This is why I love your videos, Matthias. No where else would you see a woodworker hooking up a guitar tuner to a router table in the name of science. Absolutely brilliant!
Matthias I recently watched one of your videos discussing what appears to be some changes in viewing numbers on RUclips as well as one from John Heitz. You both left me with the feeling that you were getting frustrated and almost sounding like you might stop doing them. I watch some but not all of your videos due to time restraints. I have been a hobbyist woodworker for 40 plus years, now 73 years old, and I learn something new every time I watch. Just now after searching the web for 30 minutes trying to learn about speed controllers, I found this video. THANK YOU. A perfect example of how well you demonstrate and explain things. I certainly hope you do not stop doing it. P.S. I am a proud Canadian and will keep learning from you.
Good video. I was attracted by this as my hobby is electric RC car racing. There are a few different types of speed control used in RCs. The older ones (used on brushed motors) simply added more voltage the more you pulled the trigger. The newer ones (used on brushless motors) actually take feedback either through the motor wires or through a sensor cable, connected to Hall sensors in the motor, to control motor speed. The latter would seem to be the case with the last router you demonstrated. I believe my lawnmower does this too!
Thanks Matthias, for another useful video. Some years back, I bought a Skil jigsaw in the US and brought it to India where I live. I designed a power supply for 230V AC using a triac and other components and replaced the PCB inside with this one. The saw is working satisfactorily at 230V. If I redesign the circuit incorporating a microcontroller, I can have useful features like soft start and overload protection. If the built-in controller of Ridgid router is more effective in maintaining the set speed, the reason could be that speed sensors are used in the circuit for constant speed under different load conditions.
I bought the same Ridgid for my home made router table because you gave it a decent review in a previous video. I really like it for the consistent power delivery. I also bought it for the "Lift" function.
As always, great investigating and useful information. Where would we be without guys like you and the others. I have learned so much from you, Izzy, Steve R, Jay B and others. Thanks for giving your time and effort.
A common method using the electronics in the speed controller is to have positive feedback linked to current draw. The electronics basically turns up the speed control knob as the motor draws more current under load to maintain the desired rpm. Making the amount of feedback adjustable allows the user to tailor the speed control to various motors since different motors will require different amounts of feedback to maintain r's. You can achieve pretty good control this way, but I suspect the better tools with built-in speed control use a tachometer for feedback to a microcontroller driving the triac.
I have a 12 year old Freud FT200E router (3.25 hp). parts are no longer available. the speed control went bad and I had to by pass it to get the router to work. now it works at full speed only. my question is, wouldn't this be a suitable situation to use an external control? also, my thought on your test conclusion is that the more powerful the router, the less variance there would be on the speed/load rpm's?
This is the difference between speed controls with and without feedback. For constant speed you need feedback from the motorshaft so the control knows when to adjust power to the motor to compensate for load variations.
Great Video! Like a governed internal combustion engine on a tractor does the Rigid brand router have a speed sensor built into it's circuitry that accomplishes this feat or is it because it just has that much power at the lower RPMs?
This is great, I was looking into motor speed control. I wonder how well something like a Super-PID would do in this case. That's what I was looking at for reducing the spindle speed for use in a CNC router.
Nice video. I'm not overly interested in woodworking, but I can relate this to my hobby. I'm interested in model trains, and I have the same issues with speed control. A lot of locomotives made around 2007 have the same problem with slow reactions to heavy loads. It causes them to slam around any time the friction acting on the train increases or decreases. The newer ones work just like the Ridgid router, instant speed compensation, no matter what happens.
Mathias, what are the chances that you will ever get into metalworking? I have loved all of your insights about woodworking techniques, equipment, etc. Your scientific approach to everything is particularly helpful and unique. I would love to see your explanations of concepts like thermal warping and internal stresses (such as while welding and cutting cold-rolled steel, respectively) and your techniques for managing them. Also comparing different methods of cutting various metals, heat treating, case hardening, etc. etc. Think it over... :)
For the first two cuts with the cheap speed control and variac,you pushed the board through smoothly in one motion, at a consistent speed, and we could easily hear the motor slow down. For the next tests you pushed a short distance, stopped, resumed pushing, stopped, resumed pushing. Hard to compare these tests.
