How to Choose the Right Palletizing Robot Arm for Your Factory

Every week I talk to at least one factory owner who's already looked at three or four robot brochures and still doesn't know which one is actually right for their line. That's not because the information isn't out there — it's because most spec sheets are written to make every robot sound like it fits every job. It doesn't work that way. In my complete buying guide to palletizing robot arms I covered the big picture — what these robots are, what drives price, how to think about ROI. This article is narrower and more practical: it's the actual checklist I walk through with a customer before we recommend a specific model.

Start with the product, not the robot

I said this in the main guide and I'll say it again here because it's the most common mistake I see: buyers start by comparing robot brands and specs before they've nailed down their own product data. Flip that order. Before you look at a single robot, write down:

• What you're moving: carton, bag, box, drum, case, or something else

• Weight per unit

• Dimensions (length × width × height)

• How fragile or irregular the product is

• Your target line speed (units per minute or hour)

Everything else in this guide builds on those five answers.

Step 1 — Calculate your real payload requirement

This is where most sizing mistakes happen, and it's an easy one to fix. Your payload requirement isn't your product weight — it's your product weight plus your end-of-arm tooling weight, plus a safety margin.

For example: a 20kg bag with an 8kg vacuum gripper needs at least 28kg of payload, not 20kg. Add a reasonable safety margin and you're realistically looking at a robot rated for 30kg or more.

Here's how our own SZGH-B Handling Series breaks out by payload, so you have real numbers to work from instead of guessing:

One thing worth flagging: don't size to your average product weight. Size to your heaviest expected unit, including any packaging variation across suppliers or seasons. I've seen customers undersize because their "standard" 20kg bag occasionally arrives at 23kg from a different supplier, and that's enough to overload a robot at the edge of its rated capacity.

Step 2 — Match reach to your pallet layout, not just your product

Reach determines how far the robot's arm can extend from its base — and that number decides your floor layout more than almost anything else. A robot with generous reach can sometimes serve two pallet positions from one fixed base, instead of needing two separate robots.

We did exactly this for a customer stacking 1.1m × 1.1m cartons to a 1.6m stack height: because our B1850-3C-4 has 1,850mm of reach, one robot handled two pallets side by side. That single decision cut their equipment cost roughly in half compared to a two-robot layout, without touching cycle time.

Before you finalize reach, measure (don't estimate) these three things on your actual floor:

• Distance from your infeed conveyor to your farthest pallet position

• Whether you need single-pallet or dual-pallet service from one robot

• Overhead clearance, especially if your building has lower ceiling height near the line

Step 3 — Match the robot (and gripper) to your packaging type

This is where product type drives the decision more than payload does.

Cartons and boxes are the easiest case. Flat, uniform surfaces work well with vacuum grippers, and if your cycle time demands it, a multi-cup vacuum head can lift more than one carton per cycle. Our B1850-3C-4 and B2300-E-4 cover most carton and box palletizing jobs, split mainly by weight and stack height.

Bags — feed, cement, fertilizer, chemical powder — are the hardest case, because bags shift shape mid-lift and a poorly designed gripper tears them. When a chemical raw-material customer needed one robot to run an entire bag-feeding line, we specced our B2100-F-4 at 100kg payload specifically for this kind of job. If you're palletizing bags, don't just ask "what's the payload" — ask your supplier to walk you through the gripper design for irregular, soft-sided loads specifically.

Drums, ingots, and other rigid super-heavy loads need serious payload headroom. Our B3100-G-4 at 165kg payload came out of a real request from an aluminum ingot casting shop that needed to unload hot, heavy ingots without putting a worker next to that risk every shift — the kind of job where automation isn't optional so much as overdue.

Step 4 — Decide if you actually need six axes

Nearly all straightforward palletizing — flat pallet, repeating stack pattern — only needs four axes. That's why every model in our Handling Series, from the G1000-B-4 up to the B3100-G-4, is four-axis: simpler mechanics, faster programming, lower long-term maintenance cost.

Six-axis only earns its higher price when you need complex wrist orientation — picking product at odd angles, combining palletizing with sorting or inspection, or handling product that isn't presented to the robot in a consistent orientation. If a quote includes a six-axis robot for a flat-pallet job, ask why. Sometimes there's a real reason. Often there isn't.

Step 5 — Check your line speed against the robot's real cycle time

Line speed compatibility gets overlooked more than it should. A robot that's correctly sized for payload and reach can still be the wrong choice if it can't keep pace with your upstream conveyor. Ask your supplier for cycle time at your actual product weight and pick distance — not the fastest theoretical number on the spec sheet, which is usually measured at minimum payload and shortest travel distance.

If your current or projected line speed is genuinely at the edge of what a single robot can sustain, that's a layout conversation, not just a robot conversation — you may need a second unit or a different infeed design rather than a faster robot alone.

Step 6 — Confirm safety and compliance requirements up front

If you're selling into Europe or any market with strict safety requirements, confirm CE compliance, safety fencing, light curtains, and interlocked gates before you finalize a model — not after. We publish our certifications and patents openly for exactly this reason: it should be something you can verify, not something you take on faith from a sales conversation.

A simple selection framework you can use today

Put these six answers side by side and most of the guesswork disappears:

1. Heaviest unit weight + gripper weight = your minimum payload requirement

2. Farthest pallet distance from infeed = your minimum reach requirement

3. Product type (carton, bag, drum) = your gripper design requirement

4. Orientation consistency = four-axis vs. six-axis

5. Required units per minute/hour = your cycle-time requirement

6. Target market compliance rules = your safety package requirement

If you send us those six answers, we'll tell you which model in our handling and palletizing robot arm lineup actually fits — and if none of them do, I'd rather say so than force-fit a sale.

Request a Custom Palletizing Robot Arm Recommendation — send your product weight, size, and line speed and our engineering team will respond within 24 hours.

Fannie Chen is CEO of Shenzhen Guanhong Automation Co., Ltd. (SZGH), founded in 2013 in Shenzhen, China. SZGH's robots and CNC systems are in use across 126 countries. Product specifications referenced in this article are drawn from SZGH's published SZGH-B Handling Series technical documentation.