A sawyer’s study of cadence

Jean-François_Millet_(II)_014Sorry to drop off the grid.  . . with spring comes the yard work along with my hobbies and saws hasn’t left much time to pontificate on life.

March and April always getting me thinking about biking weather. I’ve spent a good deal of my life around bikes, first BMX then as a roadie.  Cadence, or the rhythm of motion, is just something I notice or maybe, I should say, pay attention to.

In road cycling, it’s something you’re continually working on and refers to the spinning of the cranks as it relates to the energy and effort put forth.  Perfection is near impossible and the pursuit leads to a lot of hyperawareness, case in point this blog. . .

In cycling, the goal is to balance maximum forward speed using the least amount of energy. The speed is easy enough to understand but the expenditure of energy, often measured in watts, is a little more tricky since it’s human, not petrol powered and comes with the another factor: fatigue.

So the right cadence is one that allows you to cover the distance in the given time and uses the least amount of energy. That’s about the depth of cadence as it relates to cycling that I’ll get into other then to say the proper gearing is often less resistant and more rotation than one might first think.

So with that in mind, understand that many of the conventional recommendations for ppi (points per inch)/ tpi (teeth per inch), also knows as pitch, for sawyers do not take ones body size or the amount of energy (watts) used to cut a given amount.  So in the 130 years since “Grimshaw on Saws” was written, the size and physique of people has changed quite a bit.  For one thing, woman for sure were never include in the recommendations, but “Let’s not bicker and argue about who killed who”.  Rather my point is, when selecting a panel saw, perspective is needed when applying the recommendations.  Understand it’s just a stepping off point and for the smaller framed sawyer, the right size may be outside the guidelines.  I’m 5’8”, 160 lbs and I really like a 6 ppi rip saw for most jobs. The same is true with cross cuts.  I often favor a 10 ppi for most work including thicker boards.

 A few caveats to all this cadence talk. . .

First is set and it’s a wee bit of a wild card.  Nothing will rob efficiency like a poorly set plate regardless of the configuration.  Over set plates hog out wood great, but that extra wide kerf takes energy.  Extremely tight set causes some wicket friction and the plate could easily get hot enough to fry an egg.  In general, if the saw was last set by an automatic setter, like a Foley power setter, you can bet the farm it’s over set.

Saw plate length I’m sure there is a rule of thumb but most average people should find 26″ works fine. However if you shop in the “big and tall” section or  your friends regularly address you as “shorty”, you may want to look at longer or shorter plate length accordingly.  I’ll be honest, I quite enjoy a shorter saw for cross cutting.

Tooth geometry is a religion, or should I say cult, all of its own.  Rake, fleam and slope all play a part, but for the purposes of cadence, I feel they shouldn’t really play a big part.  Most people filing saws use standard geometry for cross cut and rips saws.  Backsaws vary a little more, but again, not hugely from conventional geometry.

I don’t have a conclusion, rather, this is all food for thought when considering the next saw or the saw(s) to use.  I guess like all things, with practice comes insight. So when considering the next rip don’t just grab the 5 or 5-1/2 maybe try and 6 and see how it goes.

Thanks for reading and I hope everyone gets out and enjoys the spring. I just returned from the tool show in Nashua, NH.  Had a great time seeing all my New England friends.  This weekend I’ll be hanging with some VW friends and the first weekend in May is the Cheat River Festival.  I’ll do my best to keep the posts on a regular schedule.

One last note: I’ve been actively trying to add some saw related products to the site and recently added bent handles brass brushes, perfect for fine detail cleaning and also my new favorite saw filing aid, the hog bristle brush.  Both of which are made in the US and available direct through my website or my ebay store.

Joe Federici
Saw Mechanic

 

The missing fine print on using a Foley retoother

Foley_01I was asked by Dana Horton to talk a little about the use of a foley retoother, as most of the time when buying one the previous owner has never used or seen the manual.

Luckily the PDF manual can be found on-line in large part thanks to Mark Stansbury and his Foley site. So to streamline things I’m writing this as an overview and covering things the manual doesn’t. If you own a retoother, the one thing I’m leaving out that is important is adjusting the cutting heads. I think the manual does a good job going over it, but if you have issues feel free to email me.

Foley made a few models over the years but the two most common are the early 30/31 and later 385. The model 30 and 31 are the same with the exception that the later 31 was sold standard with the electric motor. The later 385 design also works about the same with some updates to the carrier system using parts consistent with the filer sold at this time.

I currently use the 285 but have owned and used the 30/31 quite a bit. Note that all the models up until Foley merged with Belsaw use the same carrier and ratchet bar system; so when buying a retoother it’s important to get ALL the parts. Very often the ratchet bars are missing or the seller also has a filer and only has one set of carriers for both. From experience I find you’re better off just passing on incomplete sets as most are missing the same part, the ratchet bars.

Foley_02If the toother you bought is complete you should have the retoother, 3 carriers: straight, crown, and backsaws and 5 or more ratchet bars. The standard bars included with most are: 13-7-4, 8-4.5, 9-5, 10-5.5, 11-6. The optional bars sold individually were 12-6.5, 14-7.5, 15-8-4.5, 16-8.5. The last two containing 15 and 16 ppi were the hardest for me to find. The ratchet bars are marked for points per inch that the bar would cut teeth for.

