True or just a Story ?

[Dilkris]

Many years ago a very well established panel beater I knew well told me that if you wanted a perfectly straight, light and convenient straight edge, you could use 6 foot (or 3, 4, or 5 foot) fluorescent light tubes as they were perfectly straight. (He used them for identifying areas of distortion/twist in car chassis - note: I'm not referring to monocoque but the ladder type ).
So - true or a Story?
I'm wanting 4 off straight edges about 5'/6' long for some alignment work in my workshop.

 

[Maker]

No chance, you can flex a fluorescent tube a little way before it breaks, they're not stiff enough to be "perfectly straight".

 

[zzr1200]

What about your "Eye Straight" most ladder chassis have a tolerance of about +/-1/16" unless it's a Land Rover chassis, then sometimes it's a "Country Mile" depending if it's a Monday morning or Friday afternoon chassis/job.... .

OP needs to post pictures....

 

[selectedgrub]

They have been used and done by some old school bikers to align their motorcycle wheels

 

[8ob]

What about your "Eye Straight" most ladder chassis have a tolerance of about +/-1/16" unless it's a Land Rover chassis, then sometimes it's a "Country Mile" depending if a Monday morning or Friday afternoon chassis/job.... .

OP needs to post pictures....

Eyeballing down a length of timber or steel to check whether its straight or not is about as good as it gets, it is in Bobs world

Start the car


Bob

 

[Dilkris]

No chance, you can flex a fluorescent tube a little way before it breaks, they're not stiff enough to be "perfectly straight".

That's interesting - how do you know they flex?

 

[Dilkris]

They have been used and done by some old school bikers to align their motorcycle wheels

Well that's reassuring - wheel alignment is my next project, which is why I was wanting straight edges.

 

[reb78]

Well that's reassuring - wheel alignment is my next project, which is why I was wanting straight edges.

String method on some cars/4x4s can work well.

 

[dieselsamurai]

Ive used a laser level to check wheel alignment before , my dewalt one is supposed to be accurate to 0.3mm over 10m

 

[dieselsamurai]

ive got something like this too which has been usefull on some building jobs

3m Extra Long Level - A1 Equipment

3m Extra Long level Suitable for screeding etc. Heavy Duty 100mm x 18mm aluminium section with internal stiffening rib. 1 Horizontal vial 1 vertical vial 2 hand holds In Stock - available for collection - check before ordering whether we can deliver to your address

www.a1-equipment.co.uk

 

[MetalMonkey]

Cheap easy straight edge would be an aluminium extrusion, plasterers straight edge, something like that. Not truly straight but "good enough" for a lot of projects and a lot more robust than a glass tube I suspect.

String method for wheel alignment, if done carefully, can be very accurate if somewhat of a faff.

 

[Screwdriver]

They will be laser straight of course and they will not bend but that's the problem. They won't bend, instead they explode. Do you really want so many delicate items in a workshop which when you break one, shatters in a cloud of cancerous dust?

 

[The_Yellow_Ardvark]

The old tube trick was a quick simple way.
Back then there was thousands of them.

The new LED ones can have a run out on them.
The most bent one was a Seimans one.
5mm run out.

 

[Pigeon_Droppings2]

Sounds like a faff that will result in broken glass and cut fingers!

When I did the front rail repair on my MR2 I used magnetic laser pointers and that worked very very well....just a cheap magnetic level with a built in laser.

Basically shine the beam down the length of what you are checking and use the beam as your straight edge...easy to stick a ruler anywhere along the beam and check.

 

[Dilkris]

OP needs to post pictures....

I am at this stage with my rebuild and I want to get the alignment approximately dialed in - (For those that understand these cars, there is some geometry regarding the rear radius arms that I am concerned about ). "Yes" I can use string and yes I can use lazers, (have some from old go-karting days). So ... I am wanting to effectively extending the length of the faces of the rear drums and those of the front discs, ( yes - I know I will have to remove the calipers...).
There is a method to my madness - once I have established a center line through the chassis from front to back.

 

[Dilkris]

The old tube trick was a quick simple way.
Back then there was thousands of them.

The new LED ones can have a run out on them.
The most bent one was a Seimans one.
5mm run out.

I am not referring to the LED ones, but the old fashioned ones - for some reason I have many of them.

 

[Dilkris]

They will be laser straight of course and they will not bend but that's the problem. They won't bend, instead they explode. Do you really want so many delicate items in a workshop which when you break one, shatters in a cloud of cancerous dust?

I appreciate some extreme care will be required.
But (if) they are straight - they are also extremely light - and I have plenty of them.

 

[Dilkris]

Cheap easy straight edge would be an aluminium extrusion, plasterers straight edge, something like that. Not truly straight but "good enough" for a lot of projects and a lot more robust than a glass tube I suspect.

String method for wheel alignment, if done carefully, can be very accurate if somewhat of a faff.

I hear you -
Sure, we can all go out and "buy stuff" - but this forum excels at identifying techniques of ingenuity which costs nowt....

 

[Dilkris]

ive got something like this too which has been usefull on some building jobs

3m Extra Long Level - A1 Equipment

3m Extra Long level Suitable for screeding etc. Heavy Duty 100mm x 18mm aluminium section with internal stiffening rib. 1 Horizontal vial 1 vertical vial 2 hand holds In Stock - available for collection - check before ordering whether we can deliver to your address

www.a1-equipment.co.uk

Great - I ideally need 4 of them .... (£95 x 4 = a money tree for me)

 

[8ob]

I hear you -
Sure, we can all go out and "buy stuff" - but this forum excels at identifying techniques of ingenuity which costs nowt....

You are more than welcome to borrow this proper job for nowt