Procolored L1800 Slows Down While Printing: CR Motor, Mainboard, Firmware, and Carriage Load Troubleshooting

Question

I have a Procolored L1800 printer. I purchased the high-torque CR motor from BCH Technologies because my printer starts printing normally, then slows down during printing, and later goes back to normal speed again. Procolored tech support suggested replacing the motherboard and the CR motor, and I have already replaced both, but the problem is still happening. I also greased the carriage rod. Do you have any tips or suggestions for what else could cause this issue?

Answer

Since you already replaced both the motherboard and the CR motor, that changes the direction of the troubleshooting. A weak original CR motor could definitely cause the carriage to slow down, especially if the motor overheats or cannot keep up with the added load from a DTF conversion. However, because you installed our high-torque CR motor and the symptom is still present, I would start looking for something that is making the motor work too hard or something that is telling the printer to slow down.

The CR motor is responsible for moving the carriage left and right across the printer. On an Epson L1800-based DTF printer, the carriage often has more weight and more resistance than the original Epson design expected. DTF modifications may add ink lines, white ink circulation tubing, cable chains, dampers, brackets, sensors, or extra attachments. Even a high-torque motor can overheat or slow down if the carriage is overloaded or if something is dragging.

One possibility is CR motor overheating. When a motor overheats, it may start normally, then lose performance as the temperature rises. After it cools slightly or the load changes, it may return to normal speed. This can create exactly the symptom you described: normal printing, then slowdown, then normal again. Since the high-torque motor should tolerate more load than the original motor, I would be surprised if the motor alone is the problem, but I would still monitor the motor temperature when the slowdown happens.

When the printer starts slowing down, carefully pause and check whether the CR motor is unusually hot. Also compare the temperature before printing, during normal movement, and when the slowdown begins. If the motor becomes very hot, the cause may not be the motor itself. It may be that the carriage has too much resistance, the belt is too tight, the carriage rod has too much grease, the ink tubes are pulling, or the carriage is carrying too much weight.

The carriage should move smoothly by hand when the printer is powered off and unlocked. It should not feel sticky, heavy, gritty, or uneven. Move it slowly from left to right and pay attention to whether one section has more resistance than another. If the carriage slows down at a certain position during printing, inspect that area closely. A small obstruction, ink tube drag, cable chain binding, or belt problem can create resistance only in part of the travel path.

You mentioned that you greased the carriage rod. Lubrication is important, but too much grease can cause problems. The carriage rod does not need heavy grease. Thick grease can collect dust, ink mist, DTF powder, fibers, and dried ink particles. Once that happens, it can become sticky and actually increase drag instead of reducing it. A light lubricant is usually better than heavy grease. The rod should be clean, smooth, and lightly lubricated, not coated with a thick layer.

If too much grease was applied, clean the carriage rod carefully and apply only a thin layer of light lubricant. Do not over-lubricate. Also check the carriage bushings or sliding surfaces. If the carriage rod is clean but the bushings are worn, dirty, swollen, or contaminated with dried ink, the carriage can still drag and overload the motor.

The CR belt should also be checked. If the belt is too tight, the motor has to work harder. If the belt is too loose, the printer may lose motion accuracy or struggle to maintain consistent carriage speed. Check the belt for missing teeth, cracks, fraying, ink contamination, or powder buildup. A DTF environment can be rough on motion parts because ink mist and powder can settle on rails, belts, pulleys, and sensors.

The encoder strip is another important item. The encoder strip is the clear plastic strip that the carriage reads to know its position. If it is dirty, scratched, foggy, or contaminated with ink mist, the printer may misread carriage movement. When the printer cannot confidently track the carriage position, it may slow down, hesitate, print unevenly, or eventually trigger a carriage-related error. Clean the encoder strip gently with the correct method and avoid scratching it. Also check that the strip is properly seated and not twisted or loose.

Because the printer slows down and then speeds up again, also check whether the printer is intentionally slowing down due to data, firmware, or print-mode behavior. Some RIP software and firmware combinations may change carriage speed depending on print density, pass count, white ink layer, print mode, or communication buffering. If the slowdown happens only on certain artwork, certain print modes, or certain sections of the print, the cause may not be purely mechanical.

I would check whether a firmware update is available for your Procolored L1800 system. Firmware controls motor behavior, carriage timing, acceleration, error thresholds, and communication with the mainboard. If the mainboard was replaced, the firmware version or configuration may not match the rest of the machine perfectly. Updating or reinstalling the correct firmware may help if the slowdown is related to motion control or board configuration.

Also check the RIP software and print settings. If the printer slows down only when printing heavy white ink areas, high-resolution artwork, or high-pass modes, the printer may be adjusting speed based on print density or data flow. Try printing a simple test pattern, then a full-color image, then a white-heavy DTF job. If the slowdown only happens during heavy ink sections, that is useful information. If it happens even during a simple nozzle check or basic test print, then the issue is more likely mechanical, electrical, or firmware-related.

Since Procolored advised replacing the motherboard and CR motor, they may have suspected a motor-control issue. However, if both parts have already been replaced and the symptom remains, I would focus on load and feedback. A new board and stronger motor will not fix the issue if the carriage is physically difficult to move, the tubes are pulling, the belt is too tight, or the encoder strip is giving bad feedback.

Check the ink line routing carefully. On many converted L1800 DTF printers, the ink tubes can pull on the carriage when it moves toward one side. The carriage may move normally near the center but become strained near the left or right side. That added pull can cause the motor to work harder and heat up. Make sure the tubing has enough slack, moves freely, and does not catch on the frame, cover, cable chain, or other parts.

Also inspect any cable chain or drag chain if your Procolored model uses one. A drag chain can bind, sag, hit the frame, or add resistance during carriage movement. If the slowdown happens at the same section of travel, the drag chain and tube routing should be checked closely.

The carriage may also be overloaded. DTF conversions often add components that were not part of the original Epson L1800 design. If the carriage has extra brackets, large dampers, heavy tubing, or stiff lines, the CR motor has to overcome more inertia and friction. A high-torque motor helps, but it does not make the printer immune to overload. If the carriage is too heavy or restricted, any motor can eventually overheat or slow down.

You should also check the CR motor driver area on the board or any intermediate motor-control board, depending on the Procolored configuration. If the motor driver is overheating, the printer may reduce power or behave inconsistently. Since the motherboard was already replaced, this may be less likely, but it is still worth checking whether the board area becomes hot during operation, whether the power supply is stable, and whether all motor connectors are seated firmly.

A weak or unstable power supply can also cause motion problems. When the printer starts printing, the motor load, printhead firing, pump activity, and other electronics may draw power at the same time. If the power supply voltage drops under load, the carriage may slow down or behave inconsistently. This is not the first thing I would suspect, but it should remain on the list if the mechanical path checks out.

Another thing to check is whether the slowdown happens at a predictable time or after a predictable amount of printing. If it always happens after several minutes, overheating becomes more likely. If it happens at the same physical location, mechanical resistance or tube drag becomes more likely. If it happens only with certain files or print settings, firmware, RIP settings, data transfer, or print mode may be involved.

A practical test would be to run the printer with the carriage path as lightly loaded as possible. Make sure the tubes are not pulling, the rod is clean and lightly lubricated, the encoder strip is clean, and the belt is properly tensioned. Then print a simple test job and monitor the CR motor temperature. If the slowdown improves, the issue was likely load or drag. If the motor still heats up and slows down with no obvious resistance, then firmware, driver electronics, power supply, or a configuration issue may be involved.

Because you already installed a high-torque CR motor, I would not keep replacing motors at this stage. Instead, I would inspect the carriage movement, reduce resistance, clean off excess grease, use only light lubricant, check the encoder strip, verify belt tension, inspect tube routing, and check for firmware updates. A high-torque motor can compensate for some added load, but it cannot fully overcome a carriage that is binding, overloaded, or being pulled by stiff ink lines.

Addressing printer issues can be a complicated process because these problems are very hands-on, especially when the symptom involves intermittent movement, carriage drag, motor temperature, firmware behavior, or DTF conversion parts. For that reason, we are not able to provide remote troubleshooting, suggestions, or support for individual printer repairs. We do offer in-person evaluation and repair through our local diagnostic facility: BCH Technologies Printer Repair Service [https://bchtechnologies.com/printer-repair-service]. Because of high demand, repairs are handled on a first-come, first-served basis, so it may take a few weeks before we can accept your printer for drop-off. Our services are structured to repair either a whole printer or specific parts, with instructions on how to proceed. However, we understand that our rates may not be the most economical option for every situation. Therefore, we strongly recommend self-help through online research whenever possible. You can start by checking YouTube or visiting our channel homepage: BCH Technologies on YouTube [https://youtube.com/@bchtechnologies]. Once you are on our channel, use the search icon next to "About" on the right-hand side of the menu bar and search for your printer model, part name, or symptom. We receive dozens of questions every day asking about videos for specific topics, and after creating videos for many years, it is difficult to remember every single one. YouTube's search function is usually the most efficient way to find the right video, and it may also suggest helpful videos from other repair channels.

Thank you again for reaching out and for purchasing the high-torque CR motor from us. I hope this gives you a clearer direction for checking the carriage load, lubrication, firmware, encoder strip, belt tension, and possible overheating causes on your Procolored L1800.