What are you machining?

[rory1]

Been doing a bit of line boring on a excavator demolition grab with my home made line borer. Holes were originally 45mm in 20mm thk abrasion resistant plate. They are being bored out to 65mm and having bushes fitted.

 

[slim_boy_fat]

^^ That's serious stuff!!

 

[rory1]

^^ That's serious stuff!!

If you've not got a machine big enough for the job to fit in then you have to make a machine to fit on the job!

 

[Hood]

Did it a while ago but it was really enjoyable making it. It was the 8 position VDI turret that is on my lathe and is in my user avatar.

Few pics below.

 

[decca]

Very nice.

 

[Hood]

Thanks, really enjoyed doing it although it was a bit scary at times as the tolerances had to be very tight for the face to the holes for the wedge clamps and if I screwed up it was a waste of both money and time, thankfully I didn't

 

[rory1]

Boring out a hydraulic cylinder on the mill to take some 65mm hardened steel bushings

 

[nickk]

thats a very slow helix on that drill,also how do you drive the tool once its on the bucket/grab?

 

[Hood]

thats a very slow helix on that drill,also how do you drive the tool once its on the bucket/grab?

Not sure if you are talking about the drill in the pic I put up or not, but if you are it is a spade drill.

Presume you are talking about @rory1 line borer in the second part of your question, looks like it is a hydraulic motor that does the turning of the boring bar (via gearbox) and using an align type mill feed to provide the auto feed.

 

[nickk]

the taper shank one in your t/stock, boring that blank disc.

 

[Hood]

the taper shank one in your t/stock, boring that blank disc.

Are you meaning this pic?

If so then it is a spade drill and it has a 40mm diameter shank and it is in a holder I made up for my tool post, normally I use them on the CNC although they are brilliant drills even for a manual lathe.
It is like this

 

[God mode restorations]

Wow. You guys machine up some proper tidy parts..awesome....I am yet to enter the world of machining. But if any of you guys are board and have some spare time. I would dearly like a set of these for my warco grinder.

 

[knighty]

@Hood the spade drill, do they just do one size, or do different sized tips fit ? (within reason)

quite fancy getting a few :-)

 

[Hood]

@Hood the spade drill, do they just do one size, or do different sized tips fit ? (within reason)

quite fancy getting a few :-)

They do a range for each series, see pic below. They are not the cheapest things out but they cut like a hot knife through butter, the one in the pic above is cutting through EN24T.

 

[nickk]

Are you meaning this pic?

If so then it is a spade drill and it has a 40mm diameter shank and it is in a holder I made up for my tool post, normally I use them on the CNC although they are brilliant drills even for a manual lathe.
It is like this

thats the one,,one of my jobs years ago, was regrinding them,[high carbon steel ones], then the company bought a m/c centre,i used to set the tools for it those drills were tipped ,i don't remember such a difference in size to the drill shank though.
View attachment 102756

 

[Hood]

There are several types of insert drills, the common type you see used on CNC are U-Drills. Think that could have been Sandviks name but it is now a kind of generic term for the type, similar in the way that a Hoover can mean any make of vacuum cleaner. You also get other offerings from the likes of Kennametal and Iscar where the whole top is the insert rather than just the flat piece like in spade drills.

I have never used the Kennametal or Iscar complete tip type but I do have/use quite a few U-Drills. The U-Drills take at least two inserts and require a lot more power than a spade drill.
Another thing about spade drills is they come in insane lengths and bore very true even at the long lengths.

Pics below of the other two types of drills I mentioned.

 

[ronan]

I have a fair few morse taper drills and reamers, but find when once i have a fairly big hole drilled, i tend to use a boring bar in the tool post.

 

[ronan]

Boring out a hydraulic cylinder on the mill to take some 65mm hardened steel bushings

What make/brand is your boring head Rory ? I have an indian one i picked, but i don't have much faith in it.

 

[Hood]

I have a fair few morse taper drills and reamers, but find when once i have a fairly big hole drilled, i tend to use a boring bar in the tool post.

I tend to drill with the biggest drill I have which is below the finished diameter then use the boring bar to complete, find it much faster, well as long as the lathe/mill has enough power for the drill that is. My Triumph lathe had the normal, well probably worse than normal, knackered gears in the headstock and you woke the neighbouring town up never mind just the neighbours . I fitted a 5KW AC servo to the spindle but it is too low on power at slower RPMs so big MT drills in 316 or a harder steel is a no go. With the spade drills however it is a different story, you hardly know you are cutting, even the one in my pic above which has a 39mm Dia insert, needs very little force to drive it.

 

[ronan]

I tend to drill with the biggest drill I have which is below the finished diameter then use the boring bar to complete, find it much faster, well as long as the lathe/mill has enough power for the drill that is. My Triumph lathe had the normal, well probably worse than normal, knackered gears in the headstock and you woke the neighbouring town up never mind just the neighbours . I fitted a 5KW AC servo to the spindle but it is too low on power at slower RPMs so big MT drills in 316 or a harder steel is a no go. With the spade drills however it is a different story, you hardly know you are cutting, even the one in my pic above which has a 39mm Dia insert, needs very little force to drive it.

You bypassed the headstock gears altogether ?