Byron Woodruff / Paint Trix Inc.

Putting Together the Drawings In our last installment in this series we had sent off a New Product Press Release. In a few weeks the leads would begin to flow. It is now time to begin the complicated task of setting up for a production run on our new tool. First, we need drawings. It is now common practice for manufactures to "out source" volume machined parts. There are companies (machine houses) who can produce the parts much cheaper when all the overhead figures are carefully looked at. These companies specialize in certain areas of manufacture (CNC Screw Machine, CNC Milling, Die-Casting and Injection Molding shops). Because they specialize, and concentrate on high volume runs, they are far more cost effective than trying to do the same work "in house." These companies manufacture "to print." They often have little idea what the part is - or what is for. Your drawings must be accurate. What ever you ask for will be reproduced - in volume. Your drawings had better be right.

During the prototyping process much of the design (sizes, tolerances, etc.) is done on scrap paper - quickly sketched dimensions - or none at all. This is fine for prototype work because much of the design can change during the machining process - often you see a better way while you are working "on the fly." So now you start to round up all those scraps of paper. You get your calipers out and measure the prototype carefully. You get out your hardware catalogs to be sure of specifications and tolerances there. If plating is involved, you refer to those charts as well, because plating increases the size of the parts.

Putting Pencil to Paper Virtually all drawings today are done on computer. They are called CAD/CAM drawings. Virtually all machine houses also accept traditional drawings (pencil drawn and later photocopied in a process known as "blue line"). What you end up with are what we all know as "blue prints." There is an art to sketching drawings. There are certain conventions that must be followed in order to minimize any questions or ambiguities in the machining process. A hand-drawn set of drawings can be a beautiful thing - much more interesting to the eye than computer generated drawings. In either case, the dimensions must be absolutely correct. The computer has no more idea than the pencil what you are drawing - nor does it care. This is a 100% human activity. You make all the judgments.

Drawings can (and often do) take longer to make than the original part itself. A tool that was made over the weekend can take a week to get on paper. Each and every part of the tool are drawn on individual "sheets." A simple tool can have a dozen sheets.

Will They Fit Together? There needs to be careful collaboration between the draftsman and designer/inventor of the tool. No machine can make a part that is EXACTLY the right size. It will always be a little bigger or a little smaller than what you ideally wanted. You must give the machine houses "tolerances" in your drawings. You must allow for parts that will be coming in a little bigger or a little smaller. In your drawings you call out these tolerances - such things as +/- .003. This means that you will accept a part that is as much as 3 thousandths bigger, or 3 thousanths smaller (about the thickness of a human hair). The tighter you want the tolerances (closer to perfect) - the higher the cost. +/- 3 thousandths is typical for most general machining.

Here's the problem: If one part comes in at .003 over and it mates with another part that comes in at .003 under the parts won't fit. You have to allow for this with all the interconnected parts. You worry about this. Yes, you want a tight fit on everything. You want precision, but there is a fine line between precision and parts that won't fit together. It's like pieces of a puzzle. You must anticipate and allow for the interconnectedness of the whole. You must get these numbers down on paper. No machine house will work with someone who can only offer such vague instructions as, "Just make sure they fit." The responsibility is yours, and yours alone.

Sending Out the Drawings After you have checked and rechecked again all your numbers you send your drawings out for "quote." The machine house will look over your drawings and give you a "part price" on what it would cost to reproduce these parts to your specs at different levels of volume. Often there will be a question or two...or three concerning some aspect of the drawing that must be clarified. Many times they will call if certain changes are acceptable to improve productivity on their part. Example: If you let us do XXX we can make that part much faster (as in cheaper). You listen and often have to end up telling them the reason the part was designed the way it was. With experience, you learn the manufacturing process. What can and can't be done - what is the most efficient way go. A good designer has this in his mind from day one of the prototyping process.

Serious Decision Time The key to any profits in manufacturing is efficiency. In every case, the more parts you make, the cheaper they will be. Making only (100) sets of parts costs the machine house nearly as much as making (500) sets because of the setup times involved and "dialing-in" the machines. You have to commit to a higher number. Typically, these numbers are in the 1000-2500 piece range. There is a drastic price reduction when the numbers increase - as much as 75%. This is where your margins come from in manufacturing. To make a profit on your tool, you will have to order a lot of parts. You have no choice. It's all or nothing. You make this call based on all the marketing information you have put together to date. You do not know for sure - you never can with a new tool. You are gambling - and it's scary when it's tens of thousands of dollars on a single roll. You suck up all the courage you have and place the order. You remind yourself, "This is what I do for a living."

Waiting and Wondering Generally, it takes 4 - 6 weeks between when you place the order and you see the parts. This is a VERY long time for the designer/inventor. Many sleepless night folks - lot's of second guessing. If you drink or smoke - you do a lot of both during this period. Always on your mind - "Will the parts fit? Did I dimension something wrong? Hell...WILL THE PRODUCT EVEN SELL!" Take it from me, you can feel awfully alone in this big old world during this period. There is some comfort in designing or contemplating the simple assemblies required for assembly - but not much. You really need to get the parts first.

The Parts are Here! Do you want to see two REALLY nervous guys? You should be there when the first set of parts are delivered. The Vendor (machine house guy) and the designer both as scared to death. I mean it. The Vendor is afraid he may have done something wrong and the parts will be rejected. The designer is afraid the either he called out something wrong in the print, and/or the parts won't fit. If something is wrong, time and money will be lost. It will take another 6 weeks to get parts. Usually, the vendor makes the first move and cuts open the box of parts. In every case, I have found they wanted to talk during this process. He wants to explain this or that - you rarely hear what he is saying. Your total focus is on the parts. You carefully pick up a couple you were especially worried about and see if the fit. In 100% of my experience, they do. The relief from all the previous anxiety is hard to describe. The parts are beautiful. Much better than you could ever do by hand. Your "baby" is honestly alive. Everyone is happy - for a moment or two anyway. You have to sign for the parts. Your eye wanders to the bottom of the invoice and the amount due. "Oh my god...I hope I can sell all these," you say inside your head.

After the Vendor has left, you take the boxes back to the assembly area. Time to spend a few quiet moments by yourself. You look over the parts carefully. A lot goes through your head - key moments in the past - concerns for the future. You realize the full scope of this "birth." Your "baby" is now twins - and then some. You quietly wonder if you will be able to find a home for all of them.

Part 4 - Marketing - Raising your Child