Small Pneumatic Vice Design

I've recently changed my occupation from Engineer to Entrepreneur, yet what that means in my case is, I just have to do more quick engineering work, while balancing some other obligations, and often not have my work be checked by an outside set of eyes. Nonetheless, I love solving all the new problems by dream job has been giving me since day one, and today is no different. My business is starting off as a machine shop, which for those who don't know what that is, is basically a facility that makes often metal parts which are precision cut using industrial machinery from an original larger piece.

The issue we have been having currently, is the time it takes for the industrial machine to cut metal, and the "loading time" which is the amount of time allotted for in this case, a human being (CNC operator) to manually remove the finished part from the operation and load a new blank piece for the machine to start cutting the next consecutive batch.

The bottleneck comes down to physical constraints of our current system set up. We use a dual holding Kurt Vice, which is a very good vice as it provides over a ton of clamping pressure and can hold two pieces at a time. But in terms of practice in this day and age of ever higher competition... innovation is not only key, it is the only way to survive in this type of cut-throat business.

To increase productivity we were thinking of implementing a "Tombstone" which is a steel square prism which can rotate at precise angles and be held firmly. The advantage of using a tombstone in a 4th axis array is that you can load not only 4 tables with a very quick change between table, but you can also machine additional sides of the pieces that are tangential to the rotation of the tombstone thus reducing loading time significantly per part, and optimizing finished product within one running cycle. 

The issue is, we need a universal set up clamps that can be easily switched out for a multitude of parts. Ideally we would like to continue using the standard vice Jaw set up we currently use, however probably a single Kurt nice could be used per table of the tombstone, and loading as many parts is key to success in this business. Therefore, I wanted to see if there was a way to have small clamps which can hold parts very firmly, yet possible be released quickly to lower the loading time of removing finished parts and loading new material.

I was considering using a pneumatic air cylinder which in essence is a 2 way piston which can thrust a rod forward or backwards in an airtight cylinder by redirecting air pressure.

The way the pneumatic piston works is by allowing air pressure to fill compartments on opposite ends of a sealed piston rod. 

So I chose to model a relatively cheap pneumatic cylinder which has a large diameter bore to provide a lot of force with a small stroke length, since the jaws in essence don't normally have to open that wide to release the part. The length of the cylinder is also key to keep the vice compact, and able to fit neatly onto a tombstone array. I was also interested in a cylinder with pretty thick squared off stock, so that they can be machined and ground flat to ensure proper precision can still be held true.

An adapter plate can then be bolted on top of the cylinder which would then allow the bolting of a precision linear rail. 

Flat Crochet Mathematics

A friend of mine approached me with a very interesting problem where the intersection of many disciplines can come into play which would make way for an interesting exercise. She was knitting flat pieces of crochet, and noticed the fractal patterns that appear, and from the number of crochet examples she had in hand, she was experimenting with various techniques to see how the overall pattern would emerge. I myself didn't know much about knitting, but the mathematical aspects of the problem were very intriguing. There must be a method of breaking down the knitting process into a formula or set program, where a simple change of parameters can provide dramatic changes in the overall pattern.

After a brief google search I learned of certain terms used in the actual physical knitting of crochet, the chain, the simple crochet, and the slip stitch. The act of knitting these flat masterpieces of tapestry also always seem to emanate from the center. An interesting method of trying to define a simple algorithm of a pattern I thought could be used with cylindrical coordinates.

The cross can represent a single crochet, the oval a chain, and the dot a slip stitch

If the center of the tapestry can be considered the origin, then the generation of the pattern can emerge with the simple variables of angle, length from the origin, and the sequence of crotchet knots at the specified point on the flat plane.

A pattern can then be made by adding additional rules to each of the parameters, such as a formula which controls the radial length "L" to allow gaps based on it's position of angle, and how many concentric circles have already been made up to that point. The sequence of crochet parameters can also be connected to the formula of L and theta, to create patterns that are unique to create radial arms, of rows of concentric rings.

Once a set program could be made to show simulated results based on user input of those specific parameters, then one could see how the resulting patterns can emerge from scale and complexity.


Specific formulas for theta can be the following

2pi/No radial arms

The mathematical looping can be flattened by dividing up the 3D curves into individual curves that start at the very bottom to the very top.

Applying a Hessian to the parameterized curve can identify individual curves either sloping up or sloping down which can be quickly represented using simple 2D vectors.