Shop Made Tools

[The Metal Butcher]

Once the axle nut is loose the torque needed on the tensioner screw to pull the axle back is very light. And even if the axle nut is left a touch snug to avoid the axle falling back off the end of the tensioner screw the torque needed is still light. The term "tensioner" in this case is a bit of a misnomer since we never want the drive chain to actually be tight. So it is really a "slack adjustment" screw. It's just that it's radial overkill for a chain tensioning screw. And given the amount of dirt that flies around the back of a motorcycle wheel when touring around the pocket can easily get filled with mud and need cleaning out. For this reason I'd rather just have a common hex head. Or like some I've seen just a slot head screw.

I do agree that Torx is a nice design. Of course Torx screws and tools are a lot more common today than they were back when I learned to poo-poo them when they first came out and the tools for them were not all that common.

Fair enough. Allens are easy to clean. Slot is never prefered by me, I work on a lot of old stuff, and even low-torque fasteners can freeze up. That and they are hard to drive with power tools.

I've just been driving some 5/16" X 4" structural wood screws that take a T30 driver, using the same cordless impact driver that I use for smaller screws with Philips, Robertson and hex heads. For this use the Torx is so much better and so trouble free that the others don't even compare.

My aunt's BF was in town helping my dad and I install some OSB, and we had him running some screws in. Even though he was German he wasn't very familiar with torx. It was obvious most of his experience was from phillips screws, because he was pushing with all his might on the impact driver to make sure they didn't cam out. I was just like "no need" and ran a few in easily with 1 hand and no pressure to prove the point. Torx and impact drivers have completely changed the way I work with screws, especially when on a ladder.

[rc4man]

A lot of interesting things here

[rcaffin]

especially when on a ladder.
And THAT is a very good point!

Cheers
Roger

[Yondering]

Back to shop made tools...
Here's a 3-jaw scroll chuck mounting plate I made for my rotary table yesterday. It started out with a "pre-conditioned" 1" chunk of aluminum plate, with plenty of extra holes in it. It took a little planning to make sure none of the new holes I needed broke into existing holes, but it turned out well.



Bottom side done, the center nub will register in the rotary table's center hole when the plate is turned over. I trued the ID of the center hole and OD of the plate at the same time, just in case I ever need to dial it in for some reason.


Top side done, complete with chuck register shoulder. I used a 4-flute shell mill with aluminum cutting carbide inserts for this work, they leave a nice finish.


All assembled (chuck bolts on from the bottom side, in recessed holes for the socket head cap screws). That's a lot of stack-up with the chuck, plate, and rotary table on the mill table. Since the plate was milled in place on the rotary table, the end results were pretty good; TIR on the first part I mounted in the chuck was a little less than .001".

[bborr01]

Well, that's rubbish! Had assumed the numbers were at least a measurement of something - either metric or imperial. Arbitrary numbers are more annoying! ....but nothing that this nice cool beer in the sun can't overcome! ;-D

I think most of the numbers referring to gauges of steel and wire refer to how many times they have been run through the draw die or rollers.

Brian

[mklotz]

A recent post on HSM had the following quote...

"The use of gauge number is discouraged as being an archaic term of limited usefulness not having general agreement on meaning." (Specification ASTM A480-10a)

I found it immensely satisfying to see that the folks who arbitrate the quagmire of nomenclature systems have finally had the good sense to say what I've been preaching for many years - the only sensible way to label things is by their sizes as measured using a decimal measurement system.

I don't expect their recommendation to have any effect whatsoever on the dinosaurs who still treasure the inferial nonsense but it's nice to know that a glimmer of intelligence is peeking through the curtain.

[cameron]

I think most of the numbers referring to gauges of steel and wire refer to how many times they have been run through the draw die or rollers.

Brian

Well, knowing that is certainly going to be a big help next time I'm trying to determine the gauge of sheet or wire by cast of eyeball!

[rcaffin]

What I REALLY hate is the BSP (NPT) sizing of threads. It makes absolutely ZERO sense.
Fractional inch measurements come way below them.

