Stihl MS 193 C Carving Conversion
After a busy summer season of home renovation projects, the beck and call of my chainsaw obsession led me down the road into the savage art form that is chainsaw carving. As the leaves turned and fell, I finally took the plunge and ordered the parts to convert my Stihl MS 193-C into a dedicated detail carver. The MS 193 is probably the most popular saw for detail carving in the Stihl line-up as it is a light-weight and nimble 30 CC saw that is more robust than its more consumer targeted cousin the MS 170, but less pricey than its professional cousin the MS 201 or MS 150. It’s lower torque and power also makes it more dime-bar friendly than the MS 200.
In order to convert the MS 193-C into a dedicated detail carver, I decided to mount a specialized Stihl carving bar known as a dime-tip to the saw. Mounting a bar with such a small tip radius involves more than just changing the bar. In order to make the most out of this specialized bar, you also need to change the drive sprocket from the stock 3/8″ pitch to a 1/4″ spur drive sprocket. On this model, that also involves changing the worm gear for the oiler (which greatly increases the oil output- a necessity for such a narrow tipped bar). Stihl offers a specialized carving chain for use on their .050 gauge bars, but I opted for the newer .043 gauge carving bar which gives the finest cuts, but uses the 1/4″ chain usually used on power pruning bars. There was a two week wait on the newer narrow gauge bar, and I paid the extra thirty dollars to have the tech do the swapping of parts in order to save me some stress (plus, I was unaware that the new clutch assembly comes with the specialized tool to lock the piston-apparently the pistons in these newer small saws are delicate and do not appreciate the standard rope/dower in the piston chamber trick.) The grand total for the conversion in my area was around $220.00. Don’t forget to get a small 1/8″ round file for sharpening the new 1/4″ chain.
Carving with the MS 193-C with such a fine carving bar and chain set-up was extremely novice friendly. The MS 193 is very light-weight and carving with it is quite intuitive. I still find tuning the MS 193 to be quite tricky. Tuning the L screw seems quite difficult. The saw seems naturally sluggish, and when you take the lag out of the saw when sufficiently warmed up, it seems to make it too rich for an easy cold start. I am no tuning master, but this saw seems quite finicky on the L screw adjustments. If you have any tips, feel free to share in the comments section below. Once dialed in, the saw performs quite well. It is slow to warm up, but, if given a couple of minutes to idle, it performs admirably.
The fine precision and control that the .043 gauge dime tip bar offers is offset by the expense and fragility of this specialty bar. The small radius of the tip makes detail carving easier and more precise, but the small radius also greatly increases the friction between the chain and the tip. The carving bar tip is subject to extreme heat and stress and requires a looser chain tension. The ideal tension reduces the friction between the tip and chain while still maintaining control of the chain. If the chain is too tight at the tip, the tip can rapidly be damaged by the friction generated heat (heat which also can damage the relatively fragile 1/4″ chain). If the chain is too loose, the underside of the bar can be damaged by the chain “slapping” the underside of the bar as the sprocket drives the chain (the chain’s movement resembles a wave as each tooth of the sprocket engages and drives the chain). A chain that is too loose can also damage the sprocket, and it is more likely to be thrown off the bar: a potentially dangerous situation for the operator (not to mention for the chain and saw). According to the fine folks at Stihl, the ideal tension for this setup involves running the chain with about 5mm of slack between the bottom of the bar and the rails of the chain. If you have any experiences or advice to relate regarding the proper tensioning of a carving bar and chain, please let us know in the comments section below.
Even with proper tension, this bar can heat up very quickly when cutting, especially when using a plunge cut, or when cutting tight curves with the tip. A rule of thumb some carvers have given is when the tip starts throwing black oil, the tip is hot and needs a couple of minutes to cool. In the fall/winter, it doesn’t take long for the tip to cool, but I definitely see why most carvers run multiple saws with smaller tips. I definitely need an “in-between” saw with a quarter or loony tip to fill the gap between the 50 cc blocking saw and the 30 cc MS193 with a dime tip. Considering a new dime-tip bar and chain costs as much as an MS 170, purchasing another saw to run a medium size carving bar (or even a stock MS 170 3/8″ low profile set-up) would take much of the stress off of the fine detail bar and greatly prolong its life.
One final note about the 1/4″ pitch chain, the .043 gauge bar limits you to the chain found on Stihl power pruners, whereas the .050 gauge bar would allow you to run Stihl’s specialized “carving” chain. I do not know how different the two chains are, but I do know that the regular 1/4″ chain works without any issues that I am aware of. I will tell you that filing 1/4″ chain with a 1/8″ round file is a bit of a pain as the chain is so small. The small bite of the chain is ideal for carving fine details, but harder to sharpen. I am sure I will get better with more practice, but sharpening this chain is more challenging than .325″ or 3/8″ chisel chain.