AC or DC small drill press

Hello,
This is my first post to the group and I am an absolute newbie. I have
a small very old bench top drill press that needs a motor. I have been
studying and searching this group and others trying to gain knowledge
prior to posting.
My questions:
For simple drilling (home use not heavy duty) which type of motor would
be better to pursue, AC with VFD or DC (permanent magnet)?
If AC is chosen, can I use a smaller hp such as 1/3 or ½ horse?
If DC is chosen, should I increase the horse power (compared to AC)?
Is it feasible to use one pulley instead of multiple? Again, the
applications would be very basic. I think I understand the performance
advantage of multiple pulleys and torque but would like to try and get
by with just variable speed.
Last, attaching the motor to the frame, is there a standard way of
accomplishing this with treadmill motors with no frame? I measured the
hole dimensions and it seems the type 56 frame would fit the mount.
Thank-you for your time.
Jeff
Reply to
zap427
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First it would be good to know what size of drills fit your chuck or what size you want to use to select the right RPM-range.
Nick
Reply to
Nick Müller
Whichever one you can source for the least outlay of hard cash. DC motors can be had from old treadmills, and the controller can be adapted. 3 phase AC motors and a VFD are readilly available.
Try to get the best of all worlds. Use a variable speed motor AND the multistep pulley, and you will be able to access the wides speed range.
I think that you would be spending rather more than you should, if you use larger than a 1/2 hp motor.
Useful single phase motors are cheaper yet. Any reason not to just stick to what has worked for as long as it has?
Cheers Trevor Jones
Reply to
Trevor Jones
Keep the multispeed pulley set. Larger drills need to be turned at slower speeds and also need more torque which is handled very nicely by the pulley ratios. The affixing of the motor to the press depends upon how the motor needs to be mounted. DC motors often have a set of holes in the one end that mount to a plate and that is how I'd do the job.
Reply to
Bob May
Thank you for your replies. I was not clear on a couple of things; there was no motor with the press, so there is nothing to compare to. Also, there is only one pulley on the chuck end.
With regard to drill sizes, I would be using 3/8 bits (I hope I am sizing right, the same drill bit used with hand held electric drills).
The chuck is odd in that it has no tightening key. Near as I can figure the bits must just be hand tightened. As I said, it is old, how old I really have no idea. It is heavy and appears some thought was put into the design.
Am I correct in thinking either AC or DC motor would be much more useable with a pulley setup and trying to avoid pulleys and just use the variable speed would result in too much power loss at slow speed?
Again, thanks for your time, I realize I am virtually "clueless" but am trying to learn. Sites like yours are a tremendous help.
Jeff
Reply to
zap427
Reply to
Roger Shoaf
The way you answered the question suggests you are correct in your assesment that you don't have a clue. The diameter of the hole that the twist drill makes and the material that one is trying to drill through are the primary factors in selecting speed and motor size.
Ordinarily, a drill press will come with a motor large enough to do the job on drills no bigger than the chuck will hold with out resorting to a cut down shank. The heavier (more industrial) the drill press the larger the moter will be, so it may work with drills that are larger than the shank.
One thing you need to consider is the total cost of putting your drill press in working order may verywell be more than buying a brand new cheap import at Harbor Freight that might be adequate for your needs.
Well if you purchased a drill press with no motor, it is not all that odd that the chuck key was lost. They do make keyless chucks, but the better ones are rather pricey so if some one were to scrap their drill press they would probably take the keyless chuck.
Look closely at your chuck, does it have any brand names or model numbers? ahow about the drill press itself?
Reply to
Roger Shoaf
Excuse me if I am using "incorrect" terminology to describe my intent for the drill press. I do not require extreme accuracy and just want the option for basic use which allows more precision then I can achieve with a handheld drill.
To add more clarity, I did not purchase the drill press it was given to me. The chuck is keyless with no identifying marks or numbers.
