Monday, October 30, 2017

My Sandbox

Morgan Demers' molding bench got me thinking about what a good idea it was to have your molding bench near your pouring area. For one thing, a flask full of sand is heavy. He also put his sandbox on casters, so it would be easy to roll from the molding bench to the pouring area. That should also reduce the chances of jarring the flask and causing the sand to shake loose in part of the mold or collapse entirely. I was sketching out various ideas when the thought occurred that the greatest chance of such a mishap was in lowering the flask from the bench to the sandbox.

What if you put them at the same height? As Uncle Dave pointed out, you could do all your molding on the ground, but a molding bench would raise the work to a convenient height. You could raise the sandbox to the same height as the molding bench. But isn't the molding bench itself basically a box full of sand? Could you pour over it? I don't see why not, and once the pattern was drawn and the flask reassembled, you wouldn't have to move it at all.

But that would require lifting the crucible out of the furnace, raising it above the bench, above the flask, and then pouring. All that extra movement of a glowing flask filled with molten metal sounded like an unnecessary risk. So eliminate it. Expand the benchtop / sandbox to make room for the furnace. It needs a bed of sand 2" thick, and maybe some firebricks to rest on and to set the lid on. But won't it be awkward and dangerous to lift the crucible to shoulder height or above? Will you even be able to see the sprue as you pour? If the mountain won't come to Muhammad...

Build some steps near the furnace. Stand at ground level to prepare the mold, then climb the steps to melt and pour. Ideas were coming thick and fast now. I revised my plan through many drawings, and made further changes during construction.

With all that weight on it, the bench needs a broader base. I had some concrete blocks left from another project. I'm no mason, and since I rent, I may have to tear this down and move it at some point, so I stacked the blocks dry. I wanted the most stable arrangement I could get. I thought of a running bond, but I had no way to break blocks, I didn't want to pay extra for special blocks, and I wanted the 4' x 4' base to come out even. I settled on a basketweave pattern, alternating directions with each layer.

Something I learned when I worked in the shipping department at Rust-Oleum: when stacking rectangles of identical size, the stack will be more stable if they don't line up exactly. Because the layers alternate directions, each block rests on two blocks. Because the layers don't quite line up, each block also rests partly on a third block.



The base is 48" x 48" x 24" with 8" steps.


I used salvaged wood (mostly laminated particle board) for the bottom of the sandbox.
Some good quality dimensional lumber turned up on the curb just in time for the sides. I used 2x6s for the molding area. Since the furnace area only needs 2" of sand, I used 2x4s there.

As usual, spring clamps and electrical junction boxes held things square for assembly.

I vaguely remembered reading that concrete could wick moisture up from the ground, and that wood structures on a concrete foundation needed a water break to keep the wood from rotting. I had several blue tarps from Harbor Frieght's free with any purchase coupons, so I used one under the box, one to line the box, and one to shed rain.


I made a lid to keep out cats and weather.


Weights, bungees, and tent stakes hold a tarp over the lid to shed water.


Sunday, September 24, 2017

The Workbench, Part 6


I forgot to put particle board on the back side of the bench when it was accessible. When I put something in the vise and gave it a good shove to the left, the bench racked to that side. Since it was now too heavy to roll, I had to crawl under the bench and reinforce it from the inside. It would have been much easier to do from the outside when I had the chance, but now the bench is rigid.

Dave recommends making the drawers shallow enough to arrange the contents in a single layer. If you have to dig through your drawers, you are doing it wrong. I started with a drawer for layout tools. For a drawer this shallow, lath was just the right dimensions. I used salvaged hardboard panelling for the bottom. I followed the directions at Build Basic. Because the drawer was shallow and the lath was thin, I glued everything together without hardware, so I didn't need pocket holes. I used 4" Square Electrical Junction Boxes and 1" Metal Spring Clamps to clamp the corners square for gluing. Checking with a machinist's square, I found the boxes remarkably accurate. Be sure to check each one, though. I did find a few that were a little off.




