Hemingway Knurling Tool drawing help

[SouthernChap]

1. There's a 2-9/16" dimension between the rightmost hole and an unspecified (and unmeasurable) location on the 3/4"R hole

You can get that location via the rightmost hole, you know the total width and you know the dia. of that rightmost hole and you can work out the location of the centre of that rightmost hole via the leftmost hole. Once you have the centre of the right most hole you have that location on the large lefthand radius.

Not seeing the whole drawing, what that latter location on the large lefthand radius is for, escapes me for now.

As for the other things you mention, I expect with a bit of extra reading (and view of the whole drawing) they'd become clear too.

You have to bear in mind, these prints haven't been drafted for people with DROs but for machining to layout lines on stock. They were probably done, at latest in the 1970s, or at least by people who's drafting training was done a good while back, when machining to layout was the way things were done.

When you scribe layout, some of the mental effort is reduced and the relative locations of the features become clear.

 

[Ischgl99]

4. What's the Y axis value for the 1-1/2" radius?

It's on the bottom drawing, the parts are identical except for the hole sizes/positions of each half. I've seen it done that way on some model drawings where it seems like they are trying to cram as much info on a single page as they can instead of doing a proper drawing of each part.

 

[GeneT45]

It's on the bottom drawing, the parts are identical except for the hole sizes/positions of each half. I've seen it done that way on some model drawings where it seems like they are trying to cram as much info on a single page as they can instead of doing a proper drawing of each part.

That's valid only if there's a note on the drawing that the parts are identical except... Otherwise, it's just an assumption.

I'm not saying you can't figure it out - obviously people have built to these plans. I *am* saying that the drawings are shoddy.

These were *not* drawn by hand, as evidenced by the lettering and, if you check out any of the construction videos, the 3D modeled perspectives. It's just not good work.

GsT

 

[SouthernChap]

It's on the bottom drawing, the parts are identical except for the hole sizes/positions of each half. I've seen it done that way on some model drawings where it seems like they are trying to cram as much info on a single page as they can instead of doing a proper drawing of each part.

It seems to be a general rule of old school drafting that one doesn't duplicate information.

I guess it can lead to more cognitive effort in reading the drawings, but I suppose once you've been trained to read these kinds of 'sparse' drawings and have a certain amount of practice, it comes naturally.

 

[Firstram]

For non critical parts I’ll measure a dimensioned feature on the print with calipers. Divide or multiply your number by the dimension on the print, in several places, and use the result as a multiplier. You can measure and divide or multiply with that multiplier get the missing number.

This works great when you’re working from photographs!

 

[MrWhoopee]

Good God! Even if all the info is there, it's definitely NOT how I would have drawn it.

 

[mmcmdl]

Obviously the engineer missed his GTD classes .

 

[Ischgl99]

That's valid only if there's a note on the drawing that the parts are identical except... Otherwise, it's just an assumption.

I'm not saying you can't figure it out - obviously people have built to these plans. I *am* saying that the drawings are shoddy.

These were *not* drawn by hand, as evidenced by the lettering and, if you check out any of the construction videos, the 3D modeled perspectives. It's just not good work.

GsT

I’m not disagreeing with you, but this is very common and I have never seen a note.

 

[MrWhoopee]

I used to do a lot of drafting, first with pencil on vellum, then with AutoCad.
My Prime Directive was: Do Not Make the Machinist Reach for His Calculator!
While it is inevitable, working with this goal in mind forces you to consider what info is needed to make the part.

Familiarity with the processes helps you to dimension the part in a manner that is consistent with how it will be made.
Even before DROs, mills had x and y axes. Establish your 0,0 at the top left and dimension everthing possible from there.
Lathes work from right to left. Zero is the right end, dimension everything possible from there.
Yes, there will always be features that need to be dimensioned relative to each other, but do than ONLY when necessary.

Your machinist will thank you.

 

[Ischgl99]

It seems to be a general rule of old school drafting that one doesn't duplicate information.

I guess it can lead to more cognitive effort in reading the drawings, but I suppose once you've been trained to read these kinds of 'sparse' drawings and have a certain amount of practice, it comes naturally.

The companies doing these kits and models seem to take that to the extreme lol. I usually redraw these drawings into something usable at the machine, it helps with figuring out what their intent was, and sometimes you find mistakes before you start cutting metal.