What did you do today (2015)

[Anonymous]

Posted by Steven Greenhough on 28/05/2015 21:42:03:
Today I ruined the two buffer bars I posted a couple of days back. Embedded a broken 1.5mm drill bit in one and a broken M2 tap in the other. "Better" versions of each ordered…

Miffed and sulking.

Fudge it, unfortunately we've all been there, more than once in my case.

One thought; are the 1.5mm drill and M2 tap connected? If so I'd say that 1.5mm was too small as a tapping drill for M2; I'd use 1.7mm.

Andrew

[Steven GreenhoughParticipant @stevengreenhough56335]

Andrew…

I was using 1.6 as my final size for the tap… 1.5 was my starter and I had a packet of cheapo drills as I expected to break a few, and did, but one broke with nothing to get hold of to pull it out. All the other holes in the second piece were then opened up to 1.6 for which I used a slightly better drill but I only had one of them so I didn’t want to work it too hard and that was ok, took what seemed like barely a fag paper out after the 1.5s. Tap was a cheapo ebay set affair but I g00gled the drill size for the tap and came back with 1.6. I’m assuming 1.7 would just give a little less engagement? I might try that next time then but first I have to re-do the pieces for which i think a different end mill may be required.

I had a bit of tallow on the tap but it felt gritty when turning the wrench and was difficult from the off…

Edited By Steven Greenhough on 29/05/2015 00:02:32

[davebParticipant @daveb17630]

Posted by Steven Greenhough on 28/05/2015 21:42:03:
Today I ruined the two buffer bars I posted a couple of days back. Embedded a broken 1.5mm drill bit in one and a broken M2 tap in the other. "Better" versions of each ordered…

Miffed and sulking.

I don't know if it helps but today I fixed the mess I made yesterday. I had 2 Dickson toolholders with broken off studs for the depth adjustment. I attempted to drill out the studs, the holders and the studs were very hard indeed. I broke a drill in one and then broke a tap in the other. Today I made a D bit from 4mm carbide rod, used this to drill out the broken drill and tap, had to resharpen once, otherwise no problem, only took five minutes.

Dave

[steve de24Participant @stevede2433577]

Steven,

For general use I'd recommend using the tapping drill sizes given in Tubal Cain's "The Model Engineers Handbook". These are for 65% thread engagement to reduce the torque required to drive the tap (and it calls out a 1.7mm drill for a 2mm tap). I would also always use a sleeve in the drill chuck, drilled to a clearance fit on the tap shank, to support the back end of the tap. That way you can't bend the tap which is the easiest way to snap it. I'd also do the sequence of operations to centre drill, drill, chamfer, and then tap without moving the drill head before moving on to the next tapped hole. It's a bit slow but much faster than sorting out a broken tap. Plenty of tapping oil and regular reversing of the tap is also called for.

Regards,

Steve

[JasonBModerator @jasonb]

Looking at that photo of the broken tap is there any reason why you can't move the hole over to the right a bit and retap it? Would save having to scrap the part and we won't tell anybody the bolt head is out of position.

 

Edited By JasonB on 29/05/2015 07:58:46

[Oompa LumpaParticipant @oompalumpa34302]

Get yourself a Zeus book. You won't need anything else.

(unless you are looking at drilling for ME thread taps?)

graham.

[Bob Brown 1Participant @bobbrown1]

For small taps I prefer to use one of these as in IMHO gives you more feel.

Bob

[martin perman 1Participant @martinperman1]

Steven,

I have in the past managed to get a tap out by making a small centre punch type tool out of hardened silver steel and then tapping the broken tap out anticlockwise until you can get hold of it.

Martin P

[Oompa LumpaParticipant @oompalumpa34302]

Well obviously, the delivery driver had it wrong and clearly delivered Mr Stevensons Hard-As-Witcheswotsits to me by mistake, nice finish though.

Made a nice backplate for my (new to me) PB four jaw.

graham.

[davebParticipant @daveb17630]

Graham, nice job! Lovely finish. I happen to have a bar of that stuff. Let me know if you need some more.

Dave

[Anonymous]

Posted by Steven Greenhough on 29/05/2015 00:00:18:
Andrew…

I was using 1.6 as my final size for the tap… 1.5 was my starter and I had a packet of cheapo drills as I expected to break a few, and did, but one broke with nothing to get hold of to pull it out. All the other holes in the second piece were then opened up to 1.6 for which I used a slightly better drill but I only had one of them so I didn't want to work it too hard and that was ok, took what seemed like barely a fag paper out after the 1.5s. Tap was a cheapo ebay set affair but I g00gled the drill size for the tap and came back with 1.6. I'm assuming 1.7 would just give a little less engagement? I might try that next time then but first I have to re-do the pieces for which i think a different end mill may be required.

