Shopsmith Forums

I can see from the posts here that it is really unclear what the issues are. Simple conversion to/from mm to inches is not an issue. Heck even google does that. Just start like this:
Then once you are there you simply keep going with any and all conversions you wish.
The bigger problem is if you want to make say a template that will allow you to duplicate a part done in mm. Here is a simple example:
Now if I simple convert this to imperial dimensions this is what it would look like:
Now if one has a tool that can snap to 1/32" such as an Incra positioner you could then produce something like this:
Now if we look at just one of the adjustments, 1-3/16 (1.1875) which should really be 1.1811 it is only off by .0064". Granted that doesn't sound like much and is isn't much until you attempt to make a set of 10 more holes it is then off by .064 which is just slightly more then 1/16" and that is not acceptable.

Does that make more sence?

Ed

reible wrote:I can see from the posts here that it is really unclear what the issues are. Simple conversion to/from mm to inches is not an issue. Heck even google does that. Just start like this:

ScreenHunter_158 Apr. 30 07.41.jpg

Then once you are there you simply keep going with any and all conversions you wish.

ScreenHunter_159 Apr. 30 07.41.jpg

The bigger problem is if you want to make say a template that will allow you to duplicate a part done in mm. Here is a simple example:

ScreenHunter_161 Apr. 30 07.57.jpg

Now if I simple convert this to imperial dimensions this is what it would look like:

ScreenHunter_160 Apr. 30 07.56.jpg

Now if one has a tool that can snap to 1/32" such as an Incra positioner you could then produce something like this:

ScreenHunter_162 Apr. 30 08.11.jpg

Now if we look at just one of the adjustments, 1-3/16 (1.1875) which should really be 1.1811 it is only off by .0064". Granted that doesn't sound like much and is isn't much until you attempt to make a set of 10 more holes it is then off by .064 which is just slightly more then 1/16" and that is not acceptable.

Does that make more sence?

Ed

The dimension for each hole should be from the same datum not the previous hole? Then your tolerances don't stack or to keep the discrepancies from stacking. So each hole is only .0064 off and not building up to the .64 at the end.

Edit: Doh. Incra positioner(precision adjustments to .001).....not the right tool then?

Since I'm thinking of making a template the idea is to locate holes based on the holes you just did. So the reference is the previous hole(s). When the real thing is made it would be referenced from a common datum and the errors are isolated from each other. A large enough cnc machine or a gang drill would be done in that manor. I just have no way to do that so hence the template.

Yes the incra can do .001 off of the last 1/32" notch so if you were at say want 1-3/16 or 1.1875 you could dial that back to 1.181 which is closer but it is still not quite the same thing as 1.1811 but that one just happens to get really close, if you go to 96mm or 3.77953 do you go 3.779 or 3.780? Either way by the time you drill the 77 holes it is unlikely to be close enough.

Lets put it this way, if I can measure the error it is too much.

Ed

Skizzity wrote:

reible wrote:I can see from the posts here that it is really unclear what the issues are. Simple conversion to/from mm to inches is not an issue. Heck even google does that. Just start like this:

ScreenHunter_158 Apr. 30 07.41.jpg

Then once you are there you simply keep going with any and all conversions you wish.

ScreenHunter_159 Apr. 30 07.41.jpg

The bigger problem is if you want to make say a template that will allow you to duplicate a part done in mm. Here is a simple example:

ScreenHunter_161 Apr. 30 07.57.jpg

Now if I simple convert this to imperial dimensions this is what it would look like:

ScreenHunter_160 Apr. 30 07.56.jpg

Now if one has a tool that can snap to 1/32" such as an Incra positioner you could then produce something like this:

ScreenHunter_162 Apr. 30 08.11.jpg

Now if we look at just one of the adjustments, 1-3/16 (1.1875) which should really be 1.1811 it is only off by .0064". Granted that doesn't sound like much and is isn't much until you attempt to make a set of 10 more holes it is then off by .064 which is just slightly more then 1/16" and that is not acceptable.

Does that make more sence?

Ed

The dimension for each hole should be from the same datum not the previous hole? Then your tolerances don't stack or to keep the discrepancies from stacking. So each hole is only .0064 off and not building up to the .64 at the end.

Edit: Doh. Incra positioner(precision adjustments to .001).....not the right tool then?

Sorry if I was way off base.
Is a metric conversion kit needed then?
There a available but pricey.

garys wrote:I don't have that problem. I simply do not do metric. My old brain is calibrated in inches, not millimeters. I'm too old to change, so any project set up metric isn't going anywhere with me. Either it is in inches, or it doesn't exist in my world.
It is only a problem if you let it be a problem.
I never build anything from patterns or instructions anyway, so I don't encounter that problem. I build from ideas in my head where metric doesn't exist.

DITTO, GARYS !

My metric converter. And a few extra thingies.

JPG wrote:My metric converter. And a few extra thingies.

Can it change acres into hectares?

charlese wrote:

JPG wrote:My metric converter. And a few extra thingies.

Can it change acres into hectares?

Only if I program it to divide by 2.741.

JPG wrote:My metric converter. And a few extra thingies.

I had this same one that I used all the time at work. When I retired it came home with me but about 2 years ago it up and died. If I'm remembering right it took 3 LR44 batteries........ and they lasted a long time. Very different then the TI one I had before that, that thing ate batteries. Just trying to remember what year I got it, maybe about 1988 or 89 when I was taking some classes on the company dime and they got the calculator for me too.

Ed

Even the lowly Microsoft program in Windows has some hidden horsepower just below the hood that most folks never think about

If you change the view when running it (calc.exe) a standard program in Windows, you can have a standard calculator transform into a Scientific, Programmer, Statistics calculator at a mouse click.

In basic you see the norm, but in Unit Conversion options you have a group of other unit conversions such as Angle, Area, Energy, Length, Power, Pressure, Temperature, Time, Velocity, Volume, Weight and Mass that you can convert in a myriad of ways to and from.

In the conversion below I show .750 inches to 19.05 Millimeters for a quick conversion.

If you have Windows, you have this built in. There are dozens if not hundreds of downloadable calculator apps if this one doesn't suit you.

If you need more there are specialty on-line calculators galore. One of my go-to ones is at http://www.blocklayer.com/roof/gableeng.aspx which I use for Gable roof calculations and mark outs.

Everett Even Microsoft Excel can be configured with one column in decimal, and another column with fractions. I just set one column up and copied it, then changed the format. You could use a formula to set D1 = B1 and copy it down just as easily formatting B for fractions. I noted after making it I likely should have set the decimal above 2 for column D so 3/8 would show .375 opposed to rounding up to .38 as illustrated, but you get the idea.

Point is there are tools you likely already have in your arsenal to do things of this nature. Excel does not natively do the conversions to metric as a format, but there other tools such a formula such as CONVERT(number,from_unit,to_unit) I will put together a better example.