Homemade Multi-Drill

-live wire-

Joined Dec 22, 2017
959
The US manuf. for DIY Gecko steppers even state you do not need a fancy regulated P.S..
It cost's more in the long run for Txfr/bridge but works out more economical in the long run when you have to start replacing SMPS every time they fail, they are not so rugged.
Max.
But if you get ones that are rated for more than you are drawing will you really have to replace them? And also, why not use a car battery?
 

MaxHeadRoom

Joined Jul 18, 2013
30,659
But if you get ones that are rated for more than you are drawing will you really have to replace them? And also, why not use a car battery?
You could use an Automotive battery if needed.
The SMPS P.S. are rated at a certain voltage/current, you cannot guarantee the current for direct fed DC motors, especially if a stall condition or other fault condition occurs etc.
Max.
 

-live wire-

Joined Dec 22, 2017
959
Would almost 100 oz-in not be enough for most materials? Is that not in the approximate range of what you need? And would there be any issues gradually stepping up the RPM?
 

Thread Starter

Cosmosus_

Joined Jul 7, 2018
15
Thanks to all of you for helping,
after prolonged research, I'm set on this DC motor: https://www.banggood.com/775-Gear-M...tail-top-buytogether-auto__2&cur_warehouse=CN
This one is used in most battery powered drills, usually on 24V.
I'll be using 6 of these motors, so if they are connected to 24V one motor draws 0.16A, then 5x0.16=0.8A with a deviation of a few Amperes.
Onward, I've been looking and have been recommended this power supply: https://www.alibaba.com/product-det...pm=a2700.7724838.2017115.1.b3c83ab4qLUWpu&s=p
Now this supply has output current 2.08A, is this maximum current? What if I connect these 6 motors, where there is 0.8A, can power supply go that low with providing less than it is made for?
I've got another question; if power supply has for example output voltage 9-40V, does this mean that if I buy the motors (link), where voltage is 12-36V, that power station will fry the motors with full voltage or does it regulate it?

Thank you,
L
 

MaxHeadRoom

Joined Jul 18, 2013
30,659
Motors draw current dependent on load, if you have a locked rotor for any reason, the current will be limited by the armature resistance.
Typically if running motor with any kind of PWM controller, the P.S. is spec'ed in at least 10% above the max motor voltage rating.
There is no automatic regulation on those supplies, just a preset pot to set the output value.
Max.
 

Thread Starter

Cosmosus_

Joined Jul 7, 2018
15
Motors draw current dependent on load, if you have a locked rotor for any reason, the current will be limited by the armature resistance.
Typically if running motor with any kind of PWM controller, the P.S. is spec'ed in at least 10% above the max motor voltage rating.
There is no automatic regulation on those supplies, just a preset pot to set the output value.
Max.
So if power supplys OV is 5~48V and OC 2.3~16A, what happens if I connect those 6 motors, wired in parallel on this particular supply?
 

Thread Starter

Cosmosus_

Joined Jul 7, 2018
15
OK, so I understand that motors current 0.18A is adle current, so when it's connected with power supply, motors need a lot more to operate at peak. I found this one power supply with more current output: https://www.alibaba.com/product-det...?spm=a2700.7724838.2017115.104.b3c83ab4kVNWnq

Output Power:
75W
Input Voltage:
110V/220V
Output Voltage:
5~48V
Output Current:
1.6~15A



I think the motor is more than enough for what I'm trying to achieve, I'm just not sure these two (supply and DC motor) are compatible.
 

MaxHeadRoom

Joined Jul 18, 2013
30,659
With no PWM or other soft start it would depend on the initial total load of all 6 motors and the ability of the SMPS to endure it until motor come up to run.
Many will fold back if a momentary O/L exists.
For my money, any SMPS is a gamble in an application such as this.
Max.
 

Thread Starter

Cosmosus_

Joined Jul 7, 2018
15
With no PWM or other soft start it would depend on the initial total load of all 6 motors and the ability of the SMPS to endure it until motor come up to run.
Many will fold back if a momentary O/L exists.
For my money, any SMPS is a gamble in an application such as this.
Max.
Ok, thank you. WHat kind of power supply would you suggest for this particular application? under 15$ or even 10$ can't I find anything suitable?
The goals are simplicity and budget, since this machine won't be used very extensively (twice per year) and I'd like to make them for other people also.
 

MaxHeadRoom

Joined Jul 18, 2013
30,659
If you want to supply these then reliability should be a criteria.
You may not find a transformer and bridge for under $15.00, but going cheap on a SMPS is a gamble.
Why not set them up and bring one in and run it for a duration for assessment.
Max.
 

Thread Starter

Cosmosus_

Joined Jul 7, 2018
15
If you want to supply these then reliability should be a criteria.
You may not find a transformer and bridge for under $15.00, but going cheap on a SMPS is a gamble.
Why not set them up and bring one in and run it for a duration for assessment.
Max.
What about the motor? Do you think it's powerful enough to drill in wood with 3mm thick drill bit?
 

KMoffett

Joined Dec 19, 2007
2,918
Wow! All this on three different forums. I agree with you Max. Buy one, set it up with a drill chuck and try it A picture is worth a thousand words, and a prototype is worth a thousand pictures. ;)

Ken
 

shortbus

Joined Sep 30, 2009
10,050
What about the motor? Do you think it's powerful enough to drill in wood with 3mm thick drill bit?
Have you thought about how you will put a drill chuck(to hold the drill bit) on that motor? And what will you use as a thrust bearing on those motors, to keep the shaft from moving once you start to drill? Even if those motors claim to be used in cordless drills, there is more involved than just the motor in any drill.
 

Thread Starter

Cosmosus_

Joined Jul 7, 2018
15
Have you thought about how you will put a drill chuck(to hold the drill bit) on that motor? And what will you use as a thrust bearing on those motors, to keep the shaft from moving once you start to drill? Even if those motors claim to be used in cordless drills, there is more involved than just the motor in any drill.
Fair enough.
I was thinking of attaching a drill chuck directly to the motor shaft, since I've seen it in so many videos and I'll only be using about 3-4mm drill bits. I'm really confused on which kind of motor should I get, geared, no geared, high torque, high speed.. I don't want to complicate things too much , just so it works and doesn't burn out after a short time.
 
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