interepted cut with boring bar

[Tundra Twin Track]

I used a 5/8” boring bar to machine over 50 sockets 6&12 point ,the deepest would have been around 2” on a 3-1/8” Socket.It took 3 inserts to do all of them,all interrupted cuts.

[darryl]

Even with that short stickout you might take the extra step of wrapping some solder around the bar to dampen it. Or lay on a strip of that sticky window sealant, something like that. I doubt if the magnitude of any oscillations would damage the cutter, but it's pretty quick to add this damping. Solder can still be used later, or just kept for damping boring bars, etc. Plus it won't pick up swarf like anything sticky will.

[darryl]

Tundra- I bet those sockets work great now Is that part of a punch set?

[rogee07]

Thanks to everyone for your advise, this has been the best response to any question I have ever asked on any forum.
thanks again.

[754]

TUNDRA I call jobs like that GRAUNCH and ROLL.....

[JRouche]

[QUOTE=rogee07;n1917552]

will be boring a 2.5" hole trough a .75" thick plate of 8620. on the back side of the plate several .25" features have been cut on the back side of the JR

We want to see/So, lets see the "features"

What are theu? We want to see?

Show us the several features in .250" off the deck..

I love great machining. It makes me want to get to the garage (shop) an do... Do anything really.

Thanks.... JR

[Peter N]

Yep, machine rigidity counts. A very slightly loose compound - even though you thought it was tight, can have some disastrous results.
This was my solid carbide 1/2" bar last week. Boring a 1.25" dia hole, 2" deep in A2, about a 0.030" doc. About 3/4 of the way in must have hit a hard spot in the material. The tiniest bit of lift in the compound and Bam! ....scratch one expensive boring bar.

[Lew Hartswick]

For interrupted cuts just use HSS tooling. Like this. :-)
...lew...

[Doozer]

Love the chain drilling.

[old mart]

If you have a bigger bar, by all means use it, but with the minimum stickout the 3/4" bar should be fine. Having a choice of inserts allows you to select the best one for that particular job. Make sure your compound slide is not overhanging either. I have got away with using carbide inserts for aluminium on interrupted cuts on steel, but I took care to keep the depth of cut low.

Sad to see your poor carbide bar, Peter, I have made some by buying carbide stock and silver soldering on the end of a cheap Chinese steel boring bar. Of course, a means to hold the round shank has to be factored in. The only carbide boring that I have broken so far was a home made 7mm which I crashed into a chuck.

[dian]

For interrupted cuts just use HSS tooling. Like this. :-)
...lew...

so you make the multifix tool holders yourself?

[Lew Hartswick]

so you make the multifix tool holders yourself?

No it was for an Ironworker die . :-)
...lew...

[Tundra Twin Track]

Tundra- I bet those sockets work great now Is that part of a punch set?

darryl the Sockets are used for bearing,bushing,seals and any related jobs,they work great!

TUNDRA I call jobs like that GRAUNCH and ROLL.....

754 they actually machined pretty decent and left good finish,sharp square faces work well.

For interrupted cuts just use HSS tooling. Like this. :-)
...lew...

Lew I bought Kennametal inserts designed for interrupted cutting.

[Fasturn]

I have a small lathe and mill in my home shop. Interrupted cuts are bad, so I would scribe a circle and endmill it close as you can. Then bore the hole. I hog on the mill before the lathe, because it's not a beast. I never liked interrupted cuts on a lathe. You can end up wearing that carbide insert ?

[Doozer]

so you make the multifix tool holders yourself?

Gave you a LIKE for that one. LOL !