indexing w/o a rotary table?

[SMR 510RR]

If you have a chunk big enough to slide one of the barrels in then just make a fixture with a set screw and you can avoid the flats on the barrels themselves.

[SMR 510RR]

Originally Posted by atomicfab

SMR, i appreciate you trying to be nice, but maybe instead of shooting something down you can simply point out that you have a more accurate method. i mean, the OP did ask for a cheap and easy way to do it w/o buying tooling.

I posted 3 ways before you posted, 1 cost nothing, 1 cost very little, and the last one cost $50 assuming he had collets.

I think that you had some creative methods for doing something like this on a drill press and I was not trying to discount you in any way. You are in here talking with people who have done this kind of work for a living on machines that cost in excess of $100,000 dollars in many cases. While your way would probably work its not the kind of solution the OP was asking for.

[atomicfab]

coming from a 1:1 background and new to the scale hobby scene i'm just trying to participate not step on toes.

i have a smithy 3in1 that is a pretty nice machine for what i do, but its about as accurate as spitting on a pie plate from my roof so i still manage to figure out ways to make things simpler and more efficient when using it. not to mention i'm finding out just how clunky a full size machine is on scale stuff.

i tell you i have been amazed at some of the things i see folks here doing, even the simple stuff.

[rlockwood]

a pin can do a good job of orienting a workpiece 90* to an existing hole.. press it into a soft rear jaw -- add a second pin that orients to the parts profile and you've taken care of rotation on all 3 part axis

even easier, though, is to mill a flat spot onto the face of the initial hole-- then you can simply clamp this face in the vise, which sets you up perpindicular. And if the holes are for the trunnion/base of the cannon, it will probably make for a better functioning piece anyhow.

[BigSki]

Originally Posted by rlockwood

a pin can do a good job of orienting a workpiece 90* to an existing hole.. press it into a soft rear jaw -- add a second pin that orients to the parts profile and you've taken care of rotation on all 3 part axis

even easier, though, is to mill a flat spot onto the face of the initial hole-- then you can simply clamp this face in the vise, which sets you up perpindicular. And if the holes are for the trunnion/base of the cannon, it will probably make for a better functioning piece anyhow.

While reading this, the light bulb kicked on. I can make one hole for the trunion shaft, press it into the cannon then then clamp the pin into the vise, this will rotate me 180* for the second hole. A square held to the front of the cannon and one face of the vise would align me, then I can just hit it with a spot center to mark my location. It can all go back into the vise and make the hole.

It's still sorta ghetto but it might work.

[SMR 510RR]

Originally Posted by BigSki

While reading this, the light bulb kicked on. I can make one hole for the trunion shaft, press it into the cannon then then clamp the pin into the vise, this will rotate me 180* for the second hole. A square held to the front of the cannon and one face of the vise would align me, then I can just hit it with a spot center to mark my location. It can all go back into the vise and make the hole.

It's still sorta ghetto but it might work.

His method was for 90* not 180 like you are going for and you would have to have some way to hold the part from rotating while you drilled the second hole if you did what you just said. Its not really a reliable repeatable setup with just 1 pin vertically because there is nothing squaring it, you would have to build a fixture to clamp the pin for A axis rotation and the part to square it to the jaws. You would have to drill 2 holes on the first side and press in 2 pins but that seems like a lot of effort to go through rather than just milling a flat on the part to start with.

[BigSki]

Originally Posted by SMR 510RR

His method was for 90* not 180 like you are going for and you would have to have some way to hold the part from rotating while you drilled the second hole if you did what you just said. Its not really a reliable repeatable setup with just 1 pin vertically because there is nothing squaring it, you would have to build a fixture to clamp the pin for A axis rotation and the part to square it to the jaws. You would have to drill 2 holes on the first side and press in 2 pins but that seems like a lot of effort to go through rather than just milling a flat on the part to start with.

I agree with everything that you're saying. I'll try with the flat and see how it goes. I'm still looking at the Grizzly site for tooling, they have lots of possibilities.

[Grizzly4x4]

Originally Posted by BigSki

After looking at Grizzy's pics, it looks like he is rotating the entire tool 90* in the vise, which would rotate the parts. Interesting idea..

That's exactly what I did.

[BigSki]

Originally Posted by Grizzly4x4

That's exactly what I did.

I'm looking at the tool on the grizzly site, it doesn't list any dimensions. Is the base of the tool square ( height and width) to ease w/ rotating it in a vise?

[Grizzly4x4]

Originally Posted by BigSki

I'm looking at the tool on the grizzly site, it doesn't list any dimensions. Is the base of the tool square ( height and width) to ease w/ rotating it in a vise?

No, it's wider the way you see it in this first pic than the second. But the distance from the stationary part of the vise was consistent so I did not have to find center of the part after I rotated.
I can get you measurements.