One aspect I didn't understand was the problems with the external controller related to quality of cut and/or long term health of the router. In the long run is there danger? From some of the other comments it was helpful to learn why you want lower rpm for the larger bits. But the issue seemed to be the router bogging down ... Were the cuts themselves poor? Might they have been poor if a harder wood were used? Not trying to be snippy. .. good video that to me provoked a bunch of questions.
I am starting to do some woodwork and been looking for a router. Most routers its very loud when its ON, but both your routers is soundless? That's what I am looking for! Can you recommend which kind I should buy that is soundless also come with speed control? Would it be possible you can provide the model # for the 2 routers you got? Maybe I can check on eBay for the same one. There are too many models at homedepot, perhaps what specification should I look under that is soundless? Thanks much if you can advise,
Great video, Matthias! I assume the cheap speed controller is basically a sine wave inhibitor. I never have used one of those, now I'm glad I haven't. Of the 4 routers I have, two have evs on them, and they work great. One off topic question, though. If you were to build only one tool leaning towards setup ease and for versatility with your router, which would it be? My shop space is limited, but I love the capabilities of your machines.
What do be routers with built in speed control do that external speed controllers don't? What causes the router to bog down when here is a load applied on one with an external speed control?
It has the ability to sense the speed of the motor and dynamically adjust power accordingly. On the most expensive routers you'd have speed controllers custom engineered to suit the motor's power curve, load profile, high currents, etc. All the external controller can do is turn down or up the power based on a dial. The best analogy I can come up with right now is cruise control in your car. The computer in the car is able to sense when you're going up a hill and give it a bit more juice. This would be the equivalent of the "expensive built in" speed control. The external one would be the equivalent of putting a stick against the gas pedal--works great until you try to go up a hill.
The external speed control works best on applications where the load is nearly constant. Routers present widely varying loads, so to control their speed some sort of feedback to the speed controller is necessary to achieve good speed regulation. The inexpensive external speed controllers bog down since you set their operational speed under no load by reducing the power delivered to the motor. Then you apply a high load by cutting a heavy router cut. Since the external speed controller can't sense this increased load, the speed drops dramatically as the available power to the motor has been reduced.
arlen raasch An external speed controller does see the increased load in the form of increased current. An external speed controller can maintain the speed by providing positive feedback, proportional to current, to the speed control circuit. The question becomes how much feedback? An external universal speed controller could be built having two knobs. One to set the speed and one to set the amount of positive feedback as a result of current or load, which can be different form one motor to the next.
in theory it may be possible to do this, but since poor speed control would result if the positive feedback amount did not match the motor being used, the manufacturer does not attempt to do so. Better control becomes possible once one has a signal that is directly related to the speed of the motor like a shaft encoder.
I like your Note vs RPM table you made. I always wondered what note my bathroom exhaust fan hums at. I used to hum slightly out of phase to hear the beats..lol i'm weird.
I have a question. do you think of your projects yourself or do you have a staff of helpers to brainstorm your ideas? I really enjoy your videos very much. keep up the good work young man.
Nice video. I bought a Harbor Freight speed controller to use on a wood lathe so as not to have to swap around the pulley belts. It didn't work in the same way your excellent video demonstrates. The lathe speed would drop rpm as the load went up making it impossible to get consistent results. I'm waiting for one of you ingenious videos on what to do with a worthless speed controller.
This is an excellent example of the old saying, there is no substitute for real quality. It's nearly always worth while spending that extra money on getting good stuff.
Very interesting video. It now poses the question, "What's the alternative?" How do we get true speed control on a router without that feature from the factory? Thanks Matthias!
Matthias Wandel I never thought about the effects of the load. The Other options can only slow the router down and will not give it more performance. It should be called a router governer instead of a speed control box.
Matthias Wandel Haha, I had a feeling you would say that. Have you ever looked into transferring the variable speed components off of a router for easier access? For situations where the router is inaccessible I mean, such as under a router table.
I thought that those inexpensive speed controls like the yellow one you demonstrate and the Harbor Freight one were incompatible with any routers with the soft-start feature? The Porter-Cable one you said is old so maybe that one didn't have soft-start but the other two I would think do have soft-start. For example on page 19 of the Mastercraft manual it says: "Soft start feature The soft start feature minimizes torque twist, which is customary in larger router motors, by limiting the speed at which the motor starts. This increases the life of the motor."
