machinist@lists.ibiblio.org

Another good tool is a bridge gauge. A long, thin bar (6-12", depending on your needs, .500-.750 wide, .200 thick) with a dovetail around 2" long at one end, running lengthwise in the top to fit an indicator. At the end of the dovetail, mill a 1" slot, also running lengthwise. From there, drill & tap fine-threaded holes every half inch down the length of the bar. Drill and tap another through the bar in the dovetail, so you can insert a lock screw and hold the indicator in place. Turn a screw that fits your threaded holes down to look like an indicator point. When you're all done, grind the bottom of the bridge gauge flat.

Now, if you need to measure a relatively large ring or boss, simply mount your indicator on the bridge gauge, rotate the indicator point down perpendicular to the bar. Screw the other point into a hole that's appropriate for the size of what you're measuring. Zero the indicator on a block stack, and tighten the set screw.

Oddly enough, I can't find any pictures online, but they're simple to make and great to have.

[–]l0c0dantesCNC guy[S] 1 point 4 days ago

Indicate tools in? errrr what? Ive indicated parts in, Ive indicated a vise, but indicate a tool? I mean, I could see doing it for a lathe tool?

Generally, I use a deadblow if its a part, or just a regular hammer if it is part of some setup function.

The bridge gauge sounds interesting! However, I am sorta confused, what are you measuring in particular? Concentrically?

[–]ernunnosApprentice 2 points 3 days ago

If you're using a drill on a lathe with a Brookfield holder, you'll definitely need to indicate it in. A lot of CNC collet holders are good enough for drill work without indicating, but if you're reaming holes to within a few tenths, you definitely want to put an indicator on the reamer and make sure it's not running out.

A bridge gauge is useful for any sort of large diameter (ID or OD), as long as you don't need to go deep. The sort of thing you'd use a caliper for, but with a tenth indicator installed, it gives you much better precision for inspecting tight tolerance parts.

[–]l0c0dantesCNC guy[S] 1 point 2 days ago

Ah, I have never seen a tool holder like that before, and I have yet to ream a hole that tight.

Also, I think I am missing something in regards to the bridge gauge. All indicators (Dial, and Dial test) I have ever used aren't really equivalent to calipers. As I understand it (And how I have always used them) They are used to compare the difference between two things, such as run-out, concentricity, flatness, ect. I suppose you could compare one to a gauge? Is that what you are thinking? Or is there another use of indicators that I am not considering?

[–]ernunnosApprentice 1 point 2 days ago

Yes, indicators are often used to measure linear dimensions by zeroing them on a block stack or against a Cadillac (aka master height gage). Then you run your part under them to get the difference from the set distance. For the bridge gauge you would fill a gage block holder with blocks that add up to the desired dimension, then zero your indicator on that. For IDs you would use fingers on the end of the block stack and zero between the fingers.

If you end up doing any kind of high-precision work, your tenth indicator will be your best friend. And a good set of blocks. For some of the stuff we do (aerospace), it's important to even check how many millionths each block is off, and try to build a stack where the + and - variations (listed on the calibration sheet that comes with the block set) add up close to zero.

[–]Deadskunks 1 point 6 days ago

if youve got time before the vblock gets sent out make yourself a set of 45 degree angle plates to send out with the block.

[–]brzcory 1 point 6 days ago

Spring loaded tap guide? That'd be a fun project

[–]l0c0dantesCNC guy[S] 1 point 4 days ago

That was actually my first project. I have the body done so far, I just need to make the shaft that goes inside.

[–]TihsdribRailroad frog crossing casting machinist 1 point 6 days ago

Don't know if you would ever use one but I made myself a slide hammer with interchangeable threaded ends in high school. Still use it all the time.

[–]killabeez36 1 point 7 days ago

I had the same projects in my machining class in college. Make yourself an aluminum handle with a threaded end that bolts into the middle of a steel hammer head. You can buy plastic and brass hammer strike faces that you can affix to both sides of the head with a threaded stud (you'll obviously need a threaded hole on both faces). You can also knurl the handle and taper the handle itself to a smaller diameter across the length of the handle up to where it meets the head. I still use my hammer all the time.

EDIT: Didn't see that you already considered a hammer before I typed that. My bad.

[–]muchachomaloaerospace composites 1 point 7 days ago

Make a couple 123 blocks. It is very useful to have more than one in some large setups.

[–]burner99 3 points 7 days ago

I don't know if it would be practical or if you would have the resources to be able to build them. Sine bars and 123 blocks seem to be a pretty power combination for setups.

I think you would probably need access to a surface grinder once you milled it for the most part.

[–]l0c0dantesCNC guy[S] 1 point 4 days ago

I have a surface grinder! I really want to make 1-2-3 blocks! Thanks!

[–]alexchallyModerator - Scientific Research Support 3 points 7 days ago

You should make the mill stop. I don't know if there is any other tool I have made that I use as much as my mill stop.

[–]l0c0dantesCNC guy[S] 1 point 4 days ago

Ok! Ill start working on it sunday! (It shouldn't take to long I would imagine)

[–]alexchallyModerator - Scientific Research Support 1 point 3 days ago

There are a couple tricky bits, IIRC the tolerance on the bore for the split clamp was +-.0005, and we were told to do it with an offset boring head and a mill.

[–]bijibijmak 3 points 7 days ago

Make a radius cutting tool holder for a lathe so you can make balls on the lathe later.

[–]l0c0dantesCNC guy[S] 1 point 4 days ago

Err, can you give me some a bit more description? Would it be the kind of thing you would need to grind for each Radius? Or is it adjustable? I have honestly not heard of that before.

