DIY budget 4-wheel alignment project. Update, done for under 20. Full write up!

Finally, it's done! Before the pics, just a quick re-cap of what I was trying to achieve.

The criteria:

- keep it simple
- must be attached to the car (so the car can be moved back on forth without it moving out of position)
- must be adjustable vertically and horizontally
- use as many off-shelf items as possible, modified as little as possible, not create a one-off time consuming fabrication etc etc
- that means anyone on Club GTI can create one
- so no lathes allowed, no MIG welding allowed
- 50 cost max

Thanks to the various ideas which cropped up in the thread, some were certainly used.

The best news? 50 max? Pfft, you'll do it for a Danster-impressing 20.


Tools needed:

1) hacksaw
2) file
3) Knife
4) spirit level
5) set square
6) 2 x jubilee clips
7) + (ideally) vice / Workmate


Parts needed and cost:
(images are thumbnail clickable)

1)| 3.75metres of 25mm metal conduit|Electrical wholesalers (I used bemco.co.uk)|7.18| 2)|4 x 25mm end caps|eBay|2.40 (for 10)| 3)|4 x 25mm plastic conduit saddles|Screwfix|1.06| 4)|4 x 600mm restraint straps|Screwfix (p.n. 85398)|4.59| 5)|4 x M5 wing nuts|Local nut & bolt shop|1.07| 6)|4 x M5 countersunk screws|Local nut & bolt shop|n/a (used Mk1 Golf wing mirror screws)| 7)|5mm bore washer spacers|Local nut & bolt shop|n/a (had already)| 8)|Fishing line|eBay|2.44| 9)|2 x used driveshaft nuts|n/a|n/a| | Total|||18.74


Making the kit:

Firstly, you'll be buying one 3.75m length of conduit which won't fit in a car! Take a hacksaw and a tape measure with you, and chop it exactly in half.

Once home, chop off the threaded ends off the conduit:




Assuming you've bought 3.75m, the length should now be perfect for the width of various cars. You want the bars within 30cm of the wheels on each side of the car, so you can use a steel ruler for taking measurements.


Once done, time to make the bars identical in length. This is critical and it does take a while. Stand vertically:



Strap together with jubilees and file:



And check:





And check:



It took me an hour to get it right.


Once happy, reach for the 25mm end caps, which are actually over-sized, as the conduit is 1.5mm wall. File down a little:




Tap in, but not quite home, and back cut the edges with a knife. You can't cut round in one action, so press the knife in at various points:




Next job is to get them on the car - not quite there:



A bit of tweaking:



VW are very kind and put pre-drilled holes all over slam panels






Next job is to get the conduit in horizontal position. Not shown, but start by resting it on 2 axle stands. Then attach the conduit saddles and do up the wing nuts into the retainer straps:






And same on the rear - the retaining straps needed a bit more work to get them to sit:




So now it's on the daily beater, try a different car - managed to use the same straps on the front:




Another set of straps for the rear - another 4.59, tut, tut - as I wanted to leave the reprofiled ones as they were on the daily:




It doesn't need to be securely fixed, as it'll stay in position:




Out with the fishing line:








The bit I l really ike about this are the pre-drilled retaining straps! I was just browsing through the Screwfix catalogue and saw the straps, the price - bingo! Steer clear of Wickes, they're 4 each! With a few mm adjustment vertically in the slotted conduit saddle mounts too, I haven't put a drill near it, and it's adjustable already for height, so you can get the fishing line across the wheel centres:





No parallelograms - the bars are the exact same length, and sit parallel to the car, just by resting on the bumpers and being hooked on the same places on the slam panel:









When it's time for packing it away, just undo the wing nuts, and it's not bulky to store






A sheet to write the results on, so you can calculate it as you go. Thanks to HPR for his guidance once again



Download a printable pdf here


Last job is to know how to interpret the results in 'minute speak' - this one is for 15" wheels. More on demand.

 

Groovy! :-)

 

I like it! Cost less than 1 tracking session! Pays for itself during the first time it's used.

Gurds

 

I decided to pick up a new steel ruler, as the scale on my old one was fading from years of sitting in a toolbox. Just get them off eBay - 1.70, as opposed to the 4 Halfords / B&Q will gladly take. I seem to buy every widget I need off eBay these days!

Some are scaled to the half millimetre all the way along, and some just like that for the first 10cm. I find half mm scales annoying, as they're difficult to read quickly. This one arrived, scaled for the first 10:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=140571230432&ssPageName=STRK:MEWNX:IT

 

On the tracking gear, I know it looks incredibly simple, but it took me ages to design it in my head! Back on page 1, I was going down a totally different road.