The router (first) is rated at 10 amps. As is the variac. In my use of variacs as you decrease voltage out of them they don't provide the same max rated current as well. I just ran my 8.5a ryobi on a 20 amp variac and while it was not as good as a good built in speed control it did quite well. The external speed control os likely a mofset or triac design that chops the ac wave at a lower max voltage. A variac lowers the entire ac wave. Leaving it to still have a smooth clean input. This provides slightly smoother operation as well as possibly a cooler internal motor. Both of those speed controls will do very poor on a brushless or induction motor but ok on a brushed DC or universal motor. The built in speed control router likely is a brushed motor that the control reads the RPM and steps up the power to the motor in response to the RPM to regulate it. It could also be converting the ac to DC then into 3 phase and carting the frequency or to DC changing the pulse on and off of a DC brushed motor. Either of these would still be labeled as regular voltage single phase ac on the tool since the conversion is done Internally I'm going to try the tinder idea on my makeshift setup. I'm not a woodworker by trade nor an electrical engineer. However needed to set up sonthing to repair a bathtub shelf.
It's not the speed controller that deter mains the maximum amount of torque from an electric motor. The way the motor is build deter mains what the motor is capable of. The last router just has a bigger motor with a slightly larger coil. If you would replace the internal speed controller with an external speed controller from that last router you would have the same results. So yes, people can use an external speed controller, just keep in mind that you can't use large router bits if your motor isn't "big" or "strong" enough. This video should be called "A router with a strong motor" because this test doesn't say, show or proof anything useful about speed controllers.
I have perfect pitch, and it's strange, because in the video when you first set the speed with the tuner, what sounded sounded closer to an F, but at other points in the video the pitch displayed on the tuner seemed consistent with the pitch I heard from the machine.
I have a furnace motor powering scroll saw...was thinking of uding a Harbor Fright reostat to make it variable speed. This has given pause on that but also thinking it might work on a scroll saw due to not needing near as much hp to run it.
I wonder if you could hack the external speed controller to accept feedback input from the router RPM? Possibly a hall effect sensor or sonically with a transducer. An arduino or other cheap MCU could do the interfacing.
If you're electronically inclined, here's a PID controller that you can build yourself. hackaday.io/project/1280-simple-universal-motor-speed-controller
I can't think of any other woodworker who could just pull out a Variac for testing... Regarding the guitar tuner... I remember in high school physics using a strobe light (with a control knob to set the flash rate) to figure out the speed on something like this. Not that I have one of those OR the Variac...
You can always built-in ones as spare part and make a fancy enclosure for it. If you don't want to play a lottery with dirt cheap ones, which can or can not hold the speed, you can order Festool ones. I just don't know any other company, which sells spare parts to ordinary mortals. Just make sure power ratings of motor and regulator are close enough, if regulator ratings is too high it could mess your speed range.
Please excuse my ignorance as I am new to the world of routers. The router I have has fixed speed and until I saw your excellent video I didn't even know that they existed with variable speed. Could you please explain (to a layman) why the speed needs to be variable? Thanks
different router bits have a limit to what speed they can operate at... say, you have one rated for 12,000rpm but ran it at 20,000rpm.... chances are it'll cause severe damage to the bit, and potential injury... i have a ryobi router, and that has a max speed of 31,500 rpm :o
killer1479 Thanks for the information. My router came as a kit with several different router bits but no information about router bit speed limitations. Is there some sort of general guideline for safe speeds?
Mick S Having almost no router experience: If they came with the router, wouldn't it be safe to say that they can be used with that router and the current speed your router uses is the correct speed? If it's from a non-asian country (Japan excluded) then I think it's safe to say they've thought it though otherwise they could face major legal action.
sashablfc Until I saw this video I didn't know there were safety limits for router speed and have happily been using all of the bits in total ignorance about safe speeds. What krtwood said previously seems to indicate that it is only when you get up to the really big bits that there will be problems, which makes some sense.
Matthew Simmons The key is circuitry with a speed sensor. I suspect the other router doesn't have a direct speed sensor, so it's probably just guessing at the speed.
You just need a less primitive external controller, modern variable speed drives are able to sense the phase difference between voltage and current and use this to sense when power needs to be increased to prevent the motor from "slipping" instead of rotating synchronously with the power frequency.
