Converting A Basic Taiwanese Drill Press To Vfd Controlled Beauty

I've had this old drill press for a while now and while it did a reasonable job at some tasks, it didn't work for many that I needed to use it for. To start with, it looked like crap which isn't a big deal but since I have been on a restoration/rebuild kick lately, I thought that I would spruce it up a bit. Next is that it's a 3 shaft machine with step pulleys and it doesn't have the range of speeds that I needed and it is seriously lacking in power. Lastly, as a tool and die maker no longer doing that kind of work, I really missed having a tool room drill press with reversing switch for power tapping.








The first thing that I did with it was strip it down to nothing and clean or sand blast all of it. It's a cheap Taiwanese machine but not built too badly and is reasonably robust. Lots to be desired in overall quality but beggars can't be choosers. I also wanted to show the process of doing this so that if there are others that want to, they can follow my lead.






I removed all of the rivets using the TIG welder to put a blob on each one and pull them out with visegrips.






As the final piece to clean up was the post, I had to figure out how I was going to make it look good. I tried to remove the bottom flange but even with some heat, it wouldn't budge. I wasn't completely in need of removing it but thought that it would be better without it when spinning it in the lathe. So on it stayed.

Now that it was all cleaned up, it was time for the changes to be made as well as the painting. First up was getting a motor ready for it and finding a VFD. I am fortunate that there are machines in my line of work that use motors and VFDs and some of them end up scrapped or salvaged for parts. The motor is a 1 1/3HP motor that is used to spin filters on dry cleaning machines and the VFD was from a small industrial washing machines that I scrapped. While the motor is a bit big for the drill press and the VFD, you can set limits in the VFD to protect it and since the motor is too large anyway, down rating it to 1HP is okay with me. This is the motor that I started with.








You'll notice that it's a flange or face mount so a new bracket was needed for the attachment to the drill press. I had some scrap steel plate lying around so it donated itself to the cause.






The pulley wasn't the correct bore diameter since the old motor was 1/2HP versus the new motor at 1 1/3HP. I decided that rather than turning the motor shaft down to fit, I would bore out the pulley. I didn't have a small boring bar so I ground a piece of high speed steel down to suit.


It's starting to come together at this point. I have been doing the machines in my shop with Tremclad Royal Blue and Burnt Orange so this one got the same colour theme.

Excellent start. I am "watching" this thread. Thanks for sharing it!

I have never seen that technique for removing rivets. I guess you remove the plates first, then TIG the blob and pull the rivets, right? Are the plates re-usable with just a bigger hole?

-brino

Since the majority of the structure was done, it was time to do some electrical work. I spent way too much time trying to figure out how to mount the VFD. It is a narrow piece and the drill press had a large hole in the side where the old motor and light switch were. I wanted to hide that as best as possible while protecting the VFD from chips and keeping the controls near the front for easy operation. I milled a piece of aluminum to hold the VFD and built a small panel for the controls.






I did some trial fitting with the belt cover on. I had to cut out the back a bit to clear the new motor mount. It had some issues though so I had to take it back off and do more metal removal on it. Unfortunately, when I painted it again, the paint didn't cure so it damaged the first coats of paint.




So back into the sandblaster and it got a new coat of paint.


For the foot switch, I found an old part that I had salvaged and cleaned it up and painted it.




This is the final enclosure along with the finished wiring. I also added an LED bulb to the hole that held the original bulb.




During testing I found that the new belt that I put on it wasn't accurate enough. At high speeds, there was a fair bit of vibration. Since it was a cheap belt I changed it out for a good quality cogged belt which is also shaved so the thickness is more consistent.




In these final images of the press, you'll see that I had to add some gussets to the motor mount as it had a bit more flex to it than I could accept.

brino said:

Excellent start. I am "watching" this thread. Thanks for sharing it!

I have never seen that technique for removing rivets. I guess you remove the plates first, then TIG the blob and pull the rivets, right? Are the plates re-usable with just a bigger hole?

-brino

Click to expand...

Thanks! What I first tried to do is get under the label to lift out the rivets. It was deforming the plate too much so I carefully ground the heads off with a die grinder and the label came off easily. After that, it was TIG time.

I wasn't sure that I was going to share this build or not. I decided that it might help some who are thinking of such a conversion and since I had to figure it out, I would share it. I found that VFDs aren't that scary and the added functionality is fantastic. I have two modes of operation other than the switch for the lamp and main power. In drill mode, it goes in forward direction only and the variable speed operates normally. In tapping mode, the foot switch becomes active along with variable speed so you can revers out.

Someone from another site that I am on made up a new label for the control panel and once I have that on, I'll post the pics. It just came in tonight so I still have to install it. I also put a larger knob on the potentiometer.

Did you turn the column to a smaller size? If so, how did you make it fit the head and the table bracket?

Bob Korves said:

Did you turn the column to a smaller size? If so, how did you make it fit the head and the table bracket?

Click to expand...

I didn't have to turn it at all. I was very surprised at how well it polished up with some open mesh emery cloth. I had to keep the speed of the lathe down since A, it scared the crap out of me and B, it shook a bit due to the flange still being attached.

Techie1961 said:

I wasn't sure that I was going to share this build or not.

Click to expand...

I am very glad you did. Cheers!

Techie1961 said:

I found that VFDs aren't that scary and the added functionality is fantastic.

Click to expand...

Personally I have not taken that plunge, but I do see the benefits!

Techie1961 said:

In drill mode, it goes in forward direction only and the variable speed operates normally. In tapping mode, the foot switch becomes active along with variable speed so you can revers out.

Click to expand...

Does the foot-switch just give the reverse then? Do you hold it for reverse or is it latching with a push to toggle between forward and reverse? Is the reverse speed the same as the forward speed?

Sorry for all the questions.....maybe it will be more clear when you have the control label installed.

Thanks!
-brino

Very nice job. I was going to post my conversion, but yours puts mine to shame. Thanks for posting, I picked up some cool tips and motivation.