Converting Drill Press to Variable Speed

[Exodus_2pt0]

Useless post, but I didn't there was such a thing as a brushless dc motor. I thought all brushless motors were AC, and the speed controller converted it to ac.

Learn something new every day.

[flyboyx]

in my area, i could just set the detrius out by the street and some metal scrap hauler would make it disappear in less than 3 hours.

all of the features you are looking for are availible for brushed permenant magnet motors. the DC control box i have on my little lathe in the video i posted above has brake functionality. watch the video again and take a good look at the controls on the box. i didn't bother hooking it up. i couldn't imagine a good use for this feature on my drill press. since you switched over to a hand tightened chuck, i guess i could see how it might come in handy for you. personally, i am going to stay with a keyed chuck for my drill press. in my experience, i don't think the convienience of hand tightening offsets the greater tightening ability(leverage) a traditional chuck provides.

an option for you in liu of a braking feature would be to add something to the spindle pulley on the top of your machine that you can easily lock in place or perhaps some sort of handle you can hold with one hand while tightening the chuck with your other hand.

as to reverse, the motor is DC. all you have to do is swap the power leads to the motor and it will run backwards. a simple separate switch would take care of that just fine.


the twist lock plug is a really cool feature, but you do realize you are going to spend another 300 bucks in order to save 30?

i understand that you are probably looking at this project as a forever tool. there is someting to be said about cool projects that don't make economic sense. i'm pretty sure you are going to have over 600.00 invested in this tool if you decide to use something other than a tread motor. that is easily 2x the value you would ever hope to recoup.

[bmwman91]

I think you made a good choice going this route. i am kinda surprised that you purchased the parts off ebay when they are so readily availible to you locally.

https://sfbay.craigslist.org/scz/spo/d/capitola-live-strong-treadmill/6935428322.html

https://sfbay.craigslist.org/pen/zip/d/south-san-francisco-livestrong-ls130t/6935314644.html

https://sfbay.craigslist.org/eby/for/d/fremont-vitamaster-triumph-by/6934989502.html

https://sfbay.craigslist.org/sby/spo/d/san-jose-ironman-treadmill/6928302480.html

https://sfbay.craigslist.org/eby/spo/d/danville-free-treadmill-nordic-track/6934834173.html

https://sfbay.craigslist.org/nby/spo/d/geyserville-golds-gym-treadmill/6934758782.html

https://sfbay.craigslist.org/eby/spo/d/dublin-treadmill/6934063194.html

Andrew: to be clear, i used a 1/7hp motor on my mini lathe. bmwman is correct. treadmills have motors that are in excess of 1 horsepower but the comparison to an induction motor is not equal. the DC version makes so much more torque. this is why they are used in treadmill applications in the first place. think of some 400 lb fat fucker jumping on that thing trying to walk up a 6 degree incline.....

You are correct that I could DIY part-out a treadmill. There is a reason why entire treadmills are so cheap. It would cost north of $200 to have junk haulers take it out of your house. I don't need a half-disassembled treadmill on my property...I have already spent a lot of money to de-junk my house over the last few years!

Also, the eBay seller apparently dropped the box on the way to FedEx and broke the controller or something. I have asked them to cancel the order, so I will keep an eye out for other setups. At the same time, I am still thinking about the $$$ BLDC setup since the controllers have braking functionality, reversing for occasions when I need to extract broken shit, closed loop speed control, and the external PSU can run on 240V input which would allow me to keep the $30 NEMA twist lock plug on the cord I made for the drill press (despite the BLDC setup costing way more than $30).

Anyway, I am still looking to see if any good treadmill setups are around online.

[MR E30 325is]

I am off to hunt for an old drill press now.....

Thanks!

P.S. Excellent work on the restoration.

[flyboyx]

for example: a 12v starter is a DC permenant magnent motor. think about how much torque those things produce is such a small package. the problem with using a starter is that it isn't designed for continuous duty. they heat up too fast.

