Dash back together and seats update

The dash is now back together, the reset button looks good and the defect on the edge is pretty much gone;

The car has been cleaned and ceramic coated so I'm ready for Saturday. 

In the meantime I had a go at profiling the seat. It does look like for comfort I need to bring my knees up quite a bit. A fellow Locostbuilder sent me a link to a thesis where it talked about seat positioning, this is one of the photos;

This also confirms the amount of knee angle that I should be aiming for. Even in this picture the pedals are lower than the seat, whereas for mine they're at the same height.

As a guide I tried some rolled up blankets as bolsters;

This is a 3 inch roll, and while it helps it's not enough. Also that's based on the back of the seat still being the same height. Adding a second blanket gave me this;

I think this is on the right track. The seat base is 18 inches deep so I'm thinking;

• First 6 inches will be a 1" thick pad
• Middle 6 inches will be a 3" pad
• Last 6 inches will be a 5" pad

Given that I want as much of the 5 inch pad as possible, I'll profile the other two layers to come up and meet it. This sort of stack (side view);

Even that might be overkill. For example many tintops just have an edge bolster for support, like these Porsche Recaros;

Or Cosworth recaros;

So I could do this;

The final option is the 'messy' option, which is a bag of PU foam and a bin bag! That would be to form a well fitting seat while I'm sat in the car. I'd still need to bump it up a bit, the expanding foam would only fill gaps where my butt wasn't touching the floor but I still want to have some padding for my back side.

I did have a thought that I could 3D print a seat pad... I have TPU and I reckon maybe 10% infill might work. I'll print a test piece and see if I can sit on it comfortably. 

Hot weekend

Well, the good weather is seven days early but fingers crossed it'll still be warm next week. This weekend it's up to 28 degrees on Monday. This will be the time when I figure out whether an all-aluminium interior was the best way to go. It did occur to me that the edge trim in the car is 3D printed, and while I left them on because they looked good, I also have doubts on whether they can survive high temperatures. Even the glue fixing them on could go a bit 'gooey'. If it does I'll just remove them, they were going to be removed anyway so it's not an issue. 

In any case, I'll get the car out and see whether it becomes unbearable in the heat. When my next post is 'third degree burns on my hips and elbows' then you'll know things got too hot!

I did discover why my diff was pretty dry though. Basically as soon as the propshaft was removed the oil would have come out, so it would have been dry since it went on the car. Such a daft thing to do and hopefully I've not done any terminal damage to the gearbox. If I have then it's <£100 for a new one, but it's not a few minutes job. 

Lets see what's on the 'to do' list;

• Heel/foot plates. Both passenger and driver need somewhere to rest their feet, it's surprisingly hard work to keep straight legs. It's mainly going to be just a bar across at an appropriate point, a bit closer on the passenger side with the driver side being just before the clutch pedal. 
• Reshape seats. Along the same lines as the above, I want to tilt the seats back or create a bolster under the thighs. I still have some pleather so I think some decently supporting foam would do. I did think about an old angled pillow that we have lying around but it's not actually that supportive. I've learned that seating actually needs to be a lot harder than you might expect to be comfortable. I can see why some seats are basically solid, or at most with a small layer of foam. 

(Later that weekend)

Well, heat is heat, and driving in a car with no roof or cooling is like having a hot hairdryer in your face. It's mostly a nice experience, but I didn't last many miles. On the subject of miles, I've started a fuel spreadsheet. Yeah I know, probably the epitome of dullness. But without a fuel gauge I need to have an idea how far I can get.

A 5.7 gallon tank gives me around 200 miles range. Just as a comparison, Malvern is around 50 miles away so I can get there and back without filling up. 

More work

 Bodywork fixes are looking good;

I'll need to rub down the paint once it cures but it looks a lot better already.