In the quote above I've made bold the most likely cause of your problem. There are two rules for buying cutting tools:

1. Never buy cheap cutting tools; they're a waste of time and money

2. See rule 1

Speak to Garry on the 'My little engine….' thread for confirmation!

Correct that the larger tapping drill results in less engagement, but not lower strength of the joint. As a rule of thumb the bolt will snap before the thread strips. I use 4 facet drills so there is normally no need to centre drill first. I'd drill 1.7mm to start with and then tap. As has been mentioned a smaller tap wrench may be helpful. For anything less than M4 I use a small (about 4" long) tap wrench that my father made as part of his apprenticeship.

Andrew

[Richard MarksParticipant @richardmarks80868]

For the uninitiated and non fishing fraternity a yak is a KAYAK.

Tight Lines

[OuBallieParticipant @ouballie]

Graham,

What the heck is that material made of?

I can get swarf coming off a nice blue, but never spark !

Yesterday removed the Austin Seven engine/gearbox using block & tackle hooked onto special hooks I made to screw into 2&3 Spark plug holes.

M18 plugs with M10 down the centres and hooks screwed in, with a bolt between.

ME experience and Workshop to the rescue.

Geoff – Vice Stand finished, photos to follow.

[Capstan SpeakingParticipant @capstanspeaking95294]

Posted by Oompa Lumpa on 29/05/2015 09:33:45:

Well obviously, the delivery driver had it wrong and clearly delivered Mr Stevensons Hard-As-Witcheswotsits to me by mistake, nice finish though.

graham.

Probably running a bit quick but if you got away with it then fine.

I used to refurbish press tooling as hard as HSS with a ceramic tip. I actually had to put on shades from the arc of molten metal that came off.

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by Oompa Lumpa on 29/05/2015 09:33:45:

My attempts at machining titanium looked like that! Now that would be a posh backplate

Rod

[JasonBModerator @jasonb]

I also use a short tap wrench on te samller size taps, often holding on the round section which can allow the wrench to slip before you put too much force into the tap. I use a spotting drill which is more robust than a ctr drill to start the hole and will if taken deep enough chamfer the hole so teh tapping does not raise a burr

The bit sticking up above the wrench can be guide by slightly loose chuck jaws or a male/female centre, I have a short bit of 1/4" steel with a 60deg point on one end and ctr drilled hole in teh other that works well to guide the tap.

[frank brownParticipant @frankbrown22225]

I did some like the m2 tapping the other day, I was putting on a felt wiper holder on the end of a cast iron lathe saddle way guide. It was about 10" high when standing on the pedestal drill base with the table swung out of the way. So pick up a mark and drill with a 1.5mm, raise drill replace with a 1.8mm. raise drill. put a "bar"? type tap wrench on circular part of tap, put tap in drill chuck, not done up. Take tap down to the hole and lock the quill. Proceed to tap, if the chuck is done up correctly the tap will spin and go up and down. Success on all three holes. Note only moving the quill up and down once the job is started mean that all the holes and tapping is concentric.

Of course if your material is Hard-As-Witcheswotsits , you may still have a problem. . .

Frank

[Bob Brown 1Participant @bobbrown1]

I agree with Frank with regards to holding the tap on the circular section.

There is a reason taps come as a tapered, second and plug or first, second and third. When tapping holes if you do not have the tap square then you increase the chances of breaking the tap, if I am tapping a part like a steam chest to cylinder I use the steam chest as a guide by drilling it with a minimal clearance drill to guide the tap.

Bob

[Steven GreenhoughParticipant @stevengreenhough56335]

Thanks all for your excellent input and suggestions to my tapping woes. I’m a bit busy out and about at the moment so I’ll try and digest and respond once the seaside fish and chips have been procured and devoured in a couple of hours.

☺

Edited By Steven Greenhough on 29/05/2015 16:01:11

[Oompa LumpaParticipant @oompalumpa34302]

Posted by Capstan Speaking on 29/05/2015 12:32:16:

Posted by Oompa Lumpa on 29/05/2015 09:33:45:

Well obviously, the delivery driver had it wrong and clearly delivered Mr Stevensons Hard-As-Witcheswotsits to me by mistake, nice finish though.

graham.

Probably running a bit quick but if you got away with it then fine.

I used to refurbish press tooling as hard as HSS with a ceramic tip. I actually had to put on shades from the arc of molten metal that came off.

I will confess, it was running quick, I turned it down a bit for the finishing passes though I was tempted to swap tips for Cermet. But then decided best conserve those for jobs that really mattered.

Roderick, I do quite a bit of Titanium and I am always careful not to let the swarf build up under the work because once it catches light you can't get it out!

graham.

