Speed car mark 2

November 2008 Update

2008-10-25T22:52:00.000-07:00

I haven't updated this for w while so thought I had better post the latest creation. The 3 wheeler never worked but the only thing I didn't try was front wheel steering. As the back end was so unstable I went on to something else. Here is a pic of the latest car

Twin Novarossi 35PLUS 21 engines with 3 speed gearbox and 4 wheel shaft drive. Its not without its problems. I used the front bulk heads from a Kyosho RRR and converted them to shaft drive. This gave me problems ensuring the bevel gears were meshing correctly and they wear out pretty quick. I think the best way would be to make custom bulk heads as a box so the gears always mesh properly.
The power to weight ratio is slightly better but I am thinking of using marine engines and a 4 speed gearbox. Here is a better design

Update

2008-07-05T00:24:00.000-07:00

The 3 wheel car it its initial form didnt work. It didnt have any grip and was difficult to control. The next step was to redo the front end with suspension and try again. This was also uncontrollable so I installed a steering gyro but this could not control the car. The problem was it was inherently unstable so next I modified the front and installed a differential

This worked and the car now tracks straight and wont veer off into the grass

Next test will be some time as I am off back to work

Here is a pic

Final Build

2008-06-21T00:29:00.001-07:00

Here is the car finished and with the body on. Testing is on Monday 23rd June at Long Marston
Airfield

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Alien 3?

2008-06-18T14:17:00.000-07:00

I need to see if the no suspension design works so am building a test car. Here are some pics

The idea it to make the car as ligh as as efficient as possible. The car only has 2 gears and is geared for 100mph. This is to find out if ots stable enough for high speed. If it works I'll be building a 3 engine version with a 3 or 4 speed gearbox and geared for 150mph

Testing will be next week

Cheers

2008-06-03T02:39:00.000-07:00

3 engine version of the same design

2008-06-01T10:25:00.000-07:00

With the shell and some nice wheels

2008-05-31T13:38:00.001-07:00

A quick design idea

Alien 2 lives!

2008-05-11T12:35:00.001-07:00

I havent posted an update for a while so here is the latest.

I got back from work and spent 2 weeks in bed with flu. I did manage to buy myself a milling machine and got to work on the Alien 2.

Here are the pics of the build

The bad news is it weighs in at 12lbs so with the same power to weight ratio as the single engine car I cant see it getting over 110

Cheers

Quick Update

2008-03-30T03:06:00.001-07:00

Hi

I have been a bit busy just recently and havent done much to the car. I have made a mock up of a 3 engine car with shaftdrive and a removable 3 speed gearbox. Here is a model

Steering Gyro Test

2008-03-18T05:18:00.000-07:00

I have been looking at making Alien 2 rear wheel drive only as the 4wd system saps the power and adds weight. The problem is traction and reaction speed when the car goes offline. To compensate I have been testing a steering gyro. Here is a video of it fitted on the RRR. I removed all the front wheel drive system and installed the gyro. I tested the car and it does crab to the right slightly but the gyro always tries to keep it straight. Here is a video of it working.

I have now decided on a configuration for the Alien 2 as follows

1m long
3 x Novarossi 35PLUS21 engines
Single 3 speed gearbox (removable and able to install CVT)
Rear wheel drive
Gyro steering

Practice speed event

2008-03-17T11:10:00.000-07:00

I had been waiting for the practice event to test the car and low and behold down came the rain!! The moring was washed out but we did manage some runs in the afternoon. Here is the vid of the event

http://www.youtube.com/watch?v=6LZ9sHUXD-k

The V2RRR went well but I only managed 82.4 mph and it was only just changing into 2nd. The problem was that the pipe has such a norrow power band that when it changed to 2nd the engine dropped off the power and stalled the engine. It sounded like it was going lean but it was the power band.

I need to reduce the 2nd speed gearing a lot to get it to accelerate after changing up but then the max speed can only be about 110mph unless I have 3 gears.

CVT Testing

2008-03-06T08:41:00.000-08:00

Here is a video of the CVT being tested. I cant embed the video so its a link to a youtube video

http://www.youtube.com/watch?v=W0BERPIp364

V2RRR Finished

2008-02-28T06:51:00.000-08:00

Here are some pics of the finished car ready for action

2008-02-26T10:53:00.000-08:00

Here are a few pics of the V2RRR with the MAC marine pipe fitted. The front tyres are Kyosho foams cut down to 10mm wide

Exhaust Testing

2008-02-25T11:02:00.000-08:00

here is a quick test of a standard exhaust on the 35PLUS 21 engine. I was using 25% Byrons fuel. The rev counter didnt work properly

I then fitted a marine exhaust and cut it down to min manifold length. Here is the full test.

The engine was tuned to give the leanest carb setting and still achieve steady rev. Here is a direct comparison to the sounds.

Best to loop the video so you can hear the difference

The prop is still too large as I got a max rev of 28,000 and i think the exhuat is too long but I cant cut it down any further so I need to do the test again

2008-02-15T04:02:00.001-08:00

Here are a couple of pics of the DRIVE pulleys for the CVT. The Driven pulleys will be made in a couple of days

Jan Update

2008-01-12T02:11:00.000-08:00

I have just started back on the cars after the festive break and there have been a few developments.

