[SScnc]

I don't know where else to post about this, if it should be somewhere else just advise.

I have been planning to build a CNC Plasma table and still will but after reading the thread " Plasma Accuracy" here I now realize what I really require is a CNC Drill. Below is a CAD drawing of the angles,they are each 2" x 3" x 1/4" and 56" long.

I searched but maybe I missed it, has anyone done a DIY CNC Drill setup here ?

I have a good (I think) design in mind and my biggest question is regarding powering the quill (Z).

The main use for this drill will be for drilling 7/16" holes in 1/4" thick structural steel angles. Allot of pieces. Right now I'm doing them on drill presses. I have four drill presses of varying size and power and can use the head of one of these (or buy another one) for a CNC drill machine.

If anyone has any info on this please let me know and thanks,

Steve

[cut more]

Hi Steve,
If these parts are the same, why not set up a bank of multiple drill presses that would drill all the holes at once? You already have 4 any ways.

I used a stepper motor and created a powered feed for my drill press.
Here is my version, I even use it for tapping.


Cutmore

[SScnc]

Hi Steve,
If these parts are the same, why not set up a bank of multiple drill presses that would drill all the holes at once? You already have 4 any ways.

I used a stepper motor and created a powered feed for my drill press.
Here is my version, I even use it for tapping.


Cutmore

Hi Cutmore,

Well, for one thing, I want to be more "high tech" than that and I'm hooked on CNC ! And also, my drill presses are all different, one is a 3/4" floor unit, one is a 1/2" floor unit, another is a 3/8" x 10" tall bench mount and the other one is a 3/8" x 8" tall bench mount.

Your stepper mount is great, even better than what I was thinking of, excellent job and thanks allot for posting the picture of it.

Are you happy with the performance of it ? I was thinking that I would need a large diameter pulley on the quill drive but if yours works good then I think I'll go with similar.


Thanks again, looking forward to hearing more details please

[cut more]

Well for the more details,
The drill -press is controlled using Mach3,A cnc4pc break-out board, and a Pac-sci stepper drive.

I am using a 570 oz./in. Nema 23 stepper. The pininon pulley is 14 or 15 tooth, and the pulley on the quill drive is 22 teeth I think. I have found that for drilling it works fine but for tapping I neeed to gear it down a bit more. I have a 30 tooth pulley I am going to install on the quill end.

I am drilling mostly fiberglass with this set-up so you may need a stronger motor for whatever you are drilling. The best way to figure out how much force you need is, Get a spring type scale(Like you use to weigh a fish), then set up the drill for whatever you will be drillinig. Hook the scale to the drill press handle and pull on the scale to drill the hole.

I am hooked on cnc's too. I started using them ~ 5 or 6 years ago. I now own (2) vmc,s, (1) router/plasma,(1) Bridgeport cnc,(1) cnc Lathe,(1) cnc drill press,(1) cnc bandsaw.

Regards,
Cutmore

[SScnc]

Thanks for the additional information, it's a big help and I appreciate it.

Wow, I just thought I was hooked on it, your list of CNC equipment is impressive! I just learned allot of this within the last several months so I'm really just getting started. I'm happy with my converted X2 but definitely want to step up to something closer to bridgeport and convert it but that will have to wait for now.

Good idea on the fish scale, I had put a bathroom type scale under the chuck of the 1/2" press just to see what kind of force it "could" do and it looked like it went to around 400 lbs.

I'll try the fish scale on the handle while drilling the 1/4" steel. I guess it should be attached to the handle at the same distance from the center as what would be the outer edge of the drive pulley to be used, correct ?

My plan for the design of the CNC drill setup is a table very similar to something like Weldtutor's design for instance, but only about 2 feet wide and 70 inches long. With strong C-channel "tracks" on each side and a strong gantry that will carry the drill head. Then clamp several 2x3x1/4 angles in known locations and program it to peck drill all the holes.

Then have the program set to go to zero, rewind, I replace the angles with new ones and hit cyclestart.

Please let me know if you see something wrong with this plan or have any other suggestions.

Thanks,

Steve

[cut more]

Hi Steve,
After the deals I received on my equipment , I wouldn't even consider converting a manual bridgeport over to cnc. I was given 2 series2 cnc Bports (working), and I bought the 2 vmc's(toolchangers) for $1200. (1) was running and I now have the 2nd running.

I think if you can hook the fish scale to point 12" from the center of the pivot, and record the force. Then record the force it takes to drill ( in pounds).
This would be = to lbf.ft
http://en.wikipedia.org/wiki/Foot-pound_force
This could then be converted to whatever units you want to use to figure what strength motor you need. If you gear down the motor it multiplies the torque by the gear ratio.
Torque
1 oz-in = 0.0070 N-m
1 N-m = 142.08 oz-in
1 lbf-ft = 192 oz-in
1 N-m = 1.355818 lbf-ft

Regards,
Cutmore

[SScnc]

Thanks for the info and equations once again.

Man, you made out great being given 2 BP's, let me know if there's any more deals like that !

I think I'm going to simplify this design, I have a large, heavy, low geared DeWalt power drill with three large threaded holes for handle attaching and a nice round section on the casting near the chuck. I'm going to mount this to a Z plate and gear down the stepper that drives the Z. Sort of a PCB drilling setup you see with Dremels but on steroids.

