Boring heads

[Ron LadenParticipant @ronladen17547]

I am confused which is quite the norm for me, please see picture below.

My boring head set arrived and all of the tools are right hand tools, assuming I,ve mounted the tool correctly it needs to be run in reverse/anticlockwise when in the side/horizontal position. The tools are fine in the vertical but I dont have reverse on the mill just clockwise so unless I am being stupid or missing something how can you use these tools on a forward running machine. Or should the tool be turned through 90 degrees clockwise until the bit is inverted..?

Edited By Ron Laden on 31/10/2018 17:31:58

[Howard LewisParticipant @howardlewis46836]

For all the jobs, so far, the actual Boring tool has been mounted vertically, rather than horizontally, as shown, BUT the holes have not been 100mm diameter! (Possibly beyond the limit for vertical mounting?)Which ever way the tool is mounted, use the shortest one possible, to maintain rigidity.

The orientation of the tool, not just the speed, may affect whether chatter occurs.

I can see no immediate problem with mounting the tool "inverted", other than needing more clearannce under the job, to allow the tool to pass through the work piece.

For accurate sizing, the final cutS need to be Spring cuts. In a 25mm deep cut, it would not be impossible to see some taper, otherwise.

Howard

[JasonBModerator @jasonb]

Ron as I said earlier

"They do come sharpened but none will be ground correctly for use in the side holes. You may want to just touch them up with a diamond slip but will need to grind then for use in the side."

Don't try running these boring heads backwards as they can unscrew from the arbor.

Having said that they can't be used on the side hole there is infact a way that you can use the cutters that you have. Rotate the tool shown in your photo 180degrees and then cut upwards from the bottom of your plate to the top.

[Ron LadenParticipant @ronladen17547]

Thanks Howard/Jason

I think it a bit strange, disappointing and to be honest bloody annoying that they supply the head with "wrong handed" tools when you consider most of the smaller mini-mills have no reverse. Wouldnt you have thought they would come with tooling to suit clockwise operation and then they could be used on all the mini-mills and all the models going up in size.

As it is if you have a non reversing mill then the supplied tooling is not correct for normal operation.

Ron

[SillyOldDufferModerator @sillyoldduffer]

Posted by Ron Laden on 31/10/2018 19:00:38:

Thanks Howard/Jason

I think it a bit strange, disappointing and to be honest bloody annoying that they supply the head with "wrong handed" tools when you consider most of the smaller mini-mills have no reverse. Wouldnt you have thought they would come with tooling to suit clockwise operation and then they could be used on all the mini-mills and all the models going up in size.

As it is if you have a non reversing mill then the supplied tooling is not correct for normal operation.

Ron

Hard to think of a use for a left-handed boring bar apart from in the cross hole!

Most boring is done from the bottom of the head because there's less risk of chatter. Sideways mounted boring of large holes is rare in my experience. The few times I've done it, boring bottom up as Jason describes.

Avoid running a boring head or anything else with a screw fixing in reverse. Don't ask how I know…

Dave

[JasonBModerator @jasonb]

It's correct for 99% of use where the tool tends to be used pointing downwards and as a lot hear said the smaller mills would not have the power to use the head with the tools sideways for bigger holes why would they be supplied with tooling that may not get used. Though it would be nice if one of the nine cutters were LH but as i said the supplied RH one scan be used to upcut should the need arrise.

Another alternative if you don't have a green grit wheel is to make up a simple 12mm dia adapter to take a bit of 6mm or 1/4" HSS from an old ctr drill or milling cutter and grind that up on a standard wheel.

[Ron LadenParticipant @ronladen17547]

Posted by SillyOldDuffer on 31/10/2018 19:49:04:

Posted by Ron Laden on 31/10/2018 19:00:38:

Avoid running a boring head or anything else with a screw fixing in reverse. Don't ask how I know…

Dave

No danger of that Dave, I have no reverse

[Ron LadenParticipant @ronladen17547]

Posted by JasonB on 31/10/2018 20:08:02:

It's correct for 99% of use where the tool tends to be used pointing downwards and as a lot hear said the smaller mills would not have the power to use the head with the tools sideways for bigger holes why would they be supplied with tooling that may not get used. Though it would be nice if one of the nine cutters were LH but as i said the supplied RH one scan be used to upcut should the need arrise.

