The swarf shop

[PeterT]

Learned many new things from Dabbler's explanation! I had a hunch that round vs rectangular had some historical significance or other practical purpose I wasn't yet aware of. The round ones have a fine pitch threaded center hole which allows them to be attached to one another, or attached to other things I suppose. Rectangular gage blocks, well the good ones, can be wrung together to make the stack. Less accurate class or even a bit of dust or fingerprint usually makes wringing difficult or impossible.

I check my micrometers with the typical 'post' type standards only because they were included with the mic. They compared well to same size gage block. You can get them onsey-twosey or progressive sets, But I wouldn't buy them if you already have a gage block set. I cant think of any reason why you couldn't calibrate mic on gage blocks directly. I suspect most hobbyist gage blocks are probably way more accurate than the repeatability & resolution of most hobbyist micrometers. At this level you can see the effect of shop temperature variation.

I've read different opinions about whether to calibrate at the max nominal opening vs minimum or even middle. For example calibrate at 1.0000 and now zero might be 0.0001". Or zero the jaws to 0.0000" and now the standard reads 0.9999. Or maybe calibrate to 0.5000" and now either min or max could deviate from 0.0000 and 1.0000. I suspect the answer lies in the mic itself, intended purpose & typical measurement range.

I'ts interesting to just measure the exact same gage block just to see how much variation you get purely from positioning or clutch / click tension etc. Micrometer screws can wear in preferential use areas just like lead screws. OTOH unless you have the ability to make parts to this accuracy (usually grinding & lapping), too many extra zeros may be more of a distraction. My cylinder liner bores were lapped to to the same tenth mark on bore gage which required a lot of work, But I'm not kidding myself, I'm sure thats an average across the micro hill tops & will probably be different when I measure them again & the assembly stress relieves & normalizes...never mind wear when it runs.

 

[Dabbler]

bonus for the keeners: this is a video about the origins of modern precision, including the best description of Johannsen's original gauge blocks. Wow were they expensive! a year's salary for a factory worker!

 

[Brent H]

You are only as precise as you

 

[Bradells]

Well, since the metal tools are still out of commission (waiting for new belts from the US mfr .... They've been sitting at LAX for a few weeks now....)


One project that I've been working on for a few months (designing, and sourcing out the work due to size), is making a commercial product actually work (... hmmm sounds like a theme I have going ...)

This product is an UnderWater Diver Propulsion Vehicle (aka, DPV, Scootz, Torpedo, etc).



Unfortunately this manufacturer really messed up on the design. They were really focused on an inexpensive unit, rather than a functional one.

There are many things to consider with underwater equipment, aside from the obvious, keep the dry bits dry, and the wet bits can stay wet ... Mainly, as a user, we are concerned with Buoyancy (does it sink, float, or stay where you left it), and Trim (does it rotate, or pitch up/down).

The manufacturer has been around the block and has several great units in its ranks, but with this one, they did have a small disclaimer when I chatted with them on the phone before purchasing a few units ... "It will be a LITTLE nose up in Salt Water, and a LITTLE nose down in Fresh Water".

Well, that turned out to be bold faced lie. It points as true as a plumb bob! (in either body of water). Clearly not what they said, and the response has been undesirable from the manufacturer, making up other 'stories'...

Well, long story short, I'm stubborn enough to make it right myself!

During the first month or so of the Covid experience, I spent researching CoG and CoB (Center of Gravity and Center of Buoyancy) calculations and determined with some guesstimating (well, a lot actually), that the body of the hull was around 4-5 inches too short!

What is one to do? Well, make an insert of course. Since the hull is 6.625" in diameter, and my mighty sherline can do 3.5", I had to shop out the part.

I found (and recommended) Aaron Machine Shop down by Glenmore/Blackfoot area, and they were more than happy to work with me on several prototypes.

The first round was my 4.5" version, as well as a 6" long version (I have plans that requires the extra lift capacity with external instrumentation), with dimensions taken from the existing parts for the sealing surfaces.



I tested them in fresh water later that weekend, and found the 4.5" to be still to heavy in the back end, and the 6" to be pretty close, needing some weight in the rear to trim it out.

I went back and ordered a 5.5" version, with updated dimensions, closing up the tolerances of the mating surfaces by a few 0.010's of inches





This one was sitting pretty well in fresh water, but was requiring more ballast in the bow of the DPV than I was liking.

