Adjustable A frames

[alexblack13]

Yes Paddy. Exactly. This method would get round all the issues with ass'y and welding in close quarters to components that look to not like too much heat. I would not take off the entire component by 'undoing' the brazing. Although I do see where you are coming from. I suspect this could be tricky and might end up with (another!) scrap A frame. I think cutting out 180 mm of tube and fitting the 'unit' then refitting the tube is a good solution. A 'slip' of pipe over the joins at the 180mm cuts to just set the mind at rest (The butt welds alone would probably suffice). This would allow fitting the unit properly and re-taping of the inserts etc to make sure alignment (using the lathe) is right, threads are correct and not heat effected.

It was interesting to learn that Gerry had one of his Kelv*** ones pick up and seize also. Hmmm!

Geoff has very kindly sent me 4 A frames to fiddle with. All have bent tubes and 1 has a twist. The ones with the bent tubes could benefit from and be repaired by the above method. With or without adding the adjusters. I am confident that using the correct weld type, these a frames could be repaired. The bends are in the correct (rearmost) tubes. Front tubes are also bent but only very slightly and could be straightened on the press.

Now... Consider this.. Lets assume that Lotus made these A frames quite accuratly. If we cut out say 200 mm of (Bent!) pipe and replaced with new pc of pipe at 202 mm long we would have built in 2 mm approx' of toe in. Enquiries have told me the figure should be around 2 mm each side ''or a bit more'' (said my question answering device!). So.. we would have approx 4 mm toe in added to rear axle. Non adjustable of course, but...Would it need to be for a st'd road car? And of course would be checked for alignment tolerance. I would bet they would not be far out. If indeed out at all.

I am close to trying this. Fitted with the poly bushes etc and nicely powder coated.

The A frames are easy to remove & replace, so a test would be not a problem. Do the mods, fit and check alignment. All ok? Remove, blast and powdercoat, refit and forget!

Just a thought... What do you guys think? .. Gerry??

Here I go again !

Alex...

[oldelanman]

Alex,

If we cut out say 200 mm of (Bent!) pipe and replaced with new pc of pipe at 202 mm long we would have built in 2 mm approx' of toe in

I think if you lengthen the tube by 2mm you will get about 4mm toe-in of the wheel (8mm overall) since the wheel rim diameter is approx twice the distance between the two outer A frame bushes. If that is correct then you need only lenghten each tube by 1mm to achieve your 4mm overall toe. Hardly seems worth using an adjuster to add 1mm when as you say for a road car you would only do it once.
Regards,

[alexblack13]

Hi ..Yes ok.. I have not done any calc's yet.. This was just an example. Thanks

Alex..

[alexblack13]

Right guys..Been beavering away with this item and I am now happy with the result. (I will have some pics and a report soon). I have the A frames going for powdering now.

Keep you posted...Looking V good now.

Alex

[alexblack13]

Right..Here are a few pics. I did not do the 'fixed length' job. Fitted the adjusters. Right way to go methinks.

Alex..

[alexblack13]

Hi All,

Just an update on the project.

Well, as standard procedure my welder has thrown a hissy fit.!!! God's struth! Everything all set up ready to go and....Nothing! took the cover off the front and...One fried switch! Problem is its one of the current control switches so I can't select the bottom two 'low & medium low settings. Patience never a strong point of mine, after I jumped out the nacked switch, I got stuck in never the less and stub welded the tubes together using quite a high wire feed rate to stop blowing holes everywhere. Good strong welds, but I admit not the neatest I have produced. Still to tidy up and paint them though.

I have re-enforced the stub joints in the pipe as I said and this has produced a 'worry free' result. Best of all they work great! smooth adjustment with little torque required.

Costs were minimal. I used 'salvaged' tubing from a rust free but bent a frame that Geoff sent me as this was exacly the same tubing & just what the job needed. (Thanks Geoff. Just to weld yours up! )

Tube adaptors were ? 15 approx for 4 each hand. Tunbuckles were about ?3 each. so just some time turning / drilling / welding etc, I think about 6 hrs a pair, so not bad.

