Thanks for the teardown. For RPM tuning measurements of 2 stroke chainsaws I've just been using an oscilloscope frequency counter lately. Just use an ordinary scope probe with the reference lead clipped into its grabber to make a simple RF loop. Just find max rated RPM and divide by 60 to get Hz, eg 10k RPM = 166.6 Hz.
LOL, I will admit, this video had me in an odd cascade of thoughts..... How mad would she be if I ran the saw in the house? To, hmm 400kV is overkill, really I only need 20-40 kV. Then of course to, hmm, to drive the coil off of it would be more of a realistic situation.
@@tinkrelectronic Short power lead to outside or as in my case from the garage and a portable mains scope and tuning procedures worry no one. At one time I worked on small motors and had several RPM measurement tools and got reasonably accurate 'by ear' but that was some decades ago so again I need something accurate. I've looked the PET RPM meters but for now a DSO will do. 🙂
Nice! It never really occurred to my to scope it. (though wife doesn't like the noise and the fuel smell.) I managed to tear a shoulder tendon on a 46cc saw, a sure sign I am getting older. =/ I really enjoy tinkering with them, but hard starts are killer for my shoulder now. Waiting on surgery. In the meantime, I might see if I can make a better PET RPM meter. =)
@@tinkrelectronic Starting technique is important to restrict the chance of injury. This has been dealt with in several ways, decompressions, and the windup method used on some Stihl saws. However my fav for saws to ~90cc is the controlled drop start there the rear handle is tucked under the right lower thigh and the saw is forced downward as the starter cord is pulled, both in one operation. Even the largest saws can be easily started using this method when warm however the Safety authorities frown on it despite it having been developed by the Swedish, the largest makers of professional saws. When cold, starting a saw is another matter especially if it hasn't been used for a while so on the ground, foot in the rear handle with choke pulled and fast idle engaged and decomp engaged, especially for the larger saws over 80cc.
Thanks for the teardown. For RPM tuning measurements of 2 stroke chainsaws I've just been using an oscilloscope frequency counter lately.
Just use an ordinary scope probe with the reference lead clipped into its grabber to make a simple RF loop.
Just find max rated RPM and divide by 60 to get Hz, eg 10k RPM = 166.6 Hz.
LOL, I will admit, this video had me in an odd cascade of thoughts..... How mad would she be if I ran the saw in the house? To, hmm 400kV is overkill, really I only need 20-40 kV. Then of course to, hmm, to drive the coil off of it would be more of a realistic situation.
@@tinkrelectronic Short power lead to outside or as in my case from the garage and a portable mains scope and tuning procedures worry no one.
At one time I worked on small motors and had several RPM measurement tools and got reasonably accurate 'by ear' but that was some decades ago so again I need something accurate. I've looked the PET RPM meters but for now a DSO will do. 🙂
Nice! It never really occurred to my to scope it. (though wife doesn't like the noise and the fuel smell.) I managed to tear a shoulder tendon on a 46cc saw, a sure sign I am getting older. =/ I really enjoy tinkering with them, but hard starts are killer for my shoulder now. Waiting on surgery. In the meantime, I might see if I can make a better PET RPM meter. =)
@@tinkrelectronic Starting technique is important to restrict the chance of injury. This has been dealt with in several ways, decompressions, and the windup method used on some Stihl saws. However my fav for saws to ~90cc is the controlled drop start there the rear handle is tucked under the right lower thigh and the saw is forced downward as the starter cord is pulled, both in one operation. Even the largest saws can be easily started using this method when warm however the Safety authorities frown on it despite it having been developed by the Swedish, the largest makers of professional saws.
When cold, starting a saw is another matter especially if it hasn't been used for a while so on the ground, foot in the rear handle with choke pulled and fast idle engaged and decomp engaged, especially for the larger saws over 80cc.