Gimme a challenge!?

[woodworx]

I want to hear about projects that you think you can machine, and I can't.....I really want a challenge here so lets hear 'em. Justin

[myxpykalix]

8969

'nuff said...lol

[woodworx]

There is no way I can mold the plastic for those rubber wheels..No cheating Jack!

[khalid]

Justin.. First tell us what you can't machine, then i will give you the challenge


Jack..
Very nice setup... What is inside the Hollow spiral?? seems some electrical cables ;) ...

[myxpykalix]

Actually that is a thin dowel used to minimize lateral forces to keep it from snapping. If you look at right side (left side the same) it has a square piece of plywood with a round .25" deep hole to keep the dowel in place.
But you actually need a dowel just about the same size as your hole to keep the bit from chattering the spirals and cracking them.
I can send you other pics and more info if you email me direct so as not to hijack his thread here.

Justin...I would take this challenge in a different direction. I would think of something that YOU want to make and see if anyone else has done the same thing and then try to emulate their example if they can give you some tips and tutilidge?
Actually here is a very complicated project I just finished that might be a great challenge for you:
http://www.talkshopbot.com/forum/messages/17997/40598.html?1238564502

[khaos]

How about ...


8970

[joewino]

Hey...that's Joe Crumley's pet when he was a boy.

[erik_f]

He came across it in that really white snow on his way uphill to school barefoot with his school project made of brick in his back pack made of horse hair.

[woodworx]

My next goal is to get the indexer. I would love to machine that kind of stuff. Dinosaur heads? I don't know, but I have seen recreations done by layering paper cutouts. This one would take thousands of layers to create. Jack, was your turning for a customer?


Since we all do so many different varieties of projects, I would like to hear of the best ways to get the customer to visualize. How far do you go for a qualified customer? Looking for a paperless, sampleless, way to create new products and display them digitally. Any suggestions out there? Maybe send me some examples. Any product, any size, just want to see the best of the best.

[myxpykalix]

Justin,
When you get an indexer let me know, I can send you some toolpaths and ideas for creations (like spirals and hollow spirals) that will allow you to make some really cool stuff that others can't do.
That particular piece was just an experiment. I turned that into a lamp with a hidden power wire.

[Brady Watson]

Easy Hollow Core Method via Legacy Woodworking (http://legacywoodworking.com/Videos/ShopTime/HollowCore/HollowCore.cfm)

-B

[henrik_o]

quote:I want to hear about projects that you think you can machine, and I can't.....I really want a challenge here so lets hear 'em.

With a very strong emphasis on the "think" part: machine a through dovetail joint flat on the table. The surface geometry (the areas we can see when the joint is assembled) on both sides must be true, i.e. a real strict angular through dovetail, not one of those rounded variants you can buy specialty bits for.

I believe this supposedly impossible task is in fact doable. The two things that are not possible is for the through parts to be of equal dimension as the thickness of the stock, nor can the internal geometry be absolutely true -- then it is in fact impossible.

But, once we realize those are absolute rules, we may have identified a solution if we deviate a little from both. As such, if we allow ourselves two deviations from the ideal dovetail geometry:

-The through parts having a miniscule height difference to the stock thickness (less than 1mm should theoretically work)

-The internal surface geometry does not need to be true as long as it does not compromise the mechanical properties of the joint more than marginally

... then yes, it should be possible.

I'm not sure my little joinery brainchild really does work however; extensive testing would be necessary to verify it.

In any case it's a pretty interesting problem in terms of thinking spatially and hey, who knows, maybe it can in fact be done. I think that even if it can't, it's a good thing to try to crack, especially if you go about it in your head. When I first started thinking about it, I had to have a disassembled dovetail joint in front of me so I cold turn it around and handle it, and I needed pen and paper to sketch possible solutions.

After some time, I didn't need to have a physical joint in front of me, and I could more and more let go of the pen and paper. Once you become familiar with the geometry, in your head, you can visualize it: make mental changes and then in your head see what happens as you assemble it (again, just with the 'inner eye'). It's really quite fascinating.

I assume it is something like this that the mathematicians and physicists refer to when they speak about visualizing mathematical problems and their solutions: you can apply yourself and come to a point where you can "see" the problem visually. The dovetail is of course ridiculously simple compared to general and special relativity etc, but still. Baby steps, huh?


