Thread: New marking gauges

Originally Posted by Colin62

Halving the linear dimensions will mean that the volume (and assuming the same density, the mass) will be one eighth of the original. You might need to add weight with some metal in the middle to get it to feel right.

Yes, I was forgetting the dimension/mass relationship isn't a simple linear matter! I did think of trying to add mass with some internal metal, but I didn't want it to show in any way. If I cut the head in half & glued some metal inside it would certainly add to mass, but it would be hard to get a joint that wasn't evident. For the sake of maintaining as much "realism" as possible I think I'll just dig out the densest wood I've got & push the dimensions of the head just a bit & that will suffice for my purpose. As I said, I won't be beating full-sized chisels into Ironwood with it!

Cheers,

Originally Posted by tony_A

They'd be just the thing for building a dolls house, do I remember you saying one was on your list of projects.

You have a good memory, Tony! That is one of the projects I'll be using miniaturised tools for, but it's not the main focus at present...

Originally Posted by LanceC

I did wonder about your mallet when looking at the photo of the chisel in the mortice. I guess the unfortunate reality is that while you've scaled down the size and weight of the tools, the density of the work piece's has remained constant. I did think the smaller cutting face may have overcome this, but based on your comment above, evidently not.

The wood density is an issue, but relatively minor because as you surmised, the small size of the tool makes it penetrate pretty easily. It's more of a "feel" thing - the mass of the mallet is so much less than I expected because I'd forgotten about the linear dimension/mass relationship and so it surprised me how "light" the tool felt. Half size means 1/4 the mass (I don't think it's 1/8th, Colin, but I need to brush up my maths so I'm not arguing yet ).

It does drive the chisel into the wood, Crows ash is a pretty hard wood on the cabinet-making scale, so it was (& meant to be) a reasonably stern test of the tools. But a head about twice as heavy would feel much nicer to use, methinks. I'll work on it.....
Cheers,

Originally Posted by Colin62

Halving the linear dimensions will mean that the volume (and assuming the same density, the mass) will be one eighth of the original. You might need to add weight with some metal in the middle to get it to feel right.

Ian

Wot Colin said. Add a bit 'o lead perhaps. Also does this bring into question the scaling?

Having said all that, those are some very cute little tools.


Regards
Paul

Originally Posted by IanW

I don't think it's 1/8th, Colin, but I need to brush up my maths so I'm not arguing yet

Half size will give you one quarter of the area and one eighth of the volume. Just think of how many 0.5m cubes will fit in a 1m cube.

Originally Posted by Colin62

Half size will give you one quarter of the area and one eighth of the volume. Just think of how many 0.5m cubes will fit in a 1m cube.

Ok Paul & Colin, you are dead right, of course, my brain wasn't thinking cubically this morning, I was getting all mixed up with mass & inertia & I don't know what else, but eventually I managed to jangle enough neurons into gear & straightened it out. I also checked the weight of the "toy" mallet head & the mallet I scaled it from, & guess what? The regular head is about 450g & the toy is a shade over 50 - the difference would easily be accounted for by the small head being of a slightly less-dense wood. So both mathematically & empirically, we have proved the theorem!

While I was waiting for some glue to dry this afternoon, I found a chunk of bull oak that I could just squeeze a head out of (between the insect galleries & drying cracks). I made it about 8mm longer & 4mm deeper & the same width as the ash head. It weighed in at 85g after cutting a handle mortise, which is precisely 70% more than the one above. With handle attached it doesn't look disproportionate & feels much more like a mallet. It's soaking up a goodly dose of boiled linseed tonight (might add another 10th of a gram! ). I'll have another play with it when the oil dries, but I think this one will do nicely, thankyou - I wasn't keen to muck about adding metal, as you probably gathered.......

All good.

Oh & I found a couple of scraps of Milmerran hairy-oak whilst ferreting out the bull oak - just enough to make a tiny mortise gauge (as long as I don't have any stuff-ups). I do like working with that stuff, it's far & away the nicest to work with of the dense casuarinas ...

Cheers,

Oh yes, the pitfalls of scaling. Not that you only wanted them to look small. You also want them to work and that's where the tricky bits come in. Millions of dollars have been lost through that.
Glad that's not the case for you [emoji6]

Sent from my SM-G781B using Tapatalk

And of course, Ian, I'm looking forward to your brace & bits build.
Cheers,
Geoff.

Originally Posted by Boringgeoff

And of course, Ian, I'm looking forward to your brace & bits build.

And the 30+tpi dovetail saw

Originally Posted by Boringgeoff

And of course, Ian, I'm looking forward to your brace & bits build.
Cheers,
Geoff.

Damn, I was hoping noone would bring that up!

I have actually given it some thought already, Geoff - the brace itself gives few qualms, but the chuck is an altogether 'nother matter. I don't think I can manage a two-jaw from scratch with my simple gear. What I was thinking was to use a jacob's chuck from a small "egg-beater" - would that be allowable, do you think?

I am NOT contemplating making auger bits!!

Originally Posted by Chief Tiff

And the 30+tpi dovetail saw

Hah! The saw is half-made already, but it's going to get 20 tpi. Your're absolutely right, of course, and the half-size copy of my 15tpi "best" D/T saw should get 30tpi. But last time I tried 30tpi (for a small razor saw), it caused many tears (of rage & frustration), until I eventually got them to look something like proper teeth. The thought of repeating that on a 110mm blade (half the length of the 'full size' D/T saw) does not appeal at all!
Besides, 20tpi is a more practical size for cutting the little joints I plan to use it for...

Cheers,

Ian,
I if you would be so kind as to notify me when you start on the miniature set of Violin makers planes,

Cheers Matt[emoji6].

Originally Posted by IanW

Damn, I was hoping noone would bring that up!

I have actually given it some thought already, Geoff - the brace itself gives few qualms, but the chuck is an altogether 'nother matter. I don't think I can manage a two-jaw from scratch with my simple gear. What I was thinking was to use a jacob's chuck from a small "egg-beater" - would that be allowable, do you think?

I am NOT contemplating making auger bits!!




Hah! The saw is half-made already, but it's going to get 20 tpi. Your're absolutely right, of course, and the half-size copy of my 15tpi "best" D/T saw should get 30tpi. But last time I tried 30tpi (for a small razor saw), it caused many tears (of rage & frustration), until I eventually got them to look something like proper teeth. The thought of repeating that on a 110mm blade (half the length of the 'full size' D/T saw) does not appeal at all!
Besides, 20tpi is a more practical size for cutting the little joints I plan to use it for...

Cheers,

Ian

Have a look at the jaws/collet from a Dremel tool.

Regards
Paul

Hi Ian,

I was thinking, instead of cutting into the body of the mallet head to insert metal, how about incorporating some metal inside the handle hole? Make it part of the handle in other words?

Lyndon

Originally Posted by Simplicity

Ian,
I if you would be so kind as to notify me when you start on the miniature set of Violin makers planes,

Cheers Matt[emoji6].

Matt, I think it'll be after a month of cold days in hades before I start on those.....

Originally Posted by BEM

Hi Ian,

I was thinking, instead of cutting into the body of the mallet head to insert metal, how about incorporating some metal inside the handle hole? Make it part of the handle in other words?

Lyndon

Lyndon, that would be about the only way to hide it easily, but you wouldn't get much metal in the handle within the head (which is where it's needed). Anyway, my slightly oversize bull-oak head has greatly improved matters, so I'm letting that rest for now.
Cheers,