I also headed out to the west coast for a week to get some salt water therapy for a while, took the 4.5" and the 6" versions along. The 4.5" version worked very well for Salt water as is (still too heavy for fresh water), and the 6" version required way too much weight to get it neutral again in the water.

Back to the drawing board a little. I had figured that the 4.5" would be great for Salt water (and it was), but since it was too heavy for fresh water, I sent it back for some more work to remove some of the Interior material.



I tested that version, and while it was close in fresh water, it wasn't were I wanted it to be, so I took it back for a further revision (along with the 5.5" version too ... if the machine is set up, it doesn't add much more to the cost to do a second).

This weekend, I took the updated 4.5 and 5.5" versions with reduced inside and outside diameters out to the Provincial Park near Brooks. Fantastic warm lake water, and great visibility too.



Still the 4.5" version sits just a little too heavy (but not horrible) in fresh water with almost 1/2 of its weight removed. The 5.5" version, I was able to get it near perfection.

Putting it on the scale at home, and just finishing up new drawings for a last prototype. Starting with removing the outside diameter, and then attaching a weight specification, they'll machine out the ID if any more weight needs to be removed.

I'm on the fence if a slightly shorter tube (say 5") would suffice, but $$ is starting to really dwindle on this project sadly.

But, once this last one is done, one last final test in fresh water, and sign off on the paperwork for a small production run!


Brad

 

[Bradells]

In another thread (https://canadianhobbymetalworkers.c...ter-machinist-than-i-thought.2318/#post-27637) Dabbler made me remember a quick little project I did back in the spring after the last snow (or so we thought!)

I was going to make a small picket fence for one of our deck garden beds that our dog has been stepping into. Over breakfast, I was wondering how I was going to assemble said fence, without a compressor, but I do have a pile of air tools laying around that would make quick work!

Last fall I was making some LP parts for some Oxygen analyzers for SCUBA, and had some spare ends and connectors, so I found one of my inflator hose connectors, and made an adapter to go directly into the back of the tool and use one of my HP SCUBA tanks to drive it (130cuft @ 3442psi of DRY air). Grabbing one of my regulators, I set it from 10 bar (~145psi) and rolled it down to 5.5bar (~80psi).



Well, fast forward a little and I got sucked into a CT/PA shopping spree (seemed everything I wanted was on sale), and picked up a compressor hose kit. I then changed over the "direct to tool" connector into a female Air QC. Now it's filled several sets of tires (I've also had to patch several tires this spring between a flat on my winters, and some leakage out of some of the summers).

Very handy, can find cheap used scuba tanks and get them filled with clean dry air if you don't have the space, noise constraints or money for a decent high $$$ compressor.





Brad

 

[PeterT]

The UDP is cool. What material are the grey (plastic looking) segments made out of? I see what look like O-ring seals on the end, but how are the parts attached to one another?
Too bad the company messed up the design like that.

 

[CalgaryPT]

Well, since the metal tools are still out of commission (waiting for new belts from the US mfr .... They've been sitting at LAX for a few weeks now....)


One project that I've been working on for a few months (designing, and sourcing out the work due to size), is making a commercial product actually work (... hmmm sounds like a theme I have going ...)

This product is an UnderWater Diver Propulsion Vehicle (aka, DPV, Scootz, Torpedo, etc).

View attachment 10171

Unfortunately this manufacturer really messed up on the design. They were really focused on an inexpensive unit, rather than a functional one.

There are many things to consider with underwater equipment, aside from the obvious, keep the dry bits dry, and the wet bits can stay wet ... Mainly, as a user, we are concerned with Buoyancy (does it sink, float, or stay where you left it), and Trim (does it rotate, or pitch up/down).

The manufacturer has been around the block and has several great units in its ranks, but with this one, they did have a small disclaimer when I chatted with them on the phone before purchasing a few units ... "It will be a LITTLE nose up in Salt Water, and a LITTLE nose down in Fresh Water".

Well, that turned out to be bold faced lie. It points as true as a plumb bob! (in either body of water). Clearly not what they said, and the response has been undesirable from the manufacturer, making up other 'stories'...

Well, long story short, I'm stubborn enough to make it right myself!

During the first month or so of the Covid experience, I spent researching CoG and CoB (Center of Gravity and Center of Buoyancy) calculations and determined with some guesstimating (well, a lot actually), that the body of the hull was around 4-5 inches too short!

