Alison's Sonic 7 Build Thread

[alison]

My Introduction and the background to this build thread are at in the Who Are You at  mevowners.proboards.com/thread/10214/hello-sheffield .

This post is to show the progress of my Sonic 7 build and please let me know if I’m making mistakes – any help gratefully received. This is the concept we are aiming for.



I collected the chassis on the 15th March, plus lots of boxes of bits. The windscreen, roll bar and body will hopefully be arriving at some point, but maybe not till June/July with the lockdown. Angus has been working hard to make a new roof design as that’s what I was after, and it was nearly ready in time, but I’ll have to wait now to see it. My donor car is a Ford Focus 1.8 with very low miles, almost too good to break up. Not having a garage we’ve put a tent up (with a solid floor). We built a frame with large B&Q swivel wheels to support the chassis on, so as to be able to make space by shuffling it around. The only things I’ve done so far are to de-bur the chassis, cut the aluminium floor to size and order a load of low profile M4 steel rivet nuts and round headed bolts, which I’m hoping will be OK to fix the sides and floor on (with a bit of locktight).

[martinw]

Hi there, and welcome

Another Sonic....yay! Naturally, I'm biased....but they do (..still!) look great and just that bit different. Testimony to Stuart's original design. I still haven't seen another one on the road other than when I've been going to a meet of some sort - we remain a fairly exclusive (but helpful!) bunch.

I'm not a million miles away in South Manchester - and my niece lives in Sheffield - so when times are better we can maybe meet up.

There is no such thing as a daft question, so ask away. Although the forum isn't as active (particularly on Ford based stuff) as when I originally built my Sonic going on 10 years ago, you'll usually get a response from a Sonic owner - or a Rocket owner if it's a more generic problem.

Have fun!

Martin

[p5curly]

It would be good to see the roof option as I have only ever seen one sonic with a roof

[kiwicanfly]

In reference to your floor fixing, you mention round headed bolts, I am guessing these are allen key drive?

I suggest you use torx head instead, you can get these much tighter and you are unlikely to damage the head or key which can happen with the small allen heads.

[buildityourself]

Hi Alison,

Great to see another build underway. We are building ours too. There is a facebook group for builders if you need quicker answers/support. See the link in the first post in the linked page below, hope you will join up.

Sonic build group

Stu

[stevew]

The screen and roof look much better than the original ones, looking forward to seeing it completed.

The chassis appears to have a couple of extra bars in the drivers footwell, are you using a floor mounted pedal box and Angus has changed the mounting from a solid floor as he put in for me? If so, depending on where you mount the pedal box can present challenges with the master cylinders poking through the bulkhead. Much better if the pedal box can be mounted up against the bulkhead so the master cylinders sandwich it, providing your legs are long enough.

Any particular reason for using rivnuts to fix the floor? It's more work than using large headed rivets and it is unlikely you will want to remove the floor.

Cheers
Steve

[davef]

Welcome Alison, as Martin says there’s no such thing as a daft question, ask away. Happy to share any pictures or advice as you go along. Good luck and enjoy the build.

[daydreamer]

Welcome, it is always good to see another Sonic builder.

RE: floor fixings, I recon the alu floor panel is the last panel to ever need removal. I fitted my floor panel with rivets and did the side pods and other panels with m4 rivnuts. This needed careful planning of the rivet and rivnut spacing.

Thought:  If you use "common" rivnuts to simultaneously fix the floor and side pods to the chassis then it will complicate the removal of sidepods only ( which I guess is a more likely scenario ).  Depending on your design the following might be fixed to the floor,  pedal box, fuel tank , battery.

Re: Tor-x vs Allen key. Tor-x is a winner hands down, the only challenge is sourcing longer, larger sizes in hardened tempers. For panel fixing I imagine it is relatively easy to source smaller, shorter items like these www.ebay.co.uk/itm/291844326091.