The problem with designing storage to exactly fit your tools is that they often only fit one way. If you remove tools and open and close the drawer a few times, the contents can slide, roll, or shuffle enough that you can't put your tools back in without tidying the drawer. To prevent this, first I traced around each tool with a Sharpie, so I'd know where everything fit.





Then I cut dividers from Bamboo Skewers and glued them alongside each tool.
Next, I set out to organize my screwdrivers so the proper one for a given job would be right at hand. I realized I had several partial sets, and other screwdrivers acquired piecemeal over the years. I decided to start over with a complete set of all the sizes and types I was likely to need. I found what I was looking for at Harbor Freight.

I built a handy storage rack from scrap particle board. It took me longer to build than I care to admit, but I didn't take shop in high school, and it does the job.

I read about a rasp plane, and thought it might be the right tool for leveling / smoothing my bench top.


It has many fine teeth that each make a shaving between the size of sawdust and the shavings of a conventional plane. It doesn't catch on edges and irregularities like a conventional plane, and it appears that if one tooth is dull or damaged, the others cut just fine. When the teeth wear out, the entire set is replaced rather than sharpened. So far, it seems to be working better than a conventional plane, but it is still slow going. I'll work on it in odd moments, and report the results. I'll add more drawers and other storage as needed. Now I'm ready to return to the furnace and foundry.

The Workbench, Part 5

This was my only vise.
Looking back at Book 2, The Metal Lathe, I saw that the lathe was fixed to the bench by four bolts, which could also be used for  leveling. I realized that I didn't need a smooth bench top under the lathe, or even a level top, just a rigid one. I tried bolting my vise to the bench, and it worked just fine. I added a second vise and a bench grinder.
Now I have two.

When I added boards to the top, I lined them up against the wall. I figured this would keep the front and back edges relatively straight, and minimize the chances for things to fall behind the bench. I forgot that:

1. I had meant to have a 3 inch overhang in the front for clamping. Because there was a double layer of baseboard, (I have no idea why) my overhang was now in back.

2. I had meant to screw particle board to the back of the bench and extending a few inches above the top to make it rigid and serve as a backstop. There was no way I was going to roll it over now.

3. With the bench top against the wall, all vibrations would be transmitted to a partition we share with the neighbors. (I live in a duplex.)

Using a crowbar, I was able to move the bench about a half inch from the wall. That should reduce vibrations in the wall, but now I had a gap behind the bench, and nothing to keep small parts from rolling off. I laid a 2x4 along the back, but with such an uneven surface, I worried that some parts might be small enough to roll under the 2x4. I cut a groove with a circular saw, stood 1/4 x 2" lath in the groove, stood the 2x4 on edge behind it, and laid 1x2s flat behind that. I screwed the 1x2s to the bench, screwed the 2x4 to the 1x2s, and glued the lath to the 2x4. A complicated solution to a problem that could have been easily avoided.
The clamps are holding the lath in place while the glue dries.


I attached power strips to the 2x4, hung a shelf from the joists above the bench, and clamped reflector lamps ($6.47 each at Walmart) to the shelf.


It may look like I am overloading the circuit, but the power strips are rated for a full 15 A, I put LED bulbs in the lamps, so they only consume 15 watts each, and I only use one power tool at a time. The power strips are to save plugging and unplugging.

Monday, September 18, 2017

The Workbench, Part 4

Two views of the bench top:



The top boards were screwed to each other, but only attached to the rails at the ends, so the top could flex upward anywhere in the middle. Not good. I screwed it to the rails at intervals along the length with the longest screws I could find.

I was saving for a car, but I splurged and bought a plane.
I had planned to level flatten and level the bench top with a hand-held 3x21" belt sander. I bought the coursest belts I could find, 36 grit. The belts ripped almost immediately. I tried planing the surface. It took a little practice, but I learned to make those famous long, curly shavings. This was going to take a long time, and because the top was so uneven, it tended to nick the blade every time I passed over a low board and then hit a higher one. I had to keep taking the blade out and sharpening it.