+Matthias Wandel Thanks for the video, it helped me a lot. We're not talking about frequency, right? The fact is that the speed of a UniversalMotor is proportional to the voltage solely ?
the main thing to remember is that it is with those big heavy bits that you need speed control and they will be working hard so need to be able to get the current they need. lesson = what you pay for you get.
Speed control needs to raise the voltage as current increase to cancel internal resistance. Using a variable voltage source to regulte RPM is not enough. Even when both methods are open loop, the current sensing one is more likely to be a closed loop since is taking the load into account as it looks for current draw. Perhaps VFD is better option, not sure for universa type motor.
***** If the main video isn't that exciting, I like to publish another video during the week before it. so if you see a video mid-week, the main video probably won't be that exciting :)
Single sockets are 110V in canada. Though, his kitchen has sockets on opposing phases, so you can get 220 when you want it. (Matthias even has a device and a video about it)
bno112300 I live in the US, and my garage is wired with opposing phase sockets. The house is older, and is wired all single phase (except for the electric clothes dryer.)
I'm certainly not an expert on woodworking or routers, but why would you want to run a router at a speed lower than its maximum? More cuts per second = smoother cut?
Just a note again to everybody. If you ask a question, but have it set so I can't reply, then I can't reply. So instead, I just delete the question.
Sorry, I can't understand "If you ask a question, but have it set so I can't reply, then I can't reply". What do you mean? Why can't you reply?
Giovanni Bianchessi
There is a function in RUclips settings, You can set it so that people cannot +reply to a comment you have made.
MrLiveEra
Ok, now I understand! Thank you very much.
MrLiveEra Why do that?
Giovanni Bianchessi Replace the words "set the question" with the words 'phrase the question' . Nothing to do with YT settings.
This is why I love your videos, Matthias. No where else would you see a woodworker hooking up a guitar tuner to a router table in the name of science. Absolutely brilliant!
Comparing one of those router speed controller boxes to the internal speed control on other routers
I see your point, and I take back my suggestion to use the Harbor Freight Speed Control. Good Job.
Great imperical and anecdotal comparison. Valuable info as always Matthias Wandel. Thanks.
Thanks for this
RPM measured by a guitar tuner. Who else but Matthias would have figured that one out... :)
That's why he's my hero
anyone with some knowledge of physics, vibrations , mems and whatnot
Matthias I recently watched one of your videos discussing what appears to be some changes in viewing numbers on RUclips as well as one from John Heitz. You both left me with the feeling that you were getting frustrated and almost sounding like you might stop doing them. I watch some but not all of your videos due to time restraints. I have been a hobbyist woodworker for 40 plus years, now 73 years old, and I learn something new every time I watch. Just now after searching the web for 30 minutes trying to learn about speed controllers, I found this video. THANK YOU. A perfect example of how well you demonstrate and explain things. I certainly hope you do not stop doing it. P.S. I am a proud Canadian and will keep learning from you.
As a musician I loved the guitar tuner for monitoring pitch/speed! Clever and entertaining - as only you can be. Thanks for this video!!
Could you make a video with 6 routers tuned to Standard E and play Stairway to Heaven
Good video. I was attracted by this as my hobby is electric RC car racing. There are a few different types of speed control used in RCs. The older ones (used on brushed motors) simply added more voltage the more you pulled the trigger. The newer ones (used on brushless motors) actually take feedback either through the motor wires or through a sensor cable, connected to Hall sensors in the motor, to control motor speed. The latter would seem to be the case with the last router you demonstrated. I believe my lawnmower does this too!
Thanks Matthias, for another useful video. Some years back, I bought a Skil jigsaw in the US and brought it to India where I live. I designed a power supply for 230V AC using a triac and other components and replaced the PCB inside with this one. The saw is working satisfactorily at 230V. If I redesign the circuit incorporating a microcontroller, I can have useful features like soft start and overload protection. If the built-in controller of Ridgid router is more effective in maintaining the set speed, the reason could be that speed sensors are used in the circuit for constant speed under different load conditions.
Great Video Matthias. Can you do a follow up to this video with what speeds to use in what situations? Just general rule-of-thumb stuff.
man I love the trick of the tuner to set the speed.. Great video
I do enjoy the videos proving the ridiculousness of some products, methods, and joinery. Great job as always Matthias.
