What's new
What's new

How to use 2 drill presses for drilling and tapping?

batkinson1969

Plastic
Joined
Jun 18, 2023
Having issue getting 2 drill press holes to match. I created jig #1 to repeatedly drill and tap the same small part many times. I use it on drill press #1. I can drill, replace the drill with tapper head and tap. It works great, but i don’t want to swap the drill and Tapmatic back and forth. I want to setup drill press #2 to drill only the pilot holes. Then continue use drill press #1 for the Tapmatic. In my first try jig #2 seems to be off by about 1/32”. I marked that by putting a piece in jig #1 and pull the handle so the tap hits and mark the piece. Then put the same piece in jig #2 and pull down to mark it with drill bit. That difference of about 1/32” is enough to bind the tap. So I can’t go all the way through with the Tapmatic. I was making small adjustments and repeating tests until I broke the tap. Now I’m trying to figure out out the get the two jigs to have the same drilling center on two drill presses. They are not identical drill presses. The jig is a piece of 4” x1/4” aluminum bolted to the table with two 1/2” bolts in dedicated holes. Not slots. Then a slot was court out to match the 1.5” wide bar stock. The jig positions the hole properly and makes it repeatable. So I’m trying to repeat the same setup on drill press 2. Maybe I need to make the mount holes on the jig larger so I can make more adjustment but that makes it difficult to put the jig back in the same exact spot. Thinking I use my pilot drill bit and part I just drilled but put it on DP#2. Put the same pilot hole bit in DP#2 then adjust jig #2 to match. So far that has been close but not close enough to avoid binding when tapping. Jig #2 is using 1/4-20 bolts. So I could use 5/16” to make the jig mounting holes 1/16” larger. The 1/16” of slop migh be enough to manually align with experimentation. If not enough, I can go up to 3/8” but that will be loose and make repeating that jig position difficult if I ever need to move it. I would prefer a more precise way to line them up identically.

Any suggestions?
 
Some sizes of tap are available in a single tool that drills the hole and then taps it. They will not work on every part, but they save a lot of time on parts with through holes where they will work.



Larry
 
I guess I don't understand why you need a jig to tap the holes when they are already located and drilled. The Tapmatic head has about .010" of lateral float for the tap driving, so the positioning of the part on the tapping press doesn't have to be super-precise. When I have done work like this previously, I set up a guide rail on the drill press, so you only have to eyeball the alignment in left-right axis. You can then just slide the part against the rail, center up the hole, and tap it. The tap will follow the hole, wherever it is, so the drilled hole location tells the story.

Two things to examine:
1. Why the jigs are different, and
2. Whether the drill press tables are both square to the spindles respectively
 
I guess I don't understand why you need a jig to tap the holes when they are already located and drilled. The Tapmatic head has about .010" of lateral float for the tap driving, so the positioning of the part on the tapping press doesn't have to be super-precise. When I have done work like this previously, I set up a guide rail on the drill press, so you only have to eyeball the alignment in left-right axis. You can then just slide the part against the rail, center up the hole, and tap it. The tap will follow the hole, wherever it is, so the drilled hole location tells the story.

Two things to examine:
1. Why the jigs are different, and
2. Whether the drill press tables are both square to the spindles respectively
When I did the drilling and tapping on same machine, the Tapmatic was easy to use. Went all the way through before I reversed it. I know the Tapmatic floats a little. I don’t understand why it’s binding up and I can’t get it to pass through. I’m not even sure why it’s binding. I put the drill bit in the Tapmatic just to see if it centered on the existing hole made on the other drill press. It seemed to line up accurately.

The reason for the jig with the Tapmatic is the parts are small , basically 2” square. So I need the jig to hold the part in position and to hold it down as the tap is extracted. I may try taking the top of the jig off, and hold the piece down with fingers. That should allow the Tapmatic to position itself, I just hope I can hold it down on reverse. I’ll clamp it and try to see if that allows the Tapmatic a little more freedom to follow the pilot hole.

I thought the same thing about the tables. I tried checking the spindle to table on both. I used an angle magnet. It said they were both within 1degree of square. But not easy to measure. I would love to know how to make the tables square to the spindle. I have a precision square and angle magnet I use to square miter saws and table saws. But it’s hard to get a good place for the magnet. I’ll try using the procision square on a long drill bit in the spindle to check square.
 
