Tractor from scrap yard finds.

Have you an battery powered lawn mower or kiddy car or anything that is not designed for the road, be it home made or bought, then this is a area for you
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Night Train
Posts: 350
Joined: Sat Jun 21, 2008 11:55 pm
Location: Manchester

Re: Tractor from scrap yard finds.

Postby Night Train » Mon Jul 19, 2010 5:05 pm

Managed a little more work today.

I welded in a bracket to hold the reversing contactor. I will need to sort out some sort of cover for it to protect the terminals from extraneous metal parts and dirt.
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I also figured where my feet would need to go to operate pedals and clamped a bit of bar under the chassis like bike foot pegs. The easiest way to weld it was to tip the tractor up on end. Fortunately it just fits with the front wheels removed.
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I extended the extraction to pull away the fumes while welding.
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I have also been working on the parking brake.
I am planning on using a length of V belt on the original drive pulley. One end will be anchored and the other end will wrap almost all the way round the pulley and then be fixed to the prake lever.
I need to figure a ratchet on it some how.

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Night Train
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Joined: Sat Jun 21, 2008 11:55 pm
Location: Manchester

Re: Tractor from scrap yard finds.

Postby Night Train » Tue Jul 20, 2010 11:14 pm

I spent a few hours in the workshop this evening, after getting a soaking in the rain earlier.
I started on wiring up the control circuit loom and the battery monitoring system.

I decided that I only really needed to be able to check the voltages of the pack and also the indivdual batteries to be able to tell what's going on to start with. So I got a cheap (free from my Dad's old stock) multimeter and a rotary 2 pole 6 way, break before make (very important that bit) switch.
I have a wire from each end of the pack and one from each link making five wires. That allows me to wire up the switch so that I have an off position, one position for each battery and the final one for the pack. The multimeter is connected to the switch and so I can check each battery voltage and the pack voltage in turn.
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I then made up a loom from the back of the tractor to the front. I decided to tape wrap the wires flat like ribbon cable. Easier for me to 'see' the loom.
At the back I have the connections for the reversing contactors and also the 'seat switch'. I might not have a seat switch a the seat won't have any movement in it but I figured that I would have the switch on the gear shift as a neutral lock out. I can always add the seat switch on series if I change my mind.
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At the controller I made my connections to the controller plug. The plug was a computor connector from Maplins with leads already connected. I soldered and sleaved the connections with heat shrink.
The loom then continues up to the dash for a reversing switch and the key switch.
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I did have an ON-OFF-ON switch somewhere but I seem to have misplaced it. I may just have to buy one.

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Night Train
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Joined: Sat Jun 21, 2008 11:55 pm
Location: Manchester

Re: Tractor from scrap yard finds.

Postby Night Train » Wed Jul 21, 2010 2:29 pm

I installed a makeshift dash today to hold the switches and fuses. It is very basic for now but allows me to resolve cable lengths and locations for stuff.

The dash holds a battery isolator with a low current switch on the back, a 300a fuse, the reversing switch and the battery monitoring switch.
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With it all connected up and a microswitch on the neutral lockout I was able to test the operation of the loom.
I jacked up the back end of the tractor so it didn't run across the workshop. :lol: I used the normally closed position on the microswitch to save holding it shut. The throttle is still the same slider pot used before.

Here is a video of how it is working with forward and reverse.
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I decided to take it off the stands and have a ride! :D

It works really well! Even though I am using a hand throttle, and I only had 2' of space to move in, it was fun going back and forth and steering it about on the floor!
I didn't take video as I needed both hands but definate EV grin as it is my first ride on my own EV build! :mrgreen:

Not having brakes yet I wanted to see what plug braking did so I connected it and had a go. I didn't notice much effect but I suppose only having 2' of driving space wouldn't allow much effect.
I think I will add the plug braking and a switch so that I can switch it in or out.

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ChrisB
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Re: Tractor from scrap yard finds.