[flyboyx]

I think you made a good choice going this route. i am kinda surprised that you purchased the parts off ebay when they are so readily availible to you locally.

https://sfbay.craigslist.org/scz/spo/d/capitola-live-strong-treadmill/6935428322.html

https://sfbay.craigslist.org/pen/zip/d/south-san-francisco-livestrong-ls130t/6935314644.html

https://sfbay.craigslist.org/eby/for/d/fremont-vitamaster-triumph-by/6934989502.html

https://sfbay.craigslist.org/sby/spo/d/san-jose-ironman-treadmill/6928302480.html

https://sfbay.craigslist.org/eby/spo/d/danville-free-treadmill-nordic-track/6934834173.html

https://sfbay.craigslist.org/nby/spo/d/geyserville-golds-gym-treadmill/6934758782.html

https://sfbay.craigslist.org/eby/spo/d/dublin-treadmill/6934063194.html

Andrew: to be clear, i used a 1/7hp motor on my mini lathe. bmwman is correct. treadmills have motors that are in excess of 1 horsepower but the comparison to an induction motor is not equal. the DC version makes so much more torque. this is why they are used in treadmill applications in the first place. think of some 400 lb fat fucker jumping on that thing trying to walk up a 6 degree incline.....

[bmwman91]

Most of the treadmill motors that I have seen are rated at somewhere between 1.5 & 4HP. "Rated" anyway. Even if they can only reliably deliver half of what is on the nameplate/sticker, it's probably more than the stock motor.

I am not super concerned with noise, I was just thinking that it would be cool to run this as quiet as possible. But then again, it is likely not worth the extra $350 to run a big brushless when eBay can get me a motor and controller for <$200. So maybe I will go for the eBay conversion first and see how it does. Worst case, I don't like it and I re-sell it on eBay, and make the BLDC one.

I just pulled the trigger on the setup below even though I may have been able to piece something like this together for a little less, but having a working motor and control all in one shot was easy. The control panel will be discarded and I'll just program up my own PWM control with a microcontroller. I want to have a tachometer and segmented LED readout, so it was going to need it anyway. I may even experiment with closed-loop RPM control!

https://www.ebay.com/itm/323840930455

[LJ851]

Hmmmm, i was unaware of this possibility.

I have a good American made Rockwell drill press and my only gripe is that i can't slow the spindle down enough and i also have a pretty heavy duty treadmill that could be a donor...

Time to check the HP rating of the treadmill.

[AndrewBird]

I literally just bought an 80's-vintage drill press the same day you started this thread and was already thinking about variable speed control.

I'd be more concerned about a treadmill motor not having enough power. 1/2hp on a drill press is not a lot. I'd shoot for a full 1hp. Go big or go home.

[flyboyx]

I mean.... you are using the tool in your shop and not in church....so.... honestly, the noise is inconsequential. It is much quieter than the induction motor that came with the tool. The tread motor will be quieter than your original also.

My point is that using sound level as a primary consideration seems a bit silly in my opinion.

It is infinitely more powerful. This particular example is a 1/7hp pma. It produces more than enough power at the slowest speed to where I couldn’t even think about stalling it. The original single speed induction was rated at 1/10th hp and could easily be stopped by pushing a cutting tool a little too deep into the stock. It is literally night and day.

If you decide to go pma, you can save a ton of money by buying a used mill and you will be thrilled once you are done

[bmwman91]

i have the solution for you.

toss that motor in the trash. go buy a used treadmill off craigslist for 100 bucks or less.

take out the motor(about 1 horsepower) and the controller. there are tons of videos on youtube that show you how to make this work. they are mostly geared toward lathes but you are a smart guy so you can adapt it to this project with ease.

here is a youtube vid of my mini lathe/mill that i repowered with a DC permenant magnet motor.

https://youtu.be/drbiL399Yr0

in my case, i bought the motor and controller new off ebay. i have about 120.00 invested in the complete conversion.

Nice! Yeah the treadmill motors were one of my first considerations. I was sort of afraid that the brushed motors would be noisy, particularly with an SCR type speed control (which is what all of the treadmill controls are for the most part). Is most of the noise in your video the spindle bearings?

[Metallated]

Cleaned up really nicely

[marshallnoise]

I ain't gonna lie, this is dope.

[Mike36]

https://youtu.be/drbiL399Yr0

Way too cool, I gotta look into this!

[flyboyx]

really nice restoration by the way!