.... I tried checking the spindle to table on both. I used an angle magnet. It said they were both within 1degree of square. But not easy to measure. I would love to know how to make the tables square to the spindle. I have a precision square and angle magnet I use to square miter saws and table saws. But it’s hard to get a good place for the magnet. I’ll try using the procision square on a long drill bit in the spindle to check square.
Do you have a dial indicator you can chuck up in the drill presses? Set it up so it will make a circle hat clears your holes in the table and see if the reading is the same in all 4 quadrants. That will tell you how it needs to be adjusted if not all the same reading.
 
When I did the drilling and tapping on same machine, the Tapmatic was easy to use. Went all the way through before I reversed it. I know the Tapmatic floats a little. I don’t understand why it’s binding up and I can’t get it to pass through. I’m not even sure why it’s binding. I put the drill bit in the Tapmatic just to see if it centered on the existing hole made on the other drill press. It seemed to line up accurately.

The reason for the jig with the Tapmatic is the parts are small , basically 2” square. So I need the jig to hold the part in position and to hold it down as the tap is extracted. I may try taking the top of the jig off, and hold the piece down with fingers. That should allow the Tapmatic to position itself, I just hope I can hold it down on reverse. I’ll clamp it and try to see if that allows the Tapmatic a little more freedom to follow the pilot hole.

I thought the same thing about the tables. I tried checking the spindle to table on both. I used an angle magnet. It said they were both within 1degree of square. But not easy to measure. I would love to know how to make the tables square to the spindle. I have a precision square and angle magnet I use to square miter saws and table saws. But it’s hard to get a good place for the magnet. I’ll try using the procision square on a long drill bit in the spindle to check square.
Squaring up the spindle with the table is best done with a tramming tool like this one: https://www.amazon.com/SST-Mill-Lat...ocphy=9032941&hvtargid=pla-591873648718&psc=1

I also have a granite surface plate I use with the tramming tool, the trick is to set the plate on the surface of what you want squared up to the spindle. Setting the plate on the table is a good start, I prefer setting it on the cross-slide vise since that's what the work is squared to. Parallels with 1-2-3 blocks are my friends 😉.

Good luck!
 
Put a straight round rod into chuck and square table to that on 2 sides 90 degrees apart. Use your most stable square, not one with the magnet. Magnetic squares are hard to feel the rock or see the light when you are in the accuracy you need.
If you do not have a straight round bar (really straight) then a brand new drill bit will work.
Tramming tools are better- using what you got is cheaper.

It sounds more like an error with holes not being square or tap not square, or both. You can drill a blank and take drill bit- put it in the hole upside down and check that too. Do one on each press and then swap jigs and do it again. At least you find out if it is a press, both presses, or jigs.

A full degree is a lot off.
 
Other than mentioning your trying to set up two drill presses to have a repeatable tool C/L alignment, you aren't providing anything close to enough information. Two drill presses of what type? Consumer grade or 1,000 lb plus industrial grade? then what's the material, repeatable accuracy, etc. I've read driving even a 1/2" drill though mild steel can take a minimum of 150 lbs of down feed pressure on the drill tip. I had a 250 lb 16" 15 spd consumer level drill press I once thought was great. I trammed it to be well under .001" in maybe a 10" circle. Even its no brand name offshore chuck gave what was to me unbelievable runouts of just under .001" with any drill diameter it held. That was until I learned a bit more and decided to check what it's alignments were under those actual tool and drilling pressures. Set a dial indicator zeroed on the top front of the table, then add even light pressure with your thumb, 10-20 lbs should be more than enough. Unless these are industrial level drill presses with at least a center table support screw like a knee mill has, there total junk since they can't and won't ever drill a straight hole to start with. Since it wouldn't be all that smart to add another 1,000 plus lbs to my shop floor to replace it, I sold that drill press and use my knee mill as both a mill and drill press.