Another alternative if you don't have a green grit wheel is to make up a simple 12mm dia adapter to take a bit of 6mm or 1/4" HSS from an old ctr drill or milling cutter and grind that up on a standard wheel.

Points taken Jason but I still dont understand why the tooling supplied only suits machines with reverse for using the tool sideways. Most of the tooling supplied wont get used if you have a non reversible mill as I do. There is 9 tools in the set why they couldnt have supplied 3 of them as a short, medium and long in LH I dont know. Sorry, just a bit pee`d off with how they have thought out the tool set.

 

 

Edited By Ron Laden on 31/10/2018 21:34:32

[Simon Williams 3Participant @simonwilliams3]

Posted by Simon Williams 3 on 25/10/2018 09:28:05:

I forgot to note that the boring tool used in the head axially is a right handed tool, but the tool needed for the radial position is a left handed tool, as it cuts on the opposite edge.

Ron – good evening,

Good to hear you've decided to buy the tool and have a go, and not so good that you've found the left hand pitfall. Obviously running the tool backwards isn't an option – the mandrel on which the head is mounted is screwed in with a right hand thread so running the tool backwards will simply unscrew the thread.

I never thought of running the tool bottom to top – how do you adjust the diameter with the tool below the work using the radial hole? Maybe it's just keyhole surgery?

I feel it's a bit unfair to criticise the tool supplier for not including at least one left handed tool in the kit. You're into advanced boring head using, and fettling a suitable tool is an exercise for the student. I dare say most purchasers of one of these boring head kits of tools would send the left hand tool back saying it's been made wrongly!

Good luck and do let us know how it goes, Would love to see a video – or at least some piccy's of work in progress, ideally with a view of how the tool is sharpened ant presented to the work piece.

Simon

[Mark Elen 1Participant @markelen1]

Ron,

I wasn’t happy with using mine (same arc kit) on Ali, so I bought a SCLCR 12mm bar with an Ali insert. You could get an SCLCL (left hand bar) and do similar. Have a look here: **LINK**

Cheers

Mark

[John ReeseParticipant @johnreese12848]

A square tool bit works nicely in the cross hole in the boring head. You can grind the tool to optimize the tool performance. It is also a lot cheaper than insert tooling.

A major problem with the small variable speed machine is very poor torque at low speeds. If the machine has a back gear or multi step pulley system it can be work well at lower speeds.

I am not familiar with the motors and controls on these machines but I would assume the available horsepower diminishes as the motor speed is reduced. If the motor has a cooling fan reducing the speed will also result in less air passing through the motor and increasing the potential for overheating,

The 100 mm hole is probably possible if one has sufficient patience. If I were to try to do the job I would probably get in a hurry which would result in smoke escaping from the motor.

[John ReeseParticipant @johnreese12848]

I would suggest making the initial hole 55 to 60 mm., just large enough to pass the boring head with the tool sticking out a bit. Getting that initial hole made will probably e the most demanding part of the job in terms of torque. Once you are actually boring you can vary the depth of cut to stay within the limits of the motor.

[JasonBModerator @jasonb]

Posted by John Reese on 01/11/2018 02:39:15:

I would suggest making the initial hole 55 to 60 mm., just large enough to pass the boring head with the tool sticking out a bit. Getting that initial hole made will probably e the most demanding part of the job in terms of torque. Once you are actually boring you can vary the depth of cut to stay within the limits of the motor.

Why will the initial hole be the most demanding part of the job?

Go back to the first page where several of us suggested stitch drilling out the waste which only requires a 6mm drill bit and even the SX2P won't baulk at that.

If the holes are drilled on a 92mm PCD that will leave the mimimum amount of metal to be removed with the boring head so it won't take long if done in shallow cuts of about 0.25mm as suggested earlier.

