boring bar from CTC

[jack620]

Hi Y'all,
I need to bore a 15.75mm hole in aluminium. The boring bar that came with my lathe is too big for the job, so I'm looking at something like this from CTC:

SCLCR/L INDEXABLE BORING BAR #I33 (http://www.ctctools.biz/servlet/the-612/indexable-iso-standard-lathe/Detail)

The tool holder appears to be oval shaped with flats on two sides. CTC don't seem to sell special holders for them, so do I just clamp it in the 4-way tool post between the flats?

I recall reading that CTC were getting a little slack with their postage times. Does anyone know if this has been resolved?

Chris

[Ueee]

Hi Chris,
Yes you can just clamp them in the 4 way, but you will need some packing as the tip is generally centered in the height of the bar. So if you get a 10mm bar the tip height is only 5mm.

Ewan

[Dave J]

I have a couple of Sanvik boring bars the same, just use them as you said using the flats. Like Ewan said you might have to pack it up, but you probably knew that anyway.
With the packers try to keep them with the tool holder for next time. A rubber band or a bit of sticky tape works well to keep them organised.

When I bought my tool post years ago they tried telling me the V bottom tool holder was no longer included as most boring bars have flats these days. They got a shock when I stated they sold them separate, so they sent me one of those out as well.

Dave

[Ruddy]

I bought some milling cutters from CTC during April and the delivery time was only seven days from acceptance of order.

[jack620]

Thanks fellas. My Hercus has a centre height of around 18mm, so packing will definitely be required.

[simonl]

Hi Jack,

I have a similar boring bar. I got it from Chronos engineering supplies
Glanze SCLCR Boring Tool Sets with 4 Inserts (http://www.chronos.ltd.uk/acatalog/Glanze_SCLCR_Boring_Tool_Sets_with_4_Inserts.html)

Looks similar to the CTC tools one.

Cheers,

Simon

[jack620]

thanks simon. I think they are identical. the description is word-for-word.

[pipeclay]

The shanks of the holders are round they just have either 2 or 3 flats machined on them.

[jack620]

Thanks pc. 2 flats I can understand. What's the purpose of 3 flats?

[pipeclay]

So that the bar fits square against the tool post.
Round is fine but there is more area in contact with it being flat.

[bwal74]

Hi,

I bought the smallest or second smallest diam boring bar from CTC tools, works fine but take small cuts otherwise the bore will bellmouth. Probably not much of a concern in alum. but in steel it will be.

Ben

[jack620]

Ok, 3 flats at 90 degrees to each other. For some reason I was thinking at 120 degrees to each other. :doh:

Ben,
thanks. I'm going for the 10mm bar that bores 13mm and larger.

[jack620]

Simon,
can you please tell me which inserts came with your boring bar from Chronos? That is, what types of metal they are optimised for?

On the CTC website there are CCMT inserts for aluminium/non-ferrous, steel and SS. They only sell them in packs of 10 for around $40+ and I don't really want 10 of the same type. I would much prefer a mixed bag. The current job is aluminium, but the next job might be MS.

Also, can anyone comment on the quality of the KORLOY brand of inserts that CTC sells?

[Ueee]

Simon,
can you please tell me which inserts came with your boring bar from Chronos? That is, what types of metal they are optimised for?

On the CTC website there are CCMT inserts for aluminium/non-ferrous, steel and SS. They only sell them in packs of 10 for around $40+ and I don't really want 10 of the same type. I would much prefer a mixed bag. The current job is aluminium, but the next job might be MS.

Also, can anyone comment on the quality of the KORLOY brand of inserts that CTC sells?

Personally i don't have any inserts from CTC, but i did get some with a glanz boring bar, which i think are the same as the CTC ones, and they are crap.
You would be better off doing an EBAY search for the tips you want and getting Mitsubishi, Iscar, Tungaloy etc. It may just take you a few goes to get the search terms right. Searching for SCLCR comes up with only bars and tips, not just tips.

Ewan

[simonl]

Simon,
can you please tell me which inserts came with your boring bar from Chronos? That is, what types of metal they are optimised for?

On the CTC website there are CCMT inserts for aluminium/non-ferrous, steel and SS. They only sell them in packs of 10 for around $40+ and I don't really want 10 of the same type. I would much prefer a mixed bag. The current job is aluminium, but the next job might be MS.

Also, can anyone comment on the quality of the KORLOY brand of inserts that CTC sells?
Hi jack,

Im out and replying on my phone while i watch my 3 yo play at bunnings playground so ill reply when i get home. I agree with ueee. I think the chronos stuff is overpriced, if i had have known about xtc back then i would have gone with them. Anyway i think you can't go wrong on ebay once you figure out the right search. When i get home ill have a look and tell you exactly what tip it is they use so you can use it as a search.

