Author Topic: Cordless blades flexing/warping. (Read 6022 times)

Lbob131 · « **on:** May 07, 2021, 12:37 PM »

Have used my cordless Metabo circular saw with the festool rail in the past to cut plywood and the results were abysmal. To say the least.
Blade flexing all over the place.
Guy on site all week with a Dewalt cordless track saw cutting plywood and most sheets were left with curve in the cut.

Fortuanetly my corded TS55 was on hand which left a perfect cut.
He was baffled as to how his saw was making bad cuts. I even adjusted the rollers to take up the slack on the rail for him.
Didn't make the slightest bit of difference.

Then it dawned on me only today what the real problem is.

Is their any point to cordless track saws with these super thin blades when they perform so badly?
Perhaps Mafell has cracked this issue?
How are Festool cordless track saws performing I wonder?

Michael Kellough · « **Reply #1 on:** May 07, 2021, 01:21 PM »

With thin blades toe adjustment (making the blade parallel to the track) is even more important.

Mike Goetzke · « **Reply #2 on:** May 07, 2021, 01:57 PM »

Strange - I've been using saws on the rail with thin kerf blades for over 20 years and have never noticed a curve to my cut. I can get non-square cut if I let the blade get dull. Think there may be an issue with sloppy bearings in the saws that had issues?

Lbob131 · « **Reply #3 on:** May 08, 2021, 05:15 AM »

Nothing to do with sloppy bearings.
Thin kerf blades are the problem.

I expect if you are not having issues then you don't cut a lot of plywood or precision accuracy is not what you require.

We sliced up 2400kg of 8 x 4 12mm plywood this week and barely a sheet ended up straight from the dewalt.
Thats 140 sheets.
And another 400 sheets in the workshop ready for processing in the next few weeks.

The guy was hailing the De walt saw and the De walt range in general as the best woodworking power tools in the business.
We were having a good ole laugh all week.
Especially as I had to straighten out his cuts until he finally gave up and had to use the
corded Festool.

The guy was checking his rail against mine for straightness.
He was blaming the plywood not laying flat at one stage.
All week he was scratching his head.

Then it dawned on me only yesterday morning.
As I had previously had the same problem with a metabo fitted with a thin blade.

pixelated · « **Reply #4 on:** May 08, 2021, 07:50 AM »

That hasn’t been my experience, my track saw is an HK-55, which uses 1.8 mm kerf blades, it has no problem cutting a strip 1/16” wide off the edge of a board, or straight cuts in general.

You might try repositioning the blade on the arbor, or check the other “tuning” factors mentioned.

Cheese · « **Reply #5 on:** May 08, 2021, 09:43 AM »

I've not had any issues using a TS 55, TSC 55, HKC 55 and a MT 55 cutting 18 mm maple ply and ripping 4/4 & 5/4 solid maple boards.

The TS & TSC both use 2.2 mm wide kerf blades so even though the TSC is cordless, the blade performs as well as the corded version.

The HKC & MT 55 both use 1.8 mm wide kerf blades, one from Festool and one from Mafell. No issues at all with either blade/saw.

Have you tried clamping the rail at both ends to see if that's part of the issue?

With the amount of wood you're cutting maybe some sawdust is accumulating under the rail strips and the rails can move slightly if not clamped down. I know first hand that that's an issue with Mafell rails.

demographic · « **Reply #6 on:** May 08, 2021, 10:44 AM »

Ive done cuts on 90mm square oak beams using my HKC and crosscut rail, 50mm deep cut one way then mark round with a square and then a 50mm deep cut from the other side to cut all the way through.
Pretty much spot on every time I did them which shows the cut is nice and straight.
Thats using a thin (1.8mm) blade.

If you're getting a measurable slant on a sheet of ply I suspect the saw has other issues.

Tom Gensmer · « **Reply #7 on:** May 08, 2021, 12:32 PM »

Thin kerf blades are not the problem.

I've been using a Mafell MT-55 for years now using the 1.8mm blades Mafell supplies and never had an issue with the blades flexing/warping. This includes using the MT-55 for glue-line ripping 2"+ thick Hard Maple, dead-straight. Also producing cabinets (mostly veneered baltic birch), never had an issue.

