Thread: What did you learn today?

That takes me back quite a few years Dean, I was working with Skilled Engineering at a pelletising plant, the other end of the iron ore mine I had previously worked at for nearly 18 years. We were rebuilding some ductwork associated with one of the furnaces, and had a new box of 1/2" bolts and nuts, for the reassembly of the ducts. We has difficulty getting the nuts to start on the bolts when we realised that all the nuts were two start threads. Some more new nuts of more conventional design and no more issues. At the time we surmised that at the Ajax bolt factory, someone had stuffed up setting up an automatic screw machine, but now wonder if those threads would be tapped rather than single pointed. Anyway a new box of nuts was the cure.
Rob.

Originally Posted by Oldneweng

Observation is very important. I am adding a hydraulic downfeed controller to my horizontal bandsaw as mentioned in a thread at the end of last year. I needed 2 longer 5/16" bolts to mount a bracket to a casting witch had blind holes. I found 2bolts and proceeded to screw them in. One seemed a bit different and when I screwed it in by hand it did not go in straight. After a bit of fiddling I took it out and had a real good look at it. I had already checked the pitch against the original bolts.

It was a double start thread. On a 5/16" x 1 1/4" bolt. Lucky I did not attempt to force it in.

Dean

Today I learned that there is always another solution for the tricky problem.

For a while now my wife has been urging me to fix the the lock on the external fly screen sliding door. I had successfully managed to avoid this, job time and again but this week it came to a head.

The cockatiel who has the run of the house nearly flew out the open door. The latch pawl on the door doesn't always engage the catch on the door frame. The cattle dog has realised this and slides open the door at the wrong moments.
Hence the little smart arsse bird came so close to escaping.

Finally at last I succumbed to the complaining and dissembled the lock / latch mechanism this morning, to find the latch mechanism in the lock has a female square opening which was opened out in the corners allowing one of the latch levers to slop in the square drive .The inside and outside latch levers have male spigots.The whole thing is made from that cheap zinc die cast stuff.

The local hardware outlets did not look promising as the lock is probably 30 years old and the hole centers were way off on the samples available. If one of the locks had possibly fitted, the folks in the big green shed wanted between $50 and $80 for similar latches/locks.

Back home, it came to me as I had a cuppa that I might use some "steel" 2 part epoxy to fill in the worn hole corners, but how to stop the epoxy from bonding the levers and lock mechanism together as it was necessary to glue and assemble to get the shape and fit of the latch levers in the square hole.

The answer was there in front of me on the table, a roll of cling wrap. A piece was cut and placed over the lever square spigots and pushed into the mixed epoxy.The whole assembly was masking taped to hold the assembled unit and left out in the sun for a few hours.The cling wrap worked a charm and allowed the epoxy to extrude into the worn places.

I have to report that the catch works and now springs onto the latch how and catches every time.

I considered taking pics but thought better of it as I would get epoxy all over the camera.

Grahame

MMMMM yet another use for cling wrap. In my younger days it was rumoured that some smart used cling wrap to cover the bowl, under the seat of the loo. Of course sooner or later some poor sod would visit the little room, and if they were in a hurry, and the lighting was dim, there would be a mighty mess for them to clean up. Another reported use was by young eager beavers, to make sex safe, cling wrap would be employed as a substitute for a condom. Where there is a will, there will be a way, or necessity being the mother of invention are sayings which come to mind. Good to hear about the successful use as a release agent Grahame, but I bet it wasn't as much fun as those young kids had with their substitute condom.

Originally Posted by Ropetangler

MMMMM I bet it wasn't as much fun as those young kids had

The fun for me is in the relief of not having my lug chewed about the bloody door and further not having to spend $50, $80 for latches or possibly $600+for a new door.

I knew a bloke who had a corner shop grocery opposite a state high school. He told me he sold a lot of cling wrap to high school students, so I can believe that.

I have another use for cling wrap and that is to cover the castors on a hydraulic press I am in the throes of completing. I like to tack castors on,instead of bolting but need to protect then from spray paint over spray.

Grahame

I regularly use plastic film to prevent glue sticking to things. I don't know what the issue was tho. I had a girlfriend who was staying with some people who had a cockatiel. With the noise that thing made I would have loved to let it fly away.

