# Maintenance truck ( Gator ? )



## Andy.Baloo (Aug 11, 2012)

right l suppose l need to show the intended use to able to discuss axle layout suspension etc,

l have a corner of the field that l set aside to plant a wood, l wanted to buy one but couldent afford one so l thought l would build my own 
its at the bottom of the field and hence is always the wettest bit, good for watering the trees but the ground is always soggy, l have tried using a suzuki vitara cut down to a pick up but its still too heavy or the tyres are too narrow which ever way you want to look at it and it sinks and leaves ruts in the track, l cant get wider wheels on the suzuki as they foul the bodywork/bulkhead

this is what 1200 kg of suzuki does to the track unless its bone dry









so l want to build a truck that is half the weight and with much wider wheels to reduce the ground pressure

given that most of the planting happens in dec.jan.feb which are the wettest months maybe l should consider 4 wheel drive or a 6x4 to spread the weight out better

the track that the truck will have to drive round is pretty smooth/flat but it does undulate a bit, here's some pics























































so you can see it dosent need to be 4 wheel drive to get across rough ground more to get traction on wet grass up hill, 2 wheel may well be enough with an LSD axle ? but what l dont want to do is chew the ground up, ( l have a buggy for that  )


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## Woodsmith (Jun 5, 2008)

Depending on how soft it is under foot/wheel when it is wet I would consider 6 wheels to spread the load (also I have a thing about 6 wheel vehicles). It could be two axle with twin drive tyres but three axle could be better.

Alternatively, if you can get really wide floatation tyres that would also be good.

A single drive axle is easy but 4x4 isn't too difficult for you to manage.
6x6 or 6x4 with twin rear drive would be harder to do.


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## Andy.Baloo (Aug 11, 2012)

layout, 4x2 4x4 or 6x4 ?

if it was anything except 4x2 l would use a suzuki transfer box which would allow me to select 2 wheel drive only when the ground conditions allowed to reduce the drive line drag/losses, if it was 2 wheel drive l think l would feed the motor into a gearbox to give me a good spread of ranges, 15 or 20 mph would be plenty as a max speed

l have a pickup body of one of these 









its brand new and unused, came of a sandwich van conversion, shame not to use it but l think its 6' long which is what is me think about a 6x6, l really dont fancy chopping it down as it new and as it would look all wrong sticking out the back of a 4x2 its a case of make the truck longer ie 6x6 or make a new pick up bed from scratch,


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## Andy.Baloo (Aug 11, 2012)

the back axle or the first back axle if its 6x4 will be this l won on ebay for £10

http://www.ebay.co.uk/itm/180925402534?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

its a narrow axle of a mini back hoe, 4.8 LSD dana diff, being narrow it will allow me to fit some wide wheels and tyres the same as these on my mower project, it is also suzuki stud patten for the wheels








this axle when fitted with wheels will be what sets the width of the vehicle and influence the front axle choice be it driven or not


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## Andy.Baloo (Aug 11, 2012)

Woodsmith said:


> Depending on how soft it is under foot/wheel when it is wet I would consider 6 wheels to spread the load (also I have a thing about 6 wheel vehicles). It could be two axle with twin drive tyres but three axle could be better.
> 
> Alternatively, if you can get really wide floatation tyres that would also be good.
> 
> ...


hi Woody

l dont think l would attempt 6x6 or driving the 4 rear wheels due to the difficulties in getting the drive to both rear axles, hydraulic drive would work here ? 6x4 sounds like it might work though ?


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## Woodsmith (Jun 5, 2008)

6x4 with an undriven rear or mid axle would be easy and would spead the load, I reckon that would be a good starting point. The dead axle could be abandoned later if unnecessary.

I'm away at the mo with little internet access but I'll pop in when I can and 'stick my oar in'. ;-)


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## PStechPaul (May 1, 2012)

There was a thread on the tractor forum about a vehicle something like what you want: http://www.mytractorforum.com/showthread.php?t=218367&page=2

It showed a "dumper" that connected the front and rear axles in a unique way, and I think it also discussed locking the left and right wheels for absolute 4WD. Of course it would only work moving in a straight line, but it would eliminate any individual wheel slipping and causing ruts.

This may also be a good application for individual motor drive to each wheel. But you would need to construct a special controller to synchronize them.

Wider tires will probably always tear up the turf on sharp turns, so maybe having multiple narrower tires on each axle might work better if you can rig up a differential for all of them.

Crazy ideas, maybe, but perhaps food for thought..


