How to: Build a DC Treadmill Motor Speed Controller for $20

hey everybody it's Brian house here for housework and today we are going to build a DC motor controller to run an old treadmill motor from parts we bought on eBay for around 20 bucks now you might ask yourself like why do I want to do this well in this case I'm building a 2 by 72 grinder sander it's like a big belt grinder and sander and to go to a store or buy one online brand new there are a couple thousand dollars and I just don't want to invest that kind of money plus I really love projects like this so building something is always going to be my choice in this case I took all the parts that I purchased on eBay and that's act it's actually only two parts that we really need to make this happen and repurposed an old power supply from a computer it was very simple to put together didn't require any soldering or you don't really need to be an electrical engineer to do this this is something very easy to do these treadmill motors are readily available on Facebook marketplace and Craigslist you'll probably have to buy the whole treadmill and then cut it up and you know harvest whatever you want out of it in my case I actually sold the controller board on eBay for almost the same amount of money as I spent on the entire treadmill itself which was about $80 anyhow this is a real simple process so I'm gonna give you a brief demonstration of how this works again we are converting AC power to DC it is a very simple thing alright so we're going to click on the power in this case the fan that was in the power supply actually is a 12-volt DC power supply which the motor controller outputs 12 volt DC so I just went ahead and used it for cooling which is kind of important the potentiometer on this particular one is 220 K which is about right for what we want to do so I didn't even bother to swap it out so let's turn the potentiometer up just slightly and see what we get [Music] all right so it's moving kind of slow these motors were designed to do that because you know when you're on a treadmill you can ramp up and down and so on these motors are designed to actually handle that and let's turn it up see what we can do [Music] that's about halfway three quarters of the way and let this thing ramp down here I'm not gonna bother turning it all the way up because it really doesn't ever need to go that fast so you can see there are many uses for something like this I have seen people put them in band saws grinders Sanders all kinds of things and to know how to do this to make this work for cheap is actually really useful for your home workshop so come along with me on this process I'll show you how we did it really simple right here on housework stay with us so the first step to doing this is to take apart the controller that you got from eBay we're really only gonna use the bottom plate portion of it the fan and the potentiometer but we're gonna mount the potentiometer on the outside of the power supply so we can take that out as well now we turn to the power supply itself we have to take it apart in this case there's probably about six screws that are holding this thing together when you're doing this you really just want to take the cover off and get it open now something to think about when you're pulling one of these apart is the capacitors which are those big cylindrical looking things they're black they may still have power in them so just take a special care when you're pulling one of these apart you don't want to shock yourself I'm gonna use the backing plate and I took two measurements just to see where the screws could go drilled holes in those plates and put it back in and mounted it in now the reason I did this was because cooling is an issue always when you're doing anything like this and I wanted the heat sink and all the electronics to sort of hover on the inside of the case itself and I wanted it to be easily mountable as well so that just made sense to me next I'm trying to figure out exactly where I want to put the potentiometer and the power switch on this thing you don't have a ton of room in these little power supplies so it's kind of important that you really take a look at how much depth and where it's gonna go exactly and then also how are you gonna mount it on whatever you're building so I ultimately decided on this particular configuration which is the potentiometer on one side and the power switch on the other there really wasn't a ton of room in there anywhere else to do this because I'm gonna lay it flat on the 2 by 72 sander as you can see here I'm using hot glue to mount this thing I love how glue it works don't judge me alright so now our switch is mounted we are going to make sure that we have the potentiometer nice and tight in there and add the knob that's kind of important since it's something you need to hold on to just make sure it's tight all right now we're gonna look at the layout for the wiring and insert the AC wire from the old treadmill power cord the green is the ground the black is the hot and the white is the neutral now AC current stands for alternating current and it doesn't really matter which pole on the AC input side you use you can switch them back and forth and it won't matter one bit okay so I briefly want to go over the wiring configuration for this thing just so you're aware of what each thing is this is the AC motor controller it's this whole piece with the heatsink on it this is comes from eBay for about 10 or 15 bucks this guy is the bridge rectifier that's actually what converts AC over to DC power and this big black line that's over here this came with a treadmill this is the wall outlet cord so that's what's coming that's what's bringing in the AC power to this whole situation you have a switch this I just harvested from the treadmill itself the fan which is up inside of this case and the potentiometer which is here and it has a fancy little connector here that just plugs right into the board down in here real quick this is super simple three wires coming out of the wall outlet cord a black a white and an earth or a green color the black goes over to the switch because it's hot there's a red wire that comes back over to one of the poles on the AC input side of the AC motor controller and then the other the white one just goes into the other pole these are interchangeable as long as they're input AC it doesn't matter which side you put it into this blue wire and this white wire are the AC output again totally interchangeable doesn't really matter which pole you choose that goes over to the bridge rectifier now there is one label on this bridge rectifier and it is right here that you really want to pay attention to it says AC red rectifiers run diagonally so if this pole is AC this pole is AC so that is why you see the blue wire coming from the AC output and the white wire coming from the AC output poles over to these two poles here on the bridge rectifier now this red and this black go out to the motor so you can see how simple this setup is again these are interchangeable as long as it's AC and DC doesn't really matter if you swap out the DC poles these two you can take this black wire and put it on this red wire and vice versa it will just simply change the direction of them it won't blow it up won't blow anything up it'll just continue to work but change the direction if you have any questions about this project please go down to the comments section and leave me a comment below I do read them and respond to all of them also there are links down in the description that show you exactly what I purchased to make this happen you need a 10,000 watt SCR motor controller and a bridge rectifier those are the two main key components and again there's links down there that will take you to exactly what I used also if you found this video useful hit that subscribe button and the like button it does help me out a lot as always I do appreciate you my name is Brian house and this is housework 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Channel: House / Work

Views: 97,867

Rating: 4.9112148 out of 5

Keywords: DC Motor Controller, how to, build, workshop, tools, DIY, Treadmill motor speed controller, speed control dc motor, treadmill motor, dc motor controller diy, dc motor controller for treadmill motor projects, dc motor controller project, 110 volt, motor speed controller at home, dc motor, 2x72 belt grinder, 2x72, 2x72 belt grinder build, 2x72 grinder, 2x72 belt grinder treadmill motor

Id: 6wqQJQnM5Dw

Length: 10min 1sec (601 seconds)

Published: Wed Aug 14 2019