Every so often, at a tool shop or browsing Home Depot, I’ll notice the worm drive circular saws (and how expensive they are). I have been curious about what the difference is. I know a worm drive is geared instead of direct drive, but why is it called “worm” drive (and if you tell me because it uses a worm gear, I’m going to snap).
What are the advantages of a worm drive vs a regular direct drive saw?
I used to sell those things. Here’s a good source: http://www.toolsofthetrade.net/articles/showarticle.asp?articleID=2310&position=1&type=article&partID=1
Hypoids are up and coming, as you can see from the article.
Your basic Skil saw has several advantages over a circular saw. First off it is more powerful. It is not going to bog down cutting thick heavy stock. Secondly it as the linked article says bomb-proof. All the parts on the saw are available as replacements. Need a switch, a new shoe, motor brushes, or a top handle? All are readily available. Lastly there is ergonomics. If you look at the saw, the blade is on the left side. If you are using the saw in your right hand, that puts you in direct visual contact with the cut. Circular saws for some strange reason seem to always have the blade on the right, requiring you to lean over the top of the saw to eyeball the cut line. This might not seem like much, but try doing it 100 times a day, and tell me then how much fun it is.
A Skil 77 is a true professional grade piece of equipment, not a dressed up homeowner POS.
You can have my model 77 when you pry it from my cold dead hands.
In addition to what Rick said, the extra ‘reach’ created with a worm-drive allows regular-sized fellas to cut a 48" piece of ply or OSB. With a regular circular saw, this cut is either impossible or dangerous at best.
Not that I’ve seen. My Porter-Cable came with the blade on the left as did just about all the other models I’ve seen online or in stores.
I have noticed that many manufacturers offer your choice of right or left-side blade.
I haven’t priced them lately, but as I recall there’s a pretty big difference. I’d suggest that, if your and ocassional handyman, the straight circular saw is adequate for your needs and budget. If you earn your living as a woodworker, or are a serious DIY’er, then a worm drive is very likely your best choice.
ALL these saws are geared. The “normal” ones use either spur, or spiral cut gears instead of a worm reduction.
As for your real question:
-The little extra reach noted above.
-Also you don’t have the motor hanging off the right side to catch on “X”. This doesn’t matter much if you are just cutting sheets of plywood on sawhorses, but can occasionally matter when you are trimming things in-situ in a construction project.
-A “normal” saw has the cooling air intake for the motor located quite low, where it can suck up sawdust off the sheet you are cutting, The worm drive saw has the intake locate higher up.
As for the difference in price:
The worm drive saw is a little pricier to build. For consumer grade tools, this matters a lot. For “professional” grade tools, not so much. Thus all the worm drive saws are made for daily use by tradespeople. There are heavy duty “normal” saws, and they are much closer in price to the worm driven saws.
Occasionally Costco has the worm drive saws at well below the going rate. I’ve been tempted. but have not yet succumbed.
I forgot to mention that the “normal” design only allows bevel cutting by tipping the blade anti-clockwise as viewed from behind. Some of the worm drive saws can tip both directions. If you only have access from one direction, this allows some cuts that are otherwise impossible.
::: Wanders over to Amazon and searches “circular saw”:::
First ten results
Blade on right:
Porter Cable 324Mag
Skil 5750
Dewalt
Milwaukee
Black and Decker CS1000
Hitachi
Black and Decker CS1030L
Skil (no model number)
Another Hitachi
Blade on the left:
Porter Cable 423Mag
Better look again. 
Huh. Add the word “Left” into your search and you’ll find two pages of the things (PC, Dewalt, Makita, Milwaukee, Panasonic, Hitachi).
I agree though, dunno why they seem to push the blade-on-the-right saws. They do however offer them in both versions so my point still stands
Blade on the right exhausts the plume of sawdust, nail fragments, broken carbide teeth, etc. away from a right handed user.
Gotta be for consumer safety. With the blade on the right, a right-hander’s body will be mostly or entirely clear of the plane of the blade, safe from kickback or from anything the saw might kick up. A left-side blade requires at least the user’s arm to cross the plane of the blade, but then a pro or experienced handyman is both less likely to get hurt that way and less likely to sue if he does.
