Thread: Drilling 30mm hole through 10mm plate

You could fit a standard caliper screen on something the size of my UPA5-S6, but then you would never be able to use it in your mill, you'd have to send it to one of us with a big mill......like me

Ew

Just remembered I have the BORDO brand in the TCT hole saws. I have the 25, 28, 30, 32mm. All unused so far so don't know how they perform. Mine have a capacity of 25mm. Instructions say remove ejector spring for holes deeper than 13mm so just be aware of that.

Nev.

Originally Posted by Michael G

Well yes - he only has one.

Michael

Out done by Michael himself who possesses a Wohlhaupter, a Kaiser and a Tree. As for a digital boring head, way over my head. Why, I'm struggling to make a bloody arbor for my Kaiser!

BT

Originally Posted by Anorak Bob

Out done by Michael himself who possesses a Wohlhaupter, a Kaiser and a Tree.

Only the Tree and Wohlhaupter at the moment Bob - for a number of reasons the Kaiser is now with Peter (PDW). However, they are cool little things so if you ever spot a Metric Kaiser with a SK40 taper at a sensible price do let me know. Gummed up with missing parts no problem!

Michael

Originally Posted by Michael G

Only the Tree and Wohlhaupter at the moment Bob - for a number of reasons the Kaiser is now with Peter (PDW). However, they are cool little things so if you ever spot a Metric Kaiser with a SK40 taper at a sensible price do let me know. Gummed up with missing parts no problem!

Michael

Just like this one hey Michael? Latter model than ours and this sold for 53 EUR more than mine.

http://www.ebay.de/itm/KAISER-Plan-u...p2047675.l2557

BT

Originally Posted by SurfinNev

Just remembered I have the BORDO brand in the TCT hole saws. I have the 25, 28, 30, 32mm. All unused so far so don't know how they perform. Mine have a capacity of 25mm. Instructions say remove ejector spring for holes deeper than 13mm so just be aware of that.

Nev.

Do the instructions refer to a recommended RPM for the 30mm cut?

Originally Posted by Stephen H

Do the instructions refer to a recommended RPM for the 30mm cut?

According to Starret and RUKO (http://www.automationdirect.com/stat...wcutspeeds.pdf), around 300 RPM.

I've also found that with thicker plate it helps to start the cut and once the kerf is established, drill a number of small diameter holes through the plate in the kerf - some of the swarf leaves the cuts through those holes and the saw doesn't jam.

Here's a simple demo..

40 year old AEG 2 speed drill, 25mm sutton hole saw, Rocol cutting fluid, 10mm thick flat bar.

Drilled a bit over half way, then flipped over and finished from the other side.. total time less than 5 minutes.

IMG_0696s.JPGIMG_0697s.JPG

Ray

Originally Posted by Stephen H

Do the instructions refer to a recommended RPM for the 30mm cut?

Instructions say 500-1600 RPM. That I assume, just covers a range of materials. Nothing specific.

Nev.

[QUOTE=jhovel;1752801]Here it is

Thanks mate! I was in a bind today so in knocked up a simpler version. I needed about 21.7mm holes in 3mm RHS. I used a step drill up to 3/4 ( I don't know why people bag step drills, I have been using the same one for years and it still punches holes in 10mm). And followed up with a Ben Super drill!

I did not bother making it fancy. I just drilled a hole (next imperial size up from 9mm) and used a grub screw from the bottom to secure the 1/4" hss. It held strong enough. When I make some more I will grind up a broach from 1/4 hss and drill an 8.5mm hole. It should pass through easily enough and give enough of a key to help setting the dept of cut.

Could you get rid of one of the relief angles in the cutter by drilling the hole a few degrees off perpendicular? Anyone got a thought on that?

Hi Ben,
the original cutters hat came with mine only had a relief angle at the bottom, parallel to the cutter bottom - maybe 5 deg. t also has a positive cutting angle - maybe 15 deg. The outside face of the cutter is ground to have a tiny relief at the smallest possible diameter - which means the curve has a slightly smaller radius than the small hole, but a little offset. It also means the bigger the hoe the bigger the relief.
In use, it peels off swarf which is the full size of the cut in width, just very thin. I have never tried it in brass or aluminium, but suspect it won't work well at all.

Boring Cutter for Drill Press.

The wealth of info in this thread intrigued me to the point of making a prototype simple cutter like Ben has mentioned.
I needed something to make 24mm dia holes in 12mm mild steel plate.

I used a 1/2 inch UNF by 6 inch Grade 8 bolt as the shank, cut down to 100mm clear length, and a piece of quality 3/16 HSS square tooling as the cutter.

Drilled a 6mm hole at 90 deg across the bolt shank 15mm from the bottom face.
Drilled a 3.8mm dia hole into the bottom, approx 3mm offset from centre, and at approx 10 deg off vertical, and tapped 3/16 BSW, so as to position the end face of a 1/2 inch long grub screw in the middle of the cross hole. The grub screw offset hole axis is at 90 deg to the cross hole, when looking at the bottom of the shank.
The grub screw end face was ground flat.

The cutter has 10 deg bottom relief, the cutter face is at 6 deg, and the end relief is 15 deg. The top two corners of the cutter have been slightly ground, so as to more snugly fit wedged into the round hole by the grubscrew. (The cutting angle is relatively small, because I was cautious about grab and feed control in my drill press).

Works like a treat, peeling off steel shavings like butter, after you find the feed sweet spot.
Use cutting fluid for shank lubrication as well as cutting.
How did I ever exist without one of these?
Thank you everyone.

cheerio, mike

Boring Photo! P1140404.jpg