The use of the guitar tuner is so simple, but seems obvious now. I didn't see it for what it is (frequency gauge). Awesome video, thanks!
Never would have thought to use the guitar tuner to estimate RPMs. Excellent video as always!
I bought the same Ridgid for my home made router table because you gave it a decent review in a previous video. I really like it for the consistent power delivery. I also bought it for the "Lift" function.
Another splendid demonstration from the engineering viewpoint.
THANKS!
this video is very clear & the lighting was awesome. - I felt like I was right there with you!
2:55 ahhhh it looks like a cute duck!
As always, great investigating and useful information. Where would we be without guys like you and the others. I have learned so much from you, Izzy, Steve R, Jay B and others. Thanks for giving your time and effort.
Good info. How about a design for an external speed controller that does work - perhaps using the guitar tuner idea for feedback to a variac circuit.
A common method using the electronics in the speed controller is to have positive feedback linked to current draw. The electronics basically turns up the speed control knob as the motor draws more current under load to maintain the desired rpm. Making the amount of feedback adjustable allows the user to tailor the speed control to various motors since different motors will require different amounts of feedback to maintain r's. You can achieve pretty good control this way, but I suspect the better tools with built-in speed control use a tachometer for feedback to a microcontroller driving the triac.
I have a 12 year old Freud FT200E router (3.25 hp). parts are no longer available. the speed control went bad and I had to by pass it to get the router to work. now it works at full speed only. my question is, wouldn't this be a suitable situation to use an external control? also, my thought on your test conclusion is that the more powerful the router, the less variance there would be on the speed/load rpm's?
Excellent video ... and you now own the prettiest 2x4 in north america.
This is the difference between speed controls with and without feedback.
For constant speed you need feedback from the motorshaft so the control knows when to adjust power to the motor to compensate for load variations.
Great Video! Like a governed internal combustion engine on a tractor does the Rigid brand router have a speed sensor built into it's circuitry that accomplishes this feat or is it because it just has that much power at the lower RPMs?
very interesting! Plus now you have a 2x4 with a fun pattern on it!!
This is great, I was looking into motor speed control. I wonder how well something like a Super-PID would do in this case. That's what I was looking at for reducing the spindle speed for use in a CNC router.
Nice video. I'm not overly interested in woodworking, but I can relate this to my hobby. I'm interested in model trains, and I have the same issues with speed control. A lot of locomotives made around 2007 have the same problem with slow reactions to heavy loads. It causes them to slam around any time the friction acting on the train increases or decreases. The newer ones work just like the Ridgid router, instant speed compensation, no matter what happens.
Very interesting comparison of internal and external controls.
I never thought about using my clip on guitar tuner to meter speed, very cool!
Mathias, what are the chances that you will ever get into metalworking? I have loved all of your insights about woodworking techniques, equipment, etc. Your scientific approach to everything is particularly helpful and unique. I would love to see your explanations of concepts like thermal warping and internal stresses (such as while welding and cutting cold-rolled steel, respectively) and your techniques for managing them.
Also comparing different methods of cutting various metals, heat treating, case hardening, etc. etc. Think it over... :)
For the first two cuts with the cheap speed control and variac,you pushed the board through smoothly in one motion, at a consistent speed, and we could easily hear the motor slow down. For the next tests you pushed a short distance, stopped, resumed pushing, stopped, resumed pushing. Hard to compare these tests.
dude i just discovered your videos and freaking love them!
One aspect I didn't understand was the problems with the external controller related to quality of cut and/or long term health of the router.
In the long run is there danger? From some of the other comments it was helpful to learn why you want lower rpm for the larger bits. But the issue seemed to be the router bogging down ...
Were the cuts themselves poor? Might they have been poor if a harder wood were used?
Not trying to be snippy. .. good video that to me provoked a bunch of questions.
Thank you for demonstrating this. I often wondered about the external speed controls.
Matthias I always enjoy all your videos Thank you for your efforts. Do you know what amperage is when there is a load at full speed?
I am starting to do some woodwork and been looking for a router. Most routers its very loud when its ON, but both your routers is soundless? That's what I am looking for! Can you recommend which kind I should buy that is soundless also come with speed control?
Would it be possible you can provide the model # for the 2 routers you got? Maybe I can check on eBay for the same one.