What is one to do? Well, make an insert of course. Since the hull is 6.625" in diameter, and my mighty sherline can do 3.5", I had to shop out the part.

I found (and recommended) Aaron Machine Shop down by Glenmore/Blackfoot area, and they were more than happy to work with me on several prototypes.

The first round was my 4.5" version, as well as a 6" long version (I have plans that requires the extra lift capacity with external instrumentation), with dimensions taken from the existing parts for the sealing surfaces.

View attachment 10164

I tested them in fresh water later that weekend, and found the 4.5" to be still to heavy in the back end, and the 6" to be pretty close, needing some weight in the rear to trim it out.

I went back and ordered a 5.5" version, with updated dimensions, closing up the tolerances of the mating surfaces by a few 0.010's of inches

View attachment 10168

View attachment 10165

This one was sitting pretty well in fresh water, but was requiring more ballast in the bow of the DPV than I was liking.

I also headed out to the west coast for a week to get some salt water therapy for a while, took the 4.5" and the 6" versions along. The 4.5" version worked very well for Salt water as is (still too heavy for fresh water), and the 6" version required way too much weight to get it neutral again in the water.

Back to the drawing board a little. I had figured that the 4.5" would be great for Salt water (and it was), but since it was too heavy for fresh water, I sent it back for some more work to remove some of the Interior material.

View attachment 10166

I tested that version, and while it was close in fresh water, it wasn't were I wanted it to be, so I took it back for a further revision (along with the 5.5" version too ... if the machine is set up, it doesn't add much more to the cost to do a second).

This weekend, I took the updated 4.5 and 5.5" versions with reduced inside and outside diameters out to the Provincial Park near Brooks. Fantastic warm lake water, and great visibility too.

View attachment 10167

Still the 4.5" version sits just a little too heavy (but not horrible) in fresh water with almost 1/2 of its weight removed. The 5.5" version, I was able to get it near perfection.

Putting it on the scale at home, and just finishing up new drawings for a last prototype. Starting with removing the outside diameter, and then attaching a weight specification, they'll machine out the ID if any more weight needs to be removed.

I'm on the fence if a slightly shorter tube (say 5") would suffice, but $$ is starting to really dwindle on this project sadly.

But, once this last one is done, one last final test in fresh water, and sign off on the paperwork for a small production run!


Brad

Cool little project. Definitely keep us posted (action pics will be required).

 

[Bradells]

The UDP is cool. What material are the grey (plastic looking) segments made out of? I see what look like O-ring seals on the end, but how are the parts attached to one another?
Too bad the company messed up the design like that.

Yeah, 2 orings per seal. One for water, the other is a debris seal.

It is locked in by pressure difference in the water column, and a camed nylon strap to keep it there, so no fasteners.

It is made of SCH80 PVC. One way to keep costs down is to use common engineered materials. The motor and nose caps are injection moulded plastic.

Similar aluminum designs are 3-4x the cost


Brad

 

[YYCHM]

What exactly is this thing used for?

 

[Tom O]

Just a thought couldn’t you have a Sliding weighted ring around the body that can be tightened in position to achieve the buoyancy requirements?
It works on the triple balance scales! Lol

 

[Bradells]

What exactly is this thing used for?

Glorious fun underwater! https://video.fyyc3-1.fna.fbcdn.net...=cd05e6475b0ed022035f187c21c43410&oe=5F3A4C05

Mainly to access areas normally inaccessible by shore, or we don’t want to pay for a boat.

Other times it’s to aid in carrying the amount of equipment needed for a dive. Some dives are really deep

, others are really long (caves).

If Covid hadn’t of happened, I would be in Italy right now working on an archeological dive, with the guys in the above YouTube clip.

Just a thought couldn’t you have a Sliding weighted ring around the body that can be tightened in position to achieve the buoyancy requirements?
It works on the triple balance scales! Lol

That is one way to go, unfortunately, that does affect streamlining and instrumentation placement slightly (compasses, water flow, cameras, other scientific clap traps). Not to mention, how to (while underwater mind you, usually with think, non dexterous gloves) to keep it there!

Knowing the displacement of an object (volume, easier to get close with today’s 3d drafting programs), and knowing the weight of the unit, we can get very close on the first go at getting the weighting correct.

But with these DPV, the biggest challenge is offsetting the weight of the motor assembly, and that is done by cantilevering weight on the nose with a large empty volume in the rear middle.

