Hasn't my welding improved?

The implied message in the title and photograph above is a deception.  The lovely aluminium weld above is by Martin Keenan or one of his chaps and comes from the rear tunnel cover that I asked him to make for me.  I made him a template as seen below and he did the rest.

Am I happy?  Very much so.

The part is relatively heavy at 770grams so I wouldn't want to do too much panelling this way but the front of  the driver's footwell is going to need similar 'jiggery-pokery' so I'll get another template sent once I've sorted out the final reverse motor mount.

Martin is also going to supply my tanks - fuel, swirl and catch; again all from templates.

For some reason Blogger is turning my photos clockwise by 90degrees. Please accept my apologies if I cause you to twist your neck!

TC

Raising the bar.

A bit more chassis related progress.  We really are getting close now.  I think.

So, the car is going to run with a rear ride height of 100-105mm.  The standard chassis isn't designed to run that low and hence, if it did, the Panhard rod would likely come into contact with one of the chassis tubes.  Consequently, something needed to be done.  I actually forgot to take a 'before' photograph but figured that a picture would help, so what you can see directly below is me holding the original (downward sloping) tube against the new one.

The new tube therefore looks like...

Neat, I hope you'll agree. 

Other works well under way include the prop catcher (here shown at a bizarre angle and highlighted in red.)

Also, the aforementioned water-cut bracket for the Digi Dash 2 arrived and has been tacked into place:

The bracket can be seen behind the paddles.  

The next major(ish) job requires the propshaft so that will be ordered next week.  In the meantime, Kate is going to help me to trial fit the bodywork on Saturday.

Watch this space....

One step backwards, two steps back

Almost a week ago now we set about fabricating the main supports for the reverse.  All went pretty well, although we did decide that we should put something on the back too - so I need to sketch something and get it water cut so that it will bolt straight onto a chassis tab that I'm yet to make also.

Naturally its all just tacked at the moment... although that didn't stop me from connecting a battery and seeing if it worked...

I did even have a video but I managed to delete it by accident, clever lad that I am. Actually I've been a bit dull. 2/3 times the gear seems to work a treat - out it pops'n'spins turning the prop flange as planned.  However, 1/3 times the bloody gears don't mesh properly and you get a nasty chattering sound.  Why?  Well, neither gear has a chamfer to help it mesh.  DAMMIT!  The point is that no real harm is done at the moment but its only trying to turn a shaft in a high quality bearing.  It's going to have to move at least 515kgs.

So, what now?  Well, I thought things through enough when I 'designed' the system that I've had the expensive gear hardened so that the the cheaper one wears.  This was a great idea at the time.  Unfortunately convention would have me chamfer the smaller gear.  Ah, woe is me.  Time to adapt; either try to chamfer the big gear with the Dremmel or get a chamfer put on it by a machine shop and see what happens.  I've not decided what the right thing to do is yet.

In other news, last weekend's racing at Donington Park was originally planned to be my RGB debut - hilarious level of optimism obviously.  Not being able to drive a glorified climbing frame, I travelled up to watch yesterday instead.  Most folk seem to be going faster.  Al Boulton dominated Class F as normal while Tim Gray took another outright win by a country mile.    Perhaps the most important thing for me was the fact that Paul Rickers' 4C8 R1 is still going strong.  Good news!

Next time - a sexy water-jet cut dash mount.

500 pounds of ballast!

I got home this evening to find that the custom drive gear for my reverse mechanism had finally arrived.  About time too!

So, it was more-or-less straight out to the shed to see if everything would hang together as planned.  Ah yes, the plan.  The plan was originally to use an unmolested starter motor from a Honda Civic to engage on a cog mated to the propshaft-to-gearbox-output-shaft adaptor to drive the car in reverse; rather like a milk float.  A very slow milk float.

Now, while I can't really claim the original idea as my own, the system that I was essentially copying didn't quite meet my brief.  Dan's (http://danstuff.info/) method engaged the starter with a button and a mechanical lever.  This sounded far too complex and involved more components than is, to my mind at least. strictly necessary.  The idea was therefore to have a purely electric system.  The problem was that the planned system would work brilliantly right up until the point that you realised that the electric motor would get in the way of the propshaft - a fairly critical component when looking to propel the car in either direction.

After much head scratching I decided that the only way forward (or backwards as it were) was to replace the driven gear on the starter motor - the 'slave' gear was already as large as I could get it.  I originally planned to fit a standard 2.5MOD gear of the correct PCD and O/D to the innards of the original gear - having had the original external teeth machined down.  We did get as far as machining the teeth off before I conceded that it was likely to be a horrible bodge - welding to hardened steel wasn't going to be terribly easy and the need for a fairly small centre bore meant that I couldn't get a HPC-supplied gear off the shelf anyway.  The picture below shows the original gear in its current state as well as a portion of the 'nose' of the starter which I cut-off to provide greater clearance for the new driven gear.

I obtained a quote from HPC Gears, having sent them a decidedly non-engineering drawing and the original part.  While it took a while to be delivered, apparently due to outsourced spark erosion, I can't fault the part itself.

This then gave me the kit of parts seen below.  

Inclusive of the machined bushes, both gears and reconditioned starter, this lot owes me about £500 i.e. about the same as MNR charged me for a reverse box a couple of years ago.  The upside is that the new electric kit is much lighter than a gearbox.  

