Motors Project: home made buggy - UPDATED

So, finally got round to recycling a thoroughly written off VW polo. I suspended the engine and literally built the basic chassis around it, until it could be supported with tressels
the whole chassis is made frome recycled material - most from an old fence i took down (just doing my bit for the environment (total cost so far = £0))
First thing is to learn how to weld; after a bit of practise, it started to look like this so i figured i was allowed to start now


engine supported in chassis now


ch424 came round and helped do the front end; this is a steering axle held up ready for welding. there is a yellow oxide produced when the galvanised steel is welded - the zinc burning maybe?


This is me attaching a ring around the vertical axle which the hub rotates on. this holds the wheels on if they leave the ground (quite likely). the shocks are attached at the front aswell; a general view of the whole thing so far (a couple of days ago)


ch424 quickly grindind some angle iron; that grinder is imense (2kw!!); it can go through 4mm angle in less than 20seconds


patented method for compressing the springs to assemble the front suspension.


the buggy can support itself! it roles cleanly without sticking - hubs AOK


our first attempt at steering, unfortunately it was too flimsy and bent around when turning the steering wheel. tried to weld strengtheners to it, but discovered it was actually cast ally. besides, it suffered very badly from bumpsteer. Simply ground the whole lot off and started again.


new type of steering; this pretty much removes the bumpsteer, although is not perfect - when the car is pushed forward, the suspenson sinks, making the wheels point away from each other, forcing them apart and the suspension to sink even more . I can solve that by changing the side the wheels are controlled from.


pretty much as it is, except the steering and brakes now work well enough. The only way to test it is to find a field and give it a really hard time, and break the bits that can be broken, and make them stronger/redesign them.


more coming this week hopefully !
Profqwerty

[EDIT] Sorry about the original pics! I hope these are better size [/EDIT]

 

http://www.mihov.com/eng/ir.html

Nothing like 20 meg of un-compressed photos to stop people reading a thread...

BC

 

Jeez sort put the pics or ur gonna break these forums!

 

Really nice project, keep it up!

What sort of welder are you using? I'd like to learn to weld and have looked at getting one before but all the different types confuse me tbh.

 

Nice!

Im waiting to see what breaks now, I would throw on a helmet before trying it out though. Dont kill yourself.

 

Aren't those shocks going to be mighy hard when running in something that'll weigh next to nothing?

Also want to know about the welding equipment

Nice

edit: reminds me of

 

Quality! From the pictures that engine looks held in by seriously flimsy bits of metal but Im sure it works! Good job

 

ChriX: I'm using MIG; it's the simplest to do as the welder automatically regulates the arc, and feeds flux into the weld by itself. It's much more convenient (strictly speaking, an arc welder is better for angle iron, but I would never get the quality of weld.

speedfreek: I'm going to put a 'pod' around the driver to make adsolutely sure their not crushed should something happen. there will also be a roll cage around the whole thing *incase* it tips over

RTT: the way they are mounted means their actually quite soft; a person can bouce on it with about 5cm of movement. There will be much more metal to add, so it will become heavier. I may add concrete blocks (from the fence of course) to keep the front down if it picks up too much whilst accelerating.
The project was loosely based on the HL2 buggy; from the back they both look pretty much identical

Bindi: I was pretty surprised when i first saw what held it in the polo, just three rubber mounts with 3mm ms bolted to the car body. I simply re-used the rubber mounts, welding them carefully onto (thick) angle iron.
Although in my application it will be under more stress than in the original car so it is something I will keep an eye on.

I will be putting a continuoty (sp?) circuit across all major joints; if one fails the engine will cut out to avoid major damage.

 

This is cool, subscribing...

 

I know what you mean, prof, but within a car you have the entire chassis to take some of the strain. What it looks like youve got there is a single vertical strut holding the engine in. Now the downward force may work great but forces from any other angle, when you're bouncing around the countryside, is gonna rip that straight off and put 300kg of hot steel in the back of your head. Personally, I'd weld some angular joints to it to make it a triangular cross brace at a bare minimum, and also weld some triangular struts to a horizontal bar running behind the seat to make sure if the engine decides to fly, the only way it goes out it is backwards.

