Harbor Freight drill press mod- lowered rpms to 200 to improve results drilling metal

[Raspy]

No worries on getting my hair caught- to say I have a receding hairline would be a compliment

:laughing::laughing: I'm with you brother.

 

[4570Man]

I like some of the ingenuity here. There's no such thing as too slow especially once your tooling gets less than sharp. My mill goes down to 40 rpms and the big lathe goes down to 14 rpms. I wish the lathe went even slower so I could weld in it while powered. My Jet lathe goes 40 rpms.

 

[pmsmechanic]

This is one of the better ways to do it,

SR

I disagree with your statement and others that are similar. My experience is that this is a horrible way to achieve speed reductions. The belt needs to be overtightened to get any drilling done without slippage. There needs to be a planetary reduction gear setup on the spindle for this belt system to work properly.

Just my not so humble opinion.

Edited: So wrote this last night and this morning I had a closer look at your picture. It's amazing what a good night's sleep reveals!

Last night I didn't notice your chain drive reduction system at all. I like your engineering but I would like to see the chain on the final drive, not the initial one.

I drill hole over an inch and find the double belt system very frustrating. Someday....when I get a lathe I would like to take the planetary gears out of a small automatic transmission and adapt it to the spindle.

 

[Big Barn]

I disagree with your statement and others that are similar. My experience is that this is a horrible way to achieve speed reductions. The belt needs to be overtightened to get any drilling done without slippage. There needs to be a planetary reduction gear setup on the spindle for this belt system to work properly.

Just my not so humble opinion.

I would have to agree with you regarding over tightening of the belt to reduce slippage.

I used a gear reducer on my vertical bandsaw to reduce blade FPM for cutting steel.

 

[PILOON]

I would have to agree with you regarding over tightening of the belt to reduce slippage.

I used a gear reducer on my vertical bandsaw to reduce blade FPM for cutting steel.

View attachment 506724

That idea I like, must study my installation carefully to see if I can adapt your solution as I have a couple of reduction boxes and in fact even a variable speed unit.
Now if I could only reduce my press drill speed as easily as this bandsaw solution.

 

[Mendonsy]

There is another completely different way to do this. I have the same drill press that Sawyer Rob has (but with a different brand name) which I have converted to variable speed. I replaced the 120 volt motor with a 230 volt, 3 phase motor and added a Teco FM50 inverter drive that converts 120 volt power to 230 volt, 3 phase. That allows me to adjust the motor speed from about 6hz (180 rpm) to 120hz (3600 rpm) without changing the belt ratio. With the belt set to the lowest speed that give me a speed range of 30 rpm to 600 rpm at the spindle.

 

[Sawyer Rob]

First of all, I have several drill press', but the one I pictured above doesn't belong to me. I was only showing what I think is a better way to lower the RPM's of those style of press'.

When I have a big hole to drill, I use my all GEAR DRIVE Solberga, made in Sweden...

When it comes to BIG power and drilling bigger holes, it's one mean machine,

It has a pretty good selection of speeds too,

It has lots of good features and mega power, so you better have everything you are drilling bolted/viced down good, cuz something IS going to happen.

I have three other "belted" floor drill press' for lesser jobs...

SR

 

[GLyford]

There is yet another way, which is to use a DC motor, speed controller and power supply. Common source for these is a treadmill, but if you use all the parts from a treadmill, then you have to modify the controller board so that it doesn't insist on starting at zero speed.

Here is one version of this:
Drill Press - Treadmill motor conversion - The Garage Journal Board

Another:
Use a Treadmill DC Drive Motor and PWM Speed Controller for Powering Tools - All

I added a jackshaft to an old benchtop Delta, I swapped a plate and pillow blocks (sorta, I made my own out of aluminum plate and flanged bushings) in place of the motor, and hung the motor on the plate, off to the side. The old motor 4-step pulley was put on the shaft and a new 3-step one was put on the motor. The motor drives the largest step on the shaft pulley. I got fancy, I jammed a piece of angle under the motor mounting plate so I could push on it with a bolt to tension the belt to the jackshaft. Since I could no longer reach the switch on the motor, I added a handy box with a power outlet and two switches, and a floodlight socket pointed at the work surface. I used to have pictures I could link to, but those died when comcast stopped supporting personal web pages. I can take some more, just not right now.

As far as speeds go, I never used it on anything but its slowest speed from then on. I never missed the faster speeds even with tiny drill bits. I'm not running a machine shop by the hour, I don't need theoretical best productivity.

I replaced it with a floor model import with a deeper throat that could also run MT bits if I had to (only needed it a couple times so far)...it functionally has the same jackshaft setup from the factory, except it is on a pivoting shaft between the motor and spindle. And I still leave it on the lowest speed.

 

[4570Man]

The speed controller on a DC or VFD on a 3 phase motor are no good for this application. They don't have any toque at low speed.

 

[vidio1]

I don't understand the need or want of all these "solutions" for speed reduction on machinery. Are you running a tapping head? Just to see if you can?

There is a reason speed/ feed charts are universally excepted. They're not perfect, but they are a very good start point. When you drop the speed on a cutting tool you HAVE to increase the load/ pressure on that tool for it to cut. This causes micro chips on the cutting edge reducing it's cutting ability and build heat.

As far as VFD or DC motors as a solution. Both could be a viable fix. A GOOD VFD uses some sort of closed loop feedback, different brands have different names for their version. Properly adjusted they have 95% of the torgue at low speed as full speed. The same could be said for DC using PWM with feedback. These fixes aren't cheap though.