novice got a magnetic vice

[metalmad]

Hi all
I bought myself an Easter present in the form of a magnetic vice the other day,
and happly went about milling great gobs of metal from the "Tiny" by putput that i have just started.
Anyway much to my surprise, the magnetic vice gave way and damaged my job.
I guess I deserved, it but Im not a machinest and have never used a mag vise before.

 

[Noitoen]

Usually when you "clamp" something to such vice you must do it next to the stops on the side of the vice and use some scrap metal next to the part to aid in the clamping. Needless to say, you must cut in little steps as the clamping isn't all that strong.

 

[metalmad]

Hi noitoen
yep I had the vice against the stops with some scrap around it,but as u can just see from the roll marks,it did not save me

 

[modeng2000]

Are you machining aluminium?

John

 

[metalmad]

Hi john
yeo the engine case is aluminium
maybe I should change my name
eg
Heavyhand Pete
Strongarm Pete
Stupete
lol
cheers Pete

 

[modeng2000]

Hi Pete, It is just that aluminium is not magnetic and so any holding will have to be from the packing but I'm sure you knew that. ??? This will stop the engine case moving sideways but not from lifting up.
Hope you can recover the item and I guess you will have to use a normal vice for this one.

John

 

[Noitoen]

Didn't notice it was aluminium ??? Maybe you could stick it with double sided tape and then use ferrous material to hold it around.

 

[bearcar1]

Yeah, attach that sucker to a piece of plate steel and then your new toy will hold the part in place. drill a couple of 'blind 8) holes' (a hole that does not pass completely through) into the bottom of the lump and tap same so you can secure the aluminum block to the plate. Nice start to the Tiny, I hope that you can recover from the mishap and salvage the piece. Those engines are so cool, but a bit, well uh, "TINY" for these old eyeballs. :big:


BC1
Jim

 

[RobWilson]

magnetic vice/ chuck, are normally used for grinding operations , never seen one used for milling ???

Rob

 

[Blogwitch]

Mag vices can be used on a mill, but it is not recommended unless it is a powerful electro magnetic one.

One of the biggest issues is the cutting forces involved, even taking normal tiny cuts on a grinder can make the part move, so the cuts must be very small when used on a mill. Using double sided tape would be pure suicide on a mill for non ferrous work,it just isn't strong enough for the forces involved, even tiny ones.

Another big issue is the ferrous swarf cannot be cleared away very efficiently as it sticks to the magnetic table and the job itself whilst machining.


Bogs

 

[metalmad]

I know what u mean about not seeing the part Bearcat
Im as blind as a bat lol

 

[jonesie]

also if you use it to machine something that is magnetic you will have to have a demag, or it will remain magnetic and be trouble. i have used magnetic v blocks in a mill but real real light cuts .you could hold the alum. in a small grinding vise on the mag, but then you might as well mount the vise on the mill table.i would stick to usung the mag only on a surface grinder, and work safe jonesie

 

[Huntinguy]

That is also a very coarse magnet... just sayin... that means the magnetic field is widely dispersed and is taller... kind of like coarse stitching in fabric, not really good for thin material or low contact material. Imagine each one of those bars on the magnet as 1/2 of a clamp.... you need two to make on clamp or complete path for the magnetic field. Not as much holding power as you think. Also the holding power of a magnet is down only. Kind of like moving a fat man like me, hard to lift easy to push. Grinders get away with it because the parts on them have already been machined and the contact area is already flat and they material contacts many, many of the magnetic sections.

To give a perspective... A grinder is running around 3000-5000 sfm and taking .001 max depth of cut with hundreds if not thousands of cutting "teeth" meaning an almost none existent chip load.... and all the cutting pressure is in one direction, lineal not radial so it is easier to block in the part. (I didn't want to confuse the issue by mentioning radial grinders or Blanchards....)