Sunday, September 10, 2017

The Workbench, Part 3

Building the bench top was a long, tedious process. First, because the pallet boards were anything but straight, I had to test-fit each board against the preceding board in four possible orientations to find the best fit. Then I drilled pilot holes for the screws. Because the whole point of this massive top was to have a rigid base for mounting the lathe and other machine tools and the boards were 1.25" thick, I used 2.5" screws. This meant I had to stagger the screw locations to prevent the point one screw from running into the head of another.

I used two drills, one to drill the holes, and the other to drive the screws with a driver bit. In the foreground is a "sled" a movable work surface to set tools and materials on. It's a scrap of particle board with short lengths of 2x4 screwed to the underside on each end to keep it from sliding off the boards it rests on. It was especially helpful in the early stages of the process, when I hadn't built enough of the top to set anything on.
I had meant to take more pictures of this process, but it was so mind-numbingly boring, that I forgot. I wore out my drill bit early on. I had extra bits in a few common sizes, but not the right size for these screws. I thought I'd just buy a multi-pack of that size, which was how I'd acquired the spares I had, but nobody seemed to carry the size I needed, except in a complete set. I had actually bought a bench grinder and extra bits several months before, intending to practice sharpening them, but I couldn't master the physical skill. The bits always came out worse than when I started.

Monday, August 14, 2017

The Workbench, Part 2

The previous occupant divided our basement into mostly small, oddly-proportioned spaces. One space just off the laundry area is too narrow for most uses, so we use it for storage. I sorted through it, removed a lot of clutter, and consolidated the rest, freeing up a space 5 feet by 12 feet. I designed my workbench to fit this space.






First I constructed slide members, rectangular pieces that support the bench top and hold the drawer slides. I wanted them to be 30" x 33" but particle board wider than 18" is pretty rare in RTA furniture, so I built each member from an 18" piece and a 12" piece. The boards at the top and bottom are pallet boards 1.25" x 3.5".  I'll add the drawer slides later.






Since the back would go against the wall, I had to start with the front side down and attach the back rails first.
I hit on the idea of using concrete blocks both to square up the assembly and to space the slide members. That meant carrying 36 blocks down to the basement. Was I sore afterward! I haven't brought them back up the stairs yet. I wouldn't recommend this method, and I certainly wouldn't do it again. It worked, but the blocks are just too heavy.

Here is the bench with the back rails attached.
Then I had to roll the bench upright. I managed to do it alone, but it would have been much easier with a strong helper.
Then I squared up each slide member and screwed it to the lower front rail. That held it square while I attached the upper front rail.


Somehow, three of the slide members ended up too tall. I sanded two of them down, but the third was much taller. I tried cutting it down with my circular saw, but that didn't work very well.The best tool for the job turned out to be a wood chisel.


Here is the wood for the bench top. South Bend recommends that a bench top lathe be bolted to a wood bench with a top at least 2" thick. I'm using pallet boards on edge. Even after sanding it level the top will be about 3" thick. I think that's about as rigid as I can get with a wooden bench. I started the top Sunday afternoon. I'll finish it next weekend.

Monday, August 7, 2017

Other Gingery Build Blogs

I am obviously not the first to build projects from Dave Gingery's designs, nor the first to blog about it, thus the title of this blog. I've been looking at other people's build blogs and pages to learn from their experience. Here are some Gingery build blogs and pages I've found. If you know of others, please link them in the comments.

Morgan Demers has a thorough and well-organized blog covering a variety of topics. Scroll down to the bottom on the right-hand side to select a category. Most relevant are the Lathe Project and Metal Casting. Check out his YouTube channel here.

Makercise Youtube channel featuring Gingery Lathe and Shaper builds.

Terry Brown has a site about "Aluminum casting etc, Lathe & other shed-type things." Note the Foundry pages, and scroll down nearly to the bottom for the Gingery Shaper pages. (42 of them!)

A retired Australian Motor Mechanic with an interest in machining, PGS has been posting videos over the past six months (so far) detailing his progress on the Gingery Milling Machine.