The link is for a countersunk head suitable for fixing through a retaining strip used to sandwich the fibreglass against the floor panel and chassis rather than using spreading washers. I recon this gives a smoother finish less likely to snagging when driving over road debris and a little protection of the fibre glass side pod edges.  Using a retaining strip ( 50mm x 3mm alu bar)  does add a little weight , as does using rivnuts in place of rivets.  On my build there is probably 2Kgs of extra weight on account of rivnuts and the bolts used in them.

For fixing in the cabin dome heads may be better.

As with all blind fixings without vibration protection ( nyloc etc ) thread locking fluid is essential.

RE: locktight,  I recommend medium ( blue)  threadlock , bear in mind if you use the red ( strong ) on a bolt with a rivnut then it is never coming out ( the rivnut will spin and the only option is to drill or pull it out and then replace with a larger rivnut )

[alison]

Thanks everyone so much for the welcome and the help. I'll have a look at torx bolts, thanks for that. The decision to use rivet nuts on the floor probably sprang from not having the confidence that we will get everything right first time, so it just seemed that if we got stuck with something later on it might turn out to be useful to be able to take it back off! It's sounding like it's the least likely bit to need removing though.

We're using the floor mounted pedal box but I didn't know the chassis had been changed, thanks Steve for the info on the master cylinders, I'll look out for that.

Thanks for the info daydreamer. I'm still trying to get to grips with how everything goes together. I've got the aluminium panels, and the side pieces seem to be the same height as the chassis, so presumably won't wrap round the chassis at all, just bolt onto the inside when folded to the right shape (haven't found this bit in the build manual yet). I've not got any fibreglass body panels at all yet so hadn't thought about the overlap round the edge of the floor, although I can see that in the build manual now I've looked more closely. A retraining strip sounds a good idea. Fantastic.

Thanks everyone.

[perthwa]

I can't believe (even now) how different the Australian compliant frame compares to the UK version..

cache.nebula.phx3.secureserver.net/obj/Qzg4N0ExRUMwNEIzMDZGN0U3RDU6M2Y3OWZiMzBhYTg3OGQ3NTc4NTM0NDZlNjZhNDliNTY=?u=e3cd41a3-256c-4b68-9dab-83bb6eaf781c
Check out my page 5 photos...If you haven't seen the difference...

Here is another snap 


cache.nebula.phx3.secureserver.net/obj/Qzg4N0ExRUMwNEIzMDZGN0U3RDU6OGJkZTQ0YTUyOGZlMzYwNWE5YjEzMzFmNzljMjFhNDQ=?u=f76d47e1-4a03-4890-85c6-a059c245abe8

[wishful4444]

Good day Alison

I understand some builders fit a non metallic strip (rubber, plastic) between chassis and floor to prevent galvanic corrosion. Whether this is necessary given that the chassis is painted I can't comment but I expect others can.

[alison]

I've checked through all my boxes of parts and labelled what's in each box. The pedals are fantastic - (photo below). Now I can't wait to get them fitted.

I've found a local company who will powder coat the chassis for me for 220+vat including collecting it which seems OK. I've worked out how to adjust the rivet gun to get roughly the right amount of squash of the rivet nuts.

I'm planning to practice my riveting skills on a spare bit of box section steel with the aluminium floor offcuts before starting on the chassis itself, so as to make sure I've got the rivet gun set right and to get the holes the right diameter. The rivets need a 6mm hole but I'm thinking the M4 bolts will need maybe 4.5mm or 5mm holes drilled in the aluminium so as to allow a bit of room for error without any danger of the bolt head going through. I plan to g-clamp the floor to the chassis and drill through the 5mm holes, and then remove the floor and enlarge the holes for the rivet threads to 6mm. The man at the powder coating company has some sort of plastic plugs he says he can use to stop the threads filling with paint if I've put the rivet threads in. I would rather drill and rivet first then powder coat to avoid any risk of chipping the paint.

The plan is to powder coat the chassis in gloss black. The car will be black down the centre and RAL 4004 on the sides. I'd like to powder coat any other bits and pieces at the same time like the suspension components. Does anyone have any recommendations about whether it's important to blank off any parts of the suspension bits to avoid getting paint on them, and if there are any parts it's good to coat or better not to?

