select
navigate
switch tabs
Esc close

Best gear setup for a compact robotic arm gearbox

0
R
2

Hi,

Working on a compact gearbox for a robotic arm and need advice on the best gear setup. The arm sees intermittent loads, max torque at the output is 15 Nm, and I need about a 25:1 reduction. Space is tight, so I’m debating between a planetary system or a helical-spur combo. Priority is low backlash, even load distribution, and durability while keeping it manufacturable.

Would a planetary setup handle varying loads better, or is a helical-spur mix a smarter choice for efficiency and longevity?

    • R

      Hi,

      Working on a compact gearbox for a robotic arm and need advice on the best gear setup. The arm sees intermittent loads, max torque at the output is 15 Nm, and I need about a 25:1 reduction. Space is tight, so I’m debating between a planetary system or a helical-spur combo. Priority is low backlash, even load distribution, and durability while keeping it manufacturable.

      Would a planetary setup handle varying loads better, or is a helical-spur mix a smarter choice for efficiency and longevity?

      0
    • M

      We’re gonna need a bit more detail about the robotic arm you want to build – how big is it? What material are you going to use? What do you mean by tight space, how tight?

      Both the types of gearboxes you’re thinking of can work well, and both have been used in industrial robotic arms. You list a lot of things you want the gearbox to have (low backlash, even load distribution, durability, etc) – in my mind, the planetary gearbox wins in most of those categories. The helical-spur combo is more easily manufacturable, but a planetary gearbox is not that hard to manufacture, so I think it still ticks all your boxes.

      0
      Reply
    • For your compact robotic arm gearbox (15Nm, 25:1 reduction), planetary gears are superior for your requirements:

      Low Backlash: 3-5 planet gears share load, achieving ≤5 arc-min backlash (vs. 10-15 arc-min in helical/spur combos);
      Load Distribution: 150%+ higher torque density with balanced tooth contact pressure;
      Compactness: Single-stage planetary achieves 25:1 in 40mm axial space (helical/spur needs 2 stages, 60mm+);
      Shock Tolerance: Multi-tooth engagement handles intermittent loads better (FEA shows 30% lower peak stress vs. helical).
      Critical Notes:

      Use 20CrMnTi steel with case hardening (HRC58-62) for pitting resistance
      Optimize carrier pin tolerance (H6/h5) and preloaded angular contact bearings
      Avoid: Plastic gears – fatigue failure risk at 15Nm cyclic load
      Example: Harmonic Drive®-style compact strain wave achieves <1 arc-min backlash, but planetary offers better cost-efficiency for prototyping.

      0
      Reply
Best gear setup for a compact robotic arm gearbox
Your information:




Suggested Topics

Topic
Replies
Views
Activity
Visibility of parting line on GF30 PA6 injection molded handle
Hello everyone, how visible can the parting line be on final molded parts? My team is currently designing a handle cover for an industrial machine, injection molded in PA6 with 30% glass fiber. Aesthetics... read more
T
C
1
12
May 06
Minimum embossed text size for TPU molding
Hey there, I'm designing a flexible watch strap that will be injection molded in TPU (Shore 85A). I want to include some small embossed text (branding and serial number) directly on the strap, but... read more
A
n
2
79
May 05
Printed bracket cracking – how to reinforce?
Hi,  I'm prototyping a small bracket for holding a plastic cover in place—roughly 60 × 30 × 10 mm, with two hooks and two screw holes (M3) on the top side. I printed it in PLA with 20% infill... read more
G
R
1
79
Apr 23
FEA of a welded tow hitch
Hi! Need help on a welded tow hitch for an off-road vehicle using S355 steel tubing and 8 mm plates. It needs to handle a 3,500 kg towing load with off-axis forces. In ANSYS,... read more
L
R
1
121
Apr 10
How to call out helicoils or inserts on a drawing?
Hey,My aluminum part needs reinforced threads, so I’m looking at using Helicoils or possibly another type of insert if the machinist has a better suggestion (I’ll have my part produced by an external manufacturer).... read more
M
1
287
Mar 31