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darryl
02-09-2015, 03:09 PM
This is a thread to which no replies would be a good thing- nobody makes mistakes do they :(

Made up a metal bar with multiple drilled and tapped holes. The holes needed to be square to the bar. Got set up on the drill press and drilled pilot holes, then saw that they weren't square to the piece. GUNH- (four letter word, a bit softer than the usual one). Found that I hadn't tightened the lock on the table, with the result that there was a forward lean to the table and the holes went off kilter. Ok- change to larger bit, crank table to correct height, make sure to lock table. Ok. Drilled out again to size for the tap- usually the hole will straighten out some, if not fully. Got that done. Mounted the tap so I could get all the starts going in straight, set table height, begin. Get two or three threads started for each hole, then transfer to vise to finish tapping all the holes. Got that done, de-burred, run tap through all holes again to clean them up. Threaded in a piece of all-thread and looked at it- Fword this time- all the holes were parallel to each other, but crooked in the piece of bar. Check drill press table- yup, forgot to tighten table clamp again :(

Ended up inserting pieces of all-thread into each hole, then clamped it upright in the mill and faced the important side of the bar, problem fixed.

I know my table is square to the spindle axis when it is clamped- I've checked it with a sweep and it's within about 10 thou across the width of the table- not bad for a drill press. But not if you don't tighten the clamp-

Paul Alciatore
02-09-2015, 04:55 PM
Well, it wasn't machining, but electronic work. I was working at my first TV station job on the night shift. In between other tasks (like airing the programs), I was soldering a connector with about 25 pins on a cable. It was one of those military style connectors with a nice metal shell and a proper clamp for strain relief. So I carefully stripped all those conductors and soldered them oh so neatly into the pins. Then I reached for the connector's shell, which was sitting on the tool cart next to me. Did I mention that the cable was already pulled through the floor from across the room, another job that took a couple of hours earlier that day? Absolutely no way of putting that shell on the cable after soldering the wires.

So, I oh so neatly unsoldered all those 25 wires, took a short break, and then soldered then back again. And I then reached for the connector's shell, still on the cart where it was before. Ahhhhhhh!

I am sure I had some unkind words for myself, but I can not recall exactly what they were.

Once again, I had to unsolder all those 25 wires. This time I did make sure the shell was on the cable FIRST. A 45 minute job turned into 3 hours.

I never told the boss about that one but there were other stories. We've all done these things.

Weston Bye
02-09-2015, 05:08 PM
Paul,
Amphenol circular connectors?
Been there, done that, but not twice in a row....

boslab
02-09-2015, 06:33 PM
I don't know anyone who has escaped the plug on wire, thread wire through hole or all it's variants, I did one on a night shift, the one where the pins are crimped to the wire with a coax crimp thingy, 2 electricians sat watching me poker faced as I did it with the shell still in the bag, not a word out of them til the last of dozens of pins was scrimped and pushed thru the plate, where barbs hold them in.
Nice guys.
Mark

JoeLee
02-09-2015, 06:35 PM
I'm surprised the table didn't swing being that it wasn't tightened to the column.
I've noticed with my Delta that downward force will tilt the table a bit, just how much deflection with how many pounds of force ...... I don't know, never measured it.
You've got my curiosity, I'll have to check.

JL.................

John Stevenson
02-09-2015, 06:37 PM
Clumsy bastards.
I have 'never' done anything like that.

Ow letgomearm.......................

Actually didn't happen to me but a friend who is terrified of heights and he had to climb to the top of a chimney at a local power station to fit a camera.
Got right to the top only to realise he's left the mounting bracket back down in the van.

boslab
02-09-2015, 06:48 PM
On a somewhat related thingy we had a guy climbed up a chimney, then fell down the chimney!, inside!
There was a tether on his harness that snagged a bit of rebar on the way down and caught him after about 80', took a helicopter to get him out, he's scared of heights now too!
Mark

vpt
02-09-2015, 06:54 PM
I've never ever had to tear a motor completely apart after just assembling to turn all the piston rings around the RIGHT way. Nope not me.

Fasttrack
02-09-2015, 07:01 PM
Paul,
Amphenol circular connectors?
Been there, done that, but not twice in a row....

Been there done that ... ... twice in a row :o

Arcane
02-09-2015, 07:26 PM
I've never ever had to tear a motor completely apart after just assembling to turn all the piston rings around the RIGHT way. Nope not me.

Had to do a cam and lifter change one day on a 350 Small Block. Figured I was making pretty good time until I went to drop the pushrods in and discovered I'd forgot to install the lifters. Did I mention I had installed the intake already and it went on absolutely perfectly? Now the intake is the last thing I put on...