I'll post as progress is made on this. If you have pics of your CNC equipment or a website I'd like to check it out.

Best regards,

Steve

[jcc3inc]

Sir,

Maybe you should consider using a punch if you have a *lot* of holes to drill!
It could be CNC controlled or maybe some sort of duplicator arrangement.

Regards,
Jack C.

[SScnc]

Sir,

Maybe you should consider using a punch if you have a *lot* of holes to drill!
It could be CNC controlled or maybe some sort of duplicator arrangement.

Regards,
Jack C.

Hi Jack,

That's a good idea and I had thought about it briefly after looking at an ironworker locally but cost is a major concern. I think I can do the CNC drill table relatively inexpensively and it should suit my need just fine. And I have no hydraulic equipment or parts lying around to raid for a punch.

I hope to be done with the 3D model of the table soon and will post it and look forward to opinions before fabricating it.

Thanks,

Steve

[SScnc]

Okay, so here's what I'm thinking on this design (pics below)...

I just started learning how to draw parts and assemble them and as you can see, still have allot to learn but you get the idea. I still have to work out the stepper drive mechanics, etc. The yellow motor represents the DeWalt drill I referred to.

The table is 36" tall, 36" wide, 70" long. The gantry verticals are 24" tall. The main structure is all 2x3 box tube and the side tracks are 1x2 channels. The gantry rolls on sealed roller bearings in the channels and are attached to the side plates in slotted holes to adjust for smooth, tight operation.

Please let me here your opinions on this design and thanks for any advice,

Steve

[DISCONNECTED]

I would definetly go with some type of punching device.Why not buy an iron worker machine and make a jig.Much quicker than drilling.You can also look into C shaped punch presses,people actually set up a number of these in a row to do multiple hole repetitive punching.
I myself cannot stand drilling takes to dam long for fabricated parts.Machined parts that have to have a close tolerance is another story.

[SScnc]

Thanks for your recommendation DISCONNECTED but again, cost is a concern and the design shown above is affordable to me and will do exactly what I need.

As for punching being quicker than drilling, I'm sure that's correct with everything setup right, however there are other parts I will need or want to CNC drill and it will be much easier and better for me to just load another prepared program.

Also, doing this on my floor drill press really doesn't take too long to do the actual drilling, what takes the time is marking the locations, handling the steel parts individually and then making sure that the bit is lined up with the marks.

And I will program it to peck drill which I think will help too.

I also envision adding a plasma cutter to the other side of the gantry at a later time.

With all that being said, I prefer to use rack and pinion for the Y and plan to order from here: http://www.stdsteel.com/gr_stock.htm

I need advice on which size R&P parts are recommended please. The Y travel will be about 66".

Thanks for any help,

Steve

[cut more]

Hi Steve,
I was out friday,
I looked at the rack site, I would go with the 20 pitch 1/2" wide. On the pinion size, that will depend on how fast you want to go and the torque of your motors.
If you plan on drilling heavy steel/stainless you might consider more vertical supports for the side rails in your design. The wider the span the more the force will be able to "spring " the rails.

Here is a picture of my Bport. and my vmc's

Cutmore

[SScnc]

Thanks for the advice on the rack and pinion setup Cutmore.

Your machines are very impressive to me, thanks for the pics, I especially like the Bridgeport CNC !

Good advice on the additional vertical supports, I'll add them and also will have adjustable feet on all of them.

One more question, I'm using a Keling setup with the 4030 drivers and 36 volt PS, what would be good stepper motor selections for the X,Y and Z for this ? I'm thinking some pulley reduction on the Z and threaded rod on the Z and X (?).

Thanks again

[cut more]

Hi Steve,
I like the Bport too. Although the first paying job I did with it I had to do ~1200 manual toolchanges in 3 weeks! That was when I started looking for something with a toolchanger. Now I just use the Bport for a few jobs.

I am not sure about which motors to use with those drives but may be Kelling could reccomend the right motors for you.

I would recommend you use gear rack on your x and y axis and a ballscrew on your z axis and here is why. The gear rack with ~3/1 reduction would allow you pretty fast point to point movement.

The ballscrew for the z axis with ~.1" pitch will give you higher torque transmitted from the motor to the load than a leadscrew, and it should last a lot longer than a lead screw. You wouldn't need zero backlash or a double nut set-up because you are not looking for extreme vertical accuracy just strength and reliability.

Just my recommendations,
Cutmore

[scrambled]

Steve-

I am installing a 3/4 inch Millwaukee drill motor on my gantry. It uses both a ballscrew and an air cylinder. I have it set so that when the ballscrew and the air cylinder are in the down end position, the drill bit just drills through the materal. At this point a magnetic reed switch will turn on and raise the air cylinder. To control the force that the air cylinder pushing down with, I am using a precision air regulator with a flow control.

When I change bits, just adjust the air pressure for the diameter of the bit and the ballscrew for the length.


I hope this helps. When I get mine put together, I will post a picture.


Steve

[SScnc]

Thanks for the additional advice Cutmore, it's all really helping.

scrambled, that's really an interesting approach, I'm very curious to see your setup. Do you have any drawings you can post at this time ? I can't wait to see the pics.

Thanks guys, this is all just the sort of advice and ideas I need to hear before cutting steel,

Steve