There are too many models at homedepot, perhaps what specification should I look under that is soundless?
Thanks much if you can advise,
I'm fascinated by the RPM/Tonality Chart you dreamed up, is that document available for D/L on your web site?
Great video, Matthias! I assume the cheap speed controller is basically a sine wave inhibitor. I never have used one of those, now I'm glad I haven't. Of the 4 routers I have, two have evs on them, and they work great.
One off topic question, though. If you were to build only one tool leaning towards setup ease and for versatility with your router, which would it be? My shop space is limited, but I love the capabilities of your machines.
I was going to get one but based on your video it wouldn't actually help in my application. Thank you for saving me the money!
My mind exploded when you pulled out the guitar tunner.
You Sir are a pure genius to say the least and simple I thank you kindly for hours of outstanding video footage. CHEERS
What camera are you using? the quality is very good :)
What do be routers with built in speed control do that external speed controllers don't? What causes the router to bog down when here is a load applied on one with an external speed control?
It has the ability to sense the speed of the motor and dynamically adjust power accordingly. On the most expensive routers you'd have speed controllers custom engineered to suit the motor's power curve, load profile, high currents, etc. All the external controller can do is turn down or up the power based on a dial.
The best analogy I can come up with right now is cruise control in your car. The computer in the car is able to sense when you're going up a hill and give it a bit more juice. This would be the equivalent of the "expensive built in" speed control. The external one would be the equivalent of putting a stick against the gas pedal--works great until you try to go up a hill.
It is the difference between speed "regulation" and speed "control".
The external speed control works best on applications where the load is nearly constant. Routers present widely varying loads, so to control their speed some sort of feedback to the speed controller is necessary to achieve good speed regulation. The inexpensive external speed controllers bog down since you set their operational speed under no load by reducing the power delivered to the motor. Then you apply a high load by cutting a heavy router cut. Since the external speed controller can't sense this increased load, the speed drops dramatically as the available power to the motor has been reduced.
arlen raasch An external speed controller does see the increased load in the form of increased current. An external speed controller can maintain the speed by providing positive feedback, proportional to current, to the speed control circuit. The question becomes how much feedback? An external universal speed controller could be built having two knobs. One to set the speed and one to set the amount of positive feedback as a result of current or load, which can be different form one motor to the next.
in theory it may be possible to do this, but since poor speed control would result if the positive feedback amount did not match the motor being used, the manufacturer does not attempt to do so. Better control becomes possible once one has a signal that is directly related to the speed of the motor like a shaft encoder.
I like your Note vs RPM table you made. I always wondered what note my bathroom exhaust fan hums at. I used to hum slightly out of phase to hear the beats..lol i'm weird.
That's some nice blade dulling action right there...
Thanks for the thorough comparisons. Always love your videos!
I have a question. do you think of your projects yourself or do you have a staff of helpers to brainstorm your ideas?
I really enjoy your videos very much. keep up the good work young man.
do you have video how did you make this table and all function and wood components?
Nice video. I bought a Harbor Freight speed controller to use on a wood lathe so as not to have to swap around the pulley belts. It didn't work in the same way your excellent video demonstrates. The lathe speed would drop rpm as the load went up making it impossible to get consistent results. I'm waiting for one of you ingenious videos on what to do with a worthless speed controller.
***** Read the instructions on the speed controller. I'm sure it says it's not suitable for induction motors, like the one on your lathe.
Matthias Wandel I should add, using that speed controller on the lathe is a good way to ruin the motor.
Matthias Wandel
Thanks for the warning.
This is an excellent example of the old saying, there is no substitute for real quality. It's nearly always worth while spending that extra money on getting good stuff.
It would be interesting to see the same comparison done with a super PID frequency control. I plan on adding one to my CNC router.
Very interesting video. It now poses the question, "What's the alternative?" How do we get true speed control on a router without that feature from the factory? Thanks Matthias!
zuggyrama The cheapest option to get speed control when you have a router with no speed control is to buy another router that has it built in.
Matthias Wandel I never thought about the effects of the load. The Other options can only slow the router down and will not give it more performance. It should be called a router governer instead of a speed control box.
Matthias Wandel Haha, I had a feeling you would say that. Have you ever looked into transferring the variable speed components off of a router for easier access? For situations where the router is inaccessible I mean, such as under a router table.
