Quick value: why order from Communica
When you need knobs and dials that actually fit your project panel or student lab board, availability and fit matter more than price. Communica stocks a wide selection of rotary knobs, push-pull dials and potentiometer caps from recognised maker-friendly brands so you can source the exact part with same-city pickup and VAT invoices for school or departmental procurement. Short lead times from our Samrand warehouse and branches in Pretoria and Cape Town reduce build delays and let teams keep moving.
What you'll get ordering online
Order selection guidance, clear shaft-fit specs, and accessory bundles (shaft adapters, set-screws, indicator markers, and knob removal tools). For hands-on buyers we offer branch collection options and stock checks so you don't wait on long imports.
Common buyer scenarios
- Student replacing a stripped potentiometer with a push-fit knob and shaft adapter.
- Technician retrofitting an amplifier front panel with aluminium knurled knobs and set screws.
- Procurement ordering a bundle of dials, shaft reducers and matching washers for a lab equipment refresh.
Key specification callouts - read before you order
A knob that looks right can still fail on fit. Check these specs on the product page and match to your control shaft or potentiometer spindle before placing an order.
| Spec | Typical values | Why it matters |
|---|---|---|
| Shaft type | Round, D-shaft, Splined | D-shaped and splined need matching profiles; round shafts usually require insert or grub-screw |
| Shaft diameter | 2mm, 3mm, 6mm | Diameter tolerance decides whether you need an adapter or a press-fit knob |
| Fixing method | Push-fit, Set-screw, Press-fit | Set-screws allow repositioning; push-fit is quick for labs |
| Panel depth & clearance | Single/dual-stack knobs, 10-20mm | Ensures knob clears nearby controls and markings align |
Quick compatibility table
| Knob type | Fits shaft | Accessory often needed |
|---|---|---|
| Push-fit plastic | Round 6mm | None |
| Set-screw aluminium | D-shaft 6mm | Metric 1.5mm hex key |
| Splined radio knob | Splined 6mm | Spanner or press tool |
Shaft-fit formula and a wiring example
If you need to adapt a 3mm shaft to a 6mm knob, use a reducer sleeve. Choose sleeve thickness so insertion depth is at least 70% of knob bore length for secure fit. No complex math is required, but ensure bore_length x 0.7 <= insertion_depth.
Potentiometer wiring ASCII diagram
Potentiometer (front view) [ 1 ]---///\---[ 2 ]---///\---[ 3 ] | | V (wiper) GNDTypical tone control: left = input, centre = wiper (output), right = ground
For more product categories and to browse compatible accessories, see our collections page Browse Collections. If you want to understand who we are and our local footprint, read about our history and branches About Communica or check branch hours for pickup options Branches & Trading Hours.