Postby ChrisB » Wed Jul 21, 2010 9:19 pm

Nice work, its coming on really well 8)

I just knew you where going to say you took it for a little drive :lol: :lol:

ChrisB
I reject reality and substitute my own !!!!!!

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Night Train
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Location: Manchester

Re: Tractor from scrap yard finds.

Postby Night Train » Wed Jul 21, 2010 10:49 pm

I definately have an EV grin, Chris. :D

I eventually managed to figure a way to clamp my phone to a cupboard to shoot some video for a friend of mine, Jim, whos electric pulling tractors inspired me.

This is Jim's electric tractor:
http://www.youtube.com/watch?v=pQRQXGx_5Lg

This is my video for him:
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Night Train
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Location: Manchester

Re: Tractor from scrap yard finds.

Postby Night Train » Thu Jul 22, 2010 11:35 pm

I got the parking brake sorted out by using a bit of lateral thinking. Instead of trying to get a V belt to work on the original, but unused driven pulley I decided to have a lock bolt on the holes in the pulley centre.

I used a bit of springy flat bar with a bolt in it that locates on the holes and then fixed the bar to one of the transmission bolts. I then made a push pull shaft with a ramp on it to engage/disengage the bolt. A simple lever will move the shaft back and forth without the need for a ratchet or any other complex mechanisms.

Brake on:
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Brake off:
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I also started sorting out a gear lever linkage to connect to the gear knob that was under the seat.
I made use of a couple of holes on the side of the transmission case to mount a bracket and then made a crank to work the selector.
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The selector fork is a loose fit on the selector but trapped between the washers and the nut. The other end will have a push pull shaft to a lever.

I've not made the levers for either the parking brake or the gear shift as I am thinking of making them from wood. also I nned to have the seat position finalised before I can be sure that the levers will be accessible and not in the way.

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Night Train
Posts: 350
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Location: Manchester

Re: Tractor from scrap yard finds.

Postby Night Train » Fri Jul 23, 2010 11:22 pm

I made a parking brake lever.

Brake off:
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Brake on:
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It works well enough to stop the tractor from rolling away but while playing I forgot to let off the brake before applying drive. The brake broke. The bolt in the pulley spokes was ripped out and the steel strap twisted all out of shape. I have now 'beefed' it up a lot but I might remake it in my usual 6mm steel. It will be fine for parking up though.

I also made the gear lever from some 20x2mm box tube.
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The link is a bit of 5mm rod that I had spare. I formed eyes into the ends to fit the M8 bolts.

Trying it out I found that the curved part of the lever was rubbing the back of my knee while sitting so I adjusted it.
I shortened the rod and put a twist into the lever so it is further back.
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The next thing was to make the brake pedal. That was more my usual over the top and over engineered part. :lol:
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I still need to make a bracket for the master cylinder and also I will need to bend the crank lever over a bit as the cyclinder is a little close to the edge of the pedal.

This is how it all looks from the driver's seat (excuse the view between my legs! :shock: ).
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You can see how the brake pedal fits in
The gear lever, to the right, is forward for low gear. High gear is only a 1 1/2" backwards.

I also have this master cylinder.
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It will sit low between the chassis rails and have a conventional hand brake lever over it. It will be plumbed in line with the foot brake working on the same hydraulic line so I won't leave it on when parked over night, the bolt in the pulley spokes will surfice for that.

I also tried the MR2 throttle pot.
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It works but, like the slider pot, seems to have a dead area over the first 1/4 to 1/3 of the action. I am begining to wonder if it is controller programming.
Reading the manual I can see that I can reprogramme it with a £450 programmer or by manual methods with the flashing LED. However, it doesn't say how.

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Night Train
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Location: Manchester

Re: Tractor from scrap yard finds.

Postby Night Train » Sat Jul 24, 2010 10:58 pm

I also had a rethink on the brakes today. I spent most of the day 'stock taking' my steel to see how much 'stuff' I have left to use and then how best to make a dual pedal set up.