Attaching the strings to the same, repeatable position at the end of the bars, without a welder, is the key to making it totally user-friendly, and you can have the gear set up much more quickly because of it.

But heck it taxed the mind as to how to do it! The answer was so simple when I got there!

 

nice work Chris

 

Good job a lovely product right on the spec. You could still get parallelograms if the bumpers are miss aligned slightly or bodywork is not 100%.

To solve is easy, you could add a bolt with two nuts, nut either side of the retaining straps at the hieght of the bumper, then you can adjust the nuts/bolts to move the straps of the bumper slightly, measure the string distance between the front and back poles and adjust until both sides are perfect.

 

I think that could be mis-interpreted as a major shortcoming of the device, since people can't quantify the implications of a suggested design oversight! [:^(]


So... best pull out the calculator! If a bar were (say) an inch out at one corner - a pretty noticeable chunk - the orange line would result:



Trigonometry time, 1850mm being the length of the bar + 25.4mm being the translated inch error:



So an inch out causes a (C minus B) 0.174mm width error at the corner of the box, or 0.087mm per side. And at the wheel rims this would be slightly less! Bearing in mind 0.5mm equates to 4.51 minutes, which is a miniscule amount in tracking terms, 0.174mm has no measurable effect for the user of the equipment!

As long as the bars are parallel by eye on the bodywork / bumpers, that's more than sufficient.

-costs, as they stood

 

Quick tip: Tippex mark the bottom of the steering wheel and cowling, to achieve consistency / speed of set up on centering the front wheels - otherwise you end up measuring toe in on one side and toe out on the other.

 

You could save 2.40 on your end plugs by keeping the two bars clamped together after filing to length. Then measure In 1cm say on either end and using a hacksaw just cut a slot on either end of both bars. Obviously ensuring you cut the slot square.

Just trying to keep the budget down .

 

Agreed - it was seen earlier in the thread here - and whilst any error would be small, I didn't like the bodgery of it.

Don't forget, for my 2.40, I got 10. Offers on the remaining 6!

 

I quantified this up to 2degrees on the other page, just think it is important when setting this up that people are aware. 25mm over the length a car is not easy to spot, bumpers are not straight etc...

The device is great hence why I made one on the same principle and as side kit here is perfect for the spec.

 

Aware of what?

As above, 25mm is 0.17mm toe, so you'd need a bent car to the tune of 75 mm, not 25mm, to see half a millimetre on a steel rule / + the consequent 4.5 minutes toe errror.

Easily visible by sight, and knowledge of own cars. A categoric non-issue.

 

3 degrees is easy to miss if you are not looking for it...

It has not been mentioned that it must be set it up square except by me, you mention no parralelagrams but there will be if you don't attempt to set it up square and just using a bumper and symmetrical hole will not ensure this. Every time I have mentioned setting it square you disregard... I'm sure you would set it square (or damn close) but as this is ment to be a guide then should it not be mentioned that it needs to be square? Otherwise it will start to effect measurements.

 

That is not square to the bumper....

 

You are to stop quoting me out of context, selecting pics to suit. See the second pic below, and the bold text which applies to it above, in the same order as posted originally.

That's an ex-race car, and it isn't 7.5cm shorter on one side

You might have had an issue with something else at the weekend, but are out of order if you are bringing any of that onto this thread, which IMO you are continuing doing, trying to drag down my work.

 

Enlighten me about the weekend?

I have not said a bad thing about your work but only praised it. I too use the same method which this thread informed me about in the first place, I made one comment that I thought important when setting it up... something that when I first set it up had no idea about or even the incling to think about.

Saying all that and the 'out of contect quoting'? it would be interesting to have known the string lengths when you set up that pic. (do not take that the wrong way and it is not a prove you wrong/right comment but pure interest).

And breath its the weekend...

 

Will send PM later.

 

As this thread has been linked in another thread today, just a running report on this kit.

• I have used it several times and it produces repeatable results.
• I skewed the front bar as an experiment and it produced the expected results outlined above
• With use, the set up time drops as familiarity is gained with the expected wheel hub centre measurements
• Adjustments made to the car produces results moving in the right direction on the strings
• It can't realistically be used without writing down the measurements on the guide, unless you've a photographic memory!
• I transported it to the Nurburgring last weekend, using it twice
• Overall, repeated use of it, and knowledge of it creates greater reassurance from the results of it