Cheers
Roger

[Cenedd]

What I REALLY hate is the BSP (NPT) sizing of threads. It makes absolutely ZERO sense.
Fractional inch measurements come way below them.

Cheers
Roger

There's SOME sense in it - or there used to be - as the size is the ID of the pipe the thread is for. I say used to be because pipe walls have got thinner since the standard.
But yeah, it's generally an unhelpful designation. It's only used here (as far as I can tell) for showers, hoses and computer watercooling fittings.

[cameron]

Pipes were made to provide an EFFECTIVE internal diameter in fractional and inch sizes. Studies of frictional head losses in pipes were done on pipes made to exact internal diameter, as might be expected. However, it was recognized that wrought iron pipe would, when put into service, soon develop an internal coating of rust nodules, reducing the effective internal diameter, and so an allowance was made for this by increasing the ID of standard pipe.

A piping system was expected to have somewhat better than designed performance when new, but to be able to maintain the required performance for its expected service life.

I'll refrain from making any comment about the wise asses who are so much smarter than people were back then, and who find it difficult to understand why on earth they would do something like this.

[Cenedd]

Have never suggested that I'm smarter than people were back then - specifically in a field in which 'they' were presumably experts. There's plenty of sense if you know the full path of the logic but if you don't know that, then a size for a thread that isn't that size but fits on a pipe that also isn't actually that size but could be once it's rusted....is a somewhat tricky concept to get your head round. It's likely great if you're in a situation of I've got 1/2" nominal pipe that I just bought so a 1/2" thread will be correct. From a design point of view though, it complicates things and that's more the viewpoint we're looking at as home shop'ists (apologies if I don't speak correctly for everyone) as you'll be wanting to know what size to make your OD or your bore to fit the thread size - or in reverse, what thread size is going to fit this object. Yes it's possible to do (looking up tables etc), I'm not saying that, but it does complicate things and there's a lot of room for mistakes to be made.

[Corbettprime]

Have never suggested that I'm smarter than people were back then - specifically in a field in which 'they' were presumably experts. There's plenty of sense if you know the full path of the logic but if you don't know that, then a size for a thread that isn't that size but fits on a pipe that also isn't actually that size but could be once it's rusted....is a somewhat tricky concept to get your head round. It's likely great if you're in a situation of I've got 1/2" nominal pipe that I just bought so a 1/2" thread will be correct. From a design point of view though, it complicates things and that's more the viewpoint we're looking at as home shop'ists (apologies if I don't speak correctly for everyone) as you'll be wanting to know what size to make your OD or your bore to fit the thread size - or in reverse, what thread size is going to fit this object. Yes it's possible to do (looking up tables etc), I'm not saying that, but it does complicate things and there's a lot of room for mistakes to be made.

I've always thought we stand on the top of a pyramid of knowledge built by our predecessors, who had a smaller base of knowledge to use. It is our job in life to expand that pyramid, not to tear down the work of those who were before us. I agree that the different gauges are confusing, and I cannot think of a reason not to have one unified standard gauge, but there may be one. Instead of the ASTM saying to use decimal designations, they should be codifying a standard unit of measurement. You have 999 units to the right of the decimal point. Which ones are you going to use as mill standards? Gauges are are a convenient means of designating a standard series of sizes.

[mattthemuppet]

made a couple of lathe drive dogs as I'll need to do some turning between centers soon. Small one goes down to ~3/8" and up to around 2", large one goes down to ~3/4" and up to around 3", both made from random scrap and cold blued.



literally made from a rusty nail

[cameron]

Cenedd, My apologies to you and rcaffinn as well. My remark wasn't aimed at either of you, but to a small number of
know-it-alls who think the world would be a much better place if everyone just did as the k-i-a's think best.

[Cenedd]

Cenedd, My apologies to you and rcaffinn as well. My remark wasn't aimed at either of you, but to a small number of
know-it-alls who think the world would be a much better place if everyone just did as the k-i-a's think best.

No problem Cameron. I have a few K.I.A's as thorns in my side too! Must be awfully boring being a K.I.A though, having nothing more to learn!