Monday, June 13, 2016

CNC – Support Infrastructure 2

7:36 AM Comments 0

In this entry, I want to look at the final infrastructure items related to setting up our CNC machine. Most of these items were quite inexpensive compared to the punch list we looked at in the first installment, but they can have just as big of an impact on the the efficiency of your CNC machine.

LAYOUT

Prior to purchasing the CNC machine, we had the sliding table saw in the middle of our 10,000 square foot shop, with the edgebander, dado table saw, and line boring machine close by. Once the parts were completed, we would haul them to the far bay of the shop where we would drill the drawer parts, assemble the boxes, and stage for install.

Initially, we were planning on putting the CNC machine close to the sliding table saw. Why? I don’t know…just because. Instead, we slowed down long enough to think about the most efficient flow of material and parts through the shop, and decided to move all the cabinet production to the far bay of the shop. The far bay is a large rectangle with garage doors at each end. This new plan would allow us to receive and store sheet goods at one end, cut, edgeband, and assemble boxes in the middle, and load finished cabinets out the other end.

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Here is a picture of the our cabinet space. We load the sheets where the picture was taken, cut out on the CNC to the left, edgeband the parts on the right, build the cabinets on the other side of these machines, and load out the garage door in the distance.

This was one of those decisions that seems so obvious in hindsight, but early on in the process, it was not even on our radar. In order to have the CNC in the middle of the shop, where we were initially thinking of placing it, aisles were going to be constricted, material transport and storage was going to be difficult, and parts were still going to need to be hauled to the far bay for assembly. Why it took us so long to abandon this idea and look at alternative layouts, I don’t know, but I am sure glad we did.

MATERIAL STORAGE

With the workflow all laid out, it was time to upgrade our sheet good storage. For the past six years, we have used a simple A-frame to store melamine and plywood. This was adequate in the early days, since we didn’t use that much material, but as we have grown, so has our appetite. Our A-frame rack was being overwhelmed with sheet goods, both full and partial, and it was a major downer if the sheet you needed was buried behind the 15 sheets that just got stacked in front of it. It was time we grew up and graduated to a horizontal storage rack.

I immediately headed to Craigslist, and what do you know, a buddy of mine was selling the exact kind of storage rack I was looking for! A check was written, parts were loaded, and smiles were plentiful!

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The rack came with three levels of storage, which, currently, is enough for us. We use the bottom and middle levels for 3/4″ and 1/2″ white melamine (the only sheet goods we inventory), and the top level for extra full sheets. Other than white melamine, I try to keep our plywood and melamine down to a minimum by only ordering only what we need for a job. If needed, I can always add another row of storage, but for now, we are good!

MATERIAL HANDLING

Unloading material from the delivery trucks has always been a bit of a pain for us, since we do not have a forklift. Until recently, we have never even ordered enough material to justify a forklift. We are now busy enough that one would be nice, but there are so many other places vying for our cash that a forklift is pretty far down the list. Instead, we use the metal frame cart you see in front of the material rack in the above picture. Across the street from our shop is a helicopter pilot, and this cart was sitting outside of his shop for weeks. I asked him about it, and he said it was used to move around a helicopter, but now it was not needed. For $250 it was ours! Its 3’x8′ footprint, combined with the beefy 4″x4″x1/4″ steel tubing, and 8″ heavy duty wheels, make this a perfect cart for transporting between the delivery truck and the shop.

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The final piece to the workflow puzzle was a method to easily move sheets from the storage rack to the CNC machine. We have been using two of these metal frame tables for a few years as assembly tables, but realized that by welding on some heavy-duty casters, it would make a great mobile table/cart. We added the strongest 3.5″ casters we could find, which brought the height of the cart to 1/2″ above the spoilboard of the CNC machine. Now we load up 10+ sheets and roll it in front of the machine where one guy can easily load the sheets as needed.

The items discussed here is where I spent most of my mental energy during the pre-CNC arrival planning process.  The previous items, power, dust collection, and compressed air, were much more clear cut, whereas shop layout, storage, and material transportation are more relative and will vary from shop to shop. My solutions will be different from yours, but the main issue is to take the time to figure out the best layout for your shop. If you do, it will save you a lot of frustration and work later on down the line.