I'm going to work with the bolts I've got for the moment and order some torx ones later on, and then as I replace each bolt I'll put the locktight on.

The bolts I bought (apart from being allen key instead of torx so duff from that point of view) are 16mm thread length. That's fine for attaching the floor with about 6mm spare with all thread engaged. If I'm using some going through the chassis & floor & side pods and maybe some sort of protective strip to protect the glass fibre edges, then I might possibly need longer ones. I don't have the side pods yet though to measure the thickness.

Is there any particular places I need to put/not put the rivnuts because of the shape/fitting of the side pods?
Daydreamer you said careful planning of spacing was needed and that if I used the same bolts to simultaneously fix the floor and side pods it would complicate removal of the sides. Is that because there are specific places that the side pods need bolts and/or because if I wanted to take the side pods off later I would have the floor loose round the edges whilst doing so?

Many thanks.

i.imgur.com/KkCmsQv.jpg

[alison]

[kiwicanfly]

I drilled most of my M4 clearance holes at 5mm, when you shop for Torx bolts look for the flanges head type, they have an inbuilt washer that is bigger than one seen on any other bolt, about 9.5mm.

A thing I find that is quite important when using rivnuts is that the bolt has clearance all the way round the thread when passing through the panel to be fixed. If the bolt rubs on the side of the hole it will exhort sideways force on thev rivnut and potentially lead to the rivnut spinning.

I also often run a tap through the rivnut to ensure the threads are good, essentially you should be able to easily run the bolt all the way in with your finger tips.

Another useful thing to have is a Cleco tool and fixings. These are used as temporary fixings whilst doing panel work. I can't emphasize how useful they are. I bought about 50 fixings although you might get away with less.

[daydreamer]

Hi Alison,



RE: Floor side pod fixings.

The complication I was referring to is that when the common fixings are removed both the floor and side pods will be loose. It will the work of many hands to support and align the fixing holes in the side pods with the fixing holes in the floor with the holes or rivnuts in the chassis. If the floor is also supporting items such as pedal box, battery , tank then it will be heavy and difficult handle in what is probably a confined space.



RE: careful planning of floor rivet and sidepod rivnut placement.

I do not think there are particularly special places that the fixings need to be. Rather they need to be sufficient in quantity and evenly spaced. It is this last requirement for even spacing that requires planning. I alternated rivet and rivnut at 5cm spaces. This means that my floor is fixed at 5cm intervals and my sidepods at 10cm intervals.



RE: Hole size for rivnuts fitment.  ( I like Kiwicanfly's suggestion to make oversize holes in the panel to be fitted for the reasons he suggests ) 
The supplier of the rivnut should be able to specify the exact hole size for fitment. Getting the hole size right is critical to the satisfactory operation of the rivnut. If the manufacturer specifies an odd size such as 6.8mm then just order up a drill bit in that size, it will work out better. If the hole is too large , by just 0.2mm or less, then the rivnut will not grip the panel (chassis) where it is fixed. The rivnut fixing is achieved in two ways, it expands in the hole to create a grip that resists turning and then it continues expanding on the blind side to create a lip to prevent pulling through and further resist turning. In my experience most rivnut failures relate to satisfactory grip of the panel to prevent turning. This is most often noticed when attempting to remove bolts that have seized in the rivnut. When this happens the rivnut just turns and the only way out of this pickle is to drill out the whole rivnut ( subject to it not turning while drilling ) or failing that pulling it out or pushing it through which makes a royal mess of the panel/chassis.



Note: In my build I also fitted a front chassis floor plate, in front of the bulkhead to protect the tank and other fittings in that space. This is also fitted with rivnuts so that it is removable. This front chassis floor plate, like the side pods, overlaps the main chassis floor panel and has interleaved fixings on the front bulkhead chassis member. I had not anticipated fitting this front chassis floor plate at the time I fitted the main floor panel and the result is less even fixings and spacing.