workshop – Above it All

Right Wing Tank Work

Today I spent a lot of time deburring and dimpling the right wing tank skin, stiffeners, and associated parts. I also found that the DRDT-2 works better for screw hole dimpling than the pneumatic squeezer did, so I ran the left wing tank skin back through the screw hole dimpling process, and the holes now look much crisper.

I also got a very nice surprise when Mom and Tim showed up unannounced for a visit and gave me a great little chest that Tim made for me in his wood shop. I’m going to come up with a good use for it that will not damage it. Tim said I should keep it in the workshop but I want to make sure I don’t get it dirty or scratched or damaged in other ways. It really is a nice piece of craftsmanship!

It is made of wormy chestnut, which is really pretty. I think it is finished only with linseed oil. The aroma is very nice, and I like the natural finish.

He even signed and dedicated it!

I Love Used Tool Stores!

I came away with a great haul today from Hamilton Tools. I had been looking for a right angle threaded drill attachment and talked to the proprietor of HT a couple of weeks ago. He came up with an ATS attachment, looks well used, but there’s little backlash in the gears, it runs smoothly, and it came in at about 1/3 the cost of a new one.

I also found some good files–some very fine round and flat files as well as a 1/2″ Vixen and an aggressive 1″ Nicholson.

All in all it came out to $80 for the whole purchase. I love Hamilton Tool!

Workshop 99.9%

For a while I’ve wanted to restore some capabilities I used to have at the old house, namely metalworking tools that have been sidelined since we moved way back in ’14. I’ve been putting this off in favor of getting the workshop improved for winter operations. Now that the shop is properly insulated and heated, etc., I had the opportunity to move the machines back in and get them set up. Pretty much everything has been moved in and installed. There is some cleaning and final leveling and adjustment needed, but that will be on an as needed basis. Now that everything is moved in and warm, I can set the machines up at leisure.

First, I built a table to hold the lathe/mill. I soon remembered just how heavy this thing is, and needed to buy a shop crane to lift it into place (at the old place I installed a temporary overhead hanger for a chainfall, but I didn’t want to do that here). The lathe is now installed on its new table and mostly leveled. The table needs a bit of bracing to make it solid. I’ll tie it into the wall if it becomes an issue.

While I was buying the shop crane at Harbor Freight, I took advantage of their New Year’s Day 25% Off Sale and bought something that’s been on my “want” list for a while.

Now, of course, I needed a new table on which to mount the sheet metal machine. I decided that a single table to hold it and the mini mill was the best idea. I moved the credenza that used to support the drill press and some other tools to the far wall and installed the new table in its place, then lifted the machines up there and installed them.

This represents what I hope is the last bit of tool installation for the shop, and now I will have the capability to make small metal parts that may come in handy during the RV-10 build. My original plan had been to build a metal shop in the basement of the barn, but that was going to require pouring concrete and building a whole new set of walls. My primary project is now the RV-10, so that will have to wait for some time, maybe forever. But at the moment I’m pretty happy with the shop I’ve put together.

The main thing left to do is to install racks and hangers for the various completed aircraft parts that I want to store in the warm shop. I will probably end up bagging the rudder, vertical stabilizer, and elevators and storing them on the mezzanine with the horizontal stabilizer once they are fully complete. The tail cone will have to be bagged and stored on the main level of the barn. I don’t want to risk dropping or damaging it trying to lift it to the mezzanine.

Paint hood plus!

Today I modded the paint hood by placing the blower closer to the bottom plenum and got a much better air flow through it. The face velocity, while I wasn’t able to measure it directly, is quite substantial. I found that it works great for catching sanding dust when working on fiberglass fairings as well!

Small Part Paint “Hood”

I had an idea for a painting “hood” to capture vapors and paint overspray for use when priming and coating small parts. I’ve seen similar things before, and thought I could make my own rather cost-effectively. At first, I was going to build a frame from scratch, but I realized I had an old metal shelf unit sitting around that I wasn’t using, because the shelves were rather weak particle board.

I figured this could be the basis of my painting hood. I did some brief research on fume hoods and found that best practice for paint booths is a minimum face velocity of 150 ft/min (chemical lab hoods are typically designed for 100 ft/min, go figure…) For this shelf, the open top of which measures 18″ x 36″, the minimum flow required to achieve this face velocity would be 675 ACFM.

I hopped off to Harbor Freight and bought one of their 8″ ventilators (rated at 1590 CFM, pressure unspecified) and a flexible air duct. The 1590 ACFM should translate into a face velocity of 353 ft/min. Then, I headed over to Home Depot and bought some additional duct pieces and a cheap furnace filter.