As an aside: I did get your email regarding the previous dovetailing debate here and your clever take on it, but I found it about a month after you wrote me, lying there in my overly aggressive spam filter box. I felt bad about it but didn't want to reply so long after either, instead I made a mental note that you're a guy whom to talk to about dovetails.

Which brings us here, I guess

[myxpykalix]

Per Bradys link above is similar to how I made my hollow spirals:
http://www.talkshopbot.com/forum/messages/33571/33679.html?1219926690

http://www.talkshopbot.com/forum/messages/33571/33746.html?1220321932


8971

[woodworx]

Henrik,
This is the kind of "thinking" that moves us forward as a machinist. Without getting into too much detail, I think breaking down the geometry of the dovetail and trying to machine the joint as a flat panel project could be done. Who is to say that the dovetail joint can't be altered slightly to accommodate being machined as a flat panel? Thermwood machines will do the joint, and they make a special bit for doing dovetails. Not sure if that is cheating though. I think you are actually looking for a true full dovetail.

I am a conceptual person and can visualize things before the pen hits the paper, so I do understand where you are coming from. If this kind of joint was to be developed,I see no reason why a parametric program similar to "Free Doors" couldn't be designed. That would be a money maker for sure.

[Gary Campbell]

Henrik, Justin...
If you look on the Thermwood and/or eCabinets forum you can find a post that explains this tecnique. It also refers to the fact that Thermwood didnt "invent" this joint, they simply included it and the required tooling into their design and machining abilities and made it available to their users.

Woodweb has articles on this ranging from the how to, to persons of varying viewpoints from the more "purist" side to explaing that true dovetails are full thru, and cut with a saw and chisel, half blind round pin dovetails are a "bastardized" version that is able to be cut with a jig and router or special purpose machine, and then go on to name the nested joints as anything but dovetails.

In any event, there is a need to use flatbed nested material and cut joinery in drawer parts that is appealing to the customer. It is possible, it has been done before, and I assume there are many variations available, but not yet widely used.

I adapted the router and jig method for cutting in a non flat orientation on the ShopBot. I have also sent the hard code (without variables) out to be adapted to Gcode for those so inclined. So my challenge is, as you asked for it, would be: I think I can adapt a flatbed nested drawer joinery method for use on a ShopBot, (or other CNC) can you?

By the way... in which way would your parametric program be similar to "Free Doors"? not the free part, I guess!

Gary

[henrik_o]

No, no, no, gentlemen. I am not talking about the Thermwood technique (I don't think they have a patent, others are selling the kits). That technique produces a through joint that is visually very different from a traditional dovetail.

I am talking about doing it flat on the table, producing a dovetail joint that, when assembled, is visually indistinguishable from a 'true' through dovetail joint, as it would appear if both mating pieces were cut vertically in a jig like Gary's or the one I have (or the robot Morris built).

Can it be done? I'm not sure. Maybe.

[Gary Campbell]

Henrik...
Besides throwing down the glove for Justin, I do foresee a few problems with the joinery as you describe it.

It would be diffucult, if not impossible to cut the acute angles required for this joint with both pieces coplanar using any imaginable bit capable of production speed work.

I am sure that is why the joinery noted above has mutated from the traditional look we expect. Can we be sure that our customers feel the same? We presently use a different drawer side media for our standard and high end product. Using a lesser cost and similar looking, but less costly to produce construction joint for drawer boxes is an option I shall be looking into.

To test this theory I brought 6 samples to 3 local designers, some half lap, some dovetail, some butt joints. materials were solid maple, finger jointed birch and edgebanded plywood of different thickness'. I asked them what points of each, Ie. cost, look, joinery, species would detract or add to the marketability of the product.

It was unanimous... the plywood sides were a negative. "Solid Wood" is the buzz word. Most liked the FJ narrow strips of birch. (our green product standard)

Our high end custom stuff will always have full 3/4 thick solid maple with dovetail joints.
Gary

[wberminio]

Gary
You're right.

Solid Wood Dovetailed drawers are a major selling point.

Years ago,I was unloading my Solid wood dovetailed drawers outside a building on Riverside Dr,NYC.
A guy walked by,did a double take-and asked me where I was working.
He was a designer that lived in that same building.
We worked together for many years,until he retired.
Solid wood /Dovetailed Drawers!


Erminio