(BTW, Steve’s Blog site Woodworking for Mere Mortals is great fun and, once in a while, actually informative grin; Be sure to sign up to follow his blog!)

Anyway, on to the gift! A very nice S4S piece of Cocobolo, about 1.2 bdft!

Don’t know what I’m going to make with this, but it’ll definitely be for SWMBO…

Hope you all had a great Christmas! God Bless and have a Happy New Year!

Mark

The longest legs on this one are 11 3/8” long, so it’s a little bigger than the ones I’ve seen posted elsewhere.

You can get my Sketchup Model on the 3D Warehouse by searching for “Jawhorse-Sawdust”

Mark

The first step was to understand the Golden Ratio (post 1), the second step was to figure out the geometry of a simple 4-arm divider (post 2 & 3), and the final step is to apply this theory to the 3-arm divider I want to make:

I just rearranged the two isosceles triangles from the 4-arm divider to produce a 3-arm divider. Now “Z” is not directly measurable, but it can be calculated. Once you select the X of your choice, and then calculate Z, you can use the second equation to calculate Y.

The cross piece (dashed line) is the same length as the line segment W, so you’ll need to calculate that length as well (W = X – Y). Because A=B=C=W, once you know W, you know how far down on the legs to place the cross piece.

Remember that all these measurements are from fastener to tip (or from fastener to fastener for the cross piece). You’ll need to add a little bit of length to accommodate the fasteners…

Now I have to do something with all this. I’ll be putting together models for both the 4-arm and 3-arm dividers in Sketchup, and then I’ll try to actually construct them! I’ll post as I can…

Cheers!
Mark

(I believe this is all correct, but don’t use this for any mission-critical or potentially injurious tasks until you’ve tried it out! grin)

What we’re talking about is essentially two arms of the same length, joined somewhere between their ends so that they can pivot around that point, and the distance between the arms at one end is some proportion of the distance between the arms at the other end. E.g. given a ratio (proportion) of 1:2, if I make the arms 2 inches apart at one end, the arms are 1 inch apart at the other end. The result is a divider having 4 arms in the shape of an “X”

(For those who are interested, this divider creates two similar isosceles triangles, and since the legs of the triangles are fixed, the law of cosines says that the bases of the triangles must be proportional however far apart they are set.)

This formula is generalized so that you can make a divider of any length and any proportion, including a cross-beam Golden Ratio divider. Just decide how long you want the overall divider to be, decide what proportion you want, and plug those numbers into the formula to determine how far from one end you need to put the pivot on the arms of the divider.

Enjoy!

Mark

BTW, if you use ratios, greater than 1, you are actually calculating the distance Y, not X…

I’ve been intrigued with the Golden Ratio (Golden Rectangle, Golden Section, Golden Mean etc.) for some time, and I’m getting ready to make a set of Golden Ratio (or Fibonacci) Dividers to assist in design and layout of some projects I’m thinking about.

I’m not going to review this topic in any great depth as there are excellent discussions of it right here on Lumberjocks (e.g. David's post). Suffice to say the Golden Ratio has many interesting features and appears to be significant in nature and aesthetics.

Specifically, the Golden Ratio is 1.618034, and is often given the generalized mathematical name “Phi”. One of the more interesting characteristics, to me anyway, is that the inverse of Phi is Phi-1. That is, 1/1.618034 = 0.618034
I think there is a mathematical categorization for such numbers, but I don’t know what it is.

Anyway, I found these “Phi rules” on Woodcraft earlier today, and thought I’d try my hand at generating my own template for such a rule. Here it is…

There are basic instructions in one of the PDF files. While the “English” scales are very close to being accurate, I DO NOT guarantee that 1 inch actually equals 1”. Even if the English measurements are off, the rule is internally consistent, so if you’re not into precision, you can still use this to lay out Golden Ratio dimensions.

Linked are a 24 inch Phi rule, which you’ll need a large format printer for; be sure to turn off scaling!

I also created a smaller 10 inch rule that you can print on standard letter size paper. This is the one with the instructions on it.

Enjoy!

Mark

I live in Iowa, about 30 minutes from the Kreg factory, so I’ve arranged with KregRep (on the User Community site) to drive to Huxley, IA to pick up the prize in person. I’ve also asked for a tour of the facility, and I’ll review my visit here in the next couple of weeks.

Mortise and Tenon, and biscuits, and all that stuff is great, but the Kreg jig really got me started quickly and making useful, nice looking work without the frustration that traditional joinery can produce. I’ve now got the time to spend learning and practicing these other forms of joinery, but can still quickly put together what needs to be done!

Thanks to the Kreg Tool Company!

Mark

Of COURSE the cap is still holding!!!! I USED KREG POCKET HOLES!!!!

LET’S GET STARTED!

Ready to build!

Got the handle in the sides pretty easily…

Top & Bottom… CHECK!

Hammering a nail!

All done! (I love daddy’s face shield… better than the goggles!)

Thanks Grandpa Ken!!!

Cheers!
Mark

Here’s my entry:

I’M GONNA NEED MORE SCREWS IF I’M GONNA FIX THIS LEAK!!!

Mark

What do you make of that?

No, really, what DO you make of that? We’re not going to use it for a floor any time soon (maybe someday when we finish the basement…)

In the mean time, any thoughts on what you’d make from bamboo?

Mark

So, I’m going to start licensing my images using the Creative Commons license, and here I’m testing HTML code generated by www.imagecodr.org

Here’s a image of a drawing I made last night to visualize cutting an isosceles/equilateral triangle on a table saw:

Let’s see what happens…

  by  whitsittms 

Ok! Outstanding!

The CC license I’ve chosen is the ” Creative Commons Attribution-Noncommercial-Share Alike 2.0 Generic” license. This essentially says you may freely share this image as long as proper attribution is given (to me) and you may also adapt this work (i.e. create a deriviative work, or modify this work) as long as attribution is given, and you redistribute your derivative under the same CC license!

All of this is strictly for NON-COMMERCIAL Purposes!!! If you wish to use this for commercial purposes, which I’m not particularly against, all you have to do is to contact me and get permission.

Clicking on the image should take you to the Flickr page with the full size image on it… Click on the little CC icon below the image for license details…

Cheers!
Mark

I discovered that this item was being clearanced in my local store for $129 (regularly $179 – $190), plus I had (yet another) Harbor Freight 20% off any single item coupon, which HD honored (your mileage will vary…). So, I picked up a fairly nice starter table for $103 + tax.

Plus, it’ll work great with my Bosch 1617EVSPK !!!

It’s no Rockler or Kreg, but it’s also not a Harbor Freight…

Yahoo!!!

Mark

The answer is very straight forward:

1. Share/upload your model into the Sketchup 3DWarehouse.
2. Open a web browser to find your model in the 3DWarehouse
3. Copy the URL to the model and add it to your LJs posting.

For example: Knock-Off-Wood Simple Bed modified by Jawhorse (Mark Whitsitt)

That’s all you need.

Mark

Here is my new Jawhorse used as a miter saw stand… it’s also a 48” x 24” work table, with the right fixture in the clamp… Since my shop is in the garage, I don’t have a dedicated space and everything has to break down or fold up or tuck away. The Jawhorse lets me have a variety of tool stands without taking up a ton of space. Plus, it is a very nice clamping stand as is!

I really like this device and it really is what they claim in their advertisements! I’d recommend it if you’re interested.

Peace!
Mark