Last lot of inserts i bought were oscar and i have found them to be great value for money and pretty good quality, well for the basic stuff i do anyway.

Iscar. Not oscar. Stupid phone!

Cheers,

Simon

[jack620]

Thanks guys. CTC also sell Tungaloy and Mitsubishi inserts. Unfortunately also only in boxes of 10. I might just order the bar from CTC and look on EBay for inserts as you both suggest.

[simonl]

Hi Jack,

My boring bar is a 12mm bar, SCLCR and it takes a CCMT0602 insert.

Hope this has somehow helped.

Simon

[pipeclay]

You would probably find buying individual tips to cost more in the long term than buying boxed lots.
Individual tips maybe as high a $7 each,then if you add postage another few dollars,could put an assortment of 3 or 4 different types very exspensive.
I take it you are using these tips on a backyard machine,if thats the case I wouldnt be worrying too much about the gradeof tip you get for Steel,Aluminium or Cast.
You would be better off making sure the tips have the correct nose radious suited to your machining conditions.
If you decided that you were going to chase particular grades you may be back here in a few weeks to a month telling us that they have arrived and your about to start using them.
Not sure how much you have used Indexable inserts before,most are very forgiving for a backyarder.

[Dave J]

The sharp aluminium ones are supposed to leave a nice finish one mild steel.

Dave

[Jekyll and Hyde]

The Mitsubishi inserts I have from CTC (NX2525 off the top of my head) are supposedly for stainless steel, but do just fine on aluminium, likewise the random Sumitomos that came with the lathe do fine.

Personally though, in this situation, I'd just grab hold of a piece of HSS and grind up a quick boring bar to do the job - even a broken drill bit would do... I'm a fan of HSS for aluminium, although I head straight for carbide on any kind of steel turning.

Probably worth noting that for carbide running in a 15mm bore on aluminium, the ideal spindle rpm is likely to be well over 5,000rpm (depending on grades of carbide etc...)

[Dave J]

I am with you on HSS on aluminium, but I find I get good results on steel as well with HSS.
I just have the cheap HSS boring bars with 90 degree one end and 45 the other and have sizes from around 10mm up to 11/2 inches. For some small holes where drilling wont do, I weld the HSS to the end on some round bar.

With aluminium I find I get a brilliant finish with HSS. I could see where the sharp positive rake inserts would do a good job as well, but having packets and packets of inserts laying around is out of my price range, as I am only a hobby shop and cant justify the cost to machine something, where HSS cost just cents per sharpen.

Mike,
I will chase up that comparison for you with the steel using the aluminium inserts.

.
Dave

[jack620]

Thanks again for the info.

Yes, I'm just a backyard hack with a Hercus 260. Point taken about us backyarders not needing a special insert for every material.

The CCMT0602 insert comes in a 02, 04 and 08 tip radius. According to the man at CTC, 04 (which is 0.4mm radius I believe) is the most common.

If the insert for boring aluminium also does a good job on MS, I would be happy to buy a box of those.

I'll see if I have a piece of HSS I could grind into a boring tool. I have plenty of old drill bits I could grind, but I can't picture how I would mount them in the tool post. :?

BTW, I should have mentioned- the hole I need to bore has a shoulder in it, so I need a tool that can bore and face. The 15.75mm hole steps down to 8mm, so I'll drill with right thru with an 8mm drill bit and then bore part way to 15.75mm.

Chris

[jack620]

Sorry to keep harping on about this, but I've just had a thought. The boring tool I already have has a 1/2" diameter bar in a holder (see photo).

Is there any reason why I can't fit boring bars like these into my holder?

9 PCS. 1/2" BORING BARS WITH CARBIDE TIPS #G14 (http://www.ctctools.biz/servlet/the-415/2%22-BORING-HEAD-1-fdsh-2%22/Detail)

One of those bars should be able to bore a 15.75mm hole.

[simonl]

I have wondered that previously. I'm certainly not an expert but the way I see it is they do the same thing. Only in one setup the tool is moving and in the other setup it's the workpiece. Perhaps the rake angle may need to be different.

Or is this a too simplistic way to look at it?

Simon

[Dave J]

Those boring bars are not real great unless you sharpen them up. Whats wrong with using that bar? You can sharpen the tip so you can bore it and face it inside with the same tool.

With my comment above about carbide in the home shop, it was not meant to be anything negative toward anyone, just my view as money for tools is short in my shop.

By all means give the carbide a try, I would go for the sharp aluminium inserts and then use them for steel as well.

I do find you can get pretty well mirror finish with HSS on aluminium with the right grind and hone.

Dave

[jack620]

I tend to agree with you Simon. The tool doesn't know whether it's rotating or workpiece is rotating. As long as you can set the cutting tip of the tool on centre height I can't see why it wouldn't work.

