Hal The Van

[WVvan]

Thanks guys,
To vent the box I'm planning on making a "airtight" top then use a hose to vent the highest point of the top out the side of the van. Since hydrogen is lighter than air the van wall end of the hose will be higher than the battery box end.
The battery box sits under the bed so I have a height limit of 12". This makes it tricky because the battery height, to the top of the terminal screw, is 11".

Dave

[WVvan]

Battery Box continued :

While the glue was setting I realized that the board I inserted in the middle to counteract the bowing should be a permanent addition. Since it was too late in the build process to use biscuits I instead used glue and screws to secure it in place.


Now to the end pieces. My idea for securing the box in the van will be to bolt it to/through the floor. These end pieces will be where the bolts go. The blocks have a 1-1/2" square cross section.


Glue and screw the blocks into place.


I put four screws through the box base and four more through the side of the box into the end blocks. These screws are placed so none are in the center since that is where the bolt will go.


Since these are six volt batteries I will be hooking them together in pairs. The cables from each pair of batteries will exit the side of the box between the batteries about an inch from the bottom.


I need to transfer the location of the batteries inside the box to the outside of the box. Most people could just eyeball this and get it right but it's the kind of thing I usually mess up. So I created this from a nearby cardboard box.


Slid it down the side of the battery box and place against the side of a battery. Then just draw a pencil along the edge of the cardboard on the outside of the box. Do this for both pairs of batteries.


Now how big to make the holes? Here is an example of the cables I'll be using. This is a "0" gauge cable. When you talking about cable gauges, "0" is also written as "1/0" and pronounced as "one aught". Note that "1/0" is NOT the same as "1" gauge.


A quick lesson on cable sizes. American wire gauge (AWG) is the standardization system used for electrical cable. The AWG size is determined by the cross sectional area of the conductor. Excluding the four largest sizes, "0", "00", "000" and "0000" where "0000" is the largest, as the gauge number increase the wire diameter decreases in size. So a 10 gauge wire is thicker that a 14 gauge wire. This seemingly backwards numbering system originally referred to the number of times a wire had been drawn through a die which stretched out the wire making it longer and thinner. So the more trips through the die, the higher the gauge number and the thinner the wire. I always had trouble keeping the backward numbering straight until I read about it's original meaning.

The gauge will tell you the conductor size but not the size of the wire including insulation. In this case it's a little under 1/2".


So let's make the holes 1"x2".


Here's my method for making a square hole. Drill a hole in opposite corners of the square.


Use a saber saw to cut outward from the holes to create your square.


Paint on a primer layer.


continued -

[WVvan]

Battery Box continued:

Supplies: Ace Hardware:
T-nut 5/16 - 18 $.60 ea (2)
bolts 5/16x3" $.33 (2)
washers 5/16 $.07 (2)

Need something to keep the batteries from moving around in the box. I'll refer to them as hold-downs.
Sketch out a quick plan.


Cut it out of some scrap lumber. Because the divider I added to the box isn't dead center there is a 1/2" difference between these two.


Glue and screw together.


Place hold-downs on the battery. Then drill through the side of the box and through the base of the hold-down. Here I'm checking that the hole I've drilled matches the bolt.


On the inside-the-box end of the hold-down hole I'll add a T-nut. To install a T-nut you have to create a slightly larger hole than the size of the bolt. In this case the bolt is 5/16" and the T-nut requires a 3/8" hole. After you install the T-nut it's hammered in.


In this photo you can see the T-nut installed. These hold-downs would stop the batteries from jumping up but I want them more secure. Using left over rubber mat scrap from the van floor, cut out pieces for the hold-downs.


Secure the pieces with double sided tape onto the bottom side of the hold-downs top cross piece. The rubber will act as a cushion against the top of the batteries.


Since the added rubber causes the holes in the box and in the base no longer line up take the drill and enlarge the hole in the base downwards. Don't go deeper than around 3/4".


As the bolt is inserted through the side of the box it will enter the inclined part of the hole in the hold-down. Then as you rotate the head the threads on the other end draw the bolt farther into the hold-down. This causes the hold-down to tighten down on the top of the batteries. When the bolt gets to the T-nut it's tightened into place. Everything fits very snug.


This finishes up the base portion of the battery box.




And of course my every move is being watch by Project Foreman Tiger.
Also in the picture is Tiger's assistant Bob.

[WVvan]

Building an acrylic lid.

Now that the battery box base is completed, time to start on the top. These are lead-acid batteries so they will produce hydrogen as they are charged. Hydrogen is lighter than air so it will raise (see Hindenburg) but is also explosive so it needs to be vented outside (see Hindenburg). I'm gong to make a "airtight" acrylic lid for the battery box. As the hydrogen is produced it will rise to the top of the lid where it will be vented via a hose to the outside of the van.

I've never messed with acrylic before so this is a first for me. The only information I have on the subject I got from reading the Internet and through trial and error. You have been warned.

Supplies:
Lowes
acrylic sheet - 2' x 4' - $19.37

Tap Plastics - www.tapplastics.com
TAP Acrylic Cement (1 pt) - $11.50
IPS Weld-On 16 Cement (5 oz tube) - $6.75
Small BD-25/2 Hypo Applicator - $3.25

Start with a the sheet of acrylic.


Need to cut the acrylic so everything is at right angles and the edges are as smooth as I can make them. This requires extra careful set-up of the table saw to stop any side-to-side movement in the sheet. To keep the acrylic in place as I feed it through the table saw I made a feather board. You can see it to the left of the sheet.


The feather board has two purposes. It holds the sheet tight against the fence on the right side. It also prevents kick-back since it only allows the material to be moved in one direction. The saw blade is adjusted so it's just high enough to cut through the acrylic. I found that if you set it higher it can cause chipping.

After some work I had a bunch of acrylic pieces.


Even though I made careful cuts the edges are slightly rough.


Not having tried this before I'm not sure what level of roughness is allowable. To smooth this out 220 grit sandpaper is recommended. From what I've read you're not supposed to run sandpaper across the acrylic since that tends to round the edge. The preferred method is to run the acrylic across the sandpaper. With that in mind I wrapped a sheet of 220 grit around a scrap 2x4 and clamped it into the vice at the end of my worktable.


Then I'd carefully pull the acrylic pieces across the sandpaper being sure to keep them perpendicular to the sanding block to prevent rounding. I'd always use two hands but needed one to take the picture.


This step is fairly labor intensive. After some time I realized that this was going to take a while so I wised-up. I switched to 100 grit sandpaper and turned the 2x4 on it's side so I'd have a larger sanding area. I was always careful to make the block level.


After smoothing out the pieces with the 100 grit I'd switch to the 220 grit for the final finish.

Mistake Number 1. I'm sanding one piece at a time. If I'd been smart I'd clamped the two top pieces together and sanded them at the same time. I'll come back to this point.

After much work I got the edges just right on the pieces that needed it. Smooth edges are not required for all the pieces I'm using.

Clean the edges that will be glued with alcohol. This bottle shows how often I use rubbing alcohol. The local Phar-Mor closed in the 1990's.


I'm ready to glue the first two pieces together. The pieces need to be held steady while the glue sets so just using your hands is out of the question. Using some leftover metal parts, from the sofa-bed that I'm still building, arrange the pieces to stand on their own.


The vertical clamp is being used to keep some pressure on the edge to be glued.


Mistake Number 2. At this point I should have done a dry fit with the other pieces.

Moving on. Here is what I bought to glue together the acrylic sheets. A better description is solvent cement. It has all the usual warning labels along with it being a possible cancer causing agent. I don't think my exposure will be enough to worry about.


I'm going to use the glue in the white can. It has the consistency of water. Squeeze some air out of the plastic bottle and suck a little cement up. Not a lot is needed.


Here is the reason for all the work at getting the edges so smooth. Since this cement is water thin it doesn't fill any gaps. The parts you are gluing have to be in contact along their complete edge. I'm applying the cement via capillary action.

Here is the where the edge of the vertical acrylic piece rest on the side of another piece. Notice how the edge looks.The acrylic is about .2" thick.


This is the needle end of the applicator bottle. I'm squeezing out a little of the cement along the edge of the vertical acrylic piece and capillary action is drawing the cement into the space where the two pieces touch. The edge looks blue where the cement has been drawn in. This is the reason for all the careful sanding prep work. Without it this wouldn't work.


The directions said it sets up quickly but not to stress it for 24 hours. Not wanting to take any chances I let it sit.


continued -

[WVvan]

Acrylic lid continued:

It will be easier for me to describe what I'm doing if I include a diagram. This is a layout of all the pieces I've cut from the acrylic sheet.


This is a side view. Pieces "Top A" and "Top B" have a slight incline from the end pieces to where they meet in the middle. The high point in the middle is where the vent tube will be installed.