Some data points not supplied by the OP are:
-- Were the blades sharp?
-- What brand blades?
-- Feed rate?
-- Appropriate blades being used for the task at hand?
-- Which Metabo saw are you using? One of the cordless Metabo saws has been discussed extensively on the Mafell forum, I haven't read the entire conversation but my memory is that the saw being discussed is more of a framing saw, and did not perform well on the track.

I'd suggest buying a fresh batch of blades and see if they perform any better. If the issue persists, the machine is not properly dialed-in (not just snugged to the track), the machine is not suited for the work being asked, or it's user error, or some combination of the above...

Lbob131 · « **Reply #8 on:** May 08, 2021, 01:18 PM »

Thin kerf blades are the problem..

My corded Festool TS55 blade has a cutting width (kerf) of 2.2mm.
The blade width is 1.7mm.

My Metabo KS18 LTX 57 is using a Trend blade with a cutting width of 1.7mm.
And a blade width of 1.1mm.
That is clearly the problem.

I don't know the blade widths of my work colleagues Dewalt saw but I expect its similar to my Metabo.

Festool sell the Wood Universal blade suitable for the TSC (2055551) witha cutting width of 1.8mm (kerf) and blade width of 1.2mm.

The 496302 is 2.2mm cutting width. (kerf)
Blade width is not specified.

Unless the blade width (not kerf) is 1.7mm then cordless is a non starter IMO.

Michael Kellough · « **Reply #9 on:** May 08, 2021, 01:19 PM »

A thin blade per se is not the problem, but the condition of the blade and the saw are more critical since the blade can flex if the teeth on one side are not as sharp or if the toe is not set correctly. Even the 2.2mm kerf blades flex some when the toe is off or the teeth are chipped on one side.

A good sharp thin blade tracking correctly is a significant benefit to a cordless saw.

It’s not too surprising that lower quality saws might have issues running thin blades since they probably don’t take time at the factory to get the toe adjustment perfect and they probably include lower quality blades.

Lbob131 · « **Reply #10 on:** May 08, 2021, 05:29 PM »

I have no issues with my 20 year old Festool TS55 plunge saw at all.

My Metabo and my work colleagues De Walt have no easy adjustment for toe in or out.
I expect that is factory set.
The kerfs are thin, the blades are thinner still and that is the problem.
And with constant non stop sawing, the blade warming causes even more blade warping issues on these super thin blades.

I have seen nothing on the UK Festool website showing that 1.7mm blade thickness (not kerf) are available for cordless festool plunge saws.

On the UK website..https://www.festool.co.uk/accessory/496301---160x2,2x20-pw12#Overview

No "blade width" specification is given for saw blades with "cutting widths" of 2.2mm.
Am I to assume it is 1.7mm?
The same as my current TS55 blade?

On the issue of feed rate. With my ts55, I'd say about 3 seconds to cross 1.3m x 12mm thick plywood.

Tom Gensmer · « **Reply #11 on:** May 08, 2021, 05:48 PM »

Quote from: Lbob131 on May 08, 2021, 05:29 PM

I have no issues with my 20 year old Festool TS55 plunge saw at all.

My Metabo and my work colleagues De Walt have no easy adjustment for toe in or out.
The kerfs are thin, the blades are thinner still and that is the problem.
And with constant non stop sawing, the blade warming causes even more blade warping issues on these super thin blades.

I have seen nothing on the UK Festool website showing that 1.7mm blade thickness (not kerf) are available for cordless festool plunge saws.

Your personal experience does not constitute a global fact. A more accurate statement would be "I am experiencing problems with the thin blades I'm using", as it reflects your experience. The fact of the matter is, there are multitudes of professional tradespeople putting out amazing work using 1.8mm blades, so your assertion that "thin kerf blades are the problem" is, on its face, obviously false.

Lbob131 · « **Reply #12 on:** May 08, 2021, 06:00 PM »

Quote from: Tom Gensmer on May 08, 2021, 05:48 PM

Quote from: Lbob131 on May 08, 2021, 05:29 PM
I have no issues with my 20 year old Festool TS55 plunge saw at all.

My Metabo and my work colleagues De Walt have no easy adjustment for toe in or out.
The kerfs are thin, the blades are thinner still and that is the problem.
And with constant non stop sawing, the blade warming causes even more blade warping issues on these super thin blades.

I have seen nothing on the UK Festool website showing that 1.7mm blade thickness (not kerf) are available for cordless festool plunge saws.