While the dash was off I had a look at the odometer reset button. After several hours of looking for the parts, I put things together and planned out where it would show on the dash. Then a few hours redesigning and printing the bezels got me here;

It looks good with the speedo temporarily behind the bezel, but I can't put everything together until the paintwork is polished and finished. I'm optimistic it will work well, then I'll be able to use it as a fuel gauge. 

I'm on countdown to Malvern now, two weeks to get it spot on. I'll do the paintwork in the week and get it all back together, then one last run on the weekend to make sure it'll make the journey. Then a clean and ceramic polish to finish. 

Gearbox oil, jacking point, wiring clamp, bodywork fixes

 I got lots of little jobs done yesterday. Start with the biggest one, the gearbox oil. 

I've wanted to do the gearbox oil for some time now, I'm aware that I've replaced all the other fluids except for Gearbox. So I bought a couple of litres of the recommended GL-4 oil and had a look at what is required. While the job itself is quite awkward on the MX5, it turns out the drain and filler plugs are both accessible from the engine bay in my car. The filler plug was first, that needed some persuasion but came off in the end. The plug itself didn't show any signs of issues apart from 20+ years of gunk. I'm 99% sure it's never been changed.

The drain plug was similarly easy to come off, and that's where I found an issue. It turns out there was very little oil in the gearbox, nowhere near the 2 litres that should have been in there. Once it was refilled and the plugs went on, then the job was finished but I wonder how much damage has been done by the gearbox being empty. I suspect sometime in the near future I'm going to need a new gearbox, at least for now it should be happier. Second gear is still the noisy one so I won't push it. 

That was the main job I wanted to do this weekend, and it turned out to be a lot quicker than I thought. 

I actually started the day with the rear jacking point, partly because I thought I would need it to do the gearbox oil. The jacking point was pretty straightforward, although my welder was not happy for some reason. Lots of sticking wire and burn backs on the tips. Part of it was welding upside down, but I think I'm overdue a new tip and shroud anyway. I'll do that before I need to weld again.

So I now have a rear bar in the right position for the jack, which should make lifting the entire rear a lot easier. No pics unfortunately, I seem to be forgetting photos of work in progress.

The next job was the wiring loom clamp on the engine. The one above the exhaust had melted and distorted so it needed to be replaced and reinforced. The design is as before, but now I have a layer of 1mm steel round it to keep the shape. Once it was all bolted together I could see it was going to be a bit stronger, and at least the wiring and the coolant pipe that is being held by it won't drop on to the exhaust. I'll still monitor it to see if it's sufficient, I may have to upgrade to ABS if this isn't good enough. I don't like printing in ABS mainly because my printer can barely cope with the temperatures, and it warps really easily. 

The last jobs were the bodywork. Just under the passenger dash I had a scratched panel where I managed to drop it during fitting. It shouldn't have bothered me but I found I was looking at it every time I drove. It actually took a lot more work than I thought as the scratches were quite deep. Still, half an hour of sanding and polishing got it back to 'nearly' sorted. I left the panel at 1200 grit as I don't want the panel shiny. 1200 grit is roughly where it started, a slightly matt finish with no swirl marks. 

The other mark on the bodywork was again on the passenger side, a dent where filler didn't work properly, and then the paint also chipped. It's another thing that I didn't really need to fix, but I've done it anyway. Or at least I'm halfway done. I filled the hole yesterday, I'm about to go at it with some sandpaper to get it flush, then touch it up with some paint. It is just pretty labour intensive work, a couple of hours at least I reckon. But it'll be worth it. Again it's because it's so close to the passenger seat that it's very visible.

I'm also tempted to have a look at the odometer reset button, just see how much work it would be to restore it. It would be mainly replacing the 3D printed part, as well as cutting a small notch out of the panel. I just need to make sure I can get it in the right place. 

Oh yeah, and the rev counter is bouncing again. I am hoping it's simply a bad connection, but I suspect it might need a new one. 

More miles, first issue

More miles now, and a full tank so an opportunity to work out my mileage again. 