I had previously joined the edge of "Top A" to "Side A" using Weld-On #3 solvent cement and capillary action. This was my first try at joining acrylic and I was more than happy with the results. I let it set about a day then removed the clamps. The joint looked perfect and I stressed it without any problems.

Everything looked good until I started dry-fitting the other pieces. That's when my previous bone-headed mistakes came back to bite me. I should have known better.
In this picture "Top A" is joined to "Side A". I'm dry fitting "Top B" while "Side B" is just laying on the bench waiting for it's turn.


Mistake #2: I hadn't dry-fit the pieces before I started gluing. Now when dry-fitting "Top B" I find that it doesn't mate up against it's common edge with "Top A". Not even close.

With "Top A" already joined on one side my options on getting the two to mate as close as the Weld-On #3 required were limited. I used a new sanding station I just bought for this project but I could never get the two edges a tight as they needed to be.


But I had a backup plan. Considering ahead of time my skill level I had also ordered Weld-On #16. This was a thicker solvent cement with the ability to fill small gaps. It's not as thick as airplane glue but thicker than #3. Small warning. You don't squeeze it out of it's tube. It's thin enough that it just flows out.


That helps correct Mistake #2 but now I'm bitten by Mistake #1. When I was doing all the edge sanding on both Top pieces I should have clamped them together and sanded them as one piece. These two pieces started out the same size but with varying amounts of edge sanding they are now a different width. This becomes obvious when I dry fit "Side B" onto the edges of the two Top pieces. So back to the sanding board. I lucked out in the fact that "Top B" was wider so it was the one that needed sanded down. If it had been "Top A" that would have been a real hassle.

Get all my mistakes corrected and clamped together for more gluing.


Beside the squeeze bottle, a hypodermic needle comes in handy for applying the Weld-on #3. I don't know if all hypodermic needles are made from the same material but the one's I had laying around didn't react with the Weld-on #3 and worked fine.


Final step was to glue on the end pieces then do a test fit onto the top of the battery box.


Looks and fits OK.

Now to test it. I'll substitute a water-tight test for an air-tight test. I'll admit to wussing out at this point. If it failed the water test I'd have to wait till it dried out before I could fix it so I just went ahead and reinforced all seams with the Weld-on #16. Even the one's I thought I got just perfect.

Since the Weld-on #16 is runny I would tilt the box so that whatever seam I was treating would be the lowest point. After an hour the Weld-on #16 would set-up and I'd move to a different seam.


After all seams have set-up, fill with water.


Success! Not a single leak.


continued -

[WVvan]

Acrylic lid continued:

Supplies:
Lowes
nylon hose barb splicer - 5/8" x 5/8" - $1.41
Loctite Plastic Bonder - 20 Min -.85 Oz - $5.72

The battery box lid has been assembled and water tested.


Now add vent hose fitting.
Here are an assortment of parts for the venting system. Most of these I'll be using later. For the lid I'm using one of the 5/8" x 5/8" hose barbs.


Only need half of the fitting. Used a hacksaw to cut it.The fitting had a ring around the center to separate the two hoses that normally would have been attached. Cut it so all of that ring is on one half. I'll use that half and call the ring the base.


Need to find the diameter at the base.


Closer to 11/16" than 5/8"


Will use a 3/4" spade drill bit. Figure out the hole location. Ultra fine Sharpe works really well for marking on the acrylic. Cleans off with alcohol.
Choose the location just below where the two Top acrylic panels meet. This is the highest point so hydrogen gas will collect here.


Supported the lid from underneath with a piece of 2x4 to reduce the chance of cracking it as I drilled.




Maybe not dead center, but close enough.


Do a test fit of the hose barb. The barb is pushed through the hole from inside the lid. The barb base is up against the lid on the inside. Looks OK.


Here is what I'll be using to attach the hose barb to the lid. I've read that the if you use a slower setting epoxy the joints will be less brittle. That's why I'm using a 20 minute epoxy versus the 5 minute kind. Instructions recommend roughing up the acrylic with 220 grit sandpaper first, which I did.


Mix up the epoxy and apply liberally.


The connection between the acrylic lid and the hose barb has to be air tight. I used clamps with a piece of scrap wood to hold the base of the barb tight against the side of the acrylic lid. I put a piece of plastic shopping bag between the epoxy and the wood so the wood wouldn't also get stuck. I figured I could always just pick off pieces of the bag after it set up.