So I came up with this.
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Night Train
Posts: 350
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Location: Manchester

Re: Tractor from scrap yard finds.

Postby Night Train » Mon Aug 02, 2010 11:36 pm

Things have moved on a bit.

I now have a throttle pedal. It is from a Land Rover Deender TD5.
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I have finally stripped the tractor back down to it's components for painting. I have opted for satin black on red oxide. Unfortunately, now that the tractor has been taken outside piece at a time I can see where the red still shows through the black and there are definate 'holes' in the black paint so it will need repainting to cover those and the chips and scrapes from building it up again.

So now it is outside and I have the brakes on it.
The pipes are stainless braided flexibles in red sleeve made up for me by david at Llama 4x4.
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The red goes with the red calipers.
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So here she is.
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I added my retro voltmeter to the temporary dash.
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I will need to try and find a 350A ammeter to match.

I also put some 'carrots' on the controller terminals.
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It now lives in my carpeted furniture moving trailer. Looks made to measure.
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The only snag is that the brake pedal is too hard to press. I will need to change the effective lever ratio on the pedal. It has worked out at around 2:1 and I need to change it to somewhere nearer 5:1 or better at 8:1.
Then I need to get on with making the wooden seat and body shell for it incorporating all the lighting.

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Night Train
Posts: 350
Joined: Sat Jun 21, 2008 11:55 pm
Location: Manchester

Re: Tractor from scrap yard finds.

Postby Night Train » Wed Aug 04, 2010 11:13 pm

To solve the brake problem I decided to combine shortening the lever at the cylinder end and then adding a second link as a multiplier.
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You can see from the other side that the lever from the pedal pivot is now very short and that now works on an adjustable pull rod onto a 2:1 lever pivoted on a frame bolted above the master cylinders.
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The return springs are a big snug but it shouldn't be too much of a problem.
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I also decided to tackle the throttle pedal. A bit of loom and a plug arrived for it today. I tried it but nothing happened and the controller flashes throttle fault.

I removed the throttle and checked the readings again. After a few more trys and checks I discovered that my £1.99 multimeter that was Dad's left over stock wasn't reading right.
I had to set it to 20k and it quite happily read something low and flickery at one end and 5.6k at the other end. What I didn't realise was that it didn't read low ohms accurately unless I then switched it down to 200ohms and the 20ohms.
Testing with my quality DMM it told me that it was about 2k to 5.7k so no good.

I toyed wi thte idea of doing something else with the pedal and the MR2 throttle TPS but then decided that as the TD5 pot was scrap I might as well open it up and have a look inside.
It has 3 resistance tracks, three wiper tracks, three wipers and three resistances.
I found one track that was 5k, great. Unfortunately the only way it was connected to the pins was via a wiper track that had a 2k resistance in line.
I decided to 'hotwire' it and so I soldered a wire from the pin to the wiper.
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I then checked it and found that the pedal at rest didn't allow the wiper to hit zero so I set about adding more range of movement both inside the pot and in the pedal.
I had to grind away a bit of the pedal so that it stopped higher when the pot read zero.
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Great stuff. I now have a 5k throttle pot that goes from zero!
I put it back on the tractor and...

...Still no go.
Long story short, with a lot of messing about and fine tuning I discovered that I had rebuilt the pot to work from 0-5k and the controller wants 5k-0.

So I had another play with the insides of the pot and manage to get a set of connections that allows me to have 5k-0. Of course, now the pedal didn't have enough travel at the other end of the pot. It means that I now have 5k-0.7k so I can't get full throttle.
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So the following morning, having finished working on it at midnight, I sorted out the throttle finally and fitted it.
It works great!

The snag now is that there is no activity from the controller for the first 20mm of pedal travel. So I reworked the pedal to remove the excess travel and measure the pot resistance. It was 4.7k so I have set the pedal to start from 4.75k.
I now have an almost instant throttle response.

The only thing left is to fit a hand brake lever and to make some ramps for the back of the trailer so I can get the tractor back out again! Then I can start on the body work.


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