Gingery Metal Shop Series a new playlist at Paul's Garage. He's made some interesting videos on other metal working and DIY topics. He plans to work through the whole series.

My Garage John Schwytzer's page: Workshop, My Charcoal Furnace,
The New Propane Furnace, The First Melt at My New Shop, Foundry Tools, How to Cast Parts, Casting Problems, Lathe, Change Gears, Shaper, Mill, Drill Press, Other Projects, Sundials.

Jason Harris has a page called miBot documenting his Gingery Charcoal Foundry Build, Casting the Base for the Gingery Milling Machine, Calculating Change Gears for Thread Cutting, and Building the HobbyCNC 4 Axis Stepper Driver. Unfortunately, it appears not to have been updated since 2007. (Update: Jason says he bought a mill and built the Gingery Atkinson Engine and Stirling Engine.)

Rick Sparber has a large number of useful articles on his Metal Working pages. Of particular interest are the articles listed under Foundry: My Hartman Electric Furnace, A Simple Controller for an Electric Furnace, Casting and Machining Parts for the Updated Gingery Metal Shaper, Gingery Drill Press, Foundry Procedures, Home Made Crucible and Tongs, Welding a broken Kanthal Heating Element, and A Variable Volumn Flask. The articles under Plastic Injection Molding are about building and using Vince Gingery's Plastic Injection Molding MachineMachining contains a huge number of articles divided into 14 subtopics. Note A Thrown Together Sheet Metal Finger Brake, which is similar to  Dave Gingery's Sheet Metal Brake, and a series of articles about the Gingery Shaper. All articles are in pdf, so you can download them for further reference.

http://www.backyardmetalcasting.com/index.html a huge treasury of information. Seven furnace designs. Flasks, Refractories, and Crucibles. Casting Brass and Bronze. Melting Iron. Charcoal vs. Propane vs. Waste (Cooking) Oil vs. (Used) Motor Oil as Fuel. And, of course, his Lathe Build.

http://www.myheap.com/ Joe Hildreth's project pages. He covers such a wide range of topics, I found his Site Map most helpful.

Jim Builds a Lathe.

Bill's Home-Built Gingery Metal Lathe, and Fun with Molten Metal!

http://sourpuss.net/projects/lathe/ Click on each photo for details on that part of the project. Also note Blacksmithing pages at http://sourpuss.net/projects/forge/

Brian's Metal Casting Project

Not a blog, but forum thread where xlchainsaw describes in great detail his castings for the Gingery lathe, and then how he changed his mind and converted a wood lathe to turn metal.






Saturday, July 22, 2017

The Workbench, Part 1

I designed a workbench based on the plans in Uncle Dave Gingery's Shop Notebook, but adapted to the space and materials I had available. Dave used plywood for the "slide members"—the ends of the storage area under the bench that brace the legs and hold the drawer slides—but why buy materials when free materials will do the job just as well?

In my neighborhood, people buy a lot of ready-to-assemble particle board furniture. It's designed to not be repaired, so when one part breaks, they drag the whole thing to the curb. There's usually not much damage—one or two broken panels, maybe a caster, a drawer pull, or some other piece of hardware broken off—and the other panels almost like new. Perfect for building something, just not the same thing. Apparently they can afford to keep replacing their furniture, and most of them don't mind my picking up their cast-off pieces. Sometimes they even help me load them. So I have free pallets, free particle board, and occasional pieces of dimensional lumber people put out with the trash.

I was cutting slide members from free particle board, but my cuts with a circular saw weren't very straight, and my miter saw only has 8 inches of travel. Add the portion of the blade that extends into the slot in the table, and you can make a cut of about 13 inches—fine for cross-cutting shelves or dimensional lumber, but rather limited for cutting large rectangles of panel products. I don't have money or space for a table saw, and I wouldn't use it all that often anyway. While looking at panel saws, track saws, and various DIY options on the web, I found this:

http://www.sawmillcreek.org/showthread.php?141564-Diy-track-saw

The two boards on top guide the circular saw, the hardboard indicates the exact location of the cut and width of the kerf, and the bottom two boards provide an edge to hold the work perpendicular to the cut while holding everything together.