The problem also is that your engine sits ON the back axle. If you'd had made it mid engined, by bringing it forward about a foot, it would be a lot more stable and less prone to nose-in-air syndrome and you wouldnt have to use your concrete

How close are you to any sand dunes?? That thing will ROCK running over them. Soft, plenty of wheelspin, endless fun.

Im dying to know what you're doing for gears, pedals, radiator, sump etc

 

What a great project, subscribed tbh!

I have to agree with Binders, if you can face taking it to bits, shift that engine forward about a foot and weld it in a bit more. What you can do is simply weld a sort of cage around it.

 

Corrected. Triangles eff tee double u.

 

Very true.

 

You wouldn't catch me test-driving the thing, but it looks like a good laugh

 

There's no way I'm going to get in that thing.

Might be better once the roll cage is on. Cool to see you got the steering sorted!

ch424

 

more!
i eat my words: the steering is still crap. I managed to solve most of its problems, but it is still just too flimsy; it would take a lot of hard driving for me to feel completely safe in its hands.
I removed what i had and put it on top. before, when it went forwards, the car sank on the suspension, forcing the wheels to point away, so it sank more, etc. now as it goes forwards, the wheels point inwards if it sinks, so it controls its height automatically, however it can't go backwards too easily.
Ideally each wheel should have a morse cable like on outboard engines, so the steering is completely within the suspension units, and no dodgy flexi-joints that aren't lined up properly, however this is WAY expensive (like £100) and i need TWO!




It's not weak, but just bends too much giving little steering (maybe when moving it will work better)


The brakes work; this is the pedal - it looks bodged ( and by god it is) but is def strong enough to survive. I used the same system as in the Polo, as it is the easiest/simplest method of balancing the braking.
The big question is: I am using the handbrake cable inputs on the old rear DRUM brakes, as this is simple and effective, BUT will it lock at high speeds? at the moment I have been running it down the hill in our drive, and it has variable braking, only locking when the pedal is stood on, but will the higher speeds cause the wheels to lock?



battery mounted in its own little pod (not fully built)


rear suspension mountings
I am presently using the axles to hold the wheels from rocking sideways - will this be strong enough? when rocking it backwards and forwards, the wheels skid on the ground and the axle/engine joint seems fine. there are lots of torx bolts holding what i assume is an outer bearing which is taking the sideways force.


unused wiring harness (lots of it) I'm not goign to cut it incase feel like adding fan, windscreen wiper etc later.



I decided against moving the engine; there isn't much room - i have been steadily adding extra support/bracing struts. there's the beginning of a roll cage in the making, unfortunaetely isn't much like the HL2 one! ( that was deemed not strong enough, strictly aesthetic!)
I am planing on going over the whole thing at the end, adding strengthening pieces where necessary.

triangles fuh tuh wuh

Thsi is a MAJOR learning experience for all concerned me thinks

profqwerty

 

Haha! Looking good!

In this photo you can see where the original car hit the kerb when it was written off... perhaps time for a new wheel? Nobody was hurt in the crash though, so don't worry people.

As for "I am presently using the axles to hold the wheels from rocking sideways - will this be strong enough?" - that's how it was in the original car...

ch424

 

High speeds wont cause the rear wheels to lock under braking, but a bumpy road will. As for the steering/suspension problem: you could add a brace like this (poor solution):


or modify the steering setup like this:


Extend the horizontal part(red line) on each side so you get more precision/leverage when you link them with a rod (blue line), making sure the distance between the pivots (black dot) is exactly correct so that both wheels face forward at the same time. Then remove your current steering linkage from one side only.

 

I see what you're saying Xeno; I tried this, and it then suffers bigtime from bumpsteer. it has independent suspension units, and unfortunately when they pivot the wheel stays perpendicular to them.
This made it much easier to build, but unless the red bit is massive (which may be the way forward) and the blue bit is as close to the hinge as possible, then any suspension movement causes major problems as the wheels are forced apart as the wheels are forced up.

having the linkage at the front does solve the problem it has with sinking when going forwards though.

I think overall your method is better

I will have a go tomorrow: suspension/steering, mark V
OMG this is complicated. there are now lots of little tack welds all over the chassis which are half ground/half broken off.
So far I have narrowly escaped major injury only 3 times - what's a good number for a project like this?

Profqwerty

 

Can you not look at a lego technic car or something to see how they do it?
The really big cool ones have susoension don't they?