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View Full Version : Arrrrgh, New jaws for my new vise



Black Forest
11-20-2014, 04:47 AM
I am making new jaws for the new vise I bought the other day. I want the new jaws so I can machine a 3mm bench at the top of the jaws so I don't have to use parallels.

So the plan is to make the jaws install them on the vice and then use a 6mm end mill and take a pass right down the place where they meet 4mm deep.

Now I tell ya, these jaws are a machining marvel. They are 18 x 22 x 135mm. They are within .005 of a millimeter of being on size. That is as close as I can measure with the tools I have. Drilled the holes and countersunk for the bolt heads, champfered all edges of holes, used a file on all the edges to take the corners off instead of what I usually do and walk over to the belt grinder and run the edges across the belt. Mirror finish because I used my Walter face mill with all new edges on the inserts. These little pieces of steel should be in an art museum.

Go to install them on the vise and what...........the holes don't line up! I forgot to move the drilled hole centers over the radius of the drill so now my holes are 3.2mm too far to the outside. Arrrrrrgh!!!!!%&"!.

Break out the GOOD TIG welder and weld the holes closed and re-drill. Normally I layout with bluing, lines and punch pricks but this time I didn't do that and used the mills DRO's without a reference to check I was where I needed to be.

It took me a long time to make these simple jaws as I thought they should be as perfect as I was capable of making them in honor of my vise.

iMisspell
11-20-2014, 05:26 AM
.... I forgot to move the drilled hole centers over the radius of the drill so now my holes are 3.2mm too far to the outside. Arrrrrrgh!!!!!%&"!. Did the simulare thing two weekends ago on a swivel/pivoting spinxeder base. Milled a slot in the bottom of the plate to except an alignment key, was working in Incremental mode on the DRO off the side of an end mill, never switched back to Absolute to work off the center of the end mill, key slot looks alittle goofy and a bit deeper then i wanted.

tjs
11-20-2014, 05:54 AM
I had to relocate holes in my magnetic break away torch holder for my cnc plasma table build.
Stuff happens.

Toolguy
11-20-2014, 10:23 AM
I have been off exactly .100 a few times because of forgetting to factor in half the edge finder diameter. Oh well.

Old Hat
11-20-2014, 11:22 AM
Once a serious large injection mold reaches the size large enuff to mold
one of those Southern Colonel Sanders Style lawn chairs... it's worth
exceeds a year's wages by even the wealthyest standards of most members here.

When one discovers one of these types of mistakes, there is a responce that you don't forget.
Those around you will notice there's no detectable movement for at least a few seconds.
No matter your ethnicity, what ever color your face normally is, the color is gone.

In some cases your hearing kinda shuts out the world for a while, while you feebly hope
that you just missmeasured just now and it's realy still all OK.
By this time you are sweating, but your skin is ice-cold to the touch.

It's happened to all of us, even the G/M and the Owner.
The only difference is the Owner can go get in his car and disappear.

krutch
11-20-2014, 12:44 PM
I forgot to set over for the edge finder on a quantity of chuck jaws for a large firm. Had about a third of them drilled off. I was in la la land and didn't check the first jaw or even any until it dawned on me about the .100" set over. I sure felt small that day. Luckily I still had enough not drilled wrong to get the end user up and running so they accepted a split order instead. How my boss didn't fire me is beyond my understanding. Maybe he had done the same or similar thing one time.

RichR
11-20-2014, 12:57 PM
Hi Black Forest
Considering how beautiful that vise is, I think a picture of it fitted with the new jaws would be appropriate.

rowbare
11-20-2014, 02:09 PM
How my boss didn't fire me is beyond my understanding. Maybe he had done the same or similar thing one time.

He knew that YOU would never make that mistake again. He couldn't be sure about your replacement though.

bob

becksmachine
11-20-2014, 04:10 PM
Ok, just last week;

A friend/customer had asked me some time ago about a lathe he wanted to buy, a fair sized LeBlond, 20" swing, 6'-8' centers.

As many on this board can understand, this lathe comes complete with a 10 hp. 3 phase motor which he has no means to operate as the friends shop does not have the required 3 phase power. After discussing the pros and cons of single phase motors, phase converters, and variable frequency drives we commenced researching my inventory and found a brand new single phase motor. I invented a price and he went away to consider his options.

Last week he shows up with the 3 phase motor that he had removed from the lathe, and after testing it we determined that it was suitable boat anchor material and that was enough for him to eliminate the phase converter option. He then decided to purchase the single phase motor that I had and go that route.

So we commence dragging the motor out of the pallet rack storage, into the light where we determine that the shaft sizes are different. Back to the pallet rack to search for pulley options to fit on the smaller single phase motor shaft, and find one that has a bore small enough so that it is easily re-borable, and it is a larger pitch diameter so it will help increase the spindle speeds which is (usually) a good thing on these older machines with 300 or 500 rpm top spindle speeds.

We commence with the boring operation, and then a new keyway and setscrews. I want to polish the shaft a little, so lets hook it up to power and use some emery cloth.

Looking at the data plate to make sure it is connected for the proper voltage, I am surprised to see that the high voltage connection is 440V?? What the hell????? I have never seen a single phase motor that could be run on 440V. And even more surprised to see "3 phase" right next to the "440V". And look, there is no characteristic bulging can on the motor to indicate the presence of start capacitors. Thus commences the sequence of silence and faces changing color so accurately described by Old Hat.

Look on the box that the motor was in. Plain as day, "3 phase induction motor". Search the pallet rack some more, no 7 1/2 hp, single phase motors to be found.

Thus the only possible conclusion is that those deceitful, label changing trolls have once again been practicing their craft in the dead of night. Then again, given my powers of observation, it seems obvious that they could just as well be doing it in broad daylight and I would never be the wiser.

:p

Dave

fixerdave
11-21-2014, 01:57 AM
I've always kicked myself for my inevitable screw-ups... until I watched one of those MIT machining videos. The guy sat there and explained how you should always do your math before you get in the shop... once in the shop, it seems the part of your brain that is responsible for adding instead of subtracting numbers is too busy trying to keep the right number of fingers on your hands. Sounds stupid, until you think about it, and then it explains so much. Easy math is very hard for a brain preoccupied with survival. It's a matter of setting priorities. So, now when I screw up I just tell myself that at least I can still count to 10, so far.

David...

ptjw7uk
11-21-2014, 05:26 AM
At least your Vice jaws didn't make it into space as the Hubble did!

Peter

Paul Alciatore
02-23-2015, 12:34 AM
Believe me, we have all had those moments.

oldtiffie
02-23-2015, 02:43 AM
Two old and very appropriate maxims/idioms:

- measure twice and cut once; and

- hasten slowly.

I make a habit of marking out on blue dye - then check it.


Take a light "passing" cut to verify the cutter/vice set up 0 then make the cut.

Use one or two of these Starrett "hold-downs" to hold the moving jaw down to the top face of the fixed jaw:

http://i200.photobucket.com/albums/aa294/oldtiffie/Vise/Hold-down1.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Vise/Hold-down5.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Vise/Hold-down4.jpg

or this set-up for the same result:

http://i200.photobucket.com/albums/aa294/oldtiffie/Vise/Vyce_clamp3.jpg

or use one or two of these (machine or pack/shim as required to have all flat faces the same height):

http://i200.photobucket.com/albums/aa294/oldtiffie/Vise/Vise2.jpg

BigMike782
02-23-2015, 08:35 AM
I'd be glad to list my mistakes but the imternet isn't big enough:D