How We Price A Part │ Reducing The Cost Of CNC Machining
Analyzing The Job
When it comes to the question of pricing small quantities vs. volume, the fixturing or workholding needed, coupled with setup or setups is often substantial. Certain parts may require more than one machining application. In the interest of quoting a fair CNC machining price, we have to think about setup time versus part quantity.
Material & Part Design
The staff of PF CNC Machining deals with a wide variety of materials and has experience with how these materials react using different tools so far as feeds and speeds. Even weather conditions may affect the part outcome. Choosing the material that is most suitable for the job could significantly minimize unexpected delays. If we see an opportunity to eliminate an aspect of the part that could lower the machining cost, we would ask if the part design could be modified.
We have been asked to quote parts where the setup includes making a fixture in order to hold the part. Making the fixture could take as little as a few hours or sometimes a few days depending on how complicated the part is. The combination of the setup and fixturing along with whatever tooling cost to be incurred is what we call Upfront Cost.
If the work piece moves while being machined, the high tolerances of the part will be compromised. Maintaining a desired position throughout the force of cutting ensures a precision part. Machining a fixture or workholding devise may be required in order to complete the final part.
There is no universal system that holds all stock equally. In advance, we design and machine jigs, jaws, cradles and more in order to manufacture high tolerance parts. Our holding designs distribute the holding pressure equally to avoid dents on the part and retain the part’s overall accuracy.
PF CNC Machining also looks at parts that require multiple machining operations to anticipate the amount of workholding components needed to complete the part.
Sometimes a part needs to be held after the perimeter of the part has been cut or partially cut. Therefore all parts wouldn’t have the same shape and/or size during all the different steps of the CNC machining manufacturing process.
Once we set up, make the fixtures, and verify that the part runs as expected, the cost of the first part may seem exorbitant. However part production at that point, where all of the planning operations have been completed and tested, is when the price break begins.
Example of Cost Breakdown
If a part takes 12 hrs to get to the point where you can run 1 part and your shop rate is $80 per hour hypothetically, then your cost for that one part is $960.00.
After finishing that part you have come to the conclusion that you can run the part every 5 minutes. This would mean that you could run 12 pieces in one hour. If you add that one hour (to run those 12 pieces) to the 12 initial hours, you would have worked on those parts for a total of 13 hours.
For 13 hours at a hypothetical shop rate of $80.00 per hour, that would be $1,040.00. When divided by 13 pieces that would be $80.00 per piece. But if you were to make 60 pieces it would take 5 hours to finish and it would cost a total of $400.00 for those 60 parts plus the initial $960.00 the total cost would then be $1,360.00 or $22.30 per piece. You can now imagine how the price per part will significantly continue to decrease with the more parts you make.
If you have a machining job and you need it fairly appraised, do not hesitate to reach us at: