Thanks: 3
Likes: 14
Needs Pictures: 0
Picture(s) thanks: 0
Results 1 to 15 of 49
-
23rd May 2013, 08:35 PM #1Philomath in training
- Join Date
- Oct 2011
- Location
- Adelaide
- Age
- 59
- Posts
- 3,148
Impero II: the cousin of parting tool
A few days ago I posted about an interesting parting tool that I found in a catalogue https://www.woodworkforums.com/f65/in...g-tool-171025/
The reason I was looking in that particular catalogue was that I was trying to find one of these -
P1010650 (Medium).JPGP1010651 (Medium).JPG
It's a thread cutting tool, but (in my opinion) a little bit more exotic than most you see. Most disc type threading tools have a cranked neck - I guess for those who incline the cross slide. This one is straight. The disc rotational angle is controlled with a spline and clamped with a soft washer. By a quick count it can index 48 positions (7.5 degrees) The tool can be inclined left/ right too - the hex at the back tightens a screw drawing a male taper on the rectangular block into a female taper in the shank. The screw doing this is captive, so unscrewing it breaks the taper for easy adjustment
P1010652 (Medium).JPG
Unless I make my own, I think I'm doomed to go through life without one. This one (besides belonging to my employer) has a 25mm square shaft and my tool post only holds 18mm maximum from memory. To give an idea of scale, the disc is 53mm in diameter and the splined stud is 16mm. The only way I can think of doing an internal spline that small is with a specially made broaching tool. It would be a fiddly thing to produce.
Michael
-
23rd May 2013, 11:02 PM #2SENIOR MEMBER
- Join Date
- Oct 2007
- Location
- Sydney
- Posts
- 2,324
Michael I've never seen anything like that before. Apart from being able to be sharpened almost indefinitely, what's the idea behind that?
-
24th May 2013, 12:21 AM #3
Hi Michael,
A very interesting tool, i really like the way the head can be rotated to match the helix angle of the thread being cut.
If your looking at making one, why not swap the splines for another taper? then the hardest part becomes making the blade itself and attaching it to its hub. If you do go down the road of making one i for one would be very interested in seeing how you go about it.
Cheers
Ew1915 17"x50" LeBlond heavy duty Lathe, 24" Queen city shaper, 1970's G Vernier FV.3.TO Universal Mill, 1958 Blohm HFS 6 surface grinder, 1942 Rivett 715 Lathe, 14"x40" Antrac Lathe, Startrite H225 Bandsaw, 1949 Hercus Camelback Drill press, 1947 Holbrook C10 Lathe.
-
24th May 2013, 01:05 AM #4SENIOR MEMBER
- Join Date
- Apr 2012
- Location
- Healesville
- Posts
- 599
Nup, I don't get it Michael ?
I would need a damned good sales pitch to buy that.
I reckon I can cut threads ok now so how would that make them better, cheaper or quicker ?
What is the reason for being able to angle the disc ?
It looks like it fell out of ET's tool box to me
-
24th May 2013, 01:19 AM #5GOLD MEMBER
- Join Date
- Jul 2010
- Location
- Melbourne
- Posts
- 7,770
How about a shaper?
I've thought about making one but doubt I do enough threading really(though that wouldnt necessarily stop me lol). Wouldnt the straight type be easier to make?
The important grinding has been done for you. To resharpen you grind the top and you are good to go again.
Stuart
-
24th May 2013, 01:28 AM #6SENIOR MEMBER
- Join Date
- Apr 2012
- Location
- Healesville
- Posts
- 599
-
24th May 2013, 07:21 AM #7SENIOR MEMBER
- Join Date
- Sep 2011
- Location
- Ballarat
- Age
- 65
- Posts
- 2,656
What a great improvement on the originals.
It would have been real handy to be able to rotate the heads to suit the lead angle.
Screwcutting tools 006.jpg Screwcutting tools 004.jpg Screwcutting tools 005.jpg
Phil
-
24th May 2013, 08:13 AM #8Philomath in training
- Join Date
- Oct 2011
- Location
- Adelaide
- Age
- 59
- Posts
- 3,148
I see the advantages of a tool like this as being
- The head can rotate to match the thread helix angle - not critical for most threads but a nice touch
- The correct angle is produced on the lathe when producing the disc - better control & a more accurate angle
- Normally when I grind a tool off-hand I manage to over heat the corners so my ACME threads for example have radiused thread bases. A tool like this has more support for corners and because grinding is only on the top surface, less chance of over heating
- Easier to take threads closer to a shoulder
- Because it is HSS, breakneck speeds are not required
- You would be able to keep a box of cutters for all the thread forms and angles and swap them quickly rather than a selection of inserts or individual cutters
It may be mainly personal preference, but I like it
To make one I think I would press fit the stub into the disc but instead of upsetting/ swaging it over I'd probably TIG it in. The advantage of the spline over a taper would be that a taper could possibly slip whereas a spline will not.
Michael
-
24th May 2013, 09:52 AM #9Distracted Member
- Join Date
- May 2010
- Location
- Lower Lakes SA
- Age
- 59
- Posts
- 2,556
Michael you have a shaper and a divider. Why is the spline a problem?
PS: I've forgotten what kind of tool post you have, but can't you make a holder to take the 25mm shank? Then you can borrow the boss's cutter.
-
24th May 2013, 09:55 AM #10SENIOR MEMBER
- Join Date
- Jun 2011
- Location
- Australia east coast
- Age
- 71
- Posts
- 1,468
-
24th May 2013, 11:26 AM #11SENIOR MEMBER
- Join Date
- Apr 2012
- Location
- Healesville
- Posts
- 599
53mm dia, this tool is designed for cutting large threads in large machines I suppose.
I think that Ueee's idea of the taper should not be brushed off, the way I'm looking at it is that when cutting threads you normally only take a series of smallish cut's so the load on the tool is fairly light and rarely are the cuts interrupted.
The disadvantage of the spline would be in the sharpening, I think you would need to use a flat faced diamond wheel, the side of a grinding wheel may work for a couple of sharpening's but then you would need to dress the side of the grinding wheel ? Most likely a jig to get the top rake correct would be warranted, if the jig was made so that the axis of the cutting tool could be inserted into it then you would be able to rotate the cutter into the wheel and regrind the top rake perfectly every time. But.....you have the 7.5 degree's of the spline to contend with, as you sharpen the cutter it cannot be rotated to the centre height and you will need to adjust the tool holder height until you get to the point where you need to go to the next spline where upon you will need to start from scratch and move the tool holder height down again. With the taper you would just rotate it to the centre height.
If you rotate the cutter sideways to suit the helix angle then the top rake also has to be adjusted to suit, I can't see why you would need to do that anyway ? All the relief you need is already there.
How much are the replacement cutters Michael ?
-
24th May 2013, 11:55 AM #12SENIOR MEMBER
- Join Date
- Apr 2012
- Location
- Healesville
- Posts
- 599
Michael these rods are pretty handy for welding HSS to mild or 4140
Cobalarc Toolcraft | BOC Australia
-
24th May 2013, 12:45 PM #13GOLD MEMBER
- Join Date
- Jul 2010
- Location
- Melbourne
- Posts
- 7,770
Hi Michael,
Do you have any specs on how big a thread this can cut?
It looks like it could cut at least 6mm(maybe more like 8mm) deep. Thats one large thread!\(well atleast it is for me, now if you were cutting worns that would be a little different )
Stuart
-
24th May 2013, 01:24 PM #14Senior Member
- Join Date
- Mar 2009
- Location
- Melbourne
- Age
- 54
- Posts
- 380
G'day Michael,
The tool you have shown is a fairly nice looking piece of kit.
Before you embark on having a crack at replicating it though, have you seen this type of tool before:
DTM H65 8A Lathe Threading Holder AXA Aloris T10 Insert | eBay
It slips straight onto an AXA holder (if you have one) and appears to have the same versatility as the one you pictured, helix angle adjustment etc.
From memory I'm pretty sure you can get blades for a number of different thread forms if you need them.
I think I've seen knock off versions of these too.
Cheers,
Greg.
-
24th May 2013, 01:55 PM #15SENIOR MEMBER
- Join Date
- Apr 2012
- Location
- Healesville
- Posts
- 599
Ok....I can see it now
large threads = low TPI = increased helix angle = less/no clearance on the face of the cutter
hence adjust for the helix with the cutter
DOH