The downside is that I'm not certain if it will work.  Due to a driven gear that is larger than those on most  BEC electric reverse systems, the torque required will be somewhat greater than on other solutions.  Hence, everything needs to be sturdy, including the electrics.  Of course all it needs to do is reverse the car on flat ground and hop a wheel over a bit of wood to pass scrutineering, but I'd be gutted if I'd got this far and the thing flunked the test.  Time will tell.

While this all seems like a terrible faff, the fact is that 'rules is rules' and if they, meaning the increasingly active eligibility scrutineers, find that your reverse mechanism doesn't do what it says on the tin, then you get disqualified.  This has already happened a couple of times this season.  Its possible to form a decent argument to say that these potentially-token reverse systems are a waste of time and money and just add weight to the cars, but the diktat comes from the MSA rather than the club so its not even a fight worth fighting it seems.

I need to get some supports fabricated and get it welded in next.  Adrian has done a good job of bracing his ancillary starter motor so I need to look hard to see if I can do something similar.

TC

Tanking

As part of the effort to get the chassis itself finally completed and sent to be powdercoated, attention turned to the fuel tank.  I have no aspirations to make my own but the mounting points had to be set-out in such a way that the part, once fabricated, could bolt straight in with minimal fuss.  This meant fabricating a template that I could use to locate the mounting points while the tank maker could use it to help make the tank itself.

The plan for the tank is another good idea that I've stolen from someone else.  Matt and Ivan at Procomp Motorsport can be thanked for this.  Here's one they made earlier:

The idea is that the tank sits against the back bulkhead and above the axle on the passenger side.  While the mass of the fuel sits quite high, there are a number of advantages to this method:

1. The tank is well away from the rear of the car and therefore less likely to be interfered with in the event that the car hits a tyre wall backwards.
2. The weight is over the rear axle; Procomp's LA Golds have a habit of outrageously good starts and one suspects that this plays a part.
3. The fuel and tank should, along with the engine which is also placed as far to the left as is possible  (from a RHD perspective,) go some way to balancing-out the weight of the driver i.e. me.

So, having made a couple of cardboard templates, I the dragged out the jigsaw, files, sanding block and drill and produced the following.

Its worth noting that mine is wider than the Procomp version.  I suspect that my bulkhead isn't quite as tall as on a Locost and I have the Brikett 6-hour relay in mind so want a little extra capacity.

The tank will eventually be mounted with the same style threaded inserts that we used on the engine mounts, as seen here.  The tank will be isolated from some vibration by using 5mm thick rubber washers.  The mounting method can be seen below.

Again with chassis completion firmly on my mind, I also wanted to decide where my Digidash 2 was going to live.  After much deliberation I decided that behind the wheel would be best.

I'll now probably get the mount water-jet cut so it can be tig-welded to the column.

That's it for now.  I'm still waiting for the reverse gear and motor to return, but I've been promised that I'll see it this week.  Fingers crossed!

TC

Steering Committee

Yesterday was the first time that I'd spent a whole day in the shed for some time.  The main focus of the day was to firm-up the position of the upper steering column and to get most of the fabrication done.  Dave was thankfully not far away and was able to notch tubes and turn-up bushes as needed. His tig welder also came in very handy. As part of the job of fabricating the upper column, we also needed to determine where the paddle was going to sit and also make the stand-offs to suit.  

The main support is in place, but it the outer column needs a couple of stabilising tubes to make sure that it doesn't move.  I was originally planning to drill lots of holes in the outer column but will now leave it as-is as there is some 20-odd cm of length where it needs to be self-supporting.  The column inner is now also mostly complete.  The run is very smooth which should mean that I get a clear idea of what the front wheels are doing.  The main point is that it suits me perfectly; between the custom column and pendulum pedals its shaping-up to be the most comfortable kit car I've ever sat in.

Speaking of pedals, I also spent some time experimenting with the clutch pedal linkage which is effectively ratio-adjustable.  I hesitate to say it but it looks like the clutch feel will exceed that of most BECs, which is a very good news as some are like on/off switches.

Finally, and not unrelated to the pedals, I sliced up some ERW tube to obtain some suitably light angle with which to fabricate control-cable support brackets.  Again these are just tacked in place at present.  The bracket in-front of the pedal box in the picture above will actually just support a fabricated stand-off which will hold the cable adjuster for the 'go' pedal.  The bracket in the top-centre of the photograph, welded to the flank of the pedal box, will house the cable adjuster for the clutch cable.

I was hoping to finish the reverse gear this weekend but its yet to arrive - two weeks later than quoted!

TC

Geminus

Apparently the word Gemini is derived from the Latin for plural or twin, which is rather interesting given that Gemini is not often used as a noun and hence there appears to be some debate as to whether it warrants a plural at all.  Why is this of importance?  Well, I visited the Stoneleigh kit car show on Sunday and actually doubled the number of Geminis that I've seen in the flesh to, not including mine, four!

Here's the two new ones:

It was quite interesting to talk to the two owners, even though my modifications/specification means that the lessons to be learnt were largely limited body fitment.  In any case it was great to chat through some of the issues and also to get a good idea of where I should panel to underneath the front of the car (for aero-efficiency purposes.)

On Saturday, I really do need to bash together a panel to enclose the rear of the tunnel so that I can get a seat moulded.  I can then get the steering column welded in.  

I've commissioned HPC gears to make me a custom dual gear for the electric reverse.  This prompted me to total-up the cost of my reverse mechanism.  Holy Smoke!  Details once I get all the parts back.

TC