Needs Pictures: 0
Picture(s) thanks: 0
Results 16 to 30 of 58
-
2nd March 2014, 08:53 AM #16SENIOR MEMBER
- Join Date
- Jun 2011
- Location
- Australia east coast
- Age
- 71
- Posts
- 1,469
No, it's way too fast. Your drill press lacks rigidity and power, to put it politely. I wouldn't run a cutter at that diameter faster than 200 rpm in my Bridgeport mill.
Those superdrills are basically a single edge cutter with a pilot; I have a couple around here somewhere that I made 30 years ago. They do work well so are a good way to go, but you need to have the speed correct or all you'll do is burn the edge off and/or get absolutely massive chatter - this is why you need a nice fitting pilot hole as well. There's a good chance you'll pull the chuck loose from the drill press spindle if it starts chattering at speed because the cutting force is not axial to the spindle and any side load on a Morse taper is problematic.
580 rpm is also far too fast to run a hole saw into steel IMO and as has been observed, they cut a bad hole, oversized and rough. I've been thinking on making an adaptor for the slugger type trepanning bits for bigger holes but - it's low down on the long job list.
PDW
-
2nd March 2014 08:53 AM # ADSGoogle Adsense Advertisement
- Join Date
- Always
- Location
- Advertising world
- Age
- 2010
- Posts
- Many
-
2nd March 2014, 09:12 AM #17
According to the website, Super Drill:
Because the cutters are made from 8% cobalt and the SUPER Drill body is hardened to internationally recognised hardness measure, 60 Rockwell, the SUPER Drill and its cutters is built strong to tackle your toughest drilling.…..Live a Quiet Life & Work with your Hands
-
2nd March 2014, 09:55 AM #18.
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 27,841
Joe, Thanks very much for the drawing, a couple of questions if I may.
I assume the diameter of the thickest shaft is 25mm?
I assume the cutters/holes are at some sort of angle from the centre line of the shaft?
As I can already drill 25 mm holes, I might make one that starts at 25mm
-
2nd March 2014, 11:44 AM #19SENIOR MEMBER
- Join Date
- Jun 2011
- Location
- Australia east coast
- Age
- 71
- Posts
- 1,469
-
2nd March 2014, 12:24 PM #20
I see they also have a morse taper version. if your going to make your own wouldn't this be a better option? Knock the chuck out and fit the cutter directly into the spindle. Removes any error from the chuck or risk of damage to the chuck??
…..Live a Quiet Life & Work with your Hands
-
2nd March 2014, 12:30 PM #21
I like that super drill idea, it's been on the project list for ages, never makes it to the top however... Thanks Joe for posting it.... (BTW your monitor is ready)
Back to the original problem, I've had to drill a number of 25mm holes in 6mm steel over the last few weeks, part of a sliding gate project. I used a hole saw in an old AEG hand drill on low speed.. no trouble at all...
So, I think if the OP has a half way decent hand drill with 1/2" capacity chuck and a low speed range, forget the Bunnings drill press and do it by hand. Go half way and flip over, will make it a little easier for chips to clear.
While I was drilling the 25 mm holes in the posts, Josh used the mill and a boring bar to drill the 20 mm diameter holes in the 10mm base plates.. I got the easy job.
Ray
-
2nd March 2014, 01:51 PM #22GOLD MEMBER
- Join Date
- Sep 2010
- Location
- Lebrina
- Posts
- 1,099
Superdrills are an awesome tool.
300RPM should be fine for a 30mm hole. Work on the rule of 1000RPM for a 10mm hole, 500 for 20mm and so forth. I reckon your cheap bunnings drill press will drop enough speed when you start cutting to not overheat the cutter, make sure you use a good cutting lubricant though.
-
2nd March 2014, 05:33 PM #23Member
- Join Date
- Oct 2004
- Location
- Hobart
- Posts
- 51
I'm not clear on the difference between drilling and boring. Is it that the boring scrapes whereas drilling cuts?
-
2nd March 2014, 05:48 PM #24Philomath in training
- Join Date
- Oct 2011
- Location
- Adelaide
- Age
- 59
- Posts
- 3,149
Both drilling and boring cut, but drilling cuts material away from the bottom of the hole and boring cuts material away from the side of the hole. (Normally you have to drill a hole before you can bore)
Michael
-
2nd March 2014, 06:07 PM #25
What Michael said, plus a boring bar is a single point cutter, and is used in a boring head that allows the diameter to adjusted very accurately. So when you want a nice clean hole of fairly accurate dimensions, you use a boring bar.
Boring is done on the lathe as well as a milling machine, when used on a lathe, you don't need the boring head, the lathe cross-slide allows to to move the boring bar to adjust the diameter of the hole.
Slow motion boring video...
Then the next much more advanced stage is a boring and facing head... for that topic, I'll hand you back to Michael...
Ray
PS... Bored yet..
-
2nd March 2014, 06:17 PM #26
I have only ever used a boring head/boring bar for enlarging the ID of a hole.
Question, is it possible to cut the OD of a circle by turning the cutting point of the boring bar inwards?
Say I have milled a 100mm square piece of 12mm thick steel flat and I want to have a 4 mm high x 90mm diameter circle on top, could you use the boring head/boring for this as described above?
-
2nd March 2014, 06:27 PM #27SENIOR MEMBER
- Join Date
- May 2012
- Location
- Victoria
- Posts
- 130
Hi Gang,
I have had one of these for probably 15years, I had a good chat to the maker, from what I recall they are hardened, but depending on how much use that may not be necessary. The cutting bits are dead easy to sharpen and flipping them you can do holes in timber, upto 3" I think.
there was also a nifty tool for doing hose clamps out of stainless wire, always meant to make one but it ended up on the must do one day list.
Cheers
Bruce
-
2nd March 2014, 06:29 PM #28
I've never thought of doing it that way? Normally you would use a rotary table and just normal end-mill. Another way would be to mount it up in a 4 jaw chuck in the lathe. I won't mention CNC.. ( just did.. )
One problem that using a boring bar to do that job is that it would be an interrupted cut, on a large diameter that's going to cause problems with the boring head flexing and carrying on. Apart from those sort of problems I guess it might work?
Ray
-
2nd March 2014, 06:31 PM #29Philomath in training
- Join Date
- Oct 2011
- Location
- Adelaide
- Age
- 59
- Posts
- 3,149
-
2nd March 2014, 07:08 PM #30
Yes, I have done it like that (both ways), I was just curious whether it could be done with the boring head/bar.
In the (hypothetical) case above it would only be an interrupted cut for maybe 1 or 2 revolutions, after that it would be uninterrupted.
Yeah, that would help!
Similar Threads
-
Cut rectangular hole in 30mm wood?
By bobbavet in forum WOODWORK - GENERALReplies: 8Last Post: 11th August 2013, 08:00 PM -
Drilling a square hole!!
By spidey4fun in forum CNC MachinesReplies: 3Last Post: 14th October 2011, 10:09 PM -
core hole drilling
By AV Elec in forum HAND TOOLS - POWEREDReplies: 2Last Post: 16th February 2009, 06:29 PM -
Drilling large hole over small hole or vice-versa
By niki in forum HOMEMADE TOOLS AND JIGS ETC.Replies: 28Last Post: 2nd November 2007, 08:32 PM -
drilling long hole
By hagansrd in forum WOODWORK - GENERALReplies: 24Last Post: 18th May 2006, 04:21 AM