Secondly plastkdreams question needs to be answered, how did you build two drill jigs that far off? Whatever your design and alignment methods are there crap. I'd bet pretty much anyone here could get repeatable part location within .001" using a couple of junk harbor freight mini mills if they had to. Are your drill jigs held in a vise? If so then go back to basics, if your first drilled holes are on location, then align the second vise to those drilled holes with a dti. Your fixed vise jaw on the second drill press is a fixed reference point, call that X. Set up a part stop in that vise as your fixed Y axis part location. Double check the parts hole location with that dti and adjust the vise and/or whatever jig your using for the correct part alignment. In reality that set up couldn't be easier. Now if you want the whole set up to self align each time its required, then you need to redesign so it indexes off of something that's a known location and fixed to the drill press itself. Fwiw I'd start with this. http://www.survivorlibrary.com/library/jig_and_fixture_design_1920.pdf for the basics. Asking forum questions is extremely helpful, learning how to just go find the required information is imo priceless.
 
Something like this:


Or this:


Should provide enough weight/size to allow tapping with a Tapmatic while still being light enough to move on the DP table for self centering as the tap enters the hole.

Just machine the jaws to hold your part.
 
  1. Drill your part in the first press.
  2. Fit drill bit and chuck to second press.
  3. Put drilled part in jig with no bolts holding it down.
  4. Bring down quill till drill bit goes through hole in part.
  5. Lock quill
  6. Fasten bolts to hold jig to table.
  7. Raise and lower quill so drill bit goes in and out of hole and watch for deflection.
  8. If drill deflects you have either moved the jig when tightening the bolts or you have some other fundamental issues.
  9. If everything lines up fit tap head and proceed with job.
Before doing any of the above do a quick check for square by putting the drill bit through the drilled hole and checking if it is square to the surface it is drilled through.
 
Squaring up the spindle with the table is best done with a tramming tool like this one: https://www.amazon.com/SST-Mill-Lat...ocphy=9032941&hvtargid=pla-591873648718&psc=1

I also have a granite surface plate I use with the tramming tool, the trick is to set the plate on the surface of what you want squared up to the spindle. Setting the plate on the table is a good start, I prefer setting it on the cross-slide vise since that's what the work is squared to. Parallels with 1-2-3 blocks are my friends 😉.

Good luck!
Wow, that look like a great measurement device.
 
Some sizes of tap are available in a single tool that drills the hole and then taps it. They will not work on every part, but they save a lot of time on parts with through holes where they will work.



Larry
I like those for one-off stuff. In this case, I need to do thousands. So I have Carbide drill bits, cobalt taps specifically for the task.
 
Put a straight round rod into chuck and square table to that on 2 sides 90 degrees apart. Use your most stable square, not one with the magnet. Magnetic squares are hard to feel the rock or see the light when you are in the accuracy you need.
If you do not have a straight round bar (really straight) then a brand new drill bit will work.
Tramming tools are better- using what you got is cheaper.

It sounds more like an error with holes not being square or tap not square, or both. You can drill a blank and take drill bit- put it in the hole upside down and check that too. Do one on each press and then swap jigs and do it again. At least you find out if it is a press, both presses, or jigs.

A full degree is a lot off.
I basically did this and was able to fine tune. Seems to tap east now.
 
Do you have a dial indicator you can chuck up in the drill presses? Set it up so it will make a circle hat clears your holes in the table and see if the reading is the same in all 4 quadrants. That will tell you how it needs to be adjusted if not all the same reading.l
How does one make 2 jigs for the same part that far off?
Lol, it’s within the tolerances of a two 1/2” holes drilled through the jig and table. Apparently 1/32” is a big difference tapping 1/4” aluminum. I was able to fine tune and it’s working smoothly now. My tables were with .01 degree or better to square. I was just off left and down by about a 1/32”. That was enough to bind the tap.
 
Other than mentioning your trying to set up two drill presses to have a repeatable tool C/L alignment, you aren't providing anything close to enough information. Two drill presses of what type? Consumer grade or 1,000 lb plus industrial grade? then what's the material, repeatable accuracy, etc. I've read driving even a 1/2" drill though mild steel can take a minimum of 150 lbs of down feed pressure on the drill tip. I had a 250 lb 16" 15 spd consumer level drill press I once thought was great. I trammed it to be well under .001" in maybe a 10" circle. Even its no brand name offshore chuck gave what was to me unbelievable runouts of just under .001" with any drill diameter it held. That was until I learned a bit more and decided to check what it's alignments were under those actual tool and drilling pressures. Set a dial indicator zeroed on the top front of the table, then add even light pressure with your thumb, 10-20 lbs should be more than enough. Unless these are industrial level drill presses with at least a center table support screw like a knee mill has, there total junk since they can't and won't ever drill a straight hole to start with. Since it wouldn't be all that smart to add another 1,000 plus lbs to my shop floor to replace it, I sold that drill press and use my knee mill as both a mill and drill press.