[Michael G]

No reason why you can't do that. The overhang would be my main concern. Try it and see. I read some once that you learn the most when there is maximum uncertainty. this could be an extreme learning experience.

Michael

[Ueee]

Sorry to keep harping on about this, but I've just had a thought. The boring tool I already have has a 1/2" diameter bar in a holder (see photo).

Is there any reason why I can't fit boring bars like these into my holder?

9 PCS. 1/2" BORING BARS WITH CARBIDE TIPS #G14 (http://www.ctctools.biz/servlet/the-415/2%22-BORING-HEAD-1-fdsh-2%22/Detail)

One of those bars should be able to bore a 15.75mm hole.

I don't like those types of bars, i think all the angles are a bit wrong for them to cut well. I would still suggest welding some HSS to a bar or buying one of these L100 | Boring Bar with Holder | machineryhouse.com.au (http://www.machineryhouse.com.au/L100) and some 1/8" HSS (not sure how big the bar in the pic is but i have bored 1/2" with one of these bars). I really like these bars, you can use them for boring, internal grooves, internal facing and threading. I am biased towards HSS for most finishing and fine work. Carbide is great for stock removal, but i really hate being hit by hot chips.....

Ewan

Edit: on reading Michaels post, a small lead collar on a boring bar can really help to dampen vibrations.

[jack620]

Dave,
I don't think I can bore a 15.75mm hole with my current bar- it's too big. Or have I got it wrong?

[jack620]

Thanks fellas. Could I just grind a boring tool out of an old 1/2" HSS drill bit? It would fit nicely into my holder.

[Ueee]

Yes you could just do that, but the shanks of drills are not hard, so you have to use the bit of steel just below the flutes.

Ewan

[pipeclay]

You could,your only concern would be making sure that you can still face the bottom.
Depending on how you grind the drill will determine the ease in facing.
How deep is the bore.

[jack620]

PC, the bore is 20mm deep.

Thanks Ewan.

Would it be possible to grind the actual flutes into a reasonable shape for boring? I'm trying to picture it in my head, but if you ground the end of a drill bit flat at about 85 degrees to the drill bit axis would you end up with a boring tool (of sorts)?

[pipeclay]

I have never used a drill bit as a boring bar,if needed I weld a piece oh HSS to the end of a H/T bolt or piece of round or square bar.

I would imagine that you would grind the bottom of the drill with a small amount of front clearance,then even grind about 1/2 the diameter of the drill away at the rear and top and then procede to put your grind for the cutting edge on the front of the drill.

Because you only have a short bore I would suggest you cut the drill down to as short as possable to reduce the chance of vibration and flexing.

I wouldnt get any closer to the parallel shank than 25 to 30 mill as the shanks are softer than the fluted area of the drill.

[jack620]

Thanks, I'll give it a go.

I have an oxy torch, so brazing a piece of HSS to a bolt is also an option. Do you quench after welding?

[pipeclay]

I Mig or Stick but dont quench.

[Ueee]

Thanks, I'll give it a go.

I have an oxy torch, so brazing a piece of HSS to a bolt is also an option. Do you quench after welding?

No need to, you will not affect the HSS hardness with a small amount of heat, just make sure the end your going to use doesn't get above a really dull red (you wont see it in a well lit workshop) You would be better welding as the heat would not be there for as long. I have heated HSS to cherry red before with no ill affects, but your better to be safe. Just quench once its lost all its colour. You don't want to make the bolt or bar too brittle.

Ewan

[jack620]

OK thanks. Electric welding is not an option I'm afraid. I'll try brazing and see how it goes.

I also bit the bullet and ordered a set of the cheap 1/2" shank TCT boring bars from CTC. I'll report back when I've tried them.

Cheers

[morrisman]

You might get some ideas here ...........Mike


Boring Small Holes 1 (http://www.homews.co.uk/page138.html)

http://www.homews.co.uk/page237.html

[Dave J]

Dave,
I don't think I can bore a 15.75mm hole with my current bar- it's too big. Or have I got it wrong?

What size is that bar in the picture? a 1/2 inch one would do the job.

With the the bars you ordered, do you have something to sharpen carbide with? As they will need it and a bit of reshaping as Ewan said.

Dave

[jack620]

Thanks Mike. Those notes and drawings will be very helpful when it comes to grinding HSS boring tools.

[jack620]

Hi Dave,
the bar is 1/2". I had another look today and I'm pretty sure 15.75 mm is not achievable for a stepped hole. A through hole could be done using the end with the tool at 90 degrees, but with the 45 degree tool the diameter becomes too large when the bit is extended beyond the end of the bar (which it needs to if it is to cut the face of the step...........I think).