[Bob RodgersonParticipant @bobrodgerson97362]

Today I booked a return trip on the Durango to Silverton Narrow gauge railway. I will try to get some pictures of my trip posted tomorrow.

[Steven GreenhoughParticipant @stevengreenhough56335]

Ok guys, broken taps and drills…

*EDIT* I've done this by point rather than person as I'm on a laptop with no mouse and I HATE copy & paste editing with the little touch-pad doodahs

The material is EN3B according to the eBay sellers description. Shouldn't be a problem?

Work order – I went for the approach of marking/punching each hole, then a shallow centre drill (I have no spot drills or four-facets) for each, then 1.5mm drill, then 1.6…. and so on. Next time I'll try clamping the whole thing up more permanently and finishing each hole before moving on to the next. I did consider mounting in the 4-jaw and drilling in the lathe, I guess that would suit/encourage the single-setting approach; Would anyone recommend/consider/avoid this?

Move the hole – I could but I've already drilled the corresponding holes in the frames, as well as marked them all out and drilled the pilot holes for axle bushes etc. ; I did this first then clamped the whole of the framework together to mark the buffers for drilling. The holes appear to be off/uneven (towards the bottom) but that's because the buffer is only 10x20mm square, where the depth of the frames is 22mm so the screw heads will sit even distances from the top and bottom edge.

Drill and tap quality – Hopefully I've addressed this buy buying again, and better. Drill-wise I've gone for a couple of bits from an eBay seller that I previously bought some 6.8mm bits from (for tapping M8, bronze boiler bushes, this went fine) so hopefully they will be up to the job. There is some irony here, my Farther in Law has donated a couple of handfuls of quality drills (mostly Presto, mostly unused) from when he worked at Senior Service in Hyde. Unfortunately they are not the right sizes, in the main, for this project. I have tapped him up (great pun!) for some practical advice here and there but he's not into the subject matter and I think the engineering side of it was just work to him really.

Removing the broken bits – I had a go with the broken drill, and there isn't much left of the whole of the face now, so there wasn't much point in discussing that and it got dumped. For the broken tap, I'm guessing that if it's in an under-sized hole then it might be fairly stuck? So I'm resigned to making new pieces… In itself good practice as the lathe is still set up for milling and IMO the finish was 'adequate' but not really 'satisfactory'. The way I see it is the finish would have done fine for that particular application but not for, say, a steam-chest-valve-seat type of thing (thinking ahead a project or two). I will be posting a separate question in 'Beginners..' about suitable cutters as I've noticeably dulled the one I used… Both ends of it!

Tapping wrench (posh ones) – Other than size, is there anything between them or are they much of a much-ness? Any reason to chose/avoid a ratchet one?

Many thanks to those who have commented, this forum is a great resource and your help, as ever, is very much appreciated. Jason – extra marks for not only browsing my albums but adding pics to threads when I'm not always able to. Though I may start referring to you as Big Brother

 

Edited By Steven Greenhough on 29/05/2015 21:34:22

[John Stevenson 1Participant @johnstevenson1]

Well back on Page 61 I mentioned buying a new lathe for my girlfriend so went and fetched it today.

It was absolutely crapped up to the nines after having been stood for 30 odd years, so dragged it screaming out the Donald, threw the best end of a gallon of degreaser over it and steam cleaned to lot off before she saw the state of it. Also purposely didn't take a photo of it in the crap state.

 

So good hour and we get this.

 

 

Then crammed it into the workshop to play with it another day.

 

 

Didn't realise how tiny these things are, not much bigger than a Myford so going to have to alter this as it's 36" from floor to cross slide centre. My other two lathes which are comfortable for me are 39" but me lovely is taller than me so I reckon it needs to stand on a 4" 'I' beam section frame to be workable.

 

Reasonable tooled up, got the chucks, centres including the hard to get headstock one, all the screw cutting gears and they look new except for the normal train fitted. Missing the steadies though. It's the two speed motor version so needs proper 3 phase but not a problem. Did find 4 tins of touch up paint in the drawer though, two of the creamy colour and two of the dark grey stand. Not opened them so they might be solid ?

 

Nice machine and still cheaper than a Myford.

Edited By John Stevenson on 29/05/2015 22:14:26

[Neil WyattModerator @neilwyatt]

Posted by Oompa Lumpa on 29/05/2015 09:33:45:

Well obviously, the delivery driver had it wrong and clearly delivered Mr Stevensons Hard-As-Witcheswotsits to me by mistake, nice finish though.

Now it's photos like that I wanted for the photo competiton

Looks at wrist – you have 36 hours…

Neil

[Ian ParkinParticipant @ianparkin39383]

John

whats special about the headstock centre ?

does it have induction hardened bedways and if it does can you run a file across them? and cut them?

[Author]

Posts