Although I am thinking to powder coat them I am not sure if I will. Examining the paint coat revealed a good strong bond and very like powdering. Time will tell. But I might just hammerite them again.

Not the easiest things to (retro) produce! ... I think you need to cut out the tube and replace with new tube with the adjuster fitted in to keep the heat away from the turnbuckle.

I should get some final result pic's up for you all soon.

Anyone want some turnbuckles with lock nuts? PM Me if so..

Alex..

[gerrym]

Alex, nice job.

Like all things Lotus, patience and a little trial and error gets there 2nd time around (often 3rd time for me). I'll have to talk to you later re reworking my Kelvedon's.

Just replaced my daily driver, only 8 years old but maintenance getting too high. Salted roads and over complicated sub assemblies make it too expensive to keep on the road.

By comparison, the Lotus is a very green car. All nice and rebuildable. Not even too difficult to improve, especially if you have a lathe.

Off on a tangent but, does anyone have a source for really good quality suspension up-rights (the Vitesse ones)

Regards

Gerry

[alexblack13]

Hi Gerry / All,


Sue Millar should have good quality items. Not the cheapest though. How about TTR?

I am sure you will find a good supplier. They were fitted to GT6 as well I think.

Snapped my V heavy duty vice in two yesterday, Before i would set up the press I tried the vice (usually works fine!) Big bang later & half the vice & the job is bouncing along the floor. Oh.. and my Lathe also played up. It had only tripped out though. I suspected a (soldered in) relay at 1st and dismantled half the control box which looks a lot like a Gatso unit to get at it. Quick test had me scratching my head until I took the simple route and checked the overloads. Click... whirr..and away we go..What a dingbat!

I will be glad when this week is over I can tell you.


However............... >>>>>>>>>>>>>>>>>>>>>>>>Merry Xmas folks<<<<<<<<<<<<<<<<<<<<<<

May you all have a good, healthy & very happy, fun filled new year also. Enjoy and have fun...

Alex...

[bcmc33]

Alex,

As you have some free state "A" frames in your workshop - could you please measure the inner and outer cross tube bores for me?

I want to use one of the bushes to modify a gear lever and need to make a bush with with the correct bore size.

[john.p.clegg]

Brian (friend)

Not sure about your terminology but if you mean the holes into which the bushes are pressed,mine measure ,inner 1.354",outer 0.872"

John

P.S. Merry Christmas to all (except the P.C. Brigade - Happy Holiday to you...)

[alexblack13]

Brian (friend)

Not sure about your terminology but if you mean the holes into which the bushes are pressed,mine measure ,inner 1.354",outer 0.872"

John

P.S. Merry Christmas to all (except the P.C. Brigade - Happy Holiday to you...)

Has John answered the question Brian? Or is it internal tube dia you need?

Hey John, Have you got the dia's the wrong way round?... I'm a bit lost!

Cheers all..

Have a good one.

Alex...



Alex..

[GrUmPyBoDgEr]

Brian (friend)

Not sure about your terminology but if you mean the holes into which the bushes are pressed,mine measure ,inner 1.354",outer 0.872"

John

P.S. Merry Christmas to all (except the P.C. Brigade - Happy Holiday to you...)

Has John answered the question Brian? Or is it internal tube dia you need?

Hey John, Have you got the dia's the wrong way round?... I'm a bit lost!

Cheers all..

Have a good one.

Alex...



Alex..

I think that John must have the 26R lightweight version wit less than Zero wall thickness.
Oh & I second John's Christmas wishes

Cheers
another John

[bcmc33]

Many thank's John, I have a new outer 'metalastic' bush that measures 0.875" O/D, so there's a 3 thou interferance - that's what I needed to know.


Have a happy holiday, everyone.

[john.p.clegg]

Alex:- Hey John, Have you got the dia's the wrong way round?... I'm a bit lost!

No,if you check,the inner bushes are larger than the outer bushes??

John:- wit less than Zero wall thickness

Have I dropped off here or am I missing something??

John

[paddy]

I think "inner" and "outer" were being mistaken to mean internal and external diameter (of the same tube) instead of "inboard" and "outboard".

Paddy