I have a 200x50mm 600 grit diamond lapping plate which hopefully will be able to sharpen the boring bars.

[Dave J]

I see what you mean, will have to put my brain into gear, LOL
You should be right with having a grinder. I got a selection with my Taiwanese boring head set and found the sharpness and carbide quality to be low. It came with a bar for HSS so I just use that.
H&F have 18mm insert boring bar sets for boring heads that I wouldn't mind trying. These could also be used for shallow boring in the lathe.
https://www.machineryhouse.com.au/M181A

Dave

[jack620]

No worries Dave. I might get a green wheel for my little 6" GMF grinder. It currently has white oxide wheels.

[Oldneweng]

I chipped the last corner of my last tip for my small boring bar (14mm hole) earlier in the week. I had a double ended boring bar I made up from MS just after I got my lathe. It is just a bit of 20mm square with 2 different sized round sections turned on each end. The smaller end was a suitable size for what I needed so I finished it off. This only required drilling a suitable hole across the round section for the HHS tip. The end was already drilled and threaded M8.

I drilled 5mm and used a 5mm broken drill bit to grind up a tip. I used the flute of the drill flattened off slightly, undercut some relief underneath and towards the back and removed the back edge of the other flute as well. This bar was for thru boring only. To cut to a shoulder requires the cross hole and clamping hole to be drilled at 45 deg angles and a small clamping grub screw.

I used this bar to bore from 14mm to about 16mm in MS 25mm round turned cylinders to make a sheet metal bender for flashing etc for a verandah build which has been going on for several months now.

Yesterday I was going thru all my indexable tool holders in order to find replacement inserts for them all and then document this for the future. I have a container of the tips from those sets of 9 or so toolholders that are useless. Inside that container I found 1 tip for my small boring bar in a plastic bag. I don't remember where I got it from.

I have ordered 10 new Mitsubishi ones from ctctools. They don't have any to suit my larger boring bar or my main turning tool. I have decided it may be easier to buy a new main turning tool.

Due to the recent arrival of a new grandson I will be going to Adelaide next week so will try to find some info then.

Dean

[jack620]

Thanks Dean, I'm glad to hear that the flutes of a drill bit can be ground into a suitable boring tool. Have fun in Adelaide.

[Dave J]

Due to the recent arrival of a new grandson I will be going to Adelaide next week so will try to find some info then.

Dean

Congratulations, my little grandson who lives with us is a bit over a year old now, cant wait until he is a bit older and can keep me company down the shed, LOL

Dave

[jack620]

Dave,
you'd better get in quick before he discovers computers.
Chris

[Dave J]

LOL, I have 3 other grandsons that live 3 doors away that are like that with computer games (but so are there parents) I will do my best to teach him like I did my son, with computers being great for research, but not brain dead games. I have plenty of Lego and Mecano with wind up and electric motors, gear boxes etc here for him as he gets older to interest him. Worked with my son, so hopefully with him as well LOL.

Let us know what you think of the bars from CTC, as I have never bought any bars from him.

Dave

[bwal74]

Hi,

My two eldest boys (primary school) are just starting to get interested in the lathe and shaper (they have no choice really, they are both in the garage which doubles as my toolshed and kids spare leisure space).

My baby boy (15mths) absolutely loves the machines.

Ben

[Ueee]

Hi,
I know we are way off topic here but being a proud father i can't resist. Some of you may have seen pics of Arthur (now 2) with Blondie, but here is one on the day that Freddie came home. I really hope i can keep him and his little brother (7 months) away from video games and in the shed. Not that we have any video games in the house to influence him with, but his Uncle is an absolute addict it amazes me how a 30yr old can still be into them.
Arthur loves going for a horse ride at the old carousel here in the city, i'm a bit worried i may find him trying to ride Freddie one day.......
Ewan

http://i1151.photobucket.com/albums/o622/ueee84/IMAG0531.jpg

[Dave J]

Just saw this one in Aus and thought it looked OK for you, not sure what it's like but the price seems reasonable for a set.
Titan Machinery - CARBIDE BORING BARS 4pc set (http://titanmachinery.com.au/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=110&category_id=24&option=com_virtuemart&Itemid=66)

Dave

[jack620]

thanks Dave

[.RC.]

Hi,
I it amazes me how a 30yr old can still be into them.




Because they are enjoyable to play :)

Like making chips...

[shedhappens]

I set up a .250 slot drill in the lathe to bore a small stepped hole to fit a pressure relief valve in an oil pump a while back, the hole had to be fairly accurate and I didn't have a ream, the finish was quite good and the valve was a nice sliding fit.
I drilled a bit of bar to suit the slot drill and held it with a grub screw, I turned the bar to the diameter to suit the tool height and got into it with the angle grinder to get it into the tool post far enough for bolts to hold it.

john