Silvey HDG-6 Grinder
Setting Up & Using A
If you just purchased an HDG-6, congratulations. Your days of tediously filing depth-gauges are over. Once you learn how to use your new grinder, you will use it often and your chains will perform better than ever.
Depth-gauge maintenance is important, but like most pro saw users you probably haven't been giving your chain's depth gauges the attention they deserve. Since you have been filing these by hand , you probably haven't lowered them often enough or accurately enough.
With your new grinder, depth gauge maintenance will be a breeze. Since it is quick and easy to do, you will make it part of your regular sharpening routine. This regular maintenance will lead to better performing saw chain.
While the HDG-6 is easy to use, it is a little tricky to set up, especially the first time. No matter how much experience you have using a chisel grinder, learning to use the HDG-6 will take a little time.
The purpose of this information is to minimize your learning curve. The time you spend reading this and studying these images will give you a better understanding how this grinder works, show you how to adjust it, and teach you how to overcome common problems first-time users frequently have.
How The HDG-6 Works
The HDG-6 is a marvel of simplicity. Unlike a chisel chain grinder, where each cutter tooth is carefully advanced and indexed, the HDG-6 processes depth gauges like a factory. By using the chain's cutter teeth as a cam to raise and lower the grinding head, the chain can be fed into the grinder with a hand crank, giving the grinder almost automatic operation. Once set up, an HDG-6 can grind the depth-gauges on most any saw chain in a couple minutes or less. If you have never seen the HDG-6 work before, your jaw will drop the first time you see it work.
Assembling Your Grinder
If you bought your grinder in our store, it was probably assembled. If you ordered it and had it sent to you, it needs to be assembled. This isn't a big deal. If yours isn't assembled, remove it from the box and use the photo to guide you. Don't forget to put on your safety glasses!
Determining How Much Depth-Gauge Material To Remove
Before you do anything with the grinder, you first need to learn how much depth-gauge material needs to be removed from the saw chain you're working on. If you don't know or can't remember the proper depth gauge setting, call us or consult a manufacturer's handbook. Depth-gauge settings can vary from chain to chain, so it is necessary to consult a guide for this information.
Above, this person is using a straight edge and a feeler gauge to measure depth-gauge height. The straight edge rests on the top corner of two consecutive cutter teeth (the highest point on each cutter tooth). The feeler gauge is used to measure the distance from the top of a depth-gauge to the bottom of the straight edge. This illustrates just one method of measuring depth-gauges. Various tools exist for this purpose.
Depth-gauges that are cut too low cause the chain to cut rough and vibrate. They also increase kickback potential, another dangerous condition. A chain with depth-gauges that are too high will not feed well, and may require extra feed pressure. This increases the wear on the cutting attachment and leads to operator fatigue, another dangerous condition. It is important to follow the manufacturer's recommendations.
For example: If your depth-gauges measure .020 of an inch, and you know the correct depth-gauge setting is .025 of an inch, simple subtraction will tell you you need to remove .005 from your depth-gauges. (.025 - .020 = .005)
Consult a manufacturer's handbook or web site for information on proper depth gauge height for the chain you are using.
Now that you know the proper depth-gauge height and how much material you need to remove, you can start setting up your grinder.
Mounting The Chain On The Grinder
Before you do anything with this grinder, put on safety glasses. Now that you have your glasses on, the first thing you'll do is to mount the chain on the grinder. With the grinder motor off, tilt the grinder head back. Place the chain on the top pulley, which is under the lifting foot.
Place the chain in the top pulley. Make sure the cutter teeth are facing (going into) the grinder. If the chain is facing the opposite direction, it won't work. Remove it and turn it around.
The chain can be mounted in two directions. Mount it so the cutter tooth is facing into the grinder. If yours is mounted backwards, remove it and turn it around.
Shown is a properly mounted saw chain. Notice the cutter tooth is pointing into the grinder.
Next, you'll adjust the position of the tension pulley assembly for the length of your chain. Start by loosening the mounting bolt on the tension pulley assembly. The whole assembly will slide up and down on the stand's main tube.
Position it so the tension pulley is about two inches below the bottom of the hanging chain and tighten the mounting bolt. Now, check to be sure the tension pulley is aligned with the top pulley. If it needs to be moved, loosen the mounting bolt and reposition it.
Lift the handle and place the chain's drive links between the two roller bearings. When you release the handle, the spring holds tension on the chain.
Now, lift the lower chain pulley mount up by its handle and place the lower portion of the chain in its slot. Be careful not to tip the grinder over. Lift, while steadying the grinder stand.
Make sure the spring has plenty of tension on the chain. If it does not, reposition the tension pulley assembly and try again. Having plenty of chain tension is good and will help you in the next step.
The stretched spring indicates plenty of tension on this chain.
Now that the chain is mounted, raise the grinding wheel by turning the adjustment screw on the top of the grinder. Raise the wheel to where it is well above the chain. This will get the grinding wheel out of the way so the stroke can be adjusted without any interference from the grinding wheel.
This knob adjusts the height of the grinding wheel.
Adjusting The Stroke
Now the wheel is out of the way, you can adjust the stroke. Begin by tilting the grinder head forward. Now, turn the crank handle so the depth gauge on the first cutter tooth moves towards the foot. Turn the crank and follow the cutter tooth while it passes under the foot. Continue turning, while watching the grinder head raise and lower as each tooth passes under the foot.