Sometimes weight is needed in the rear too, usually when we determine how much weight is needed, and then adjusting an ounce or few back to get the proper ‘trim’ or ‘attack’ in the water when the unit is let go.



Brad

 

[Tom O]

Well there is the submarine type chambers front and rear with a air pressure cylinder mounted underneath with a preset auto surface in case of losing it overboard.

 

[Chicken lights]

How hard is it to get dive certified?

 

[Bradells]

How hard is it to get dive certified?

Not too hard...

You can do a ‘discover scuba’ usually in a pool in an evening. Gives you some of the basics of the gear, and how to breath underwater.

From there you can do an ‘open water’ course, usually takes a few weekends and a few evenings of time (or 3 days of vacation in warm water). This gives you more of the mechanics and safety to go diving on your own (with a partner).

For northern diving, I’d recommend adding a drysuit certification to the open water. It adds a little more time, and an extra dive or two to the course (not necessarily a bad thing!)

After that, the best thing to do, is just go diving. Join a local dive group, get experience. After a while, you can take further courses to diversify and expand on your knowledge.


For me it was a very steep and slippery slope from an innocent day of snorkelling in Central America almost a decade ago.... now I dive in Caves, Deep (60m), rebreather, cold and dark......

But most of my memorable memories are simple shallow dives looking at pretty fish!


Brad

 

[YYCHM]

Have you dove those underground rivers in Mexico?

 

[Chicken lights]

Not too hard...

You can do a ‘discover scuba’ usually in a pool in an evening. Gives you some of the basics of the gear, and how to breath underwater.

From there you can do an ‘open water’ course, usually takes a few weekends and a few evenings of time (or 3 days of vacation in warm water). This gives you more of the mechanics and safety to go diving on your own (with a partner).

For northern diving, I’d recommend adding a drysuit certification to the open water. It adds a little more time, and an extra dive or two to the course (not necessarily a bad thing!)

After that, the best thing to do, is just go diving. Join a local dive group, get experience. After a while, you can take further courses to diversify and expand on your knowledge.


For me it was a very steep and slippery slope from an innocent day of snorkelling in Central America almost a decade ago.... now I dive in Caves, Deep (60m), rebreather, cold and dark......

But most of my memorable memories are simple shallow dives looking at pretty fish!


Brad

I looked into it a year or more ago, and it meant I’d have to sacrifice 6-8 weeks of being OTR to complete the basic course, if I remember right.

But it would be so cool if I had a weekend in Florida or Texas to go spend some time in the water

I’ve gone surfing a couple times, swimming a bunch, the oceans just have a pull to them that is hard to describe. It’s the ocean, man, she’s a pretty cool lady

 

[Bradells]

Have you dove those underground rivers in Mexico?

I’ve only been to Mexico once, last summer for some training in the cenote basins, so I haven’t gone much into the caves there yet.

There’s lots to see down there, highly decorated caves, as well as new discoveries still being made!

I’ve been in the Florida caves, as well as salt water Belize (same karst as Mexico caves). The caves up here and out in Vancouver Island have eluded me the last few summers due to fires.... this year, I’m broke....

I’d like to get back.... I can’t quite find a tamale that I like up here as much as down there and in El Salvador....


Brad

 

[DavidR8]

Brad are you on the coast or inland?

 

[Bradells]

Brad are you on the coast or inland?

Calgary,

I try to get out to the coast once a month (~90% of my extended family are on the island)

Brad

 

[CalgaryPT]

I’ve only been to Mexico once, last summer for some training in the cenote basins, so I haven’t gone much into the caves there yet.

There’s lots to see down there, highly decorated caves, as well as new discoveries still being made!

I’ve been in the Florida caves, as well as salt water Belize (same karst as Mexico caves). The caves up here and out in Vancouver Island have eluded me the last few summers due to fires.... this year, I’m broke....

I’d like to get back.... I can’t quite find a tamale that I like up here as much as down there and in El Salvador....


Brad

Brad you might this guy's channel. He has built submarines and ROVs, but for the past years has been building a 74 foot all steel origami boat. It's modelled on a Chinese Junk and he's built it all himself in his backyard in Tulsa, OK. It's intended to be a research and exploration vessel and people have been coming from around to world to help him. Lots of metalwork, casting, electronics, etc., but mostly I like how he just learns about something and shows off his way of mastering it.