Manufacturers have been wildly exaggerating their horsepower claims for years, referring to “instantaneous braking horsepower”…
Which is meaningless, because depending on how little duration you calculate the stop, horsepower would rise towards infinity.
1 horsepower is 750 watts. Any tool or appliance fed on a 120v 15amp branch circuit (12 amp at 80%), can’t be much more than 1hp, the inrush current would trip the breaker.
This is the third and oldest treadmill I have scrapped the motors out of. I repowered my drill press and lathe with the other two. This is the heaviest of the three at 39.5 pounds. It measures 14 inches long and is 4.5 inches diameter. I don’t have a dynamometer and I’m not about to build one just to prove something to you guys, so the world may never know. What I know is that the motors on my lathe and drillpress have served me very well. And that is what I care about. Just passing on what I think have been some of my sucesses. This could be valuable to someone. By the way 1 horsepower is 745.699872 Watts.
Impressive RindertW,
You surly show that you are not just a prettyface/internet voice, but a real down to earth DOer-of-Things.
Best Regards
treefarmer Steve unruh
Hi Garry,
I talked with my friend who is an electrical contractor. He looked at your post and gave me a refresher about a bunch of things I had half forgotten. I didn’t want to talk before because I wasn’t sure.
First these treadmill motors are direct current. They use a motor controller to feed them current that has been rectified. The ‘inrush current’, as you put it, only happens with ‘locked rotor’ (not moving) alternating current motors that are connected to ‘mains power’. The stuff that comes into the house from the pole.
So then, our calculations become very simple. Power is voltage multiplied by current, P=VI. This particular treadmill came with a 20 Ampher slow blow fuse. So Power = 120 volts x 20 amps = 2400 watts or 2.4 kilowats. If we divide 2400 watts by 746 watts per horsepower we get 3.2 horsepower. The fuse doesn’t blow when the motor uses 3.9 horsepower for a short time because it is designed not to. That’s why it’s called a slow blow.
Rindert
My wife likes it. What I care about. 
As I am sure you know. Make sure you grab the power supply. 
They are typically high voltage and fairly expensive. You sometimes can rip things like caps and mosfets off the boards as well for the motor driver circuit.
Really, what I do is just take the whole system off the treadmill and and put it on the new machine I want to repower. Not a single electronic part left behind.
What is the best way to get a stuck spark plug out of an aluminum head? I think the corners are rounded off on the plug. The other one came out, but this one stuck.
I would start with these: 6 point socket, heat, solvent, work back and forth from lower to higher setting with an adjustable impact wrench, then get creative if these don’t work.
I would try candle wax and six point socket. Try tightening just a little and then loosening. Don’t jerk or hammer it, just a steady twist for a full minute. It always works for me.
The problem is it won’t grip to twist at all. It is soaking in pb blaster. The space is too thin to get an impact socket on it. I think I am going to grind down the socket slightly to see if that gets a better grip. I had never heard of using candle wax before that is a neat idea.
SeanO’
Look into special auto lugnut removal sockets sets. Tool trucks items for sure. Maybe Harbor Freight. Princess Auto.
These are inside angled spiraled toothed. The better qualty are already thin walled. El cheapo’s could be outside wall ground down to fit into a deep spark plug socket well.
Ha! IF you are dealing with Ford Modular aluminum V heads then there are already broken off spark plug kits out there to choose from. And good-luck to you.
tree farmer Steve unruh
I’ve always used hammer shock. Never heard of keeping twist pressure on for a full minute, but I sure will try it next time. Thanks for this tip.
I went and got another 13/16 spark plug socket and a 3/4" 6 sided socket, I tried the 13/16th and had the same issue.I got all mentally prepared to hammer it on the 3/4", and well it fit, and came right out. Just like the other side did. smacks head I put them both back in to keep dirt out while I go get new ones, but I am going to look to see if they are the same. I am guessing they aren’t.
I always use copper never seize on spark plugs, especially with alum. heads.
I use the nickel-based never seize on just about everything, especially spark plugs and anything that’s outside. i’m sure the copper would work too, but the guy who put me on to never seize many years ago used the nickel.
I did compile a lot of hints for removing stuck and broken fasteners here:
https://spaco.org/MachineShop/StuckFasteners.html
copper is just for higher temps.
Using a bit of anti-seize when you install them helps quite a bit.
I am unfamiliar with this sort of treadmill. Does it plug into a standard 15 amp receptacle? Electrical code specifies a continuous current rating for a branch circuit at 80%, so P=ExI, 1,440 watts. A 20 amp will be 1,920 watts. Try running the microwave and toaster on the same branch circuit…
I buy the DC motor part, makes sense for the torque, and to avoid the inrush current. (Induction motor starting current is not from locked rotor, rather the rotating field in the start winding trying to near instantly accelerate the rotor. )
Anyways, I buy that the DC motors can be torque-ier on a given branch circuit (unless resorting to PLC’s). (Variable frequency drive). It sounds like a good obtanium item. But those numbers don’t jive.
It will trip a 15 Amp breaker imediately. It needs a 20 Amp breaker, minimum. Not perfectly certain but I suspect this was among the first treadmills sold to consumers, back in the 1980s. Slightly more modern ones would probably be more usefull to us. This one has a rated speed of 3200 rpm, whereas newer ones seem to be around 6000 rpm. New ones weigh about a third of what this one does. New ones are usually rated at 2 or 2.5 horsepowers. New ones don’t trip a 15 Amp breaker.
