Question on parallels in my vise.

[tripletap3]

I do a lot of drilling into barrels using this v block set up on top of parallels in my vise. I noticed that when I tighten the vise the parallels become slightly loose. Normally I would attribute this to a unsquare part if only one parallel was loose but I’m positive my v block is square and both parallels are loose the same exact amount. Second I am using a Kurt Angloc vise. Shouldn’t that push the v block down onto the parallels? Should I tighten the sphere set screw up more on the vise? Im not sure if I have it adjusted right. Thanks.

 

[kd4gij]

Use a deadblow to seat work in your vice. I use kurt's at work every day. All vises wil lift some even kurt.

I agree, the Kurt is a good vise, but they lift too.
You can try tweaking the ajustment a bit, but wont get rid of all of it.

The dead blow hammer works well, though sometimes you just dont want to hit your work piece at all. What you have in the vise looks like one of those said work pieces.
8ntsane

 

[Metalmann]

I do a lot of drilling into barrels using this v block set up on top of parallels in my vise. I noticed that when I tighten the vise the parallels become slightly loose. Normally I would attribute this to a unsquare part if only one parallel was loose but I’m positive my v block is square and both parallels are loose the same exact amount. Second I am using a Kurt Angloc vise. Shouldn’t that push the v block down onto the parallels? Should I tighten the sphere set screw up more on the vise? Im not sure if I have it adjusted right. Thanks.

View attachment 42188

Just get a GOOD quality dead blow. The cheapies are too rigid, and sometimes make bounce-back worse.

For that setup, it wouldn't really matter that much for cross hole drilling. Parallels are mainly for alignment.

High precision/repeatability cuts; may require full contact with parallels.

 

[Phils69]

Man that's a nice vise, did u just buy it? I'm looking at buying a Lagun mill with no tooling with it so I'm going to need one. Kurt vises are the cats meow. The play in the parallels is normal as stated above. You may have trouble tapping your work down in that setup though. Like said above it doesnt have to be down on them for what you are doing. You just want to make sure it's not cocked higher on one end than the other. If you have any try to stick of .003" shim between the parallel and block for a quick check.

 

[Ken_Shea]

Tightening the vise too tightly when it is not required will aggravate the lift as well. For drilling when all cutting pressures are downward it just does not need to be that tight, try supporting the opposite end of the rifle and just snugging up the vise, perhaps that will stop the lift.

Ken

 

[tripletap3]

If you want to keep the parallels tight you typically tighten the vise a little, give the work a few taps with a hammer, tighten a little more, tap a few more times, and repeat until the vise is as tight as you need it. If it's not that critical, on my vise that lifts I just pull the parallels out after tightening.

Thanks everyone. That is generaly how I secure items in the vice. My line of thinking has been what does it matter as long as the part stays straight and secure so it's nice to hear that.

 

[Terrywerm]

As near as I can tell from the photo, the gun barrel probably has a slight taper where it rests in the v-block, meaning that the work is not truely perpendicular to the drill anyway. If that is the case, it doesn't really matter if the v-block lifts off the parallels slightly.

 

[tripletap3]

As near as I can tell from the photo, the gun barrel probably has a slight taper where it rests in the v-block, meaning that the work is not truely perpendicular to the drill anyway. If that is the case, it doesn't really matter if the v-block lifts off the parallels slightly.

That particular barrel has a straight profile from the sight post gas block to the flash hider so it is not tapered. I think what you are looking at is the section that has been machined down to mount the M203 grenade launcher to. What I am doing in this photo is cross drilling the flash hider into the edge of the barrel so I can drive in a 1/8” steel pin. This will permanently mount the flash hider to the barrel. It is required to make it legal in some situations. I have very little room for error and my calculations have to be correct otherwise I will drill though the bore. I don’t think the rifle would shoot well after that. :lmao:

 

[Terrywerm]

Tripletap, thanks for the explanation. It was hard to tell for sure from the photo, but I simply realized that if the outside of the barrel had even the slightest taper, the parallels would only get you close to drilling perfectly perpendicular, but not quite there.

Oh, and yup, I agree.... drilling into the bore would not be good! anic: