At Last!. I have started on my car ;-) PART 2

It's a barn :)

6 sections:
Workshop
Elan bay
Son's car bay
General storage section
Tack room
2 loose boxes (stables) on end
 
Days 142-144 - Nothing
Day 146 - Took rear top wishbones to fabricator to convert adjustable rod end system so we can adjust them insitu.

Day 147 & 148 - Nothing
Day 149 - Picked up skimmed and lightened discs. The disc and hub mounting faces weren't parallel - and they were new! so a little more work was required. Discs are now 3.465Kg lighter in total. |A little more fettling is planned which should see the reduction close to 4.7Kg :)



 
It removes a lot of weight and all of it from the outer edge. Sculpting extends 5mm into pad area but does not, apparently, affect braking adversely. If my very experienced racer guru says so and does it on his cars then that is good enough for me.

Day 150

Contrary to what I said earlier, we are now going to do a little bit of drilling :) Nothing to do with cooling, clearing gas, dust, etc. Purely as a weight reducing exercise. Drilling will remove an additional 1.27kG - Over 300gms from each disc making a total of over 1kg per disc. And, remember, this is rotational mass.

Holes will be 10mm diameter and chamfered to a 1/3 of their depth each side in order to reduce the chances of cracking.

Rear discs bolted to mill. Next job is to finalise CNC program and check it works, hence the pencil in place of a drill! Hope to start drilling tomorrow. Bought new Cobolt drill bits for the job. Drilling in pairs front to front so discs holes match and are handed.

 
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Okay, makes sense. Will you be offsetting the hole pitches so that each pass of the hole over the pad surface is stepped, if you see what I mean? Not the same pcd.
 
Yes. Adjacent holes overlap slightly so there are holes covering the whole disc width. Hopefully you will be able to see tomorrow.
 
What makes this even better is the fact that you are doing the bulk of the machining work and programming. Good stuff! I miss having direct access to machinery these days. Hopefully the old lathe I aquired will be functional sometime this year.
 
I do what I can. Left the skimmming and sculpting to the expert with the right machinery as that had to be right. Drilling holes I can do :)
 
Day 151. Spent day getting stables ready for a horse and a mule that are coming to stay tomorrow, so no car work :-(

However, I did buy a 10" rotary table so I can do a better job of drilling the holes. Off to Norfolk on Monday to pick it up so a slight delay on completing discs.

 
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I am, but the bed doesn't have enough Y movement to do a disc in one go. I am going to have to turn the disc 180 degrees and this will allow me to do this more accurately and quickly. And, as you say, a useful tool.
 
Day 152 - Nothing

Day 153 - Even I can get caught out. A few years ago I saw advertised in the 'New Products' section of Practical Classics or similar (can't remember which now) carbon fibre seats at a very good price. So good, in fact, that I should have smelt a rat. Bought a pair only to find the backs were covered with fibre glass. Rang them up and fell for their explanation.

They weigh 4.6Kg. Not heavy but not that light either. Decided to have a go at removing some of the weight today. My drilling discovered that the back structure is all fibre glass and the only carbon fibre is a thin veneer on the front!

These will have to do until I can afford a decent pair :-( Removed 250gms so 1/2Kg the pair.

 
Day 154 - 230 mile round trip to pick up rotary table. Bolted to mill bed and it fits. However, an inch smaller would have been better (now there's a statement you won't hear a man utter very often!).

I will play with it (unlke this statement!) tomorrow and upload photos of it in action (the table).
 
Day 155. Fitted rotary table to mill bed and it fits, fortunately :) Out to lunch and over to London for a car meet tonight and parcel delivering tomorrow so won't start drilling discs until Thursday at the earliest :-(

 
Day 156 - Nothing

Day 157 - Started drilling discs tonight. Holes still have to be chamfered and 4 holes have to be drilled between wheel stud holes. As they stand they are each 1Kg lighter than standard items.