As for adjusting the head when upcutting, once the cut is complete and the tool above the work move the work, wind on the next cut, lower the tool and then reposition the work back on ctr using the handwheel scale and then take the next cut simples.

J

[Ron LadenParticipant @ronladen17547]

Thanks guys, I,ve had a good nights sleep and calmed down, sorry about my bit of a rant last evening I was just annoyed when I saw the tooling.

Anyway I have started the chain drilling to remove the bulk and I have found that one of the boring tools is not to badly shaped and sharpened (well to my inexperienced eyes anyway) I will touch it up with the diamond slip and it should be ready to go. I am going to try with the bit on the underside and bore down from the top, dont know how that will work out but I will see. The tool is one of the shorter ones and a bit chunky which I thought would be better than trying with one of the lighter duty ones. Light cuts and feed and I,m hoping the SX2 will cope, will let you know how I get on, thanks for all the advice guys.

Ron

[Ron LadenParticipant @ronladen17547]

Chain drilling done, thought I would be clever and chain drill with a 10mm cutter, did the first hole and then came to my senses and changed to the 6mm drill bit.

[JasonBModerator @jasonb]

Ron if you are trying one of the supplied tools make sure the back edge does not rub on the cut surface.

[Ron LadenParticipant @ronladen17547]

Posted by JasonB on 01/11/2018 10:23:10:

Ron if you are trying one of the supplied tools make sure the back edge does not rub on the cut surface.

Thanks Jason, I think it would have cleared but I relieved it a bit anyway. Pics below show the tool I am going to try and the way it will be mounted, dont know if it will work but worth a try.

[EmgeeParticipant @emgee]

Ron

I think you may need to rotate the tool 90 degrees so the face of the tip is cutting.

Emgee

[JasonBModerator @jasonb]

Edge on will be OK for light cuts I have used them that way when machining the outside of a part.

[JasonBModerator @jasonb]

looks like it will just clear but not sure what the finish will be like as it is slightly negative rake

[larry phelan 1Participant @larryphelan1]

For holes that size,I chain drill and then clean up as much of the points left using a file. This makes it much easier on whatever cutter you use next. Would not like to try a hole that size using a boring head,sounds like a job for the lathe.

[Ron LadenParticipant @ronladen17547]

Posted by JasonB on 01/11/2018 12:19:47:

looks like it will just clear but not sure what the finish will be like as it is slightly negative rake

Thanks Jason, as you know I have no means of adjusting that at the moment but I am going to get a green wheel on order

Ron

[Simon Williams 3Participant @simonwilliams3]

(Don't tell anyone I was mad enough to suggest this, but a diamond disc in the angle grinder will shape the tungsten carbide tool.)

It's a bit rough and ready and will need stoning up with a diamond file afterwards, but it can be done.

Keep up the good work, thanks for the photo's

Simon

[Ron LadenParticipant @ronladen17547]

Success, it went really well with no issues at all, I am really pleased and enjoyed doing it.

I must admit I was nervous though having not done it before and a largish hole in 25mm material, I was worried that it may push the mill too far but there was none of it. I would go as far as saying that the mill coped with it easily, there was no worrying sounds and not once did the mill seem laboured, no chatter or slowing or hesitation.

I did take it steady though, started with 0.125mm cuts until I got past the worst of the chain drilling and then used 0.250mm cuts from there on. I did try a 0.500mm cut and again no issues but stuck with the smaller cuts and a finishing cut to complete. Ran the mill at 550rpm, I know they say that the mini-mills power goes up and down with the revs but at 500rpm it obviously had enough. Pleased with the finish too, the carbide tool cut really well.

Thanks for all the help guys but I really do need to say a big thank you to Jason, he has helped me no end and his advice encouraged me to have a go when there was question marks raised over trying this on a mini.

Thanks

Ron

 

 

 

 

Edited By Ron Laden on 01/11/2018 19:26:22

[EmgeeParticipant @emgee]

Well done Ron, hole finish looks good.

Emgee

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