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Post by kraftt on Jun 8, 2020 21:46:15 GMT -5
My new MT55cc was just shipped, FINALLY, after a seemingly absurd (to me) time to ship (Ordered May 26). Has anyone else had longish delays with Timberwolf lately? They wouldn't ship what they had and the rest of the order later without making me pay more shipping, and I was kind of off-put by that (and being a cheapskate, opted to wait instead of paying another ~$30 for shipping).
Anyway, other than that being irksome (and probably off-topic), Timberwolf mentioned in their shipping emial that the MT55 has a "motor modulation" feature; I remember reading elsewhere that it is something that many have experienced; has anyone had any issues with cutting quality using those slow speeds, other than it seems weird to have a modulation like this? Coming from a background where VFDs are used all the time for exacting speed / torque control, it seems odd to have modulation on the speed like that, but if it doesn't affect cut quality, I don't really care other than think it's odd.
From Timberwolf: I think this has to do with how mafell gets around not having a riving knife. They employed an electronic safety measure to comply with protection regulation. " ...MAFELL has combined the benefits of enhanced active safety, improved handling and enhanced cut quality – without a riving knife. According to the manufacturer, active kick-back protection averts the danger of recoil when the blade enters the work more effectively than a riving knife. In addition, design measures introduced alongside standard EN 60745-2-5, which entered force in 2007, have increased the passive safety of saws that dispense with a riving knife..." |
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rob2
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Post by rob2 on Jun 9, 2020 1:01:11 GMT -5
Timberwolf mentioned in their shipping emial that the MT55 has a "motor modulation" feature; I remember reading elsewhere that it is something that many have experienced; has anyone had any issues with cutting quality using those slow speeds, other than it seems weird to have a modulation like this? Coming from a background where VFDs are used all the time for exacting speed / torque control, it seems odd to have modulation on the speed like that, but if it doesn't affect cut quality, I don't really care other than think it's odd. Modulation does seem odd. Nowadays, when constant speed electronics on tools is a norm it is strange to see MT55 revving up and down when idling. None of my other saws, routers, osculating tools, sanders etc. does this. I don't think it affects cut quality as it stabilizes under load. However, torque on lower speeds is noticeably lower. Namely, it won't cut through 2x4 at setting #2. Also, when you cut material that requires low speed (plastic, for example) and that material is thin, i.e. does not offer much resistance, it might continue to modulate even while cutting. |
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Post by hecon5 on Jun 9, 2020 6:28:21 GMT -5
That cut quality isn't a problem means this is all just academic (to me, anyway).
Jumping down that rabbit hole/physics vortex:
I bet it's a lot easier to monitor for kickback (and reduce kickback likelihood to begin with, actually), especially at the low speeds with the motor modulating. Then, the saw blade will act much more like a hand saw (as you push / pull the saw through the material), followed by a rest period at the top and bottom of the stroke. With the slow periods, the material will have time to flex back into position, as will the saw blade, and instead of getting any blade warp or material warp, they're perpendicular to each other during all cut actions. Note that we're talking minuscule amounts of flex for the blade and material, but with plexiglass/thin materials, a little would make a big difference. The other benefit to this mode is similar to impact wrench work theory: with a lot of short burst high energy strokes instead of one tremendous "oomph" stroke, you are more able to overcome the static friction of a rusted on nut, and you're also far less likely to have the wrench ripped out of your hand and into your face/arms/legs/neighbor, etc. With a modulating blade, the cuts will act more like a lot of short bursts, overcoming static friction between material and the blade, and thereby reducing the kickback likelihood.
Since kickback is driven largely by static friction between the blade and the material (it's what happens when the blade sticks to the material and the torque, instead of moving the blade through the material moves the saw because the static friction coefficient of blade:Material is higher than the static friction of the the saw:track/surface, and the equal/opposite forces are put into overcoming the "easier" obstacle of the saw:track coefficient and moves the saw). Speed modulation means a larger "whack", and shorter duration, so that if you did start kicking back, the saw will very soon slow down and 'reset', allowing the kickback to stop before it rips out of your hand.
Since the lower speeds don't cut 'harder' materials like 2x4's, it sounds like they're actually torque controlled vs speed controlled. Torque control on VFDs is by nature unstable speed-wise (you're targeting a force output, and not some arbitrary RPM), so low torque will almost certainly have a speed modulation outcome unless you've bounded the controls with speed bounds, which means more electronics, more cost, and considerably diminishing returns vs. 'outcome improvement', whatever that means with a saw. The goal of a saw is to cut. If it's cutting well, not much reason at all to further tune the speed control.
As to why a router won't: my router has electronic speed control and doesn't do it. The torque on the lowest speed setting vs the highest speed setting isn't really that large of a difference (the diameter of the bits are at most ~50mm, and even that's a huge bit; diameter of the MT55 blade is 162mm, which is a HUGE difference in terms of lever arm on the shaft) so it never really gets low enough to effect torque output considerably at the low speeds; from what I gather, there's a fairly large span between the upper and lower settings on the MT55 and a considerably larger "arm", so we do see modulation.
I could also be quite off track (heh), and it's due to bad speed control, but from what I've read, and the fact that everyone who has Mafell tools seem to think they are clearly designed with intent (even the shifting score cut and 45 degree bevel offset seem to be intentional for various reasons), I'd imagine this was also intentional.
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rob2
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Post by rob2 on Jun 9, 2020 11:43:59 GMT -5
... everyone who has Mafell tools seem to think they are clearly designed with intent (even the shifting score cut and 45 degree bevel offset seem to be intentional for various reasons), I'd imagine this was also intentional.