Turn this handle in the direction that feeds the cutter teeth into the grinder.
If the cutter tooth on your chain hits the foot and then slips on the chain pulley as the crank is turned, the foot is too low. Use the stroke adjustment screw (under the grinder head) to raise it. Keep raising the foot until cutter teeth will travel under it, raising and lowering the grinder head in the process.
If the foot is adjusted too high, it will barely raise the grinder head as the chain passes under it. Use the stroke adjustment screw to lower the foot. This will increase the "stroke" or the amount the head is lifted by each cutter tooth.
This adjusts the stroke and height of the foot.
It is important to adjust for as much stroke (lift) as possible. To get adequate lift, it may be necessary to increase the chain tension. This will increase the chain's grip on the upper pulley, allowing more lift without slipping. When everything is adjusted properly, the foot will raise and lower the grinding head without slipping the chain on the pulley.
Turning this crank feeds the chain into the grinder. The foot sitting over the chain raises and lowers the grinding head as the chain passes under it.
Adjusting The Wheel Depth
Now that you have the stroke adjusted, it is time to adjust the height of the grinding wheel. With the grinder turned off, start by positioning a cutter tooth's depth gauge under the grinding wheel and begin lowering the wheel with the depth adjustment screw on the top of the grinder. This is a big black knob you initially turned before you adjusted the stroke.
Shown is the depth gauge just passing under the grinding wheel. It will now pass under the foot, which will raise the grinding head enough that the wheel misses the cutter tooth.
Adjust the wheel so it almost touches the depth-gauge on the chain. Rotate the crank several times. This will move teeth under the wheel and allow you to check your adjustments before turning the grinder motor on. It will also help you determine if the depth gauges are uneven. If the wheel touches some depth gauges, but not others, you may need to raise the wheel to where it barely touches the highest depth gauges.
If you find the grinding wheel is also hitting the backs of the teeth, raise the grinding wheel with the depth adjusting screw (on top) and increase the stroke with the thumb screw that is under the grinder.
Once the stroke is increased, lower the grinding wheel again and recheck your adjustments. When everything is set right, turning the crank will raise and lower the head, while the grinding wheel barely touches the tallest depth -gauges.
This shows the cutter tooth passing under the foot. Notice the grinding wheel is above the cutter portion of the tooth.
If you took your safety glasses off, now is a good time to put them back on. Also have a look around for any combustibles that could be ignited by the sparks you are about to make. Make sure there are no pets, children, or observers that could be injured by flying debris. This is especially important if you are turning your grinder on for the first time. Cracked or out-of-balance grinding wheels can explode.
Turn the grinder on. You should not be seeing any sparks.
Now, turn the crank handle, feeding the chain under the cam lever foot. Again you should not be seeing any sparks. If you see sparks, turn the grinder off and figure out why.
Once you have turned the crank handle several rotations without seeing any sparks, mark a spot on the chain with a piece of chalk. Using the chalk mark as a reference, rotate the hand crank until all the depth gauges have passed under the grinding wheel.
Next, lower the grinding wheel slightly by turning the depth adjustment screw counter-clockwise. Turn the crank handle to check for sparks. Repeat this process until the grinding wheel just touches the highest depth gauges.
If the chain slips on the upper pulley, it may be necessary to increase the chain tension. This will increase the traction the chain has on the pulley.
Setting Up The Grinder To Cut The Depth Gauges
If you remember on our initial measurement of the depth gauges on our sample chain, we determined we needed to lower the gauges .005". On the top of the wheel depth adjustment screw, you will see it is marked in increments of .005. We are going to take half this on the first cut. Remember, it is always easy to remove more material, but impossible to put it back once it is ground off.
This black knob is for adjusting the height of the grinding wheel. Notice the marks on the knob indicating that 1/8 of a turn changes the grinding wheel's height by about .005".
The label on the wheel depth adjustment knob indicates that 1/8 of a turn is .005", so turn the knob 1/16 of a turn,and make the first cut. Using your chalk mark for reference, turn the crank until all the depth gauges are cut.
Now, turn the grinder off. Remove the chain and check the depth-gauges. They still should be a little high. Your measurement should indicate it is necessary to take a little more. Remount the chain, reset the grinder, and make another pass.
Again, turn the grinder off and check them. They should now be perfect.
One secret to success with this grinder is to never adjust the stroke, once the grinding wheel depth is set. Anytime a stroke adjustment is necessary, back the wheel adjustment screw out and reset the wheel depth after the stroke has been reset. This is necessary because the stroke affects the wheel height. Many users have been confused by this.
Also, be patient with yourself. You probably didn't learn to operate your square-chisel grinder in one setting. Don't get frustrated if you struggle a little at first. It's a tool worth learning to operate well.
As you get used to operating your grinder, you will be able to streamline some of these steps. Most operators who use their grinder regularly are able to cut the desired amount in one pass. When depth-gauges are never filed, the steps taken to identify the tallest depth gauges are also not necessary. Even more, most operators run a standard length chain, so the initial chain length setting is not necessary either.
Click here for a short video of the HDG-6 in action.