The first journey from full tank to full tank was 102.5 miles for 12.3 litres, which works out to be 38 miles per gallon. This fill up was 21.23 litres and it got me 162.8 miles, which is 35 miles per gallon. Given the first was motorway and the second was 'fun' it looks about right. 

Now the issue. Coming back home I got a clunk clunk under the car right under my feet. Everything seemed ok so I got home and had a look;

 The tensioner bolt for the alternator has decided to undo itself and escape. Thankfully it's just a standard bolt so I'll replace it with some threaded rod and some nylocs so it can't go missing again. Nothing else looked loose so I'm counting that as a win.

Oh yeah, and I forgot the main thing about an open top car... sunburn! My face feels like I've been in the sun for hours, I assume it's a combination of the actual sun along with the drying effect of the wind. 

I also want to look at a jacking pad for the rear. Something in the centre within reach of my jack would be ideal. At the moment it's going on one of the boot supports;

It works but it's sketchy and lopsided. If I put a bar or flat panel at roughly the same depth then that'll be a centre lifting point. With the jacks just ahead of them it works out quite stable;

The front should also get similar treatment although I don't have many ideas there as the front of the car hangs down too far for the jack to get under. 

First 50 miles

 This morning dried up so I thought I'd take the car out on it's maiden voyage. A quick first few miles and back showed everything looking good, no leaks and no spray of diff oil so that's all sorted. A short wee break and a few more miles, visiting various relatives on the way. Everything seemed to be quite healthy. There were some unusual 'smells' but I can't tell whether they were from the car or from the outside world. After all it's a UK spring and all sorts of stuff happens!!

Once I'd got back and got the feeling back in my legs (heel rest and seat pad to be done very soon!), I had a look under the bonnet and round the car.

Firstly the screens worked well. I no longer have the draught on the top of my legs which was part of the wind chill I had from Bristol. I still get some wind buffeting in my face but it's tolerable to drive without a helmet now. I tried a few different screen angles but it turns out the one I had that 'looked ok' is actually the best one. So that's a huge tick in the box for getting to the kit car show.

Everything under the bonnet held up well despite the additional heat. Well, apart from one bracket. It's PETG but it's right above the exhaust, and it's in tension rather than compression;

 I suspect if it gets any more pliable the coolant pipe will become detached and drop on the exhaust. I need to reprint a new bracket and then encase it in steel, similar to what I did for the fuel pipes. 

Oh, on the subject of fuel pipes, no petrol smell anywhere. That particular demon has been well and truly exorcised.

The main thing that I think needs some work is the rear suspension. I modelled the upper wishbones off a Westfield design where the MX5 upright is next to the damper;

The problem is I then also included a camber adjuster;

I was thinking that the damper and the upright were close enough to not put rotational forces on the bracket. Unfortunately I was wrong, it is basically twisting the bracket on the bushes. It's not enough to unwind the bolt but at some point something is going to get upset. 

I have replaced the washers above with a solid plate as below;

But essentially what I need to do is make the wishbone wide enough to accommodate two bolts. The second bolt will then provide the shear strength to prevent rotation. That then gets me back closer to the Westfield design. The fact that Westfield used the design at all suggests it does work with the right layout. Another Westfield design also puts the damper off from centre;

As a short term fix I could just weld the plates together, but that won't allow me to change the camber and that's on my 'to do' list. I am wondering whether I have enough material to redo them entirely, including enough on the wishbones so I don't have those spacers (but still have the option of camber adjustment). I may have the bush tube but I am 99% certain I don't have enough of the seamless tube. 

Then I'm wondering whether I should change the design so the damper is directly above the upright so forces get transferred in a line rather than rotationally. But then I could make it so the joining plate is horizontal rather than vertical. 

I guess some planning/design is in order.

(The following morning) so I'm having an early morning conversation with Copilot... yeah I know. Copilot is only as good as the questions you ask it. In this case I asked what the friction force was for the plates, and it came back with around 400lbft of torque required to overcome the friction of the steel surfaces. That's on a fully torqued M12 bolt with clean surfaces.