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## Andy.Baloo (Aug 11, 2012)

hi thanks for the link, just having a read now

just waiting on a pal of mine before deciding which way l am going, he owns a scarp yard and buried under a mountain of aluminium is an electric airport tug that would have been used for towing dozens of baggage trollies around the airport, the batteries have been weighed in but the rest is there, should have pics of it in the next day or so, l would guess its very low geared to tow around several tons but l maybe able to alter that, to them its only worth its weight in scrap so if the motor is 100 kg then it will be less than £20, got to investigate it at that price 

l have been chewing over the suspension or lack of it 
do you think it would be ok with no suspension or no "sprung" suspension,
little tractors have the rear solid and a front that just flops left or right, the intended use is pretty much flat ground l was thinking it would be ok ??
l started off thinking about a 4 wheeler but soon decided that a 6 wheeler was way cooler lol
but as soon as you have 6 wheels traction goes down 

there are a few slight hills around my track which wouldent worry a 4 wheeler










but if l add in an extra axle with no suspension then l start lifting wheels
which depending on how l arrange the driven axles will cause me to lose 
drive










so..... l was thinking of a rocking arrangement on the back axles, with no springs ?? 
if l arrange the 2 rear axles so the diffs face each other l could make a subframe to lock them together as one unit with a pivot point through the chassis rail )which would be 4"x2" box section), l would be looking for about 4" of travel before the axle tube comes up and stops on the chassis with a rubber bump stop, if the 1st axle is coming up 4" then the rear must be going down 4" also, 8" would be plenty of travel ??











between the 2 rear axles on the subframe l was thinking of mounting a lada transfer gearbox to split the drive, this has a locking diff in it to enable to me feed both axles equally or leave open on flat ground to reduce bind, it also a has a 1 to 1 ratio or a 2 to 1 ratio which will no doubt be useful,
both rear axles will be these
http://www.ebay.co.uk/itm/221073413318?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

they are 4.88 ratio LSD diffs made by dana, they are narrow track and have the right stud patten for my flotation wheels/tyres, in fact thats what they were off, so if any of the 4 rear wheels are touching the floor then we should move










dose that sound like it will work ??

Andy


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## Woodsmith (Jun 5, 2008)

Hi Andy,
That rear bogie won't work unless you mounted every raise on the ground square on.

It has the same problem as a four wheel vehicle where the axles are rigidly fixed to the chassis. As soon as one of the four wheels lifts on a bump the weight is taken by that wheel and the diagonal one. The other two wheels would loose traction and spin. Even with the locked diff in the Tbox it wouldn't make any difference unless you welded the diffs in both axles as well.

We should get together and discuss 3 axle suspension layouts.
You could have a look at a system similar to the Scammell Pioneer/Explorer rear bogie. Some smaller 6 wheel road scrapers had the same layout.

The best set up would be a 4x4 layout. However, if you want 6x4 then leave the rear axle dead and have a system for raising it off the ground. You could pivot the frame like a GamaGoat.





I noticed in your 'shed' photos that there is a 6x6 Argocat.
Have you seen the AMPhibian thread by JRP3?
Could you use that?


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## Andy.Baloo (Aug 11, 2012)

hi Woody

l could quite fancy a gama goat  but l would need one with a rollcage 

l was relying on a couple of things with my rear suspension, its a works truck and not an offroader so shouldent see to severe ground conditions 
as the track has been graded with an excavator to keep thing smoothish and all the gradients are approached head on and also l was hoping the LSDs in the axles would transmit the drive even if 2 wheels are off the ground,

perhaps linking the 2 rear axles with a leaf spring like my praga might help out, but then l would have to add in control arms to keep the axles upright
http://www.youtube.com/watch?v=qd6j-hHzc6M&feature=plcp

not to sure what l am doing up front yet might have that driven as well, was looking at a suzuki vitara chassis and thinking about using the first 5' of that, it gives me suspension, steering and an alliminium diff all neatly package in a 4"x2" box section chassis that would be easy to cut down and then extend the back along over the axles with some more 4"x2" box










l could certainty use this rolling chassis as a test bed for the rear suspension and try out different designs using the petrol engine and box thats still in it  ??


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## Woodsmith (Jun 5, 2008)

The Suzuki front end would certainly make the build quicker, easier and more effective.

For the back end you could use twin inverted leaf springs on each side to control the axles.
Like a simple version of this.








Being light and off road use you could dispense with the axle gimbals and reaction arms and rely on the soft leaf springs to do the work. No need for swing shackles, just bolt the spring eye to tabs welded on the axle case.
Even just using a single spring each side and simple rubber bushed lower radius rods would work off road. Two pairs of these radius/track/tie rods off a scrap car would work.









On my 6x6 LR the leaf springs had rubbing blocks on the sides of the chassis to control lateral movement of the axles and relied on the spring twist to allow for cross articulation. Worked well enough even with 600lbin multileaf springs.


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## Andy.Baloo (Aug 11, 2012)

hey Woody you arnt near your lada transfer box are you ? or do you happen to know the distance across the output flanges ??

Andy


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## Woodsmith (Jun 5, 2008)

I can measure for you when I get home. 

Just in Bolton to see a man about a possible EV project car. He is late, apparently after 6pm means around 7.30-8.00. No point me going home, I might as well wait it out parked in a dark alley on a council estate with my car doors locked.


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## Andy.Baloo (Aug 11, 2012)

Woodsmith said:


> I can measure for you when I get home.
> 
> Just in Bolton to see a man about a possible EV project car. He is late, apparently after 6pm means around 7.30-8.00. No point me going home, I might as well wait it out parked in a dark alley on a council estate with my car doors locked.



lol, sounds a very nice location, if you dont mind measuring that would be great

Andy


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## Woodsmith (Jun 5, 2008)

Will do.