Your personal experience does not constitute a global fact. A more accurate statement would be "I am experiencing problems with the thin blades I'm using", as it reflects your experience. The fact of the matter is, there are multitudes of professional tradespeople putting out amazing work using 1.8mm blades, so your assertion that "thin kerf blades are the problem" is, on its face, obviously false.

I can do amazing work with thin kerf blades also. But at a snails pace.
So my assertion is correct imo.
Try slicing 150 12mm sheets of plywood a day and cordless saws with their thin blades are absolute rubbish.
Snails pace and building sites are not compatible.
Now if a 1.7mm (blade thickness) can be fitted, then it might be a whole different story.
Yes thats my experience and my work colleague's experience also. As he found out this week.

FestitaMakool · « **Reply #13 on:** May 08, 2021, 06:25 PM »

^400mm a second sounds fast. My experience with thin kerf Makita circular saw goes back to 2008. I’ve never experienced bad cuts except when pushing to hard and fast. And I almost never do that, so my cuts have been fine even with just a clamped edge to ride the saw along.

What every woodworker and carpenter have told me about getting nice quality cuts whether it’s with a manual saw or a motorised one: “Never push the saw, let the saw do the job!” “Want to go fast as possible? Get the handsaw or blade sharpened to the max, and/or buy a larger more powerful motorised saw”

At least half your speed and see what that gets you.

Crazyraceguy · « **Reply #14 on:** May 08, 2021, 07:21 PM »

Quote from: Lbob131 on May 08, 2021, 06:00 PM

I can do amazing work with thin kerf blades also. But at a snails pace.
So my assertion is correct imo.
Try slicing 150 12mm sheets of plywood a day and cordless saws with their thin blades are absolute rubbish.
Snails pace and building sites are not compatible.
Now if a 1.7mm (blade thickness) can be fitted, then it might be a whole different story.
Yes thats my experience and my work colleague's experience also. As he found out this week.

It's just my opinion, but 150 sheets a day seems like more than the intended use of a cordless saw in the first place, even at only one cut per sheet. That is corded tool territory and still pushing that pretty hard. That's just the saw itself, the blade is taking that too.

Vondawg · « **Reply #15 on:** May 09, 2021, 10:53 AM »

“It's just my opinion, but 150 sheets a day seems like more than the intended use of a cordless saw in the first place, even at only one cut per sheet. “

^ This^

Cheese · « **Reply #16 on:** May 09, 2021, 12:38 PM »

Quote from: Lbob131 on May 08, 2021, 06:00 PM

Now if a 1.7mm (blade thickness) can be fitted, then it might be a whole different story.

Unfortunately, that's not really the solution either. The saws designed to run thin kerf (1.8 mm kerf & 1.3 mm plate) blades were designed around the thin kerf blade specifically to give them additional power and extended battery run time. If you just throw a regular kerf blade on those saws, the cutting will be slower and the battery run time will be shorter.

For instance, the original Festool TSC 55 with a regular kerf (2.2 mm kerf & 1.7 mm plate) blade when compared to the new Festool TSC 55 K version with the thin kerf blade, takes a longer time to cut and reduces the run time of the batteries. Thus, the reason Festool switched over to thin kerf blades for the new TSC. More power...more run time.

yetihunter · « **Reply #17 on:** June 15, 2021, 02:07 AM »

One cut with the KS 18 LTX 57 and then I threw it in the garbage. I’ve never seen an arbor wobble so much. I’m not alone. Do a look-see on another certain forum for a brand that uses Metabo batteries and a track system that Bosch shares. We discussed how horrible of a product the Metabo saw is. It can’t cut straight to save it’s life. As for the Dewalt, I can’t speak on it. Ridge Carbide makes a couple of $110 blades for it that have a thick plate, kerf and more carbide than you could dream of. You mentioned Trend blades so I’m presuming you’re either in the UK or whereabouts? I just ordered what appears to be Leitz blades (Mafell/Festool OEM) branded as Bayerwald. Dewalt tracksaw is 165x20, correct? They have a 24, 36 and 48. May be worth checking out?