Dean

SPOTTING DRILLS

I'd not heard of these but reading another forum, they reckon they are more accurate for centering stock i.e. before drilling with a 118 degree jobber drill. The 60 degree centre drills I've been using are actually meant for the 60 degree lathe centres and are not ideal for centering jobber drills . The 120 degree spotting drill provides a ideal centre for the 118 jobber drill.

Steffan Gotteswinter did an interesting video some months ago on this very subject. I still don't have any spotting drills, and use centre drills for locating holes as accurately as I can when it matters. I am keeping my eyes out for some spotting drills but the prices looked pretty scary when I have seen them for sale. You'd have all the incentive you need to dig through the big pile of swarf to find the one you dropped I recon. Here is Steffan's vid on the subject. https://www.youtube.com/watch?v=Ot8wPGQW3JI&t=657s

Originally Posted by Ropetangler

I am keeping my eyes out for some spotting drills but the prices looked pretty scary when I have seen them for sale.

There are a few spotting drills available at reasonable prices. Thanks for that link to Steffan's movie.

6mm HSSCo8 NC SPOT / SPOTTING DRILL 120 DEGREE 8224020600 EUROPA TOOL OSBORN #P2 | eBay

Originally Posted by morrisman

Thanks for that link to Steffan's movie.

Movie? You have been watching Bruce Witham too much.

Don't centre drills have a 118deg point on the small diameter? You usually only use this to locate a drill anyway? A lot of YouTube guys only use them to produce a shallow indent so as too avoid blunting them. The idea is to have a sharp and rigid starter drill.

Dean

Originally Posted by morrisman

There are a few spotting drills available at reasonable prices. Thanks for that link to Steffan's movie.

6mm HSSCo8 NC SPOT / SPOTTING DRILL 120 DEGREE 8224020600 EUROPA TOOL OSBORN #P2 | eBay

There are some spotting drills which don't require a second mortgage, but in general they are pretty expensive. Thanks for the link to cncpoorboy's eBay listing, I have purchased from him in the past. He has lots of pretty good sounding tooling, with much of it post free to Australia, which makes it competitive price wise. I think that his prices seem to be rising, perhaps it is an exchange rate thing, but this set of taps cost me a few cents over AU$ 80 in 2016 M12 M10 M8 M6 M5 M4 M3 SPIRAL POINT TAP & DRILL SET EUROPA TOOL / OSBORN #40 | eBay
Just on using centre drills for positioning holes, even Steffan suggests that if you only drill down to the depth of the starting cone of a centre drill, ( in other words don't drill down as if you were establishing a centre for a tailstock centre, but just make a shallow divot, somewhat like an enlarged centre pop), then the following drill which is generally going to be ground with a 118º point, will fit the depression without vibration, thereby increasing the life of the drill bit, particularly if you are using carbide drills. Perhaps for bigger drills, there would be the need to use a spotting drill, or other short stubby drill bit to establish a good centre for the following drill bit.
Rob

There are people out there who don't think much about what they do -
I needed to make a couple of brass hat shaped pivots. I found an old bit of brass in the box (probably from a box of 'assorteds' given to me) only about 30mm long but 3/4" diameter which was what I wanted. It had been used as a drift at some stage by someone so I though I'd turn the mushroom off and then make my pivots. I could not understand why I could not get a centre drill located properly - every time it was presented it wobbled off centre.
In the end I parted off to start again and found this
P1040096.JPG
Someone had tried to drill a 7/64" hole in the piece all the way down and snapped the drill in the hole.
Wasted some time, material and blunted a couple of drills.


Michael

OOOPs Not guilty your honor. That would really peeve any one off.

Originally Posted by KBs PensNmore

OOOPs Not guilty your honor. That would really peeve any one off.

Thats one way of putting, happened to me yesterday.

I learnt today that if you push hard enough with a 1/4 drill bit in a cordless drill and it slips ,you can drill into your wrist /sever an artery and lodge it in the bone,at least 20mm,pull it out and spurt blood at least 1mtr into the air.......bob here is a photo taken about 2 hours after the event before it went blue,had to hide it from my wife plus a 50mm cut on the back of my leg ,I was under strict instructions as I was having surgery in two days time that i wasnt to do anything ,especially in the shed as I would get sent home if I had any cuts,got away with it though ,she didnt see them ,nor did the surgeon ,told her after the event big mistake ,.bob

Ouch. I hope that everything heals up properly.

Michael