PDA

View Full Version : Marking gauges



Arron
15th July 2004, 02:02 PM
This is a set of matching gauges - pin, pencil and knife below, and a beam gauge (??) above.

After seeing MajorPanic's beautiful marking gauges on this site, it takes a little courage to put up my own efforts. I think it is worth it though because there is a couple of good ideas here which I have pinched.

I have wanted to make a set of gauges for a long time but have not been happy with the available methods of locking, and have baulked at the idea of cutting tiny, precise mortises for the knife point. The locking method used here consists of a dowel with two cutaway sections. One section is cut away square such that if it is lined up with the beam then the head can be removed completely. The other section is adjacent and has a slope, such that it acts like a wedge. The dowel will thus not fall out because it is of full thickness on either side of the cutaway sections and is held in place by the beam. Also, the beam and head will not separate unless the square cutaway section is lined up precisely with the mortise, something unlikely to occur by accident. Locking requires simply moving the dowel left with a thumb, and requires no readjustment of the hand. To unlock, move the dowel right, or tap it on a table if it is firm. I think this method is better then a conventional wedge that can be lost, and better then a screw in a wooden thread which usually requires a (tiny) repositioning of the hand to do up.

The knife point in the knife gauge is simply a blade form one of those knife sets in a $2 shop. There is a 12mm hole drilled in the beam. Two sections of 12mm dowel are split lengthwise. As always, one piece will be slightly thicker then the other, so the knife blade is put between the two thicker sections and forced into the 12mm hole. Initially push the assembly in just far enough so that the correct angle can be found for the knife - it should be set to pull away very slightly from the head to counteract the tendancy of the workpiece's grain to steer the gauge. About 3 degrees from parallel seems best. Once you are happy with how it performs, push it home. To replace the blade, just punch the assembly out.

These are the first things I have made strictly with hand tools. Not something I intend to do very often, but very worthwhile because it is a great skill builder. The timber is Euro oak.

Arron

bitingmidge
15th July 2004, 05:17 PM
I don't suppose you'd be holding an event shortly and offering them as the door prize? :D :D

I have a spot for it in the Pool Room right beside the one of the Major's.

Hey Arron have you thought about what you are going to make when you have made a couple of every kind of tool, or is it a bit like me and the DC ducting....worry about that when the time comes?


Love your work!

P

Wood Borer
15th July 2004, 05:50 PM
Very nice.

I highly doubt they would work in Melbourne though. If you give me one, I will gladly test it out for you. :D

- Wood Borer

IanW
16th July 2004, 08:59 AM
Arron - I've always liked the idea of quick locking mechanisms for gauges, and there are a couple of other ways of doing it, like having a slightly oval beam which twists to lock. But when it came time to make some gauges for myself I went all conventional, partly because I wanted to use a wooden thumbscrew. Yeah, cutting a neat mortice for the cutting knife is a pain. I used a bit of hacksaw blade for mine. I didn't angle the blade the way you advise, partly because it would have been to darn tricky for me to get it right (your solution was too intelligent for me, but I've filed the idea!). I rounded the end of the cutter and bevelled it on the side toward the fence. Since I use it almost exclusively for marking across the grain, this works well. Also used a hacksaw blade for the marking knife, as you can probably see - didn't quite smooth the edge where the teeth were. I've since modified it with a second bevel so I can use it left or right hand, but am going to make an improved version, someday, with a thicker blade.
The pencil gauge is a more recent addition. To fit the brass end to the beam, a friend turned a stub dowel on a piece of 3/4" brass and drilled the holes for the pencil and knurled-head screw (from Lee Valley).
What I thought would be the most difficult part, fitting the dovetailed brass wear strips turned out to be quite easy. I cut the grooves with a router, using a bit made by grinding the profile on the end of a broken 1/4" drill, then hacksawed the strips out of 1/8th brass and filed to fit by eye. They are a firm sliding-fit with a dab of Araldite to hold them.
The scribe is an old small chainsaw file, chucked in a battery drill and run over the grinder to taper it - the ferrule is an old cartridge case, which has a nice taper.
The wood is She-oak, which Colen Clenton also favours for his beautiful tools - (but I thought of it first!!)
Cheers,

Wood Borer
16th July 2004, 09:15 AM
Ian,

These look great too. I love the sheoak, I have a bit drying in the backyard and I have a Colen Clenton awl, square and marking gauge made from it. A beautiful timber.

You must be proud of your work - you have good reason to be.

- Wood Borer

IanW
16th July 2004, 11:50 AM
Actually, Woodborer, the only things I've remained reasonably satisfied with are the things I've sold/given away on completion and never seen again! Like most of us, if you look at something you've done, you can always see little flaws in design or execution which get to really annoy after a while. I suppose this is a good way for an amateur to be - keeps the interest alive!
Cheers,

AlexS
16th July 2004, 11:52 AM
Very nice Arron & Ian.
I made a set with a cam lock. One face of the beam is coved and a cam locks in it. For the cutting gauge blade I used a piece of old jigsaw blade, not angled.

Driver
16th July 2004, 01:15 PM
Great work, Arron and Ian!

I'm knocked out by the ingenuity and skills shown by some of the contributors to this site. You give the rest of us something to aspire to. Well done!

Col

derekcohen
16th July 2004, 07:01 PM
Arron and Ian

Such fabulous work, both of you. This just fires me up to build my own! Thanks for sharing.

Regards from Perth

Derek

MajorPanic
16th July 2004, 08:14 PM
Hi Ya Arron,
Excellent work on the gauges & knife!!!! :D
It's a real learning curve as you have no doubt learnt..... accuracy & working with small pieces :mad:

I've got an idea for a multi-purpose gauge, pin, knife & pencil just by changing brass inserts in the beam. All I need is a metal lathe & a milling machine ect, ect... oh some skill wouldn't go astray either ;).

Once again great work!!