that effects our shape. Since we are using the diameters of the different sections of the profile of the engineering section we have to think about how we are going to compensate for the additional dimension. In advanced mathematics, especially math that deal with expressing electrical sine waves we work with phasors. This discussion is not going to get into the depth of phasor math, but we can learn a simple lesson involving phasors and use them along with trig and a simple compass to modify our previous discussion, expand on it and create the entire engineering section. Don't get to bogged down with the terminology and don't let it intimidate you. I'll explain graphically what I mean here.
I've some up with a final engineering profile, see below. We are going to use this for the rest of this blog. I'm confident that it's accurate.
In the second photo below I've divided the engineering hull into additional sections so the we can recreate the entire hull. We'll be splitting the hull up into sections, building each section with card stock and assembling them into a whole. Before we move on to that part we need to follow along the top and bottom of the hull and take those lines back to the point of convergence. From the point of convergence we could use a really big compass to cut an arc between certain points after we do the math for each diameter from the previous post.
In the next post I'll show show what I mean graphically.
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