The Artful Bodger
02-09-2015, 07:58 PM
The client moved all the computer and communications equipment into another room but when everything was connected up something was not right. We went onto the network and tried to fault find remotely. The indications were that all the cables on the multiplexor were on the wrong sockets, we sent them an email to ensure that cable number one was on the first socket but still no joy and they assured us that cable number one was on socket number one.

Nothing for it but to quickly book air tickets, Wellington to Auckland, Auckland to Singapore, Singapore to Karachi, Karachi to Pershawar and a Cessna from Pershawar to Kabul.

They were right, cable number one was on socket number one but the German makers of the multiplexer had numbered the sockets '0,1,2,3,4,5,6,7'!

I bought a nice carpet while I was there!

bborr01
02-09-2015, 08:27 PM
The first car engine that I ever rebuilt was a 66 VW that I found in a farmers barn with a broken piston on cyl. #3. That is the one that always breaks a valve and smashes a piston. So I found a used piston, cylinder and head and proceeded to tear everything down to clean out the aluminum shrapnel and inspect things. So about 4 hours later the slinger was where it was supposed to be.

In the years that followed I drove a long line of VW's and generally found the ones that had blown engines and do the same rebuild but I never made that mistake again.

We're humans and therefore fallible. I don't let it stop me form taking on almost any job though.

Brian

ftl
02-09-2015, 08:53 PM
Changing a rear motorcycle tire.

After mounting the new tire, I noticed that it did not have a lot of tread compared to the new one that was sitting there leaning against the wall. The second time I did it right.

J Tiers
02-09-2015, 09:40 PM
I never make errors.

The one time I thought I had, I checked and found that I was mistaken......

danlb
02-09-2015, 09:57 PM
I've learned to ALWAYS put the cover/boot/strain relief on BEFORE I put a connector on the wire. Then I learned to always put it on the correct direction.


Dan

Mcostello
02-09-2015, 10:56 PM
Worked to make a hydraulic connection type "o ring" block, when done foreman says "which ones have the tapped holes?" They had to use a bolt and nut instead of just a bolt, still worked.
Was told to press a shaft into an arm,both pieces made by 2 different excellent machinists. Lined up the shaft with the front of the hole and the sides. Oh by the way did I mention it was my first time with a 50 ton press? Shaft went in fairly easily for about 1/4", then got hard. Found out I was trying to assemble a 1/16" press fit. Someone miscommuniated the sizes.

thaiguzzi
02-10-2015, 02:45 AM
My motorcycle shop days; one of my mechanics (a stoner) was doing an oil change on his own OIF T140 custom Triumph, after work and the shop closed. Dumped the old oil out, pouring in the new oil, and we are all standing about watching as the new stuff is creating a rather large puddle underneath the bike, with his boots in it. Forgot to put the drain plug back in. We were laughing, It took him a minute or two of choice words before he joined in too...

PStechPaul
02-10-2015, 04:05 AM
Quite a few years ago I had built a special temperature controller to be used in an experimental cancer treatment machine designed by a doctor in Jackson, MS. I had been working on it until late at night, and I packed up my tools and various boxes of things I would need, and early next morning I drove to the airport and unloaded my car. I searched for the box with the controller, and it was not there. I called the office, and sure enough, they found the controller sitting on my desk. So they had somebody drive to the airport and put it on a later flight, and eventually it arrived and we got it installed and it worked as expected. Rather embarrassing... :o

Black Forest
02-10-2015, 04:12 AM
The client moved all the computer and communications equipment into another room but when everything was connected up something was not right. We went onto the network and tried to fault find remotely. The indications were that all the cables on the multiplexor were on the wrong sockets, we sent them an email to ensure that cable number one was on the first socket but still no joy and they assured us that cable number one was on socket number one.

Nothing for it but to quickly book air tickets, Wellington to Auckland, Auckland to Singapore, Singapore to Karachi, Karachi to Pershawar and a Cessna from Pershawar to Kabul.

They were right, cable number one was on socket number one but the German makers of the multiplexer had numbered the sockets '0,1,2,3,4,5,6,7'!

I bought a nice carpet while I was there!

Ya sure, blame the Germans!:mad:

Paul Alciatore
02-10-2015, 04:40 AM
Well, I've gotta be better at something. Leave it up to me for that to be screwing up.

And yea, probably an Amphenol circular. Remote control cable with a wire per function or status light. That's how they did it back in the 60s. None of that serial stuff.