The ratchet bars fit in all the carriers the same. The carriers have 3 slots that the tabs on the ratchet bars slide into. Once together the carriers then slide into grooved wheels on the machine. Next check that the rake angle is set correctly for your needs. The machine will cut from 0º-30º by loosening the “T” handle or knobs depending on the unit. Don’t expect the angles to be perfect. If you use the unit enough you can mark your corrected angles on the gauge.

Foley_03Note: It’s REALLY important to tighten the knobs. The unit creates a lot of vibration and in most cases any mistake made will destroy the plate.

With the rake angle set the next step is to set the feed rate.  Locate the feeder paw in the center of the unit and lift it upright. Now look at the cutting head just below and manually rotate the flywheel so the head is in its highest position. This allows the carrier clearance, and you to check the feed rate. At this point no saw is attached to the carrier.

Foley_04The ratchet bar can be set for 2 or more pitches (space between teeth AKA points per inch). Looking at the leading edge of the bar there will be 2 or 3 numbers. The first number will be higher, the second lower and so on. The numbers corresponds to the PPI it will cut and the placement in the order denotes how many teeth the paw skips between passes. The first number is achieved when the paw grabs every tooth. The second is skipping a tooth and the third number is skipping 3 teeth. To adjust the paw, rotate the knob directly at the end. This allows you to reduce or increase the distance with each full rotation. With the carrier installed slide it up to the paw, flip the paw over, and manually rotate the wheel. Adjust the knob to correspond to what’s needed for your PPI.

I want to stress it’s really important to hand rotate the machine to check you’re grabbing the correct number, then test run the machine to make sure the adjustment is good. A little play is needed so that it doesn’t jump a tooth. Note that no saw is in the carrier while this is being tested. How the paw grabs the tooth is something that needs to be checked EVERYTIME you change the bars or carriers. It’s also important to adjust the rake angle BEFORE you adjust the paw as the angle affects the travel. Failure to set the paw properly will result in the retoother jumping between the smaller and bigger PPI on the bar and you will need to start over.

Foley_05With the paw set, lift it back up and now slide the carrier out. The handle always, always, always goes to the left. The only exception would be a pull stroke saw. Keep in mind the handle is often removed or you may be toothing a new backsaw plate so it’s easy to mix up and the results will always suck. …BTDT. When I retooth new backsaw plates I use a sharpie and put an “H” where the handle will go. I also mark every carrier bar “ <————— HANDLE” denoting proper position.

The saw plate is held fast by three tabs and wing nuts. The plate with or without handle is loaded and centered on the bar. A simple gauge (that should be included with sale!) is used to align how proud the toothline is held on the carrier. As you can imagine, the prouder it sits, the more is cut off. The bigger the teeth, the prouder it sits. Once adjusted tighten the wing nuts.

Be real mindful here. Vibration is something this machine makes in spades. If the clips aren’t seated well, they can slip allowing the nuts to loosen, and then any number of things can happen and none will result in a smile. I wouldn’t go so far as to use mechanical aids to tighten them as the other issue is they aren’t real heavy duty; just double check and wiggle the tabs to check they are seated.

Once happy I like to manually slide up to the cutting head and manually rotate the cutting head to see how much will be cut. The gauge used is very basic so it’s good to check you’re not taking more than necessary.

At this point we’re ready to rock and roll. Pull the carrier back out so the machine can run a bit before it starts cutting. I like to use a gel type cutting fluid on the edge of the saw. When ready flip the paw down. Do one more manual rotation; maybe flip the power on and off just to check that it’s grabbing correctly, then let her rip. Once the saw completes cutting, turn it off. Flip the paw up and slide the carrier out.

Foley_06There are a few caveats on running the toother. As stated earlier the toother makes a good deal of vibration. On top of that, the carrier is long and fairly lightweight. This amplifies the vibration and in extreme cases, like cutting rip teeth with 0º rake, the unit can skip a tooth. I find if I use both hands to help support the carrier it reduces the vibration quite a bit. I’ve also experimented with a wooden block to act as a guide. Whatever you can do to minimize vibration through the cutting process is good. Also in the event things go south, stopping and restarting the toother in the middle of a cut is not possible. If you stop you will need to start over; it’s best to joint the saw flat and start again.

The force of cutting, along with the condition of the cutting parts, will cause the plate to bend. Because of this I use two identical retoothers, one for backsaws (less abuse) and another for panel (more abuse). Either unit in good working order produced a slight bend that’s easily fixed. However if the cutting head chips or dulls the effects vary but most often results in extremely bent plates that require smithing.

As you can see there are plenty of pitfalls and I’m leaving out resurfacing the anvil and hammer, AKA the cutting parts. This comes with its own set of trouble. However, all of these things aside, a properly adjusted retoother is useful and makes short work of retoothing when needed; I don’t hesitate to use mine.

If you’re in the market to buy one, I strongly recommend downloading and reading the section about setting and checking the cutting parts. When going to look at one, use a scrap piece of printer paper. A properly adjusted unit should cut a “V” in the paper when the flywheel is manually rotated. If it doesn’t it’s out of adjustment. Also take a flashlight and check out the cutting head. If you see chips, the head will need to be surfaced. You can read more about that in the manual.

Hopefully this gives you an overview and a little respect of the process. If you have other questions, feel free to ask.

Joe Federici
Saw Mechanic