Every take out robot quotation arrives as a single number, and the first thing a production manager does is compare it with the hourly rate of the operator it would replace. That comparison is wrong often enough to be worth a calculator. This is the one I use on the factory floor: six formulas, four steps, and a 12-month test that decides whether the investment stands up.

I am Mr. Chen, Technical Director at ROBOT (Ningbo) Intelligent Technology, working on practical molding solutions for global factories since the company was established in 2004. Our scope runs from hopper dryers and auto loaders through servo robot arms and central conveying to turnkey plant planning, and my attention sits on the three numbers that decide whether automation works on a shop floor: cycle time, uptime, and the specification that actually matters in production.

One point first, because it shapes the article. Our published prices are subject to change with supply and market factors, and we send an updated price list after you make contact – which is why this page is a calculator and not a price list. The payback calculation is something you can do on your own numbers before you ask for a price.

The Calculator in Six Formulas

The model has six steps and they run in order. The first three are arithmetic on your own data, the fourth prices the result, and the last two test the quotation against it.

Two things in those six lines come from us and everything else comes from your plant. The published take-out time of the model is ours. Your cycle time, your operator intervention time, your loaded labour cost, your part contribution and your demand are yours, and they are the inputs that decide the answer.

Step 1: Measure the Time You Actually Lose

Formula 2 is the one most payback models get wrong, because it assumes the machine was waiting. Stopwatch a hundred consecutive cycles and log the seconds an operator spends at the machine: walking over, picking, placing, safety checks, jam clearing. That is your manual take-out time, and it is usually longer than anyone on the floor thinks.

Then subtract the published robot take-out time for the model you are pricing. These are the minimum take-out times from the published SPRE specification tables:

Two cautions. These are published minimums, so best case at a set speed, not the average a cell will see with real parts, runners and regrind. And machine tonnage decides which model can reach the mould, so the tonnage-to-model mapping is fixed before any calculation starts.

Step 2: Turn Cycle Time Into Parts and Into Hours

Worked illustration, with the assumptions stated so you can replace them. Take a 30-second cycle with 5 seconds of manual take-out, one machine, two shifts of 10 hours and 20 operating days a month. Put the robot take-out at the published 1.7 seconds for the 700I class and the recovered time is 3.3 seconds per cycle, which takes the cycle to 26.7 seconds.

Formula 1 then gives 120 shots per hour before and 135 after, so Formula 3 returns 15 extra shots per hour. Formula 4 turns that into 9,600 extra parts per month across 400 run hours, and the operator time released works out at 3.3 seconds per cycle against 120 shots per hour, which is 0.11 operator-hours per hour run, or 44 operator-hours a month.

That last figure is the one most people miss. Three seconds of take-out time sounds trivial until it is multiplied by every shot in a month, and it is the line that turns a cycle-time argument into a labour argument, because 44 operator-hours a month is a measurable amount of attention that can be redeployed rather than removed.

Step 3: Price the Two Saving Lines Separately

Released operator hours are worth your loaded hourly cost, but only where the freed time has a defined destination. A plant that removes an operator and sends the work offshore has not saved anything; a plant that moves the freed time into inspection, packaging or a second machine has. Model this line as redeployed hours rather than headcount, because the first survives a conversation with a production manager and the second does not.

Recovered capacity is worth contribution per part, and only where demand exists for the extra parts. A plant already selling everything it produces cannot monetise a faster cycle – the extra shots become work-in-process inventory and the payback clock stops. Where the demand does exist, the extra parts are worth their contribution margin, not their selling price, because the resin and the machine time were going to be spent anyway.

Unattended running is the third line, and on many plants it is the largest. If the robot lets a machine run through a window with no operator on site, the value is that window multiplied by the value of the hours in it. That line needs its own safety design, because the robot interlock and the guarding are part of the investment, not an accessory to it.

Step 4: Run the 12-Month Test

Now put the quotation into Formula 6. The investment side is not only the robot: it is the robot plus end-of-arm tooling, installation and commissioning, safety guarding, mould-side changes, training, and the machine hours lost during installation. The saving side is Formula 5.

Then apply the test. If payback months come out below 12, the investment stands on its own within the year and the discussion moves to reliability, service and the next machine. If they come out above 12, you have three honest options: recover more seconds, price a higher-value saving line such as unattended running, or do not buy the robot yet.

Read that table as a specification you can hand to a supplier. It says what the automation may cost, before anyone argues about what it costs, and it is the fastest way I know to get a comparable quotation from several sources instead of several brochures.

Where This Calculator Breaks

Published take-out time is a floor, not an average. Any model that uses 1.7 seconds as the achieved time on your floor is optimistic by construction. Measure what the robot actually does with your part and your runner, and use that number in the second pass.

Changeover eats gains. A robot handling label feeding, vision, or a family of grippers spends time on changeover, and the take-out figure does not include it. On a high-mix plant the gain per cycle can be far smaller than the take-out difference suggests.

Uptime is not in the formula and it has to be. An operator who is replaced by a robot that stops is a worse outcome. Add the expected machine loss, the response time and the spares plan before you sign the number off.

Demand and process can both be the real constraint. If the resin, the mould or the cooling time is the limit, a faster cycle produces nothing, and if there is no order for the extra parts the capacity line is worth exactly zero.

What to Send When You Want the Numbers

Seven details let us return a written quotation and a model recommendation instead of a catalogueue: machine tonnage, current cycle time, measured operator take-out time, part weight and cavity count, shift pattern and daily output, whether confirmed demand exists for additional parts, and the destination market for documentation. Add the changeover profile, because gripper complexity is a specification question.

The published lead time is about 7 days for samples and 20 to 30 days for mass production, counted from the deposit and final product approval, and we can provide the certification and export documentation your market asks for, as set out in our published FAQ. Because a quotation is only useful against a specification, I would rather see your cycle time data than your target price. Send it through our contact page or to sales19@nbrobot.com, and read the published robot arm range so we can start from the model that matches your tonnage. If the cell is one part of a wider cell, our whole plant planning team works on the same logic upstream.

Frequently Asked Questions