Paul,
Amphenol circular connectors?
Been there, done that, but not twice in a row....

vpt
02-10-2015, 07:48 AM
I remembered another one I didn't do. The bike oil change reminded me of it. After building a car from the ground up, complete restore. Best of the best motor, trans, suspension, brakes, the whole bit. After about 10 miles on the test drive I ask the passenger if he hears that funny noise. By the time I got back to the shop the trans was feeling quite notchy and starting to grind a bit. Apparently transmissions need oil in them? :confused:

NiftyNev
02-11-2015, 03:12 AM
Engine oil change. Only ever left the sump plug out, once in my life. The mess you have to clean up that once, always reminds you to double check it is back in.

darryl
02-11-2015, 03:35 AM
The oil thing reminds me of a guy that used to work with us. He came to work one day and looked at us all funny- then said why do you guys hate me so much? What- we don't hate you, what do you mean. Well, one of you unscrewed my oil filter last night- when I backed out I saw it laying in the driveway.

Apparently he couldn't think of anybody who would do something like that, and just thought it must have been one of us. Finally convinced him that we didn't do it. Somebody must have forgotten to tighten it.

crusty
02-11-2015, 04:23 PM
When I was a mechanic, we had a lube guy who drained the oil from a MGB-GT, checked the brakes, greased the suspension etc. then filled it with oil.
- then the smoko bell rang, he went & had his cuppa.
He came back from smoko and filled it with oil....... I mean filled it! an MG 1800 won't take 2 gallons of oil, it was completely FULL.

vpt
02-11-2015, 08:28 PM
Speaking of oil, how does 8 gallons fit in a 6.0?

http://img547.imageshack.us/img547/4333/zegf.jpg

danlb
02-11-2015, 11:38 PM
I've been learning to weld. My buddy knows this. He called and asked if I could make a disk sander for his drill press. It seems his $40 Forstner drill bit ( 3 - 1/8 inch ) was leaving burned marks on the bottom of the depression he was milling in the wood plank. He just wanted a 3 inch diameter disk on a 1/2 inch stem. He'll glue sandpaper to the disk.


I cut an octagon from 3/8 x 3 inch bar. I drilled a 1/2 inch hole. I cut a 1/2 inch diameter cold rolled bar to fit. The bar fit the hole like a glove.

As I set it up on my welding table I wondered several times if the bar was truly 90 degrees to the plate. I did a plug weld with my TIG welder and it came together perfectly.

When I put it in the lathe to face it square I found it was .075 off from one side to the other.

In the future, I will not assume that something that looks straight will be that way after I finish welding it. Fit. Tack. Check and re-align. Weld.

Dan

Black_Moons
02-12-2015, 01:21 AM
I cut an octagon from 3/8 x 3 inch bar. I drilled a 1/2 inch hole. I cut a 1/2 inch diameter cold rolled bar to fit. The bar fit the hole like a glove.
As I set it up on my welding table I wondered several times if the bar was truly 90 degrees to the plate. I did a plug weld with my TIG welder and it came together perfectly.

When I put it in the lathe to face it square I found it was .075 off from one side to the other.

In the future, I will not assume that something that looks straight will be that way after I finish welding it. Fit. Tack. Check and re-align. Weld.

Dan

Oh yea, they move a lot. Fit, Tack, Check, Hit with huge hammer, curse as tack brakes, tack again with spacers so it has clearance to move when you hit it with hammer, check, hit with hammer, tack some more, hope it hasent moved again as hammer won't move it anymore, weld in alternating spots to keep too much heat outta one area and prevent weld distortion stress from popping tack welds.

Check again, hit with BIGGER hammer and/or torch, bend part into alignment since the welds are not going to bend anymore by this point, DONE!

Abaker
02-12-2015, 08:08 AM
Done the oil plug oops too. In my defense I don't have a garage and it started raining halfway through the process.

In my most recent "learning adventure" I learned that a 63/64 drill can have a shank that is a .010" plus interference fit to the hole it drills. How do I know that you might ask. Well, when you leave a drilling operation using power feed running in a horizontal mill and the table rams the drill in at about 250 RPM things happen. I was really lucky because it just stalled the mill and tripped the overloads on the 5 HP motor. With the kind of force that a geared down 5HP motor develops things tend to break. Expensive if not irreplaceable things inside mills. I was even able to recover the drill with out damaging the point by holding an aluminum block over the tip and pounding it back out of the hole with a BFH. Once I figured out the size difference I just put the drill in the lathe and turned the shank down to fit in it's own hole.