I cut the bottom shelf (which was warped from water damage) to have an opening for the air filter to fit over. Then I duct taped the edges of the hole to provide a better sealing surface. The furnace filter was easily secured to this with duct tape. The furnace filter will operate at an air speed of 572 ft/min.

I had some duct tape and heavy (25 mil) plastic sheeting around. These, combined with the parts I had bought, and a small piece of scrap plywood, yielded this:

I then added a pressure tap and put my manometer to work. The differential pressure across a clean filter is almost negligible. I then covered the filter mostly with a piece of scrap plastic and the differential pressure across the occluded filter measures 0.52 inches of water column at the high speed setting on the ventilator. It will be interesting to see how much the filter changes from clean to dirty and how well it will work. I may have to use a more expensive filter rated for a smaller particle size for paint and primer.

With the dP confirmed, I then finished assembling the unit with more plastic and metallic duct tape. The screen on top should allow for even painting of even small parts.

The ventilator will soon be hooked up to an exhaust duct to pipe fumes out of the workshop. Next step would be to borrow a pitot tube from work that we use to balance dust collector duct work and measure the actual air velocities in the hood and the duct.

Workshop Progress

Well, due to a lot of other obligations, I haven’t really begun building the -10 in earnest yet. But that is about to change!

Part of the “other obligations” has been to improve the workshop so I can work in relative comfort year round, in order to hopefully reduce the total build time. This has involved lots of amateur carpentry, drywalling, electrical installation, and in general plenty of relatively satisfying work. I only have a few items left before I can start finishing the tail kit and order the wing kit.

Some highlights:

New large doors (for getting big pieces in and out of the shop–this will be the main exit for the fuselage once it is done)

Ceiling mounted utilities including compressed air and electricity. Plus, LOTS of LIGHT. 21 can lights to provide warm incandescent list (3 switched zones to save power) and banks of fluorescent tubes mounted in the ceiling corners to provide bright flooding light.

A whiteboard for lists, calculations, sketches, etc.

Looking toward the main work area

In general, the shop is now (or will soon be) warm, draft free, and almost outfitted for work. I have to finish the ceiling insulation, build some shelves, and move the lathe and mill in (that may be able to wait a bit) and things will be good to go.

brief update

I’ve been spending time this summer getting the workshop ready to go so I don’t freeze my butt off working on the RV-10 in the winter. Pics will follow once I’m substantially complete.

Also I have been working on finishing up the instrument rating. Once I have that in my pocket and the workshop is ready to go, it should be full steam ahead on the RV-10 construction (I expect some interruption in productivity due to the expected release of Fallout 4 in November).

Practice Project: Plans Binder

I figured I could use some practice with basic sheet metal techniques. While I took the EAA RV Assembly SportAir Workshop back in January (Thanks to all the folks at EAA and KFDK who made that happen!) and completed the Van’s airfoil practice kit, I still have a ways to go until I feel my driven rivets are good enough to fly. So, I figured I’d do a little work.

At the same time, I was looking for a proper 11×17″ binder to protect my plans, but when I looked at the prices at Staples and other office supply shops (including Amazon) I figured I could do better for less (the cost of a simple binder at Staples is ridiculous–well over $40 for a thin binder, and better ones get up near $70-80 each!).

So I figured I’d combine the two needs into one. I ended up with a sturdy, handmade binder made of 3003 aluminum sheet (0.040″). I obtained the aluminum sheet from Metal Supermarkets, which conveniently has a retail location a short drive from my office. The piano hinges were sourced at Home Depot, and the D-ring was cannibalized from an inexpensive 8-1/2 x 11″ binder. Total cost, approximately $40, but I got some valuable practice at riveting, drilling, countersinking, dimpling, and deburring.

I didn’t use the pre-drilled holes in the Home Depot hinges because they were simply too large for the rivets I wanted to use and larger rivets would have been a waste here. You can see variability in the degree of the shop head development because I was experimenting with different settings on the rivet gun. I decided not to re-do them simply to remind myself of the significant differences.

I back riveted the hinges to the spine and covers using a large stainless steel plate I happened to have lying around. I may polish the plate to get a better finish but this was acceptable for the purpose here.

A bonus to this binder is it is rigid enough to stand up and hold the plans properly without deforming the binder. I may add a clasp and a handle in the future, as well as possibly some holes for hanging hooks if I find that may be useful.

A time lapse of some workshop construction

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EAA Table+

Finished the first work table last night.

I added a 1.5″ lip all the way around for clamping, and built the top using 1/2″ plywood with a 3/4″ MDF tabletop. The plywood is glued on to make the table rigid, while the MDF is affixed with recessed screws.