parallels

[RobinHood]

Good post @Susquatch .

That kind of was my point about converting from one system to another - humans have been doing it forever.

Here is another example: long before the invention of currencies people were trading things. That is a form of conversion as one bag of potatoes may equal one shirt at the Taylor. Or a certain amount of meat is equal to a wagon wheel or new shoes for the horse…

The conversion ratio could vary from town to town depending on the abundance of a given item in the trade taking place.

 

[jcdammeyer]

Just to swing the thread back to the original subject here's what I have for setting up work on my mill.

The cheapy parallels came from Busy Bee decades ago. Still using them.
Did buy a set of higher precision ones, still wrapped in oiled paper. Haven't needed them yet. Level of my work doesn't warrant it.
The 1:2:3 blocks are occasionally pulled out.
Hardly ever use the V Blocks but it's nice to have them.

I think if the mill was better quality I might be pushed to do better work but for now the cheapy parallels, with a few accidental nicks have been adequate.

 

[Manfred]

This might be relevant for a few of us living relatively close to each other - given how expensive shipping within and to Canada from the USA is (unless I am missing something):

3" Thin Parallels | Buy Precision Tools | LittleMachineShop

Great for the small vises on a mini mill, this set of ten pairs of thin parallels come in a case and are compatible with a variety of mini mills. Order today.

littlemachineshop.com

 

[Janger]

The $57 CAD set from HD included free shipping from USA. Shipping is a crock. How can this box come from California for free when other shipments that are lighter are expensive? shipping never makes any sense.

With exchange and shipping I suspect the LMS set will cost more. Anybody know the total? Unless you can pool an order and combine shipping. That would be a good idea.

 

[PeterT]

I bought that LMS 3" set for a slightly different application - supporting fussy small parts on either underside so that I could drill through holes through the part. My regular parallels want to flop on either side due to their own weight. Amazingly, short parallels are not really that common. I suspect they were made for mini machines but I find them to be useful.

 

[RobinHood]

Someone could just get another set of 6” wide by 1/8” thick ones and cut them in half. Then two people can have a set of ~3” wide for a good price and shipping won’t be show stopper…

 

[PeterT]

I actually tested that. I cut a scrap one with my disc grinder. Got through it OK but it wasn't very pretty. I didn't really care about the edge not being straight or square as long as no burrs. But it did have that smoky tan color to it (heat). It was well hardened that's for sure.

I've found singles of inexpensive gage blocks online which might be an option too, but they are typically thicker material.

 

[RobinHood]

Maybe a CBN wheel on a surface grinder with flood coolant might get through them a bit easier?

1A1R Ultra-thin High Precision Cutting Wheel

1A1R Ultra-thin High Precision Cutting Wheel

www.cbncut.com

 

[PeterT]

Lets see... who do I know with a surface grinder... hmmmm..

 

[Tincup]

Before retirement, and working in the distribution business,
We didn't call it freight, it was fright!

 

[RobinHood]

Good one Peter… I do not (yet) have a CBN cut-off whee…

 

[LenVW]

I grew up in the Metric system myself. I do agree that there are more people in the world using it than the SAE system. Converting between the two does introduce a source of error which requires additional attention to detail.

Maybe it is because I am so used to converting from one unit of measurement to the other at my job, this becomes a non-issue. I don’t even think about it other than recognizing which units I am currently in and to which units I need to go.

You were lucky @RobinHood . When I was going through school we had to learn Imperial and Metric. The conversion calculator and factors were always in use (.03937” = 1 mm).
And then they thru French in there as well as Dutch, German, Spanish, Norwegian, . . .

 

[Chicken lights]

You were lucky @RobinHood . When I was going through school we had to learn Imperial and Metric. The conversion calculator and factors were always in use (.03937” = 1 mm).
And then they thru French in there as well as Dutch, German, Spanish, Norwegian, . . .

Sprechen sie deutsch, ja?

je parlez vous francais un peux

endelez, muchacho, por favor

yet I’m horrible with metric

 

[jcdammeyer]

Sprechen sie deutsch, ja?

je parlez vous francais un peux

endelez, muchacho, por favor

yet I’m horrible with metric

I have a simple question. The scales on my lathe, mill are both marked in decimal divisions. I used my caliper to determine a dimension off a drawing of a Curliss steam engine an hour or so ago (printed with no size adjustment on A4 paper) and read off the number 0.375 which is decimal.

I'm old enough to have started in feet and inches and also lived in Europe for a few years where driving kilometers per hour wasn't strange. What's interesting is the speedometer on the car had a dial with numbers between 0 and 200 or so. So driving what I did was line up the dial with the posted number along the road. (Really glad it wasn't furlongs per fortnight which I find confusing).