Very informative. Thank you. Answered a lot of questions for me. You just saved me some time and money.
You have great videos. I learn something each time. Thanks.
Good video, thank you. for info the Bosh 2.25hp is doing really well at controlling speed (
0:45 wow that's actually pretty cool... Impressive that u thought to do that
I thought that those inexpensive speed controls like the yellow one you demonstrate and the Harbor Freight one were incompatible with any routers with the soft-start feature? The Porter-Cable one you said is old so maybe that one didn't have soft-start but the other two I would think do have soft-start. For example on page 19 of the Mastercraft manual it says: "Soft start feature The soft start feature minimizes torque twist, which is customary in larger router motors, by limiting the speed at which the motor starts. This increases the life of the motor."
Really like the look of that ammeter.Can you do a video on it?
The router (first) is rated at 10 amps. As is the variac. In my use of variacs as you decrease voltage out of them they don't provide the same max rated current as well. I just ran my 8.5a ryobi on a 20 amp variac and while it was not as good as a good built in speed control it did quite well.
The external speed control os likely a mofset or triac design that chops the ac wave at a lower max voltage.
A variac lowers the entire ac wave. Leaving it to still have a smooth clean input. This provides slightly smoother operation as well as possibly a cooler internal motor.
Both of those speed controls will do very poor on a brushless or induction motor but ok on a brushed DC or universal motor.
The built in speed control router likely is a brushed motor that the control reads the RPM and steps up the power to the motor in response to the RPM to regulate it. It could also be converting the ac to DC then into 3 phase and carting the frequency or to DC changing the pulse on and off of a DC brushed motor. Either of these would still be labeled as regular voltage single phase ac on the tool since the conversion is done Internally
I'm going to try the tinder idea on my makeshift setup. I'm not a woodworker by trade nor an electrical engineer. However needed to set up sonthing to repair a bathtub shelf.
No questions from me. Well said. Well done.
It's not the speed controller that deter mains the maximum amount of torque from an electric motor. The way the motor is build deter mains what the motor is capable of. The last router just has a bigger motor with a slightly larger coil. If you would replace the internal speed controller with an external speed controller from that last router you would have the same results. So yes, people can use an external speed controller, just keep in mind that you can't use large router bits if your motor isn't "big" or "strong" enough. This video should be called "A router with a strong motor" because this test doesn't say, show or proof anything useful about speed controllers.
Hey Matthias,
can you show us a result comparison in between different RPMs ?
:)
I have perfect pitch, and it's strange, because in the video when you first set the speed with the tuner, what sounded sounded closer to an F, but at other points in the video the pitch displayed on the tuner seemed consistent with the pitch I heard from the machine.
Matthias, thanks for the great information. Great for when I eventually buy a full size router.
I have a furnace motor powering scroll saw...was thinking of uding a Harbor Fright reostat to make it variable speed. This has given pause on that but also thinking it might work on a scroll saw due to not needing near as much hp to run it.
Maybe it is already asked by someone else but, how about Variable Frequency Drive ? would that be a better option ?
yes, asked many times. Not suitable
I wonder if you could hack the external speed controller to accept feedback input from the router RPM? Possibly a hall effect sensor or sonically with a transducer. An arduino or other cheap MCU could do the interfacing.
If you're electronically inclined, here's a PID controller that you can build yourself. hackaday.io/project/1280-simple-universal-motor-speed-controller
I would love to see you either design or just build a mechanically expanding table
Great comparison. Thanks for sharing.
I can't think of any other woodworker who could just pull out a Variac for testing...
Regarding the guitar tuner... I remember in high school physics using a strobe light (with a control knob to set the flash rate) to figure out the speed on something like this. Not that I have one of those OR the Variac...
You can always built-in ones as spare part and make a fancy enclosure for it. If you don't want to play a lottery with dirt cheap ones, which can or can not hold the speed, you can order Festool ones. I just don't know any other company, which sells spare parts to ordinary mortals. Just make sure power ratings of motor and regulator are close enough, if regulator ratings is too high it could mess your speed range.
Love your stuff
Cheers
Thanks Mathias very informative!!!
Please excuse my ignorance as I am new to the world of routers.
The router I have has fixed speed and until I saw your excellent video I didn't even know that they existed with variable speed. Could you please explain (to a layman) why the speed needs to be variable?
