Handheld coder part
Encoder wheel and sensor for handheld coders
What turns the roller turning into the timing the print head fires on. It is the second half of the same job the roller starts, and the thing to look at once a new roller has not fixed a geometry fault.
Also known as: encoder disc · shaft encoder · rotary encoder · timing sensor · pulse wheel
Ask for a price on this part
Parts are sold against your machine, not against a picture. Send the model plate and a photograph of the part in place and we confirm the fit in writing before anything is dispatched.
When this is the part that has failed
- Print still stretched after fitting a new roller
- Print spacing changes with how fast the machine is moved
- Characters overlapping or gapping at one end of the message
- Intermittent geometry faults that come and go
What it is
- Function
- Converts roller rotation into the pulses the head prints against
- Wearing parts
- The optical or magnetic sensor and the disc it reads
- Usual cause of failure
- Ink mist or dust on the sensor, or a cracked disc
- Diagnosis order
- Clean the roller, replace the roller, then suspect this
Does it fit my machine?
The encoder is matched to the machine electronics rather than to the cartridge, so the model plate identifies it better than a photograph does — though send both. On many machines it is supplied as an assembly with the roller shaft rather than separately.
Replacing it
- 1
Rule out the roller first
A worn roller and a failed encoder produce the same symptom. Clean and then replace the roller before you touch this — it is the cheaper part and the more likely cause.
- 2
Inspect the sensor
Ink mist settles on an optical sensor and a fine film is enough to lose pulses. Clean it gently with a dry lint-free swab and retest before ordering anything.
- 3
Check the disc
Look for a crack, a chip or a bent disc. Any of the three gives intermittent faults that come and go with position.
- 4
Fit the replacement
Note the connector orientation before unplugging. Seat the new assembly square — a disc running out of true reads as a speed variation that is not there.
- 5
Test at two speeds
Print the same message slowly and then quickly. If the two come out the same length, the encoder is doing its job.
How we sell parts
- Fit
- Confirmed in writing against your model plate before dispatch
- Invoice
- GST invoice under HSN 8443 32 50 at 18%, against your GSTIN
- Delivery
- Anywhere in India, or free store pickup in Pune
- Bulk
- Quoted directly for resellers and service providers
Frequently asked questions
- I replaced the roller and the print is still stretched. What now?
- The encoder is the next thing. The roller physically follows the pack; the encoder turns that rotation into the pulses the print head fires against, so a dirty or damaged encoder gives exactly the same distorted print as a worn roller. Clean the sensor first, because ink mist on an optical sensor is enough to lose pulses, and only replace it if cleaning does not restore it.
- Is the encoder sold separately from the roller?
- It depends on the machine. On many handhelds the encoder and the roller shaft are one assembly and are replaced together; on others they are separate parts. Send the model plate and a photograph and we will tell you which yours is before you order.
Related parts
Guide roller
The wheel that rides the pack and measures how far the machine has travelled. Everything about print geometry depends on it turning cleanly and staying in contact.
Main board
The board that drives the head, the screen and the connectivity. It is the most expensive part in a handheld and the last one to suspect, because almost everything blamed on it turns out to be something cheaper.
Cleaning kit
The cheapest thing on this page and the one that saves the most money, because most cartridges thrown away as dead were blocked rather than empty.
Working across other brands and machine types too? Read the full spare parts guide, which covers continuous inkjet, thermal transfer and laser coders as well.