Devils advocate: If you’re familiar with Bosch Expert thin kerf blades from Italy, imagine the amount of steel and carbide removed to get them sold here as Diablo for $6 a pop. They bend by blowing on them. Never heard of someone having an issue. I used to think the Diablos were ridiculously thin but then I met Makita. Here they sell what I thought was the thinnest circular saw blade I’d seen. However, in Japan, many brands offer 1.0 kerf blades for their 125mm circular saws. It’s insane. I’ve not used them enough to comment. Anyway, I was on the thicker plate bandwagon (was super anti thin kerf), and yes, the plates on the Mafell (and the HK) are not at all unsubstantial for their kerf. But, at the same time, I’ve been using the cheapies (Diablo) at work and I’ve noted that the results go against my prejudice.

For the Dewalt, try some thicker blades, who knows? For the Metabo, you have at least one person on the inter webs telling you that on their own specific unit…it was the saws fault.

Fredbear · « **Reply #18 on:** September 12, 2021, 05:31 PM »

Theres an old saying, “let the saw do the work” which I would apply to the thin kerf blades/cordless saws. Never had a problem with mine unless they’ve been used by someone else on site who has used them either freehand or with too much force.
IMHO , cordless doesn’t replace corded but can be more convenient and can achieve very good results if appropriate care is taken

Coen · « **Reply #19 on:** October 14, 2021, 05:06 PM »

Quote from: Cheese on May 09, 2021, 12:38 PM

Quote from: Lbob131 on May 08, 2021, 06:00 PM

Now if a 1.7mm (blade thickness) can be fitted, then it might be a whole different story.

Unfortunately, that's not really the solution either. The saws designed to run thin kerf (1.8 mm kerf & 1.3 mm plate) blades were designed around the thin kerf blade specifically to give them additional power and extended battery run time. If you just throw a regular kerf blade on those saws, the cutting will be slower and the battery run time will be shorter.

For instance, the original Festool TSC 55 with a regular kerf (2.2 mm kerf & 1.7 mm plate) blade when compared to the new Festool TSC 55 K version with the thin kerf blade, takes a longer time to cut and reduces the run time of the batteries. Thus, the reason Festool switched over to thin kerf blades for the new TSC. More power...more run time.

(Attachment Link)

Well, is that why 4-year old used TS 55 R's without blade are locally selling for 75% of the price of a new TS 55 F with blade? Maybe there are more people that don't like the thin blades.

And Festool deciding to apply the same thin blades to the mains-powered saws... they could have easily opted for a stronger motor there. Or a more efficient one maybe.

I still don't understand how slightly changed teeth and a 20% thinner blade results in 100% faster cuts. If you ask me... some cut quality was sacrificed. But that's my gut feeling, have not seen actual real-world comparisons.

Cheese · « **Reply #20 on:** October 14, 2021, 10:57 PM »

Quote from: Coen on October 14, 2021, 05:06 PM

1. Well, is that why 4-year old used TS 55 R's without blade are locally selling for 75% of the price of a new TS 55 F with blade? Maybe there are more people that don't like the thin blades.

2. And Festool deciding to apply the same thin blades to the mains-powered saws... they could have easily opted for a stronger motor there. Or a more efficient one maybe.

3. I still don't understand how slightly changed teeth and a 20% thinner blade results in 100% faster cuts. If you ask me... some cut quality was sacrificed. But that's my gut feeling, have not seen actual real-world comparisons.

1. Don't know what others want or think they want but I became a true believer in the 1.8 mm kerf blades after I purchased a Mafell MT 55. Mafell offers both of their 55 saws (corded & cordless) with 1.8 mm kerf blades. I believe that the Festool & Mafell blades are both manufactured by Leitz. After a summer of Mafell MT 55 use, the situation was clear from my perspective, go thin to win. I was much happier with the results especially when ripping solid wood. I purchased a MT 55 and I noticed the rip cuts were cleaner than what I was getting with either the TS 55 or the TSC 55, both of which used 2.2 mm kerf blades.

Interestingly enough, here's a comparison of rip cuts in aromatic cedar, which has a Janka hardness level similar to Mahogany, Maple, Cherry & Birch.

In the 2nd photo the TSC 2.2 mm (2 batteries) cut is on the top while the HKC 1.8 mm (single battery) cut is on the bottom.

2. Ya I agree, attaching a thinner kerf blade to the saw instead of incorporating a stronger motor was a copout. Pennies saved at the moment, yet for the future we all know there will need to be some further motor/power enhancements, 50+ years of tool improvements have validated that premise.

3. I don't know either, some of the Festool math is suspect.

However, I can't imagine that Mafell would jeopardize their reputation by supplying their saws with inferior blades...way too much to lose from their perspective.