Parts catalogue · Robotics · Melbourne

Servo horn arm adapter for 25T standard servos, PETG (fits DS3225 and MG996R horns)

A 25 x 98 x 5 mm arm that bolts on top of a standard servo's own horn and turns it into a long, drilled arm for linkages, sensor turrets, grippers and pan-tilts. A 9 mm relief clears the horn hub, a 6 mm hole reaches the horn screw, and slots on both sides of the shaft take your horn's holes, with counterbores for the screw heads. At the far end are M3 holes at 38, 48 and 58 mm plus a 16 mm cross pair. The DS3225 version also has a fixed hole at 24 mm, the arm hole on DSServo's drawing; the MG996R version is slotted 8-28 mm. Printed to order in our Melbourne workshop.

From A$8Made to order Studio renders, real photos coming

From A$8 for the one adapter or a pair. Printed to order in Melbourne and shipped Australia-wide; we confirm the final price and lead time before anything is printed.

Get a quote → Email us about this part

On the quote page choose Request a quote (no file needed) and name this part and the option you want.

Two black 3D printed flat servo arms side by side, each with long slots near one end and a row of small holes at the other — Studio render: made to order, real photos coming: the DS3225 (back) and MG996R (front) horn arm adapters in black PETG.

Order status. Only the DS3225 arm hole at 24 mm is published; other horn holes are not, so the adapters use slots and a free coupon with radius marks comes first. We print your adapter to the holes you read off it.

What does it look like in use?

Renders are computer images of our own design, made from the same model we print. This family is made to order: real photos of our first prints are coming.

A black horn arm adapter on an orange horn on top of a plain grey servo-sized box, which sits in a black bracket on a grey extrusion — **In use (render)**Render: the DS3225 adapter on a generic orange horn and a plain grey servo-sized box in our 08 bracket. Box and horn are stand-ins, not products.

Specifications: material, size and what it fits

Spec	Detail
Material	PETG, 4 walls, 25 % infill (load-bearing), 0.20-0.24 mm layers, no supports, printed flat
Size	98 x 25 x 5 mm, about 10.5 g. Hub relief 9 x 2 mm, 6 mm hole over the horn screw
Horn fixing	3.4 mm slots and holes with 6.2 mm counterbores from the top (2.5 mm clamp). DS3225: hole at 24 mm + slot 8-16 mm, slot 8-24 mm opposite. MG996R: slot 8-28 mm, slot 8-24 mm opposite
Accessory holes	M3 holes at 38, 48 and 58 mm from the shaft + a cross pair 16 mm apart at 48 mm
Fits	DS3225 horns (arm hole 24 mm from the shaft, DSServo datasheet drawing) and MG996R horns. Other horn hole positions are not published, which is why the holes are slotted. Swept a full turn against a servo outline: no contact
Hardware	Not included: 2 screws into your horn (M3 for a threaded metal horn, M2 or M2.5 self-tapping for a plastic horn). They must not poke out of the far side of the horn
Fit coupon	Free with an order: a 3 mm strip with the hub relief, the 24 mm hole, both slots and radius marks at 10, 15 and 20 mm

DSServo, DS3225, Tower Pro and MG996R are trademarks of their owners, named only to describe fit. These adapters are our own design and are not affiliated with or endorsed by them.

How much does it cost?

Guide prices for printed parts, in Australian dollars. Shipping is extra; we confirm the final price, including any business minimum, before printing. Bulk and custom sizes are quoted per job.

Option	From
One adapter or a pair, PETG (4 walls / 25 %)	A$8
DS3225 or MG996R version	Same price
Fit coupon	Free with an order
PETG-CF or PA-CF	Quoted on request

Who it's for

Robot-arm and pan-tilt builders, RC and animatronics makers, and robotics classes using DS3225 or MG996R standard servos.

Get a quote →Bulk or custom enquiry

Safety & use

Installation & use. Designed for the uses described on this page only. Fixings are not included: use the sizes listed, check they are tight before use, and check the parts regularly for wear or damage. Not for safety-critical or overhead load-bearing use. Damage caused by misuse, modification or overloading isn't a fault in the product.

Robots. Powered joints can pinch and move unexpectedly. Keep fingers, hair and cables clear while powered, check the full range of motion by hand after fitting, and use the screw lengths listed on this page. PETG softens near 70 degrees C. A printed bracket is for hobby, education, research and prototype loads.

Load. This part carries servo torque. Use the servo's torque limit and the stated screw lengths, and use metal brackets for production machines.

This doesn't affect your rights under the Australian Consumer Law.

FAQ

Common questions

Which servos and horns does it fit?

Standard-size 25T servos such as the DS3225 and MG996R, using the horn that came with the servo. The DS3225 version has a fixed hole at 24 mm from the shaft (from DSServo's drawing); both versions have slots for the other horn holes.

How does it attach?

It sits on top of your horn with the hub in its 9 mm relief. Two screws go down through the slots into the horn's holes, and the 6 mm centre hole lets you reach the horn screw.

What can I mount on the end?

M3 holes at 38, 48 and 58 mm from the shaft plus a cross pair 16 mm apart: a linkage, a sensor, a small camera or the next servo's bracket.

Is printed PETG strong enough?

For hobby, education and prototype loads, yes: customer parts are printed with 4 walls and 25 % infill. For arms loaded at full torque all day, ask for PETG-CF or PA-CF, or use metal.

How do I order?

Use Get a quote and choose Request a quote, naming the DS3225 or MG996R version and the quantity. We confirm the price and lead time before anything is printed.