Secondly plastkdreams question needs to be answered, how did you build two drill jigs that far off? Whatever your design and alignment methods are there crap. I'd bet pretty much anyone here could get repeatable part location within .001" using a couple of junk harbor freight mini mills if they had to. Are your drill jigs held in a vise? If so then go back to basics, if your first drilled holes are on location, then align the second vise to those drilled holes with a dti. Your fixed vise jaw on the second drill press is a fixed reference point, call that X. Set up a part stop in that vise as your fixed Y axis part location. Double check the parts hole location with that dti and adjust the vise and/or whatever jig your using for the correct part alignment. In reality that set up couldn't be easier. Now if you want the whole set up to self align each time its required, then you need to redesign so it indexes off of something that's a known location and fixed to the drill press itself. Fwiw I'd start with this. http://www.survivorlibrary.com/library/jig_and_fixture_design_1920.pdf for the basics. Asking forum questions is extremely helpful, learning how to just go find the required information is imo priceless.
In this case I’m cutting 1/4” aluminum with wood tools. I’m a long time wood worker but new to working with aluminum. I was able to figure out how to center both jigs. It’s working smooth now. 1/32” is apparently a long way off tapping aluminum. I finally got close enough to get a good set of threads on a part. Then I used that part partially threaded onto the tap and raised and lowered it into the jig. I rotated the table about 1/10th of a degree to get the part the slide into the jig without rubbing and with less than a hairline clearance on both sides. Tightened the jig bolts and I’m in business. I did have to clean my pulleys as they started slipping once I had it lined up. Cleaned pulleys with brake cleaner and a dry rag. The belt was a little shiny so I cleaned the belt with brake cleaner and rubbed some 220 grit on it. No slipping now. I added some wd40 to the tap and now it goes through like butter. Thanks for feedback
 
How about one jig on two identical sub plates? So part stays in jig that gets moved back and forth.
Great idea that I’ll remember. If the part bolted into the jig I would totally do that. that would make sense. But it just slides into a notch with a few thousandths extra width. I made it that way for east mass production.I was able to center the tapper on the pilot hole better today and getting good results now. Hoping to dry tap in mass with cobalt tap but I used cutting fluid and HSS tap so far. I’ll switch to more expensive colbalt taps when I can make an another 100 or so without breaking a HSS tap.
 
Great idea that I’ll remember. If the part bolted into the jig I would totally do that. that would make sense. But it just slides into a notch with a few thousandths extra width. I made it that way for east mass production.I was able to center the tapper on the pilot hole better today and getting good results now. Hoping to dry tap in mass with cobalt tap but I used cutting fluid and HSS tap so far. I’ll switch to more expensive colbalt taps when I can make an another 100 or so without breaking a HSS tap.
You might think some more about what cutting tools are best suited to your thousands of parts made of some unspecified grade of aluminum. Some aluminum grades are great for fabrications but are not ideal for machining operations. Tools made for steel may not be ideal for aluminum. The geometry of the cutting edge is just as important as the tool material. Look for tools recommended for cutting aluminum. Is a carbide drill bit really ideal? Is a cobalt tap really ideal? Check high quality tool makers' websites to see what they suggest. For instance, Guhring has taps they recommend for through holes in aluminum and they are a cobalt type, but note these specific taps are best for cutting aluminum and not so much for cutting steel:

I understand cobalt taps are great for heat resistance, but are more likely to break if, for instance, the jig is out of position. Solid carbide drills are very expensive and break or chip if used in non-rigid situations. Non-rigid situations might include using light duty woodworking drill presses for metal work. HSS or cobalt drills are cheaper and work fine in aluminum. Carbide router bits and saw blades make a lot of sense for woodworking, but that does not mean all tools for all jobs should be carbide.

Larry
 








 
Back
Top