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250W weak motor?

jdm1

Aluminum
Joined
May 3, 2020
Hello, I am beginner hobbyist and could use some help with little problem.
I've got a 2nd hand drill press, 250W single-phase brushless, AC 220V, 1400 rpm, sized 18cm high x Ø18. I can drill 13mm in free machining steel but on other less friendly materials it stalls easily. I've measured the 6μF capacitor at 0F, got a replacement which measures correctly, but the issue remains. I can stop the motor pulley without any effort or risk. I don't think that is normal? To what should I look now?

 
Can't measure wattage because ATM I don't have a clamp meter and my DMM manual says no more than 25VAC in 6 or 10A ranges. I measured resistance at the motor poles, with no cap, at 85Ω

Tried bypassing the switch / protection and that made no difference.

Took apart the thing, no signs of rubbing, overheating or other damage.

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1 horsepower (HP) is approximately equal to 750 watts So your motor is roughly 1/3 HP.

I suspect on the small machine you are working with is purposely built to keep the operator from getting sucked into the machine and getting hurt. That is why the motor stalls so easily.

Use the graduated pulley to best mechanical advantage. Use good tooling that is properly sharpened. Clamp your work down so nothing is moving or allowed to grab and move.

Pay attention to the safety rules.

Someday when you move up to a real machine and the knowledge you gain now will help you to perform good work.

Don't hold onto a motor pulley with your hand again, next time it could make your body parts unusable.

Don't post about hobby machines at this website, they get really twisted about it.
 
250W at 1400RPM comes to 1.7 N-m of torque (or for us, 15 in.-lbs.). That is roughly what it takes to open a typical jar of pickles (or maybe in your case, Giardiniera). You have a very small motor, I don't think that what you are experiencing is out of the ordinary for that size.
 
I'm not sure I 100% agree that all is well. But it is not ridiculously weak, as you grab it I see your hand twist a bit. And it will drill holes.

Probably the drill press is made to operate at somewhat higher rpm, and that means not much torque at the drill. That is common with smaller drill presses, which are just not made for heavy work.

It may be possible to change pulleys or add a countershaft to get lower speed and more torque, but likely the better way is to obtain a more powerful machine if you need to drill larger holes.

It is also possible to drill a small hole first, and then use the final size drill to finish the hole to size. Small drill should be the size of the solid portion of the drill point on the larger drill.
 
250W at 1400RPM comes to 1.7 N-m of torque (or for us, 15 in.-lbs.). That is roughly what it takes to open a typical jar of pickles (or maybe in your case, Giardiniera). You have a very small motor, I don't think that what you are experiencing is out of the ordinary for that size.

Thanks, your and JST answers are the best ones,based on physicas, relevant to the question asked, and without any condescending attitude.
 
Nothing personal, small hobby machines are not allowed on this forum. I have fairly big machines for a hobbyist and sometimes they still give me grief.

This would be a good option: The Hobby-Machinist
 








 
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