CVTech of Canada has finished the design of the CVT and is in the process of making the drive. I have started mocking up the 3 engine chassis with 2mm aluminium plate and will fit the drive when I get it.

The drive is adjustable with different weights and also the spring tension can be adjusted. This should allow fine tuning of the system to match the engine power and revs. I have a drawing of the CVT and will post it here if the company will let me

The V2RRR is being put together and I have changes the back belts to 3mm to reduce drag. I have uprated the JP engine to a team edition and will run 50% nitro to add power. The car is now geared for 120mph at 37,000 rpm

I had trouble with the electric car. The tyres were no good as they had zero grip so I have changed them for foams from the USA. I also left the power on and the 2 main LiPO packs are shot. This car is on hold for now.

Back to work tomorrow and then back on the project on Feb 26th

CVT Update

2007-12-22T01:58:00.000-08:00

Sorry for not posting for a while but I was tied up with a new job and now the Christmas season is upon us so not much time.

I have been busy and have struck a deal with a company to build me a Constant Variable Transmission for the speed car. The company is CVTech-RD in Canada and make CVTs for snow mobiles. A young engineer there has designed the CVT and here is a quick mock up of the system

THis is just the preliminary model to show the main parts. The final version will have all the adjustments etc..

The system will be 60mm dia and 80mm centres. It will allow the car to rev from 0-35,000 rpm and from 0-25mph then stay at 35K and accelerate to 150mph maintaining 35K revs (Theoretically!)

I will design the car around the CVT. The layout will be 3 x .21 engines wit a possibility of 4WD but I might opt for rear only with long chassis and gyro steering.

Final Design

2007-11-14T09:25:00.000-08:00

Here is the final design for the 3 speed box. I am going to install a diff and so the rear belt will be 3mm with a 44t pulley on the layshaft.

Contender

2007-11-13T08:10:00.000-08:00

I have been sent some pics of a car a guy in the USA is making for the speed event. I know him as Gary O. The car will have 4 engines and is shaft drive. Here are some pics

Best of luck Gary and hope you get it all finished AND TESTED before the event

Design Layouts

2007-11-13T07:03:00.001-08:00

I laid out the 3 speed gearbox onto a plate to see if there are any problems. Here is the first layout

As you can see its overly complex and has too much rotating mass

The next layout I tried was this one

This got rid of 1 shaft and 2 gears but also the brakes. The brakes are not as important as top speed so I'll go with this design for the 1st prototype.

This layout has the advantage of being able to easily add extra engines. Just install with a layshaft and feed it though to the gearbox 1st shaft with a pulley

Serpent Clutch Design

2007-11-11T14:02:00.000-08:00

To use a Seprpent style clutch for the 2nd speed the assembly needs to be fitted to a one way bearing to allow it to release after the 3rd gear has kicked in. The drawing above shows how I intend to fit a one way from an R12 to the clutch

Design Concepts

2007-11-10T01:36:00.000-08:00

The date is set for the 1st Speed event practise for March 16th 2008 at the Shakespeare County Raceway, Long Marston Airfield. I have started on the design concepts for the car that I will be using for the event.

The plan is to have a number of transmission design concepts with only a few fixed objectives. These are to use IC engines to go as fast as possible. Apart from that anything goes.

The design concepts will use the lessons learned from the design and running of the 3 engines Alien car of 2007. It was apparent that the 3 gearbox design didn't work and a single gearbox is required.

The design concepts are

1, 2, 3, or 4 engines
single or separate clutches.
2, 3 or 4 speed gearbox
Belt or shaft drive.

The plan is to test each concept, optimise the design and then list the pros and cons of each to see what parts when used together will result in the highest top speed.

The first design to be tested is the 3 speed gearbox. I have designed the 3 speed box to be able to accelerated the car quickly and keep the car on the power band.

The car needs to engage the clutch at 12,000 rpm no more than 30 mph. This will stop the huge clutch slip I had with the Alien car on starting.

Next the 1st gear will top out at 32,000 rpm around 60 mph.
2nd gear will engage and the revs cannot drop below 22,000 rpm 24,000 optimum

2nd will top out at 32,000 rpm at around 90 mph.

3rd will engage and the revs should not drop below 22,000 with 24,000 optimum. 3rd will then top out at 35,000 rpm at 120 mph

The trial will be with a single .21 engine to see what speed can be attained. and see if there are any flaws in the gearbox design. I don't think 1 engine will pull this gearing so another engine will be added until I can increase the gearing and the top speed.

I have built a 3 speed gearbox using parts from a Schumacher R12. It has the following gearing

Pinion 36
Spur to layshaft 48

1st gear 16/60
2nd gear 24/52
3rd gear 40/44

Pulley to back axle 1/1

I have the gearbox installed on a test bed and have attached an electric motor and a rev counter to be able to set the clutch pawls to engage at the correct speeds. This is 6000 rpm and 10,000 rpm. Here is a vid of the test