That's just confirmation bias. Not everything is intentional, some things are just flaws. |
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rob2
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Post by rob2 on Jun 9, 2020 11:49:39 GMT -5
I think this has to do with how mafell gets around not having a riving knife. They employed an electronic safety measure to comply with protection regulation. Makita, Bosch, others do just well without riving knife yet have no perceivable modulation. |
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Post by aas on Jun 9, 2020 12:05:59 GMT -5
That's just confirmation bias. Not everything is intentional, some things are just flaws. I like your reasoning!.. it's still the best plunge saw I've owned though. |
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Post by hecon5 on Jun 9, 2020 12:07:14 GMT -5
rob2, do you like your MT55? Reading between the lines, it seems you begrudgingly accept it, but don't "like" it. Mine just came, and I'm pretty happy with the build quality (unboxing eval). I have another project that's needing attention, so no play time for me at the moment, but thus far, it seems pretty nice from taking it out of the box and checking it over for shipping damage. I do notice a slight "detent bump" as I plunge it. Being as I haven't actually cut anything yet, I'm not sure if it'd compromise the cut quality, and I think it has to do with the scoring shift function, but wondered if it's normal or not.
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rob2
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Post by rob2 on Jun 9, 2020 12:49:47 GMT -5
rob2 , do you like your MT55? Reading between the lines, it seems you begrudgingly accept it, but don't "like" it. Mine just came, and I'm pretty happy with the build quality (unboxing eval). I have another project that's needing attention, so no play time for me at the moment, but thus far, it seems pretty nice from taking it out of the box and checking it over for shipping damage. I do notice a slight "detent bump" as I plunge it. Being as I haven't actually cut anything yet, I'm not sure if it'd compromise the cut quality, and I think it has to do with the scoring shift function, but wondered if it's normal or not. "begrudgingly accept it" is a good way to put it. Overall built quality is superb. Dust collection is slightly better than Festool. Plunge hinge and trunions are very solid, beats all competition. These are important for me for bevel cuts. The way it slides on the rail is inherently worse than Festool. Score with shift is iffy (will disassemble and get rid of that). Moving away from splinter guard when beveled is unforgivable. Speed modulation is annoying, but seems inconsequential. Also, lack of on-board splinter guard on right side. I'm not a fan of any particular brand, each has positives and negatives. What is best tool for you, might not be best for someone else with other needs. "detent bump" as you plunge it is what it's supposed to be. If you look at the pivot you'll notice a gap opening up between washers. |
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Post by hecon5 on Jun 9, 2020 13:03:57 GMT -5
rob2: thanks! I appreciate your candor on this site (as well as everyone else's). To me, hearing about faults in a "this is a brown line, but it's wavy, when it'd be nice to have it be a straight brown line" is immensely more useful to me than "Oh I love this tool and there's no downsides" as it screams "I don't know how to adjust my tools or use them, and don't know its limits". Right this second, the MT55 has so many adjustments I'm not used to having available that it is "envelope-less" to me for now. In time, I'm sure I'll find the cases where the adjustments don't make it the ideal tool "for that specific job" and it'll be time to get more tools.
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Post by aas on Jun 9, 2020 15:05:39 GMT -5
The way it slides on the rail is inherently worse than Festool. You could always try it on the Festool rails - it does that too. |
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Post by aas on Jun 9, 2020 15:06:55 GMT -5
"Oh I love this tool and there's no downsides" I see you've had a look at the FOG then! |
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rob2
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Post by rob2 on Jun 9, 2020 16:38:20 GMT -5
"Oh I love this tool and there's no downsides" I see you've had a look at the FOG then! To be fair it was FOG 8-10 years ago. Not any more. Festool bashing goes unchallenged these days. |
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Post by mafellme on Jul 18, 2020 6:52:29 GMT -5
I connect a 32mm hose using Tom Gensmer’s tip of connecting only the quick change hose end ‘receiver’ that comes with stock Nilfisk hose. It ‘clips’ over/onto that rib. and won’t pull off. 
Do you have a specific part number for that Nilfisk connector, please, or is it only available if you buy a complete Nilfisk hose? I've not seen that one before.
I'm in the UK and I'm not really sure how to find that particular component - even though the Nilfisk dust extractors are rebadged by every man and his dog (Mirka's extractor is a Nilfisk Attix, for example, but I use a Starmix/Metabo extractor).
I use a Mirka tapered hose (MIN6519411) with my DEROS sander and with my MT55cc, but it has a very basic rubber connector which strongly mates to the ridges on the outside of the sander port, but only mildly grips when inserted inside the MT55ccs larger dust port, so it often falls out when the corrugations of the hose snag on the edge of a workpiece (when doing kitchen worktop hob/sink cut-outs, for example).
I'd be keen to buy a second Mirka hose to use just with my Mafell (they're amazing value for a 4 metre tapered anti-static hose) if I could get that Nilfisk quick-connect adaptor for it. I'm reluctant to shell out for a full Nilfisk hose unless it's competitively priced - I find most branded anti-static hoses to be painfully overpriced.
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Post by kraftt on Jul 18, 2020 9:00:43 GMT -5
Nilfisk 107417866 = 32mm AS Quicksystem Nilfisk 107417867 = 36mm AS Quicksystem Nilfisk 107417868 = 38mm AS Quicksystem  |
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Post by mafellme on Jul 18, 2020 9:24:36 GMT -5
Nilfisk 107417866 = 32mm AS Quicksystem Nilfisk 107417867 = 36mm AS Quicksystem Nilfisk 107417868 = 38mm AS Quicksystem
Many thanks for taking the time to post the info and pics. Much appreciated.
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