Anyway. We all use 99.99999% of the time a decimal system for machining or driving. Whether the units are millimeters as in 25.30 or inches as in 0.996 we're still dealing with graduations on scale, or a decimal readout which determines how far we turn the dial.

Past that the only thing to learn in the machining and wood working world is that 30mm is about this much (holding up thumb and finger) and an inch is about this much (holding up thumb and finger). If that's too difficult I'm guessing that thumb and finger are probably not safe near any sort of spinning metal.

So my question is really why this is even an issue. There are so many other things to spend energy on.

 

[Susquatch]

It isn't an issue for someone like you who knows that

30mm is about this much (holding up thumb and finger) and an inch is about this much (holding up thumb and finger).

But for some people, that isn't the case. A young engineer in the division I worked in who had only learned metric in school ordered an imperial fastener for a project he was working on. Being unfamiliar with how big an inch was, he assumed that one inch was about 1 millimeter and ordered a small hook for the project. The finance people had no familiarity either and approved his order. None of us could avoid laughing our heads off when this huge crane hook arrived.

 

[Chicken lights]

I have a simple question. The scales on my lathe, mill are both marked in decimal divisions. I used my caliper to determine a dimension off a drawing of a Curliss steam engine an hour or so ago (printed with no size adjustment on A4 paper) and read off the number 0.375 which is decimal.

I'm old enough to have started in feet and inches and also lived in Europe for a few years where driving kilometers per hour wasn't strange. What's interesting is the speedometer on the car had a dial with numbers between 0 and 200 or so. So driving what I did was line up the dial with the posted number along the road. (Really glad it wasn't furlongs per fortnight which I find confusing).

Anyway. We all use 99.99999% of the time a decimal system for machining or driving. Whether the units are millimeters as in 25.30 or inches as in 0.996 we're still dealing with graduations on scale, or a decimal readout which determines how far we turn the dial.

Past that the only thing to learn in the machining and wood working world is that 30mm is about this much (holding up thumb and finger) and an inch is about this much (holding up thumb and finger). If that's too difficult I'm guessing that thumb and finger are probably not safe near any sort of spinning metal.

So my question is really why this is even an issue. There are so many other things to spend energy on.

I’m usually pretty easy going and generally just try to laugh at life, but to answer your question -

Last week I had a permit load, good for 4.26 metres tall. Most bridges in my route were marked at 4.2 metres clearance, some at 4.1 metres. My load measured 13’9” tall. I’m pretty sure 4.26 metres is 14’ roughly

Legal height is 13’6”, my truck clears 11’6” easily, with a deck. There’s bridges in Toronto marked 3.9 metres (example only) clearance. What the heck is that in normal human language, yet in the USA a bridge marked 13’ I’m sending it all day long

I only use decimals when measuring tolerances, the rest of the time it’s fractions or a guesstimate, but to me I never use metric unless I’m forced to, your mileage may vary, friend

The imperial system is so easy to use, I think that’s why I find metric so confusing and backwards

 

[jcdammeyer]

I’m usually pretty easy going and generally just try to laugh at life, but to answer your question -

Last week I had a permit load, good for 4.26 metres tall. Most bridges in my route were marked at 4.2 metres clearance, some at 4.1 metres. My load measured 13’9” tall. I’m pretty sure 4.26 metres is 14’ roughly

Legal height is 13’6”, my truck clears 11’6” easily, with a deck. There’s bridges in Toronto marked 3.9 metres (example only) clearance. What the heck is that in normal human language, yet in the USA a bridge marked 13’ I’m sending it all day long

I only use decimals when measuring tolerances, the rest of the time it’s fractions or a guesstimate, but to me I never use metric unless I’m forced to, your mileage may vary, friend

The imperial system is so easy to use, I think that’s why I find metric so confusing and backwards

In this case the internet is your friend if you don't know how to do the conversions. I would choose a route that has bridges with 4.2m clearance and let a bit of air out of the tires. I remember seeing a cartoon way back where some young kid let the air out of tires to allow a big truck become unstuck under a bridge.

 

[LenVW]

I recently saw the news story about the ‘rig’ that clipped the Garden Avenue overpass in Brantford, Ontario.
The collision caused the closure of the 403 for several hours so that structural engineers could access the damage to the overpass.

Do all of these structures have a designed ’crash beam’ in case of this happening ?
Probably the older the structures, the less likely it would have incorporated this detail.

 

[Dusty]

@RobinHood wish my old white matter could master the metric system. My brain automatically thinks Imperial (SAE) then I carefully convert to metric checking twice sometimes more. LOL

 

[6.5 Fan]

I'm with Dusty in this mix up, raised in the imperial system still use it in most of my work. Years ago i asked my daughter to see if we had a length of lumber about 4ft long, poor girl had no idea how long 4ft was.