Punch Press Estimating and the First CNC Punch Press

Punch press estimating is a very common way to put wholes in sheet metal parts. Punch presses have been around since 1955.  The Wiedemann Machine Company was established in Philadelphia, Pennsylvania in 1916 and over the years developed and produced a variety of machines. Wiedemann unveiled the world’s first NC turret punch press at a machine tools show in Chicago in 1955.

PunchPress

CNC punch presses are very common and still outperform laser in many scenarios in speed.

Punch press formulas for estimating usually ask for number of hits, tools and thickness of material.   You can see a sample formula below which can be changed based on your machine capabilities.

PunchPressFormula

((onehit*.0008*((thickness*2)+1))+(nonstand*2*.0008*((thickness*2)+1))+(perimeter/668*((thickness*2)+1))+(((length/4590)*2*tools)+tools*.05))

Laser Cutting Estimating

Laser cutting sheet metal parts is very common in the industry.  Not too many years ago laser cutting was new and estimating the costs was new.  Now, laser cutting estimating has become much more accurate through software simulations.

The simplest way to estimate laser cutting time and material is using the actual laser programming software like Metacam by Metamation.   A flat DXF file can be loaded into the software and the software will accurately estimate the laser time based on a simulation  cutting the part.  The part can actually be nested giving you a more accurate time cutting the parts from a nested sheet.  Once the estimated time has been calculated you would enter that time into the cycle time of the nesting software to calculate your costs.  The Gas, Depreciation, Utilities would be included in your overhead rate of the machine which in turn gives you the cost to run the part.

There are other situations where you do not have a  good DXF file and you must estimate by estimating the number of inches, pierces, cut speed, etc.  The screen shot below shows where you would create an a formula and use the formula to enter values.  The formula would have to be customized for your specific machine and manufacturing process which in turn brings consistent estimates.

q1

Lastly, a calculator can be created to assist you in calculating the number of linear inches of cutting as shown below.

q2

There is a nice article here.

http://www.thefabricator.com/article/plasmacutting/estimating-your-cutting-costs

Saw Operation Standards

The standards for estimating saw operations includes both the actual sawing operation and the setup of the jig, clamps, etc.  The times below are in seconds.  These process times may change based on the machine and if its a manual process, etc.  In your software you should enter the different processes into the saw operation with the standards which you determine are correct for your business.   ERP Software for the manufacturing business should be able to calculate the cycle times once you enter your standards into the system.saw

Process Seconds
Brush Chips Small 7
Burr, Inch 12
C Clamp Small 10
C Clamp Large 20
Cutting Oil 2
Feed 3
Guard Remove 6
Small Unload/Load <12 Inches 5
Manual Feed Stock 10
Oil Part 5
Start/Stop 2
Visegrip Wrench 3
Large Unload/Load >50 Inches 30
Air Blast 5

The cycle time of cutting is more dynamic based on the material type and cut length.  There are also automated saws which you program in the different cut lengths required and the automated system sets the gauge in order to optimize the material usage based on the requirements.

In order to calculate the cycle time based on material you would use a formula as shown below

(Material Type Feed Rate) * Number Of Inches Of Cutting.

If the material cut speed was 30 inches a minute and you were cutting 60 inches, the total time would be

(1/(InchesPerMinutes))*(Cut Length)

(1/30)*60 which gives you 2 minutes of cycle time.

Engineering Standards For Estimating

Process Automation on the Gears.Engineering standards for estimating is critical in order to come up with a consistent way of quoting.   Standards are based on time and not dollars because shop rates are different based on each individual company.  Standards are different based on machines and skill which are relatively consistent.

Engineering standards shown are for the metalworking industry and can be adjusted based on your machines and skill level.  Software has improved greatly in the last few years with software from vendors such as Metamation Inc., Sigmanest  and others.

Sheet Metal parts take about 20-60 minutes to program or 3 minutes per 1 minutes of machine time.  CNC Lathe parts take about 20-60 minutes to program or 10 minutes per 1 minute of machining.  Machining Center takes 4-40 Hours or 30  minutes to program 1 minute of machining time.

Tool design for fixtures, drill jigs, welding jigs, etc has been approximated that the manufacturing time and cost will be 2 times greater.

You should create a spreadsheet for estimating that uses the standards shown or use an estimating software like QuoteIt! from MIE Solutions to enter the formulas which best match your requirements.

http://www.mie-solutions.com

Estimating Engineer Tasks

Mie Solutions Estimating Engineering

The estimating process is just that, its an estimate or an educated guess.   Companies many times will add to the beginning of a quote a process step called Engineering.  Engineering can mean many things including

  • CNC Programming
  • Design Work
  • Creating Solid Models
  • Creating Prototypes

During the estimating process it is key to include these costs into your quote.  Things to consider is this charge can be either amortized into the unit costs or as a separate charge.  The nice thing about amortizing the costs into the piece price is that a repeat job your profit will go up because this tasks has already been complete.   A separate charge has the advantage of lowering the price to the customer for future job orders which may give you a pricing advantage in the long run.

Hourly cost for these engineering tasks need to be taken into consideration based on the cost of the employee completing these tasks.

Lastly, a key consideration if you do lots of engineering work is becoming a partner which gives you a head up on your competitors.

Take a look at an ERP system that handles engineering tasks at

www.mie-solutions.com