Stuff you have made today

[Munkul]

Decided to take an evening out and brush up on my machining skills. The Harrison makes things really very easy, even without a DRO - everything is super stable. Really pleased how my single point threading worked out... including a very deep blind hole, about 70mm!
Decided in the end to use plain hot rolled... not the best choice but free, and good for threading practice, and by design it seems sacrificial.
Anyway, it's revived the scrapped SKF puller I got from work, and I'm pretty happy.

 

[Brad93]

Hot rolled doesn’t thread great. Was you using HSS?

 

[Brad93]

Those threads do look pretty good for mild steel though, mine are very ragged edged when using carbide thread inserts

 

[Hood]

Those threads do look pretty good for mild steel though, mine are very ragged edged when using carbide thread inserts

Shouldn't be, even at lowish rpm carbide should work well.

 

[Brad93]

Shouldn't be, even at lowish rpm carbide should work well.

On mild steel? I've never had much joy, maybe my cuts aren't deep enough or something but its literally like its tearing the steel not cutting it

 

[Munkul]

Hot rolled doesn’t thread great. Was you using HSS?

APT carbide inserts for stainless. They cut great, really sharp, and well priced too. I'll be buying more, I think. The internal threads were Yamaloy inserts from Zoro.
I bumped the compound a thou each cut to give a bit of relief on the side, it seemed to help - only cutting on one flank, so not tearing anything. Only taking it 10 thou at a time.

i also ran over it with a thread file afterwards to tidy up any rags and sharp edges but no, to be fair it was as good as could ever be expected from that hot rolled... it's pretty poor for machining I agree!

 

[Hood]

On mild steel? I've never had much joy, maybe my cuts aren't deep enough or something but its literally like its tearing the steel not cutting it

Aye, should cut fine, usually my first pass is 0.5 or 0.7 on dia and then 0.2 or 0.3 after.

 

[mtt.tr]

Aye, should cut fine, usually my first pass is 0.5 or 0.7 on dia and then 0.2 or 0.3 after.

I use a thread guide from mitsubishi always have clean cuts.

 

[MattF]

On mild steel? I've never had much joy, maybe my cuts aren't deep enough or something but its literally like its tearing the steel not cutting it

Some iron just defies best efforts.

 

[Brad93]

I like machining EN16 & 24 very easy to get a good finish

 

[Hood]

I like machining EN16 & 24 very easy to get a good finish

Almost any steel can have a good finish, secret, with carbide, is not to tickle. Take a cut at least as deep as the nose rad, especially when boring, and try to take your finish cut at that depth as well.

 

[Hood]

Been looking through pics to see if I could find anything but so far this is all I have found. Can't recall what the steel was as I didn't order it but I think it most likely just mild.

 

[Munkul]

Almost any steel can have a good finish, secret, with carbide, is not to tickle. Take a cut at least as deep as the nose rad, especially when boring, and try to take your finish cut at that depth as well.

Or cheat and use an ultra sharp positive insert for a light finish pass

Only works when there's no chatter though... tried boring 75mm deep with my cheap 12mm boring bar, in a plain holder with two screws... horrible tip-breaking chatter at any speed, feed and DOC... I think I need some sleeves, and/or a better quality bar. It gives a lovely finish with less stickout, it just wasn't rigid enough for what i tried to do, even with those inserts.

Still waiting for an insert screw for my 16mm bar, so ended up just drilling it straight to 20mm. Not ideal.

 

[Brad93]

Been looking through pics to see if I could find anything but so far this is all I have found. Can't recall what the steel was as I didn't order it but I think it most likely just mild.
View attachment 283582

Yeah that’s smart. I struggle to get anything like that. On EN24 that finish is pretty easy to achieve but mild steel always turns rough for me. Could be the headstock bearings too though or gibs need adjusting.

 

[Brad93]

Or cheat and use an ultra sharp positive insert for a light finish pass

Only works when there's no chatter though... tried boring 75mm deep with my cheap 12mm boring bar, in a plain holder... horrible tip-breaking chatter at any speed, feed and DOC... I think I need some sleeves, and/or a better quality bar. It gives a lovely finish with less stickout.

Still waiting for an insert screw for my 16mm bar.

Carbide bar for small holes. 5xD

 

[Hood]

Yeah that’s smart. I struggle to get anything like that. On EN24 that finish is pretty easy to achieve but mild steel always turns rough for me. Could be the headstock bearings too though or gibs need adjusting.

You learn your way with carbide, totally different than using HSS. You need to feed it and need to take a reasonable DOC as well. Get it chipping and you are on the right track. Stringers are not a good sign with carbide.

 

[Hood]

Here is a vid I did a year or two back to show the difference the feed per rev makes. First is too slow, second part I bumped up the FPR and it is much nicer in all respects including the finish. Same DOC for both.

 

[Munkul]

Carbide bar for small holes. 5xD

60mm stickout would have still chattered too much 50mm or less works fine. Like I say, the inserts are unreal, but its the setup that lets it down. Two screws in a standard holder, and a couple bits of flat bar packing...

Given that most of what I'll do will be small bars, I'll have to improve the setup somehow.

 

[Hood]

Bars from decent makes are much better, they are not made of cheese and tend to chatter less.
TPMR is a good insert to get on a boring bar but not as common nowadays.
Having said that my two favourite bars are a Seco with WNMG and a Stellram with EPEX inserts.

 

[qwakers]

its going apace today!

bolted to the block to stop it spreading under the weight of the concrete

corners welded in

floor being poured

and last of the concrete disposed of.