Friday, December 22, 2017

Finishing the batterybox.

Today being another fine day and another work free day (the children are on holiday so I don’t have a school bus run to make), I worked more on my battery holder. First order of the day was to put a final coat of white paint on my holder then while that was drying to weld the other end onto my securing bracket.

I was down to my last 6011 1/16th welding rods but they lasted and I not only completed the welding but tideied up the mess made by my 3/32 rods. My arc welder is very good but it only gets on well with 1/16th welding rods. Anything ticker just becomes a blobby mess.
I’ve just ground the blobbiness of my top welds into flatness as they will be sitting on top of the battery and my aim is as with the underside to be as gentle on the battery as possible. I know batteries are tough but it still pays to be gentle. Now some have asked me why I’m not supporting the middle of the battery. The answer there is I don’t feel on a battery that small that it’s necessary and if the battery does leak then I’d rather it leaked onto the road than inside a container and corroded my container.

The plan today is to install the self-resetting breaker on my battery box and to complete the construction. There is a plan to secure the battery using the bracket I’ve just welded and primed. After that I’ll try to install the battery housing under the bus and try to secure the battery in place. That’ll leave me open to install the wiring.
Out of curiosity I put the cage I’ve built onto my scales and it seems to weigh a shade under 10lbs. The battery (which according to the spec sheet weighs 20lbs) also weighed 20lbs so I know the scales are right. For fun I put my original battery base onto the scales and that also came in at 10lbs. That base would have needed extra steel and would therefore have probably come in at around 30lbs or maybe more.

The bolts I’m using to secure the cage to the ribs are 5/16th grade 8. Now I’m not 100% sure what the grade 8 means but according to a data sheet I pulled up, each bolt has a tension capability of 8050lbs and a shear capability of 6980lbs. Combined, the 8 bolts should be able to hold 64,400lbs or over twice the fully laden (27,500lbs) weight of my bus. I don’t think my battery is going to drop off anytime soon. The weakest points are the ribs (which hold the body to the chassis) and the welds on my cage (which aren’t going to break anytime soon). The maths says this is going to work.

My concern about the heavier cage was more related to my ability to lift the blessed thing and support it while bolting it in place. I may be superhuman but I’m not a weightlifter and these days my flying capabilities are limited to downwards flying (with gravity assist).

As usual, I then got side-tracked. I have been aware through this whole project how I need a better work bench and so on. I found some steel angle that would be ideal for the task and set about welding it together to be a workbench. 
I had nothing but problems. I used 6011 rods that will weld galvanized steel and will cut through paint but I only had 3/32 rods remaining so the end result was a very difficult welding session in which I managed to make one weld hold and the work moved when I was welding. Thus, the end result was nothing as I have to cut the weld off and start again. It’s looking like I need to head to the store to buy more welding rods!

The plan with the bench is that since all the steel is pre-cut (from an old abandoned project) to build a two legged bench (the welds will be sufficient for that) about 4 feet long and about waist high. I don’t need to cut any steel at all. It’s all been done before. It’s not going to be massively strong but it’ll be sufficient for most needs. I won’t put an actual top on it though I could quite easily weld some steel from one of the abandoned appliances to make a flat top. The advantage of the open structure is things can be clamped to it using ordinary G clamps.

After a while I remembered I had some 1/16 7014 rods. Letting those linger would burn off any paint or zinc so I retrieved them and had a go. By the time darkness fell with its usual thud, I’d completed a functioning work bench. That left me with another problem. Because the bench is much neater and takes up less space than the two saw horses I had been using, the detritus of 3 years working on my bus is now visible. I’ll have to clean the yard up some.
I never got as far as installing the breaker on my battery holder nor the holes in the now painted battery bracket. I didn’t even get anything done as far as my side project of putting wires onto one of the LED panels. There’s always tomorrow though. I fully expect I’ll be working on the bus even on Christmas Day!

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