 
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Day 158
Finished lightening of rear discs - Total of 2.025Kg removed from pair.

Wrote g-code for drilling front discs which I hope to do tomorrow.
 
Day 159 - Started on drilling front discs. Drilled one side and hope to complete them tomorrow.
 
Actually, we have been quite conservative as we wanted to keep a little safety factor and some friction surface :)
 
Just for my own knowledge on this matter OG, but is there a science behind where you are actually allowed to drill those holes?
 
Well, sort of. I relied on my race car guru, Graham Hatherway. on where to remove weight and drill holes.

We agreed on 10mm diam chamfered holes (to reduce risk of cracking and take extra weight off) for both front and back. Spacing of holes on the front discs was restricted by the grooves (offset front to back faces) so we matched the pattern on the rears just for asthetics. The spacing is designed so that the whole pad area passes over a hole reducing the risk of uneven disc and pad wear.

The exercise is purely one of weight reduction. Any dust extraction properties of the holes would be a bonus, but not looked for.

I must have made a mistake in earlier weighings, as the total saving is 3.2kg, or 800gms per disc. Not as much as I was hoping for but significant, none the less.
 
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Day 161. Final, final work on discs :)



CNC main control screen, for those who are interested :)

 
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Day 162 - nothing

Day 163 - Took rear top wishbones to Martin to have them modified so we can fit turnbuckles to allow insitu adjustment.

Day 164 - nothing

Day 165 - Took 4 1/2 UNF bolts (with heads removed) to my CNC man to have left hand threads put on the unthreaded section so they can be used as turnbuckles.

Day 166 - nothing
Day 167 - nothing
Day 168 - nothing

Day 169 - Found out that I can replace rear number plate with just stick on characters as car is black and acts as the backing (pre 1973 regs) - saving 400gms. Now that is quite a saving :)
 
Day 170 - Picked up wishbones from fabricator and took them to my CNC for drilling and tapping.


Walking the dog this afternoon I had a panic attack. I realised that I hadn't checked that the roll cage didn't foul the inboard dampers!

A quick check confirmed that there wasn't a problem, phew!



 
Tue true, the suspense is killing me though, and then there's the bloody fan thing too, gonna need therapy after all this...
 
Ah the fan thing, yes, that is interesting. I guess you would like to know about that, wouldn't you?..................:)
 
Day 171. Wife working so I am mother-in-law sitting :-(

Can't leave M-in-l alone in house so all I can do is a little online research.

New aluminium rod ends weigh 84.55gms each = 338.2gms
Existing steel rod ends weigh 154.0gms each = 616.0gms
Weight saving = 277.8 grams :)

Looking at where I can remove weight from the chassis without compromising stiffness.

Chassis is made from 1.2mm thick (18 gauge) steel but the added reinforement is in 2mm steel. We triangulated along the long folds where possible, as shown below:



a 10mm diameter hole in 2mm steel removes 1.23gms. A 20mm hole removes just under 5gms. So, 204 20mm holes will remove 1kg :) Hmmmmmmm
 
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Day 172 - Well, you knew I wouldn't be able to resist it, didn't you?

Drill motor overheated so couldn't finish the right hand row. 3 other sides to do on this upright and the whole of the other one.

Upright only serves to hold body in place and as a fixing point for seat belt and roll cage. No suspension which created the greatest bending moment. Roll cage will replace any reduction in stiffness along with an aluminium crossbrace.

Calculations indicate that, when complete, 301grams will have been removed.

 
I wish. I will be lucky if it ends up lighter than a standard Elan. Engine is around 40kg heavier than the original, the diff is also a lot heavier. Plus, there is all the extra stuff associated with fuel injection and turbo. But I will keep at it as whatever I remove will help.
 
Day 173 - Completed pilot holes on rear suspension uprights. Drilled and flared right hand side chassis flange. When both sides are done the chassis will be 275 gram lighter :)

Right hand tool punches hole, left hand one flares it:





 
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