If I don't get back to you then I will probably be 'helping the Police with their enquiries'. 

I figure I probably look more suspicious then the estate does. lol!


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## Andy.Baloo (Aug 11, 2012)

l just mounted up a couple of wheels on the axle to see how wide they were and how much room l had between the tyres for a chassis  not much



















l have about 26" between the tyres and 1500mmm across the out side of the tyres, the front of a vitara with the same tyres on is 1800mm wide, l can reduce the front chassis by 300mm easy enough its just 2 crossmembers but l can kiss goodbuy to the front diff and any possibility of 6 wheel drive

on the rear axles the diff flange is 80mm behind the line of the tyres so that is 160mm plus what ever gap l leave between the tyres on the 2 axles say 100mm or so, it would be nice if the transfer box was around 265mm across the flanges to slot in nicely


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## Woodsmith (Jun 5, 2008)

Flange to flange on the Lada transfer box is 330mm, just for the record.

It was good to talk to you earlier, Andy, if there is anything else you need to know, feel free to ask.

I might have a new, and potentially very quick (quick as in conversion time, not Santa Pod time ), EV project if the bidding doesn't get too silly.....


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## Woodsmith (Jun 5, 2008)

I had a thought....

Fit your rear axles as close as you like to each other, and join the drive pinions with a short propshaft to allow for any flex between them.

Get a chain sprocket and sandwich it between the prop uj and one of the pinion flanges. Machine as required to fit.

Weld a bracket, and bolt, on top of the diff, or to one side on the axle tube, a couple of bearing blocks. Fit a jack shaft with a sprocket on one end to match the one on the pinion, and a prop shaft flange on the other end. 

Both sprockets can be 3/4" pitch motorbike sprockets or you can get a nice taper lock one to go on the home made jack shaft.
The sprockets can be the same number of teeth or you can vary them to match the front axle ratio or to allow for a smaller front tyre diameter.

Drive that with a propshaft from the transfer box and then think about a drive to the front axle!


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## Woodsmith (Jun 5, 2008)

Oh, here's a link to that used lithium pack I found on Ebay that I was telling you about.
http://www.ebay.co.uk/itm/320983482231?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649


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## Andy.Baloo (Aug 11, 2012)

thanks woody

l think the batteries should be the last thing l buy 


the axles l have were originally for hydraulic drive with a motor bolted on the front like this



















the upshot of this is that they have some serious bolt holes around the front lip where the drive flange is










what l was pondering is making a "connector" like my sketch that will bolt the 2 axles together with the flanges facing each other










once the axles are locked together l can drop a transfer box between the flanges that will mount/bolt to the connector, l am considering going back to a suzuki sj transfer box as its narrower between the flanges and will allow me to mount the axle together with the wheels nearly touching, also as it selects 2 or 4 wheel drive l can have both or only one rear axle driving, it also has the bonus that it has a transmission brake on it which will work fine for my parking brake as l wasent planning on putting brakes on the rear axles 









only got one axle here at the moment but will bring another home to play with tomorrow


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## Woodsmith (Jun 5, 2008)

You could reuse the disc transmission brake from the hydraulic set up. If not I'd be interested in it as I will need to make one for my tractor.

I like the good selection of bolt holes on the pinion housing.

I once figured on doing like wise with the old Rover axles as they had unboltable oil seal housings on the nose. Once the oil seal was removed it provided 6 bolt holes for bolting on a sealed drop gearbox to provide a drive to a third axle, or an additional reduction gear.


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## Andy.Baloo (Aug 11, 2012)

hi Woody

no problem l think there is a transmission brake under my bench from the last one of these axles l used, l am more than happy to donate it to a tractor project lol,


l was wondering what l would do if/when the batteries run flat given that there is no mains power on site, l envisaged driving it onto the back of my transit and taking it home to charge, if the batts are flat clearly l cant drive it on, so l was pondering a small single or twin cylinder diesel engine that could be started and use to move it back to the truck, are there dual power source project on here, out there ?


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## Andy.Baloo (Aug 11, 2012)

well it would seem the old airport tug is coming my way for me to strip but they are saying 2 weeks or so before that can drop it off, l can almost guarentee that will double to 4 or even 6 weeks from past experience so l think l am going to try a simpler project to ease myself in a bit at a time 

l was thinking of a stand up 3 wheel scooter thingy....................

Andy


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## Woodsmith (Jun 5, 2008)

Andy.Baloo said:


> hi Woody
> 
> no problem l think there is a transmission brake under my bench from the last one of these axles l used, l am more than happy to donate it to a tractor project lol,
> 
> ...


Cheers Andy, I will need to pop down soon ish, doing a delivery, it would be good to meet up.

I would say the easy way to get the vehicle back onto the truck would be:
a) drive it up
b) winch it up with a hand winch.

The batteries should not be flat. If they are so flat you can't reload the vehicle then you have damaged them.
You should, with lead acid batteries, not use more then 50% DOD (depth of discharge) so there is always at least 50% of the charge left before you call it a day and recharge it.

Failing that, I would get one of those hand winches (or an electric one) to haul it on board.


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