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View Full Version : Why didn't I think of that.



Boucher
10-29-2009, 11:59 AM
That is the way I felt when I ran across a post on someones personal web site that showed a U shaped piece of ground plate held in the mill vice jaw with tabs extending down into the table slots. This looks like another good way to install and index a vice. I can't remember where I saw it to post a link so I will just say that sort of thing is what makes this such a great site.

Doozer
10-29-2009, 12:25 PM
Tramming in a vise to less than half a thou should take about 2 minutes.
Practice until you are good. Forget goofy fixtures.

--Doozer

rockrat
10-29-2009, 12:34 PM
While for the home shop machinist a device with a price of (lets say) $100 might not be worth a purchase, in the industrial sector that type of time savings is all the rage. Last big production run I was involved it found huge savings based on 2 minutes of time.

Dont discount an idea based solely on it merits for HSM'ers. Besides, some of us still dont like to tram in a vise every time. I only have so much time in the shop after family, work, home and public service. That idea may allocate me hours when calculated up at the end of the year. And if I have a piece of ground stock laying around, it might be worth my time.

cheers
rock~

Doozer
10-29-2009, 12:50 PM
A commercial shop is not going to use a fixture to tram a mill vise to the table and start making parts. There has to be a dial test indicator used in the process somewhere to verify the vise is parallel to the axis of travel. If the vise had keys, I would still use an indicator to make sure. Vise tram should be checked every day in a commercial shop before starting any work on the mill. If you dread indicating in a vise, it is probably because it is taking you a long time to get it right. Once you get good at it, you will look back and wonder what you were fretting about. I think indicating things in is kinda fun, especially if it is a tricky setup or an odd shaped part. I believe if a part can be strapped to the table, it should be. A vise is just a luxury or for repetitive parts.

--Doozer

rockrat
10-29-2009, 01:02 PM
I disagree, I have worked in commercial shops that did use fixtures for mounting a vise specifically for time savings. But I will agree that each shop and each setup is totally different and some shops will just make a dedicated fixture instead of using a vise.

As for my personal ability of indicating a vise, it waxes and wanes given how my day is going. Some times a few tweaks of the wrench gets me dead on. But sometimes I just give up understanding that the tolerances of the part I need don't necessitate perfection of the vise jaw location.

As with everything in life, it just all depends.

cheers :)
rock~

Boucher
10-29-2009, 01:46 PM
I all ways tram my vice upon installation. That operation is kind of like dialing something in in the four jaw chuck. It sure takes me longer than it should. Getting close to start with seems to help. I won't live long enough to attain the experience most on this board have. I do enjoy the time in the shop but making swarf is more fun than tramming.

Errol Groff
10-29-2009, 02:06 PM
If you dread indicating in a vise, it is probably because it is taking you a long time to get it right. Once you get good at it, you will look back and wonder what you were fretting about.
--Doozer

Two weeks ago I asked one of my students to pick up the center of a round part held in a Hartford head in the vertical position. Last year (he is a senior now) it would have taken him a LONG time and he probably would have been cussing me before he was done. Now it probably took him less than ten minutes and he commented on how much easier it was than previous times. He allowed that practice really does make things easier!

Nice kid who has the makings of a future machinist.

Black_Moons
10-29-2009, 05:00 PM
IMO the U has merits, it will quickly let you align it good enough for most basic operations, and at least let you align it most of the way so less bumping and tweaking is needed with the indicator dial. also just because you use it doesnt mean you can't check it afterwards with a dial, and just checking with a dial (say toss a magbase onto the vertical collumn or head, 2 seconds) will insure it has sufficent accuracy, without the longer tedious tweaking of using a dial to adjust it in perfictly.

kf2qd
10-29-2009, 10:16 PM
Sometimes all you really need is the vise on the machine and close enough. If that is all the more accuracy required then Why spend more time and money making it perfect. For Example - You have a batch of parts that have been processed on the lathe and you need to do several processes on which result in a threaded hole in the side. If you can slap the vise down quick, line up on the hole in the sample part, and do the batch. Parts come out well withingn spec and everyone is happy. AND you would have had to have lined up on the hole in the sample part so everyone is happy, the vise is back off teh table and the next operation procedes.

Accuracy that is better than is needed is just like time wasted. Everything Dead nuts is great, but the Bozo 2 machines down has his 10 parts done within tolerance and is working on the next batch before you get your vise perfectly trammed.

I have seen it happen, and have been on both sides of that scenario. Don't make money if you can deliver the parts. Unless you are working on something that needs extreme accuracy, Within spec is as good as perfect.

psomero
10-29-2009, 11:05 PM
in the commercial shops i've worked in, we would never rely on some sort of fixture to align a vise because someone would almost certainly drop it and it'd be ruined within a week or two.

John Stevenson
10-30-2009, 05:00 AM
I use the U shaped piece all the while.

If you organise yourself and sort out what vises are needed for what machine, may not apply if you only have one vise and one mill, by making t wide enough and using ground parallels behind / in front, of the U piece you can use this for different setups.

It's all down to personal choice and how you work, I don't have any vises fitted with keys because the vise may have to go on three different machines with different slot widths. Because they protrude they are liable to get damaged in transfer and if there is a burr then you need to know.

Using keys then having to check rather defeats the object of the exercise. I very rarely use the swivels on a vise , much preferring the reduced hight and rigidity but with no keys i can swivel it direct onto the bed.

As I say all personal choice but I'm on repair work and one mill may get pulled down up to 7 times in a day for different setups.

It's not just about saving two minutes it's about getting a flow going and working smart.
If I wanted the vise / mill combination to be accurate to 0.0001" then I may use the dial gauge but then again is that accuracy needed for every job ?

To be honest if I get drawings with these sort of tolerances on them it means two things. Big company with loads of paperwork hassle and chances are they don't come to me anyway. Or small clueless guy that has no idea of the real world and will be an immense pain in the arse.

I can get more money and work twice as fast working to 0.002", let some other goon chew his balls off holding 0.0001"



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