More metalwork.

March 19th, 2013

Right, where did I get to. I’ve been doing a lot the last few days so it is hard to remember everything.

I finished off the drivers side floor. It needed a little bit of doming to fit over the steering box. Joss visited and pointed out it would have been nice to dome it a lot more and have less of a cut out but I have no more steel so will need to do that later. This panel is removable (the passenger side is spot welded in) so I can replace it later on if I want.

IMG_3581_1 IMG_3590_1 Driver side floor.

I went to help Joss with some rolling for the panels on his car. The sides are 8 feet long so a bit much for one person to manage. We rolled them so they will fit the side of the car more easily. The top panels are also being made and this week things should be welded together. I’ll pop down to see the progress tomorrow or Thursday.

20130317_161819 Slip rollers.

While there I made use of some punches and made my felt washers for the brake cross shaft.

IMG_3592_1 Cross shaft washers.

Back at my place Joss offered to get the steel for my transmission tunnel and bend it as he was going to be going past that way on Monday. He also showed me how to make the curve in the firewall to make a depression where the bonnet hinge will sit. Basically you just hit it with a hammer appropriately to shift where the flange folds over.  Joss did most of the work and I trimmed it and tidied it up later with a hammer and dolly. The stick shows where the bonnet hinge would go.

IMG_3593_1 IMG_3596_1 Hinge depression.

The other night I worked on my wobbly brake pedal. You’ll remember that the hold in the pedal arm was rather bell-mouthed so the pedal was very wobbly in the shaft. I looked in my metal bits box and found a piece of brass modelling tube about the right size. It was actually a nice fit inside the pedal arm (the tube is imperial sized and I assume the brake pivot is also).

First I had to weld the pedal together. It needs to be shortened because the steering box that it fits through is raised up on a wedge so the pedal is therefore an inch or so too high. I cut the pedal in half then welded it back together. Of course this weld needs to be strong and not fail so I did it in the following way Joss suggested.

You first make sure the ends are square and meet nicely. Then on one side you file a deep V groove, going down just past half way into the metal. This is then clamped to the welding table. Two pieces of scrap are put either side of the join and everything clamped down. I pushed the two ends together after this photo was taken so there was no gap in the middle.

IMG_3597_2 Welding pedal arm.

You start the weld bead on the scrap and run right across the V making sure you fill it in nicely. I did three passes. Once that weld has cooled you can file and sand it smooth. Then you turn the arm over and do the same on the other side. When you file the V, again going past half way, you end up filing into the weld you just made. But doing this when you weld this side you can be sure you have a strong weld with the two welds joining each other with no gap in between to cause a weak point. The welds are then filed smooth. I also welded up and re-drilled the hole for the clevis pin.

To fit the brass bush all I had to do was machine the ends square and then epoxy it into the arm. I use a Loctite steel epoxy designed for repairing worn shafts and made sure I roughened the outside of the bush before inserting it into place.  Once the epoxy was dry (I left it a day) I drilled though the oil hole into the brass bush. I then had to machine a small mount off the pivot bolt itself to make it round again and so it was a nice sliding fit inside the bush.

IMG_3602_1 IMG_3605_1 Brake pedal bush.

I also had to machine up a washer to take up the sideways gap between the pedal arm and the nut on the end of the mounting shaft. This shim washer needed a little filing but now I have a nice, smoothly moving pedal with no sideways movement.

Joss bought back my transmission tunnel folded and over length so I can trim it to fit. Tonight I trimmed the rear firewall so the tunnel fits through it. I will then bend up flanges on the ends of the tunnel that will bolt up against the inside of the rear firewall.

IMG_3609_1 Transmission tunnel.

I also remade the front part of the tunnel where the handbrake lever pokes through. I had made two mistakes on that. The first was making the slot so that the panel lines up in the middle of the car. On real Austins this cover is actually slightly wider than the transmission tunnel and offset to the right a little. The right hand side of it is folded over about 1/4 to 1/2  of an inch or so to fill the gap between the cover and the tunnel. On the left hand side it fits up tight against the transmission tunnel.

The second mistake was I made the slot too long. I made it based on the total throw of the handbrake lever. But I don’t have a brake cable attached and it occurred to me later that with the braked all hooked up the lever won’t come back all the way. I posted to the forum to find out how long the slot actually is on a Ruby (6 inches) and made a new cover to that measurement. Again I used my previous messed up transmission tunnel.

IMG_3608_1 Front transmission tunnel.

I also made the slot narrower now I know the trick of having a half moon filed in the side of it to allow the handle to pass through! Still to do is the cut-outs for the speedometer drive cable and folding over the rear right vertical flange.

I previously also made up the small panel that fits over the top over the top of the gearbox. This is a simple flat piece with a curve to clear the flywheel cover and a flange on the top to hook over the bottom edge of the firewall. Here it is held with tape but a couple of small screws will hold it in place eventually.

IMG_3589_2 Tunnel cover.

The other thing I did in the weekend was turn over the speedometer drive on the rear of the gearbox. I will be rebuilding the box but needed to do this so I can see where to make the hole for the cable in the cover.

To get the cover off you must remove the flange. I tapped back the lock washer then used an air impact driver to undo the nut. I find this easier than trying to lock the box and undo it manually. With the air driver you don’t need to lock anything. The impact action removes the nut easily. The cover with the drive on it can then be removed and rotated 180 degrees. There is already an oil way in the cover to allow this although I did find that two of the bolt holes didn’t line up with the threaded holes in the box so the holes in the cover might need a slight filing.

IMG_3571_1 IMG_3572_1 IMG_3574_1

Speedometer drive.

With the drive turned around the cable can exit upwards through a slot in the front transmission tunnel piece.

Tonight I did something I have been wanting to try for ages – weighing the car. I’ve been talking to Nigel (http://nigelhamlinwright.wordpress.com/) about the weight of his Austin 7 and was wondering about mine.

Today I went and got four cheap (very it turned out) scales and decided to measure each corner of my car to find out.

IMG_3606_1 IMG_3613_1 Weighing the car.

Basically you have the car very level on a flat floor and put a scale under each wheel. This gives you the corner weights. You add those up to get the total weight. Now these are cheap scales and my old garage floor is far from level but this would give me a quick, cheap idea.

I got LF = 66kg, LR = 65kg, RF = 73kg and RR = 76kg. Total then so far is 280kg.

That’s with an empty crankcase, block and head but with a full gearbox in place. There is no skin on the car yet of course. Nor seats, fly-screen, engine ancillaries, drive shaft, radiator, battery, fuel tank, rear shocks, exhaust, fluids, instrument panel, gauges, switches, boiled sweets in the glove box, etc, etc.

I really should do it again on the flat floor of my other garage but these scales are so cheap and nasty one of then got killed when I moved the car off them. I dropped a wheel down on it a bit quickly and it ended up stripping the teeth of the little gear on the pointer. It’s all muck metal inside so not surprising. I can still use the others and just block up one wheel so the car is level on the others if I want to measure it again later.

And someone didn’t believe me I could measure it this way!

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