Thank you, for your reply (I think). Perhaps I asked for the validation of being clueless but have found a humble approach best when asking others for help.
Jeff
Reply to
zap427
Jeff, we are trying to help. Any idea of the brand of drill press that you have? Is it a table top model or a bench top?
What kind of material are you intending to drill, steel, aluminum, wood, plastic?
How big is the stuff you want to drill?
And what size holes are you intending on drilling?
There are reasons these questions are being asked.
The "no name" keyless chuck is a suggestion that you don't have much of drill press to start with. Let say for the sake of the discussion that you need a motor.
You could get one of these:
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($106.35)
And then you need a pulley perhaps one of these:
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($11.23)
Oh and you probably need a fan belt, perhaps this one:
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($3.89)
There are sometimes when it is a good deal to spend $121.56 to whip up a freebee into a workable machine, but if you put that into one of these:
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You would have spent more in parts than you would of to buy 2 brand new drill presses at $49.99 each.
Reply to
Roger Shoaf
And that still is true! No one insulted you.
Nick
Reply to
Nick Müller
Jeff..its a full moon. Some of the nicest people turn into utter assholes at this time of the month. My ex, some posters here..and so forth.
Though its true, that depending on the type of drill press, it may simply not warrant fixing it up, as the cost may exceed that of a simple Harbor Freight drill press. Now if you are doing it as an excercise..or the drill press is a very high quality and desireable one..it may warrant the expense.
On the other hand..if you scounge around and find a motor for little or nothing, its only labor and some bits and pieces.
I came late into this thread, but if you care to email me, Id be happy to give you some assistance. In real life..Im a machine tool mechanic.
Gunner
"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3
Reply to
Gunner
MUCH better and more informative.
Well done.
Gunner
"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3
Reply to
Gunner
A drill press is way better than a hand drill because: - it will drill a straight hole - it can exert a LOT of pressure - it is much easier to drill in the right spot So you definitely need a drill press. Many (most?) old ones are better than many new ones. Fixing up yours is a good idea and can be done cheaply.
Variable speed is very nice but a DP is still very useful without it. The cheapest, easiest way to get started is to scrounge a motor, buy a step pulley to match the one you have (?), or a pair. Small (1/3 or 1/2 hp) motors are all over the place for free or cheap. eBay for the pulley(s).
A tread mill motor isn't a good idea. Mounting it would be a challenge, the shaft is usually non standard, and the controller's soft-start is a pain.
If you're intent upon a variable speed, a 3-ph motor and VFD is the best choice. 3/4 hp for low-hz torque. eBay for the motor and VFD.
Bob
Reply to
Bob Engelhardt
Hi guys,
I didn't mean to sound sensitive; I sincerely meant my apology. I guess one feels a little sheepish admitting to the group they know little about a subject. I do appreciate all the answers given.
I have scoured the drill press for a name or hint of what it is. It is old and perhaps there are marks there (or were there at one time).
I did some more research and I believe the press is a camelback design. At least its appearance is like the old camelbacks found on the "Old woodworking tool" webpage.
It was something my farther gave to me, so it does have sentimental value.
I like to clean old tools up and get them working again.
Thanks again, Jeff
Reply to
zap427
If this is a floor unit, the chuck probably opens to one half inch or so.
Is this a floor unit, or a bench unit? What is the distance from the center of the chuck to the nearest part of the column that holds the head up?
Is there a name on the side of the chuck? It may be an Albrecht or the like.
You gotta have pulleys. Do you want to work metal, or wood only? If metal, need low speeds. If wood, want high speeds.
It would be useful if you could photograph the unit and post the jpegs to the dropbox (this newsgroup does not allow binary attachments, so that's the only way to publish the photos).
Joe Gwinn
Reply to
Joseph Gwinn
Well sentimental value goes a very long way on the scale of "worth fixing"
Do you have the capability of posting a couple photos in the
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drop box?
Gunner
"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3
Reply to
Gunner

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