Thanks
different router bits have a limit to what speed they can operate at... say, you have one rated for 12,000rpm but ran it at 20,000rpm.... chances are it'll cause severe damage to the bit, and potential injury... i have a ryobi router, and that has a max speed of 31,500 rpm :o
killer1479
Thanks for the information.
My router came as a kit with several different router bits but no information about router bit speed limitations.
Is there some sort of general guideline for safe speeds?
Mick S Having almost no router experience: If they came with the router, wouldn't it be safe to say that they can be used with that router and the current speed your router uses is the correct speed? If it's from a non-asian country (Japan excluded) then I think it's safe to say they've thought it though otherwise they could face major legal action.
krtwood
Thanks
sashablfc
Until I saw this video I didn't know there were safety limits for router speed and have happily been using all of the bits in total ignorance about safe speeds.
What krtwood said previously seems to indicate that it is only when you get up to the really big bits that there will be problems, which makes some sense.
What circuitry is used to do speed control correctly in the last router you tested?
Matthew Simmons The key is circuitry with a speed sensor. I suspect the other router doesn't have a direct speed sensor, so it's probably just guessing at the speed.
You just need a less primitive external controller, modern variable speed drives are able to sense the phase difference between voltage and current and use this to sense when power needs to be increased to prevent the motor from "slipping" instead of rotating synchronously with the power frequency.
Hug0agogo There is a difference between universal motors and induction motors. You might want to read up on that.
+Matthias Wandel
Thanks for the video, it helped me a lot.
We're not talking about frequency, right? The fact is that the speed of a UniversalMotor is proportional to the voltage solely ?
Wonderful display!
the main thing to remember is that it is with those big heavy bits that you need speed control and they will be working hard so need to be able to get the current they need. lesson = what you pay for you get.
Always interesting Matthias Thanks
Cool experiment! Thanks
Speed control needs to raise the voltage as current increase to cancel internal resistance. Using a variable voltage source to regulte RPM is not enough. Even when both methods are open loop, the current sensing one is more likely to be a closed loop since is taking the load into account as it looks for current draw. Perhaps VFD is better option, not sure for universa type motor.
If you have the cash, you could put super pid controller on there. Although you need to install a speed sensor in the router.
Thanks for the vid.makes me wanna get the ridged router even more....
Nice test. Don't lie I know your thinking now what can I do with this 2x4 with all the profiles. ;)
I saw a duck head take shape on the third pass. He could use that as a starting point for a flock of mini duck carvings lol
GTFO - Guitar tuner to rough out the RPM.... this, was an excellent channel to stumble across on accident. 👌+Subscribe
@AdamR nah, only 2300w :) you can buy plenty of machines with that in Sweden and we use 230v :)
Where can I find that chart with rpm to rps to the musical note.
***** If the main video isn't that exciting, I like to publish another video during the week before it. so if you see a video mid-week, the main video probably won't be that exciting :)
Have all the routers the same power?
BIG difference. Ridgid wins, hands down!
Not really sure what the speed controller unit is good for, maybe light duty applications.
Excellent Test - Thanks.
I love your science!
Are you shooting with a GoPro?
Where did you find that chart?
Does Canada use 110/120V or 220/240V? Because damn... 10-11A at 220/240V would be insane.
110/120V
Single sockets are 110V in canada.
Though, his kitchen has sockets on opposing phases, so you can get 220 when you want it. (Matthias even has a device and a video about it)
bno112300 I live in the US, and my garage is wired with opposing phase sockets. The house is older, and is wired all single phase (except for the electric clothes dryer.)
en.wikipedia.org/wiki/Mains_electricity_by_country Canada is 120V mains like the US.
Great demo thanks.
Thank you sir, was about to buy one of these for my craftsman fixed speed... now I'll pass!
Tim Royal Still useful for some applications.
My main thought for use was for larger bits, obviously the power loss and slow down makes this problematic.
Matthias, If you push the 2X4 thru fast,slow,fast,fast,slow you can get the beginning of free bird
Compartilhe a tabela das notas em rpm com nós amigo
I'm certainly not an expert on woodworking or routers, but why would you want to run a router at a speed lower than its maximum? More cuts per second = smoother cut?
and more dust, more vibration, more burning, and shorter tool life
Very interesting information.