[SMR 510RR]

That is the benifit of the block set I posted, they are square and the whole block is ground so you know they are nice and true. It comes with a square and a hex block for the same price as the one like Grizzly has and a nut for the back or a quick release handle. Combine that with a collet stop and you have a nice repeatable fixture for all your 5c collets.

[Grizzly4x4]

Originally Posted by SMR 510RR

That is the benifit of the block set I posted, they are square and the whole block is ground so you know they are nice and true. It comes with a square and a hex block for the same price as the one like Grizzly has and a nut for the back or a quick release handle. Combine that with a collet stop and you have a nice repeatable fixture for all your 5c collets.

I agree, this is a better solution.

[Duuuuuuuude]

Why couldn't you make your own block? Grab some aluminum or even acetal, bore a hole it in to fit the barrel, drill/thread some bolt holes to keep it all together, then slice it in half. Put the barrel in the block, tighten the bolts to keep it in there snug, clamp it in the vice, drill, then flip 180* and drill again.

[BigSki]

Originally Posted by Duuuuuuuude

Why couldn't you make your own block? Grab some aluminum or even acetal, bore a hole it in to fit the barrel, drill/thread some bolt holes to keep it all together, then slice it in half. Put the barrel in the block, tighten the bolts to keep it in there snug, clamp it in the vice, drill, then flip 180* and drill again.

Honestly, I doubt that I could get it as square, or keep the bore as concentric as the part they offer, and for the price, there's really no incentive to attempt making my own.

Originally Posted by Grizzly4x4

I agree, this is a better solution.

I'm leaning this way, I just spent the past few hours looking at a few different tools, this collet block set seems to be the most versatile and easiest to use.
I'll start searching for a used set of the 5C collets, I just don't have another $100 to lay out right now.

[Duuuuuuuude]

Originally Posted by BigSki

Honestly, I doubt that I could get it as square, or keep the bore as concentric as the part they offer, and for the price, there's really no incentive to attempt making my own.

I bored a 7/8" hole through a 2" chunk of acetal with a crappy paddle bit and ended up .002" off end to end. Surely you could achieve similar or better.

Once you get it locked into the block and find center, there shouldn't be much of an issue.

[SMR 510RR]

Originally Posted by BigSki

Honestly, I doubt that I could get it as square, or keep the bore as concentric as the part they offer, and for the price, there's really no incentive to attempt making my own.



I'm leaning this way, I just spent the past few hours looking at a few different tools, this collet block set seems to be the most versatile and easiest to use.
I'll start searching for a used set of the 5C collets, I just don't have another $100 to lay out right now.

Shars has basic sets that are in 1/8 increments for $40 (1/8" to 1"), in all honnesty if you are working directly with stock that is fine because you can always buy one size larger if you are trying to get something like 3/16 just buy 1/4 instead. If you ever do really have a need for an inbetween size you can buy a single collet from them for $6 so its not horrible.

I do agree though, you could probably find a nice used set for cheap if someone is going out of business or something but I would assume that stuff usually goes with any machines they are getting rid of.

[Duuuuuuuude]

Originally Posted by BigSki

Honestly, I doubt that I could get it as square, or keep the bore as concentric as the part they offer, and for the price, there's really no incentive to attempt making my own.

Yup, totally not worth the $3 in materials and 45 minutes it takes to make one.


Put your stock in the block, snug the bolts down.



Put it in the vice against the stop, use a dead center to meet up on the grubby line on top of the block, lock your axis down, move over to where you want your hole, punch it, flip the whole thing over, punch the other hole.

[Ty]

Can you just cut the stock a 1/8" long and mill the flats on that end. Face it to length and they are gone.

[BigSki]

Originally Posted by Duuuuuuuude

Yup, totally not worth the $3 in materials and 45 minutes it takes to make one.


Put your stock in the block, snug the bolts down.



Put it in the vice against the stop, use a dead center to meet up on the grubby line on top of the block, lock your axis down, move over to where you want your hole, punch it, flip the whole thing over, punch the other hole.

just bust mah ballz...

seeing the pics of your holder, it's not what I was envisioning when reading the description. That would be a decent way of solving my immediate issues. I'll head over to the local plastics distributor and see if they have any small pieces of Delrin. I know I don't have any engineering plastic laying around.

[Duuuuuuuude]

Originally Posted by BigSki

just bust mah ballz...

seeing the pics of your holder, it's not what I was envisioning when reading the description. That would be a decent way of solving my immediate issues. I'll head over to the local plastics distributor and see if they have any small pieces of Delrin. I know I don't have any engineering plastic laying around.

As long as one of us understands what we're saying.

For just doing a small run of stuff, its totally worth the time and effort. If you're going to be doing a whole bunch of stuff, buy the fixture. The nice thing about building your own is that you aren't limited to the size of collets you have on hand.

I'm not sure what the material is that I used. I thought it was acetal when I snagged it, but I think its actually pvc. It seems stout enough to use for a while, but you wouldn't get years of use out of it.