Consequences Of Hand Polishing Of Crankshaft and Benefits Of Crankshaft Polishing Machine
Manufacturers of high capacity diesel engines are maintaining close tolerances in terms of taper and ovality of crankpin and main journal diameter of the crankshaft. The maintenance of close tolerances and high surface finish results in the generation of more power, longer life of crankshaft and bearing, less noise level, low vibration, friction, and better fuel efficiency. RA Power Solutions has been working on crankshafts of marine engines and engines used for various applications with diameters ranging from 30 mm to 700 mm.
What Goes Wrong with Hand Polishing
Based on RA Power Solutions’ decades of experience, here are the main drawbacks:
- Bearing line marks and pitting remain
Minor surface damage, like line marks (from bearings) and pitting, is not removed completely by hand polishing. These defects undermine surface integrity and can lead to premature wear. - Taper and ovality get worse, not better
Crankpin and main journals often have tight tolerances for taper and ovality (i.e., deviation from perfect cylindricity or uniform diameter). Hand polishing cannot correct these and often makes them worse. - Surface finish suffers
Engine and bearing manuals usually specify key metrics like surface roughness (e.g., Ra values). Hand polishing can’t ensure you reach those finishes reliably.
What the OEMs / Manuals Require
To deliver optimal performance, crankshaft components must often meet:
- Taper & ovality between 0.02 mm to 0.05 mm, depending on diameter.
- Surface finish of Ra < 0.25 (unit depends on the standard, usually microns).
These are very tight tolerances, difficult to consistently achieve with hand methods.
Onsite Grinding and Polishing Machines: Key Benefits
RA Power Solutions has developed (and field-tested) portable onsite machines with capabilities for diameters from ~30 mm up to ~700 mm. Here are the advantages they bring:
| Benefit | What It Means in Practice |
| Precision | Grinding + polishing deliver accurate, measurable correction of taper, ovality, surface finish. |
| Time Saved | Because you don’t need to remove the crankshaft—machine can be inserted via inspection window. Less downtime. |
| Longer engine / bearing life | Better surfaces, fewer defects mean less friction, wear, vibrations etc. |
| Cost savings | Avoid repeated failures or having to send the crankshaft out; avoid hiring expensive overseas services. |
| Transferable skill | Once you have the machine, your own technicians can be trained to use it—so dependence on outside vendors reduces. |
Portable Crankshaft Grinding Machine by RA Power Solutions:
RA Power Solutions has introduced a portable, lightweight, onsite crankshaft grinding and polishing machine which is capable of grinding and polishing diameters ranging from 30 mm to 700mm. The onsite crankshaft grinding machine is revolutionary. You can insert this portable equipment through the inspection window of the engine block. There is no requirement for the removal of the crankshaft from the engine block.
RA Power Solutions specializes in crankshaft polishing, offering high-quality services to improve the performance and longevity of crankshafts. our skilled technicians utilize state-of-the-art equipment and cutting-edge techniques for precise and efficient crankshaft polishing. The use of a dedicated crankshaft polisher ensures that the polishing process is done with utmost precision and consistency.
For more information on Onsite Crankshaft Polishing, Crankshaft Grinding please email us at rajshahani@rapowersolutions.com, or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.
