Small vs. Large Caterpillars for Fine Wire Medical Braiding: Which One Is Right for Your Catheter Braiding Machine?
In medical device manufacturing, precision braiding of ultra-fine wires is critical. Even small differences in caterpillar selection can affect catheter performance, safety, and production throughput. Choosing the right caterpillar puller—small or large—can mean the difference between a flawless braid and costly rework.
MMBT by Metro CAD offers horizontal and vertical fine wire braiders from 3 to 300 carriers, designed to handle everything from ultra-fine wires to structural catheters, ensuring precision, versatility, and consistent production quality.
💡 Highlight: Ultra-Fine Wire Capability
11-Micron BenderWire Braided on an Unmodified MMBT16CHFWB Braider
- Wire thickness: 0.000433” (thinner than 1/7 of a human hair)
- Braided without any machine modifications, demonstrating the precision and versatility of MMBT’s small caterpillar
- Ideal for neurovascular catheters, guidewires, and other ultra-fine medical device applications
✅ Small caterpillar X/Y adjustability allows precise tension and positioning along the braid track, ensuring consistent braid quality even on the most delicate wires.
MMBT Caterpillar Options: Small vs. Large for Fine Wire Braiding
MMBT provides two caterpillar puller sizes to match different braiding applications:
- Large Caterpillar: Belt size 2” wide × 18” circumference
- Small Caterpillar: Belt size 1” wide × 10” circumference
The small caterpillar is ideal for ultra-fine delicate work, such as 11-micron BenderWire 304NX stainless steel wire (0.000433”, thinner than 1/7 of a human hair), which was braided on an unmodified MMBT16CHFWB braider. It is best suited for fine wire ranges from 0.000433” to 0.002”. Its X-axis (forward/back) and Y-axis (left/right) adjustability allows precise centering and repositioning along the braid track, extending belt life and improving accuracy.
The large caterpillar provides a longer belt contact area, offering steady pulling force and grip, making it ideal for thicker wires, larger cores, or long production runs. The large caterpillar adjusts only along the X-axis (forward/back), providing stable, consistent pulling over the entire braid length.
Benefits of Small Caterpillar Braiders for Fine Wire Medical Braiding
Precision and Responsiveness
✅ Fast tension adjustment – Keeps braid angles consistent on ultra-fine wires.
✅ Lower risk of material deformation – Reduced contact area prevents flattening or imprinting.
✅ Lower inertia – Ideal for wires 0.000433”–0.002”, avoiding over-damping or stretching.
Compact Footprint for Labs and Prototyping
✅ Takes up less machine space, perfect for R&D, prototyping, or tight floor layouts.
✅ Maintains uniform braid coverage for neurovascular catheters and micro devices.
Benefits of Large Caterpillar Braiders for Production and Heavy Wire
Stable Pulling for Catheter Braiding Machines
✅ Stronger grip – Larger belt surface reduces slippage at higher tension or speeds.
✅ Smoother pulling – Minimizes micro-variations in pitch length and braid angle.
Handles Larger Wires and High-Volume Production
✅ Works well on thicker catheter shafts, introducers, balloon shafts, and structural catheters.
✅ Supports more carriers and heavier wires.
✅ Pressure contact surface area is bigger on the large caterpillar, extending belt life.
Choosing the Right Caterpillar: Rule of Thumb
- Small Caterpillar → best for delicate fine-wire braids, tight tolerances, small-diameter catheters, and R&D/prototyping.
- Large Caterpillar → best for production runs, larger OD shafts, or heavier wires requiring stable pull and grip.
Product Diameter and Applications for MMBT Caterpillars
MMBT's small and large caterpillars can handle products up to 12.5 mm in diameter (~0.49 inches), allowing flexibility for:
- Small Caterpillar: neurovascular catheters, guidewires, micro devices.
- Large Caterpillar: introducers, balloon shafts, and structural catheters requiring consistent pull.
Adjustability and Setup for MMBT Fine Wire Braiders
- Small Caterpillar: Moves in X-axis (forward/back) and Y-axis (left/right) for maximum precision and repositioning along the braid track.
- Large Caterpillar: Adjusts primarily in X-axis (forward/back) for stable, long-run braiding.
Pressure and Pulling Consistency
- Small Caterpillar: Shorter belt provides less surface contact, offering responsive tension control for ultra-fine wires.
- Large Caterpillar: Longer belt ensures pressure contact surface area is bigger, giving a smooth and stable pull for thicker wires.
Motors and Machine Footprint for MMBT 16-Carrier Horizontal Braiders
| Feature | Small Caterpillar | Large Caterpillar |
|---|---|---|
| Servo Motors | 1 × 200 W | 2 × 200 W |
| Model | MMBT16CHFWB | MMBT16CHFWB |
| Length | 244 cm | 269.5 cm |
| Footprint | Compact | Slightly larger, more stable drive |
Quick Comparison Table: Small vs Large Caterpillars
| Feature | Small Caterpillar | Large Caterpillar |
|---|---|---|
| Belt Size | 1” × 10” | 2” × 18” |
| Wire Range | 0.000433”–0.002” | Thicker wires, firm mandrels |
| Applications | Neurovascular catheters, guidewires, micro devices | Introducers, balloon shafts, structural catheters |
| Adjustability | X-axis & Y-axis | X-axis only |
| Contact Pressure | Less surface area, responsive | Pressure contact surface area is bigger |
| Motors | 1 × 200 W | 2 × 200 W |
| Model | MMBT16CHFWB | MMBT16CHFWB |
| Length | 244 cm | 269.5 cm |
| Braider Types | Vertical & horizontal | Vertical & horizontal |
| Product Diameter | Up to 12.5 mm | Up to 12.5 mm |
FAQ: Small vs Large Caterpillar in Fine Wire Medical Braiding
Q: What is the smallest wire the small caterpillar can braid?
A: Ultra-fine wires as thin as 0.000433”, thinner than 1/7 of a human hair.
Q: Can both caterpillars handle the same product diameter?
A: Yes, both can braid products up to 12.5 mm (~0.49 in) in diameter.
Q: When should I choose a large caterpillar over a small one?
A: Use the large caterpillar for thicker wires, larger OD shafts, or production runs where grip and stability are essential.
Applications in Medical Device Manufacturing
MMBT fine wire braiders are used for:
- Catheter reinforcement
- Guidewires
- Stents
- Balloon shafts
- Other precision medical devices
Visit MMBT by Metro CAD at MD&M Midwest 2025
See our braiders in action! MMBT by Metro CAD will be at MD&M Midwest, October 21–22, 2025, at the Minneapolis Convention Center.
Visit Booth 3801 to see our fine wire braiders perform live and ask any questions.
Final Thoughts
Choosing between a small caterpillar and a large caterpillar depends on precision versus production stability, not product diameter.
At MMBT by Metro CAD, our fine wire braiders (horizontal or vertical, 3–300 carriers) are built to support both delicate precision braids and high-volume production runs, giving engineers and manufacturers flexibility, accuracy, and reliability in medical device production.