The second question was how much force would be applied if the shock absorber was 1 inch away from the pivot. The response was 80 lbft. Now just looking at the photos I can see it's a little more than 1 inch, but at this point it's just about multiplying the numbers. In theory it would have to be five inches away to apply enough force to overcome the friction. It's not five inches away so I 'should' be in range.

The last question was 'how to improve it', and there were two options. A friction shim or a shear pin. The friction shim is basically some other material to increase friction. Think brake or clutch pad material, that sort of thing. It makes sense but a quick google suggests I can't exactly buy a 'sheet' of this material. 

The shear pin is a much better option for this application. Basically a hardened steel pin through the two suspension pieces and the bracket in the middle. Two 6mm pins would work fine. If I can't find long enough pins to get through all the plates I'll use ones on either side and rely on the welding in the middle. So I need a maximum of 8 pins (2 per hole, 2 holes per side, 2 sides). The standard quoted is DIN 6325, and while Amazon is showing me furniture pins, Ebay has some listed for less than a pound each. I still have a couple of weekends before the show, and apart from taking the rear suspension apart this isn't major surgery. I'd have it done in half a day at most. 

The one thing I want to do today is to get the car lifted up and get the brackets realigned and retorqued, just in case it was something silly like the lack of torque on the nut. I also want to clean off the paint in case that is acting as a lubricant. When I was getting the torque figure it was based on clean steel with flat mounting surfaces. Those surfaces aren't clean or flat, so again this means the pins will work better than just trying to increase the friction. 

I have a registration!

I have to give credit to the DVLA people, they really turned things around quickly. Between paperwork and registration being assigned was 13 days. It would have been quicker if the postal service had delivered an information request on time (6 days for a letter to arrive, how is that good service?!). 

So now I have an age related plate, or at least the email confirming it. I still have to wait for the paperwork to arrive (by post!) before I can go buy my number plates. I was going to get them online but to be honest buying them from a shop is only a couple of quid more expensive. I really can't wait now, screwing the plates on will be the final step in getting it roadworthy.

Of course, I'm sat here now with the beginnings of man-flu, and the prospect of a slightly damp bank holiday weekend, so it's not as if the postal delays are making that much difference. The paperwork didn't arrive today (Friday), and we tend not to get post on a Saturday so it'll be Tuesday at the earliest.

(Later that week) It's now Thursday and I've not had confirmation that the new cheque has arrived with the DVLA, and there's no sign of any paperwork. Seriously, can the postal service get any worse? I wanted to get a few hundred miles driven over multiple weekends before I head to the kit car show, at this rate I'll still be waiting to buy the number plates!!

However it is very reassuring to know that the car now fully exists;

It also shows correctly on askmid as insured. The donor car is also gone, that just returns 'vehicle details could not be found'. So everything online looks good. 

As I mentioned above I was ill over the weekend (it managed to stay with me from when I finished work on Friday until I started work again on Monday. This week has been slowly recovering back to normal, and hopefully I'll be getting some garage stuff done this weekend. One of the first things I need to do is take it for a drive and give it a shakedown. That'll allow me to check the new diff seals, the rear suspension, and the front screens. I also want to start doing some more work around fuel economy which again needs some miles driven.

The same also applies to the foot rest and thigh pad, as well as checking the passenger side footwell temperature. It's right next to the exhaust and I didn't check how hot it gets in the car because of it. 

(Friday update)

Well, thankfully the paperwork arrived today, and a quick detour to the local shop got me two new plates which got fitted after work;

So the car is effectively finished, IE it is a roadworthy car that can be driven. Of course it's not completely finished, I still have a fair few things to do as well as simply driving and enjoying it.

I didn't get to drive it tonight as it was raining, but tomorrow is looking dry. I've got a few hours in the morning to take it for a spin and see how it drives.