Any better guesses?
Well doing a search on “circular saw left” give three pages of results. However when you get rid of results like
[ul]
[li]Way: A Text Book for the Student of the Rosicrucian Philosophy (Paperback) [/li][li]Voyage of the Narwhal: A Novel (Paperback)[/li][li]Five Years a Dragoon ('49 to '54 : and Other Adventures on the Great Plains) (Paperback)[/li][li]Treatise on Adhesion and Adhesives (Volume 7) (Treatise on Adhesion & Adhesives) (Hardcover)[/li][/ul]
and other assorted books, saw blades and other bullshit you are left with maybe 1 page of results.
This does not support your “just about all” statement.
Had a Milwaukee straight drive. Seemed fine. It broke.
Then I bought a Skill worm drive magnesium.
It was expensive, but well, well worth it. It will last me the rest of my life.
If you rip a lot of plywood or whatever, the worm drives are the only way to go. The design (IMHO) will give you a MUCH straighter cut.
Your hand on a straight drive is above the motor. It’s a bit more behind on a worm drive. This also helps control kick back.
For construction work and sawing 2x4s the standard practice is to ‘cuddle’ the 2x on top of your foot, lean over and cut it. I cut 2x12s this way. OSHA would not approve, but that’s the way it’s done. The extra length and power of the worm drive, with the handle behind the motor helps here too.
Most right handers tend to set up for a cut so that the cutoff is on the right. Having the blade on the right means that the shoe won’t tilt or drop away with the scrap.
Did anybody else visit the old Fine Homebuilding message board? The subject of worm drives vs. sidewinders tended to cause the same sort of barfights that jet airplanes and conveyor belts cause around here. The framing carpenters fell into two camps, West Coasters liked worm drives; East Coasters and Southerners liked PC or Makita sidewinders.
The worm drive adherents claimed that they liked them because they were powerful, lasted forever and were more accurate for making drop cuts for rafter ends when walking a top plate (apparently, leaving the rafter tails wild until they’re in place is common practice on the West Coast.) The Sidewinder guys didn’t want to carry the extra pounds and liked that it was easier to see the cut when the saw wasn’t spitting sawdust at you. Someone also claimed that Skil first marketed their wormdrives on the West Coast, while Porter Cable first marketed their saws East of the Rockies, which probably makes more sense than anything else.
Personally, I grew up with sidewinders and didn’t think of getting a Skil 77 until I inherited one; now, I love it. It’s powerful enough to rip anything, the weight and length make it more stable and easier to control, and of all things, it’s quieter than any sidewinder. Maybe that shouldn’t matter, but it does to me.
Yeah it is definatly a regional thing. I’ve seen arguments on jobsites when cultures colide.
I prefer circular saws. Mine is a Makita. I like the light weight and ease of use. Another thing we tend to use around here is jobsite table saws. In areas where worm drives are more prevelant jobsite saws are less common.
Snap away, because that’s why it’s called a worm drive.
Are you asking what a worm gear is? If so, the worm is a cylindrical gear sort of like a machine screw with real coarse threads. It sits with its axis as right angles to a worm wheel which is a circular gear with teeth around its circumferance that mesh with the worm. The worm is driven by the motor and as it rotates is spins the worm wheel.
This is a worm gear. It allows the motor to be offset, which lets you use a more powerful motor than can be fitted into a standard direct drive circ saw, and also lets you get a more favorable reduction ratio for higher torque.
Regarding the direct drive versus worm drive debate: I have used both kinds; direct drive is fine for light work like cutting shelves to length, but for ripping a lot of plywood cutting or framing I’ll take a worm drive any day for its ease of control, and the cost of a decent worm drive saw isn’t much more than a top of the line circular saw. Of course, for cutting precise angles or trimming masses of 2xNs to length, a compound miter saw is indispensible. I just wish I could justify a use for one.
Stranger
It’s a WORM DRIVE to take advantage of a smaller higher speed motor to drive the blade more efficiently.