If you are a backyard artist or an innovator that is looking to have a machine shop craft the parts you need, you don’t want to just call up any old shop in the phonebook. In fact, there are a few things you should consider before you ever pick up the phone. By taking these things into consideration, you’ll be assured that the parts you order align perfectly with your project.
Tolerances are going to be your first consideration. If you are not familiar with the word, this simply means to the degree of preciseness you need the part engineered to. For example, a tolerance of +/-.005 is going to be more precise than +/-.002. Depending on the project you’re working on, there are needs for different levels of tolerance. A backyard project won’t require you to specify these tolerances. This means simpler tools, such water jets, can be utilized to machine the part. However, a new handheld tool may need to have specific tolerances set to ensure it works properly. This requires more custom CNC machining, which comes at a higher price. You should have your tolerances in mind before contacting a machine shop.
After you figure out your tolerances, you need to figure out the level of surface roughness you’re comfortable with. This is measured at a microscopic level as the peaks and valleys of a specific surface. The lower the roughness of the surface, the higher the cost of the machining is going to be. This is another factor that depends on both your quality standards and your budget. Most projects in the economical range are set at RA125. Products that are required to be more polished are set at RA16 or lower. Be sure you know your roughness or at least understand the numbers before you call a shop.
Next up is the material in which you need to use for your project. A consideration in this area needs to have multiple considerations. These considerations include, what the product will be used for, the initial price of the material, and the cost of machining the material. It’s important to note that different materials take various amounts of time for machining. For example, steel takes three to four times longer to machine than aluminum. This means a higher bill for machining with steel over aluminum. However, the initial price of steel is much less than aluminum. You need to take the materials into consideration from different angles and decide on which is going to be the most cost-efficient for you.
Tolerances, surface roughness, and materials are just some of the multiple things you need to consider before calling a machine shop. You want to get as much detailed information put together into a plan ahead of time so you are clear on what you want. This will help you significantly as when you call the machine shop you’ll be able to make more informed decisions about the process your product will go through to come out with perfection.