Let it sit more than 20 minutes. Then when I went to take off the clamps I found that the shopping bag hadn't stuck at all. It just fell right off. So either shopping bags don't stick to this epoxy or it had skinned over before I put the bag against it.

Looks OK. Let it sit overnight before I stressed it. No problems.


continued -

[WVvan]

Acrylic Lid continued:

Before adding hold-down straps I'm going to beef up the lid with some more supports. None of these might be needed but since this is my first work with acrylic I'll err on the side of caution.

Add an extra panel on each end. Since this panel fits flat against the panel next to it no need for the tedious edge sanding.


Mistake Number 1. When I first went to glue these together I used the squeeze bottle to cover the new panel with Weld-On #3 then leisurely held the panel against the lid to join them. WRONG.

Live and learn. From when the Weld-On #3 first hits the acrylic you have about two seconds to finish applying the glue and get the two pieces together. Not nearly enough time for a piece this big. No permanent harm. Clamp together the two pieces then use the capillary action method for applying the cement.


Did both ends.


Then add a brace across the middle of the lid at the location of the hose barb. Had to notch the end of the brace so it would fit over the end of the barb. In this picture the lid is upside-down. The brace doesn't go all the way to the top of the lid as so not to obstruct the airflow. Used tedious edge sanding on the brace before cementing.


The hold-down strap will be made from a bungee cord I had hanging around. Need to find it's diameter. It's close to 1/4 ".


So if its .25" and the acrylic is .2" thick then four pieces stacked together should give me a good base. Cut out the needed acrylic pieces from some scrap.


Glue together 2 pieces at a time. Since the pieces are so small the "apply Weld-On #3 on one side then slap the two pieces together" technique worked OK. The problem is that once the two pieces touch each other you have about an instant to get them properly aligned.


Next join two sets of two. Because of the quick setting nature of the cement I didn't get the blocks as even as I'd like. Here I'm about to sand a block to even the edges. This is just for looks. I'll be gluing it to the lid using the flat side, not the edge


Drill a hole through the middle for the bungee cord.


WARNING: As the drill bit exited the other side it grabbed the block and caused it to spin. This is apt to happen when drilling harder materials. I thought I had a good grip but not good enough. It spun around and gave me a right little knock on the fingers. Luckily No damage.


Cut bungee cord in two. Feed one cord through the block. Add a washer for extra support.


Fold over the top of the cord. Use three 4" cable ties to squeeze and hold closed the fold. Needle nose pliers work well at cinching up a small cable tie. Clip off excess tie ends. Do the same for other block.


Glue block to end of lid. One each end.


Add a screw hook to the base block. I've glued the bungee blocks an inch off center so the hooks won't be in the way of the bolt that should go through the center of the base block to secure the battery box to the van floor. The screw hook is where the bungee cord attaches to keep the lid shut.


Take the base outside and give it a couple coats of paint.


All done.




In this picture you can see Quality Control Engineer Bob checking where the lid meets the base to see if the closing tolerances are within agreed upon specifications. Either that or she smells fish.


Without the batteries weighted the box and lid with a bathroom scale.


And one battery.


23 + (4 x 64) = 279 pounds of house batteries.
Consider this the finish of the Battery Box build.

Next up is the sofa-bed build.
Here is a scale drawing of a small part of it.
The thing at the bottom is NOT a hand grenade but if I keep having as much trouble as the sofa-bed build is giving me it might get blown-up before it gets finished. Blown-up real good.

[WVvan]

A little housekeeping.
Once I saw this photo of the inside of my garage door I knew I needed to do a little housekeeping once the weather warmed up.


So today's work was some much needed painting.


While I had the paint out I noticed the work table could use a touch-up.


Never looked better.


PS.
Just now.
Final: West Virginia 73, Kentucky 66
We haven't been in the Final Four since Jerry West took us there in 1959.

[WVvan]

Had a slight problem in the sofa-bed build. My home built sliders didn't work out so I've ordered heavy duty drawer slides from a company called Schock Metal America. It's set backs like this why I haven't started a full write up on the sofa-bed build yet.

In the mean time here's a picture of the electric actuator installed.


And a full size mock up of the lifting mechanism for the sofa-bed back I just tested. All the measurements and clearances worked out perfect.


I have lost count of all the different versions of this mechanism I've dreamt up so far. Since this one literally came to me in a dream maybe it'll be the best.
Now to built it out of metal.

Because of the delay I gave my workforce the night off. Not exactly party animals.

[AndrewST]

Nice prototype of the lifting mecanism you made and thanks for the slider company, way looking for one.