I sketched out some ideas based on what I had on hand and what I wanted to do. A 4 foot cutting length would handle anything up to a half sheet, more than enough for this project, but a set of shelves 6 feet tall turned up on a curb, so I used it. 

Front

Right Side

8 feet would be enough to cut full sheets, but if I ever need to do that, I can build another one. This jig / track / whatchamacallit stands against a wall in my shed, and fits through the doorway vertically. Since I use it outside, the panel I'm cutting can extend as far as it needs to in either direction.

I thought it would be good to post a CAD file. I read blueprints at work, but my last drafting experience was a paper and pencil class in 1990. Mwmkravchenko from Gingery Machines Main Group recommended starting with LibreCAD. So here's my first-ever CAD drawing: Track Saw. Let me know if you find errors.

ETA: I forgot to allow for the length of the shoe ahead of the blade so I could cut all the way to the bottom of the stock. I added a board 3" x 5/8 " x 30" as a spacer. I had assumed it would be easy to clamp the stock in place, but that didn't work very well. Wedging scraps of hardboard between the panel guides and the stock worked better.

Friday, July 7, 2017

...and the One Before That

Since my furnace was on hold due to weather, I decided I needed a proper work bench. All I had in my shed was a shelf (built by the previous occupant) that could barely hold itself up, let alone support any work. I'll need a sturdy bench to work on and to bolt the lathe to.

"Uncle" Dave to the rescue! "Uncle" Dave Gingery's Shop Notebook I contains a collection of projects and ideas he accumulated in his notebooks over the years, and includes workbench plans and a discussion of how best to adapt them to your needs that are well worth the price of the book.


The best kind of wood for this sort of project is free wood, and I can get broken pallets from work for free. I already had a circular saw I could make quick cuts (but not particularly straight cuts) with, and a miter saw I'd picked up at a too-good-to-pass-up sale price from Harbor Freight. But I was tired of propping my saw or my work on sawhorses or laying it out on the floor. Miter saw stands were expensive, and didn't look any more stable than sawhorses. It looked like I needed a workbench for building my workbench. I adapted Uncle Dave's workbench plans to fit my saw, my shed, and my pallets.





Here's the basic table. The base, legs, and top are salvaged pallet wood. The sides are fiberboard, and the drawer slides are 1x2s, both left over from another project. The pallets stacked next to the table provide an additional work surface and lumber storage. Salvaged pallet boards slide neatly into the space between the upper and lower surfaces of the pallets. I adjusted the height of the stack until I found the most comfortable working height for me—36 inches. Note that the table is lower than the pallet stack so the height of the saw's work surface will be equal with the pallets. There's another stack of pallets at the other end of the shelf for additional storage and to support especially long boards for cutting.




Dave's plans called for grooves in the sides, front, and back of the drawers to hold the drawer bottoms. I could set my saw to the proper depth for the grooves, but it didn't have enough travel to cut a groove the full length or width of the drawer. Jenn at Build Basic had the answer: 3/8 x 3/8 square dowels glued and nailed along the bottom edge of the sides, front, and back support the drawer bottom.

I used 1/2" finishing nails. Okay, call them "Bright Wire Brads". The important thing is that they're long enough to hold the dowels in place, at least until the glue dries, but short enough they don't come through the other side of the boards.



I knew it was important to make the joints square, but I didn't know how. I tried improvising with Legos, but the results were not good.

Again, Jenn had the answer: "Simply place a block (make sure it has a truly square corner) into the corner and clamp it tightly to each side." I'll do that when I build the big bench.

Because my drawers weren't square, it took several tries to cut and fit each bottom. Next time, I'll use a framing square, like Jenn recommends. Note the sides extend beyond the back. That's Uncle Dave's idea, so you can pull the drawer out far enough to expose all the contents without dropping it on the floor.

The drawer front is taller and wider than the sides. It serves as a stop when you close the drawer.