[–]bijibijmak 1 point 3 days ago

I guess the right term would be a "radius ball turner". Here's a video: http://youtu.be/UwGLL7cMdHk

[–]l0c0dantesCNC guy[S] 1 point 3 days ago

Oh wow, that is super cool! Thanks!

[–]QballDude 2 points 7 days ago

When I started out, I worked at a tool & die company. I made myself a set of 4 blocks measuring .500" x 1.000" x 1.500". I use them along with traditional 123 blocks for setups. They became my favorite and most useful setup blocks. I should have made 8 of them.

[–]l0c0dantesCNC guy[S] 1 point 4 days ago

Depending on if I can throw stuff on the HT order, I want to make those.

Would making a .25x.5x.75 block be worth it? I would think it would be useful for keyways

[–]QballDude 1 point 4 days ago

For me, the .5 x 1.0 x 1.5 worked best, because they can be used in combination with standard parallels and 123 blocks. But what works good for me may not be as advantageous for you. It depends on what type of parts you work on. The beauty of making your own blocks is that you can make exactly what fits your needs.

[–]mySTi666 1 point 5 days ago

I need these. Why I have waited so long I will. Ever know.

[–]tsultrim 2 points 7 days ago

I would make something like these workholding dealios. They helped me a lot with quick setups.

[–]rustytbone 1 point 2 days ago

Mitee bites rock. Whoever invented them (John Mitee?) is a millionaire because of an eccentric head screw!

A screw machine could spit these out like nothing I bet.

[–]Alex__H 2 points 7 days ago

that website, it burns

[–]tsultrim 1 point 7 days ago

Not sure how to interpret that. :)

[–]KamaKaZzie 2 points 7 days ago

he means it is badly put together, (bad lay out, poor choice of colours etc)

[–]sorazlightCNC Machinist around April 2014! 3 points 7 days ago*

You can grind lathe tool bits (if you haven't yet) for a little bit of time wasting. Standard, threading, boring, grooving. I made some 45 degree bits since I couldn't be bothered re-adjusting the compound slide on the lathe for chamfers

EDIT: word

[–]l0c0dantesCNC guy[S] 1 point 4 days ago

It is a good suggestion, but I don't really see the need. At work they will buy me any tooling I ask for (They really like me there)

[–]sorazlightCNC Machinist around April 2014! 1 point 4 days ago

Well you just said you needed something to do. Plus you save your shops money and time waiting for a tool bit. I can grind any of them up in around 10 or so minutes and get the specific size groove/or whatever my shop doesn't have, saves time on waiting for the purchased bits and future cuts. It's just basic stuff that you should really know.

[+]ohtobiasyoublowhard comment score below threshold (0 children)

[–]keirken 7 points 7 days ago

1-2-3 blocks . I use a 1.0000 cube for touch-offs and a removable stop . make the mallet it'll get used.

[–]l0c0dantesCNC guy[S] 1 point 4 days ago

I want to make the blocks, I just need to check with the teacher to ensure I can throw it in with our heat treat order.

[–]Alex__H 1 point 7 days ago

my manual milling class had me make a mill stop, v-blocks, clamps for the v blocks, 30-45 angle setup gauge, and c clamps

[–]MrNoobToYou 4 points 7 days ago

Tap handle with collets. I'll try to find the prints and send them to you. :-)

[–]l0c0dantesCNC guy[S] 1 point 4 days ago

Any luck with the prints?

[–]MrNoobToYou 1 point 3 days ago

Got them photographed. Just need to upload. Should have them in a bit.

[–]fotbrHobbyist 2 points 7 days ago

That sounds useful.

Any chance you could send me a link to the plans as well? Or just post the link here, that'd work too.

[–]amitymachine 2 points 6 days ago

This is great suggestion. I copied a set of Starrett ones while there was some down time in the shop, like this

[–]l0c0dantesCNC guy[S] 1 point 4 days ago

I thought of making a tap wrench like that, but I was told you need to cut a left handed thread, is that true?

[–]amitymachine 1 point 3 days ago

No the OD of the handle is threaded an appropriate RH fine thread. THe plunger that holds the tap is free floating. Find someone that has one and unscrew the thimble to take a look. I don't have any plans, I jsut did some R&D (ripoff and duplicate) work on the Starrett ones.

[–]l0c0dantesCNC guy[S] 1 point 3 days ago

Ah, I saw one at work, and was told it was a left handed thread. Will actually have to look at it, and see how machineable it is. Thanks!

[–]amitymachine 1 point 3 days ago

So there are several different main types of tap handles. The Starrett is a style of tis own. It has the plunger free floating and clamps on to the tap by turning the internally right hand threaded barrel down on the plunger. Here are two pictures of a Starrett #91A copy that I never finished, the body needs to have the Vee shaped into it, as does the plunger: Exploded and Assembled

The type I think you are talking about is the Ace brand type. This is the one commonly seen poorly reproduced in import tap and die sets. It operates the moving jaw via two seperate threads. The main body is tapped for the handle with RIGHT hand threads. The moving jaw stem has LEFT hand threads and is recieved in a corresponding hole in the handle you turn to lock the tap down. Here are pictures: Expanded and Assembled. The grub screw in the expanded pic hold the fixed jaw in the body. The left hand threaded jaw stem is to speed the action of the clamping mechanism and to give the wrench an extended capicity. This feature is not totally necessary for the general idea of a tap handle, and could be left out if you were making one. The only tthing you would have to do is hook the moving jaw to the rotating handle in a manner that provided free swivel.

[machinist] What are useful tools I can make? : Machinists, Lawrence London, 10/28/2013