Vice clamping

[Andy BrocklehurstParticipant @andybrocklehurst85292]

Morning all,

this is how Ive got my vice clamped to my mini mill. It’s probably not the best way to clamp it but it’s what I had at the time.

I’m constantly having to tram the mill, I would imagine the vice isn’t clamped securely, the bolts are as tight as I dare tighten them.

is there a better way to hold it down. With hindsight I now wish i bought one with holes rather than slots.

 

[JasonBModerator @jasonb]

On the longer bars get the studs as close as possible to the vice end so they have better clamping power.

I would also stand the triangular blocks up the other way so the clamp bars engage more fully with them though that will not make as much difference as moving the studs in.

lastly make sure the bars are packed up in a notch that allows them to slope down slightly towards the vice not upwards.

[JasonB]

On JasonB Said:

On the longer bars get the studs as close as possible to the vice end so they have better clamping power.

I would also stand the triangular blocks up the other way so the clamp bars engage more fully with them though that will not make as much difference as moving the studs in.

lastly make sure the bars are packed up in a notch that allows them to slope down slightly towards the vice not upwards.

Thanks Jason I’ll try that.

[Robert Atkinson 2Participant @robertatkinson2]

One option is to attach a bar what is a good fit in the T slot to the bottom of the vice. One method is to place the bar in the slot, machine the faces so they are true to the axis, clamp the vice upside down to the bar and machine a register slot on the bottom of the vice.

The vice looks a little big for the mill.

Robert.

[AStroudParticipant @astroud]

Looks like you can move a clamp over one slot on the table so they are wider apart, should provide a stiffer arrangement.

[OldironParticipant @oldiron]

Have you thought about all that weight you have hanging on the table ? That could cause you the tramming problems as you move the weight from side to side whilst milling. Also do you tighten the Gib on the non travelling axis whist milling ?

[Clive FosterParticipant @clivefoster55965]

Regrettably wrong clamp for wrong job so they will never work well even after you have sorted out the incorrect arrangement of step blocks and clamp bolt as advised by Jason.

Correct style of hold down clamp for that job are the type supplied with modular vices. Basically a thick bar L shaped in side view with tongue to go in the slot and a foot a little deeper than the bottom ridge so the clamp slopes down for maximum grip. Bolt, often a socket head is more convenient, goes close to the vice.

My experience is that the correct, L style, clamps made to the right size are generally significantly better at the holding business than the general purpose step block and bar devices. Unsurprisingly the made specifically for purpose device works better than the do anything one. But it only does that one job.

Perhaps something along the lines of these from homemade tools website :-  https://www.homemadetools.net/forum/modular-vice-hold-down-clamps-101935   will work.

The professional versions generally use short slots for the bolts rather than counterbored holes as in the set shown for this modular vice :-   https://www.mscdirect.co.uk/select-150mm-precision-modular-vice-gqv-30320k?gclsrc=aw.ds&gad_source=1&gad_campaignid=23293873908&gbraid=0AAAAADq_z2M65jjNUHgF-NB7eXBgkG9xr&gclid=EAIaIQobChMIyp2ym6mpkwMVO6NQBh04uz2xEAQYAyABEgKGefD_BwE

You could make a longer single clamp spanning all three slots with the corner cut off to clear the closed end of the holding slot as suggested by AStroud which may well generate even more hold down force. Whether the increased force is a worthwhile improvement on the proper style of clamps is an open question. Enough grip being enough. The only regular use of a wider clamp that I am aware of is on the Grerardi swivel base accessory.

https://www.cutwel.co.uk/size-2-125mm-art-105-swivel-base-for-gerardi-standard-series-vices-flex-vice-2-10-52000?srsltid=AfmBOorKN6Aa3xIn1LOjdxAGtIBhLPivL4MjGJtVcHl4fCcfps8Lf_kiEgg     Most likely for engineering convenience than grip reasons.

A sheet of aluminium under the vice will significantly increase friction between vice and table. Most beneficial if the vice base and table aren’t completely true to each other. It is worth verifying that the mating surfaces are flat and making good contact over the whole mating area. In my experience a common cause of things not holding well when clamped down is surfaces not being properly flat, damaged or having bits of “stuff” ground in.

Clive

[peter1972Participant @peter1972]

I find it hard to believe that vice is moving on the table. I suspect the gibs need careful adjustment.

[Andy BrocklehurstParticipant @andybrocklehurst85292]

Thank you for all the advice guys, in all honesty 90% of the time I use the mill for drilling holes, I make folding knives so it’s ideal for easy variable speed and drilling perpendicular holes which is crucial for making folders.

The only bit of milling it does is on the rotary table and that’s only a few tenth’s of a mm.

Yes it’s probably the wrong vice and clamps I’m using but I’ll try Jasons suggestion, if that doesn’t work I’ll follow some of the links you’ve kindly posted and get something better.

[Robert Atkinson 2]

On Robert Atkinson 2 Said:

One option is to attach a bar what is a good fit in the T slot to the bottom of the vice. One method is to place the bar in the slot, machine the faces so they are true to the axis, clamp the vice upside down to the bar and machine a register slot on the bottom of the vice.

<b>The vice looks a little big for the mill</b>.

Robert.

I think the comment I’ve tried to embolden is an under-statement!

[JasonBModerator @jasonb]

one other thought looking at the photos. Make sure the bolts are not bottoming out in the nuts or worse the bottom of the tee slots. Ideally use studs & nuts.

I hold one of my vices with that type of clamp and only one each side but don’t have problems with it moving so they do the job if used correctly.

 

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