View unanswered posts | View active topics It is currently May 13th, 2025, 6:01 pm



Reply to topic  [ 40 posts ]  Go to page Previous  1, 2, 3, 4
 Double-engine question 
Author Message
Firing on two.
User avatar

Joined: November 29th, 2008, 10:05 pm
Posts: 9259
Location: West Sussex, U.K.
Post Re: Double-engine question
I still don't buy it. I can't see it working the way it's meant to. Somebody needs to break out the Lego technic and make it.

_________________
samfieldhouse wrote:
What I like about I2F is that there is no pretence of democracy.


February 23rd, 2013, 10:53 am
Profile
Firing on two.
User avatar

Joined: March 5th, 2009, 6:23 pm
Posts: 2247
Location: Near Monmouth
Post Re: Double-engine question
@Dyane61976
Like the pics, do you have more, could you email large ones.
Also which magazine.


February 23rd, 2013, 11:36 am
Profile
Firing on two.

Joined: February 21st, 2012, 9:01 pm
Posts: 1136
Location: Avranches, Sud Manche, France
Post Re: Double-engine question
The photos I posted were taken off the net - some guy building a Dakar 2cv.
http://deuchescompetion.canalblog.com/a ... 67398.html


February 23rd, 2013, 12:57 pm
Profile
Firing on two.
User avatar

Joined: January 5th, 2009, 5:48 am
Posts: 1687
Location: Haven't a clue
Post Re: Double-engine question
I'm standing by what I said yesterday. When using a single rod linkage the 2 movements it transmits are not forwards/backwards and left/right, but forwards/backwards and rotation. If you move the gear knob to the left, the rotation is anticlockwise, and if that rotation is transmitted directly to the gearboxes then it's 1st/rev at the front and 4th at the rear.

However I've been imagining the linkage attached at both ends with a single 'clevis' type joint, where exactly the same degrees of rotation are transmitted between the levers and rods. Much like the linkage in my car. http://i686.photobucket.com/albums/vv22 ... C11160.jpg

I have just seen a way to do it with ball joints though. Perhaps this is what other people were thinking of.

Image

Personally I'm not keen on the vertical sections of linkage, Although they allow you to vary the ratio of rotational movement, I think they introduce too much flex, the front section is easy enough to use clevises though, which i think makes for a more positive change.

Image

One little issue is that the fixed bushes of the rear section may want to move up and down slightly, depending on what was used as the ball joints.

_________________
Image


February 23rd, 2013, 3:28 pm
Profile
Firing on two.

Joined: February 21st, 2012, 9:01 pm
Posts: 1136
Location: Avranches, Sud Manche, France
Post Re: Double-engine question
I know, I know it is not a 2 engine but great fun to watch
http://www.youtube.com/watch?v=TfcQ-7hI ... zdpJM3gEPA :D


February 23rd, 2013, 6:15 pm
Profile
Firing on two.

Joined: March 26th, 2010, 8:41 pm
Posts: 234
Post Re: Double-engine question
Were there any 2Cvs converted for disabled drivers using pneumatics or the like ? If so, a second system could be reversed for the rear engine etc.


February 24th, 2013, 5:12 pm
Profile
Firing on two.
User avatar

Joined: November 29th, 2008, 10:05 pm
Posts: 9259
Location: West Sussex, U.K.
Post Re: Double-engine question
There's a few 2cvcross cars that've been converted although only to negate the use of foot pedals. The throttle and brakes were on the steering wheel and the pneumatic clutch was operated via a micro switch in the gearknob, when you touched the gearknob it disengaged the clutch. It was run from a pneumatic pump off of a truck thàt was run from the alternator belt. Pneumatic actuators are cheaply available and would be a more modern solution.

I like to think that you could make a system similar to a telephone. The mouthpiece is forced to move and creates an electronic pulse that makes the speaker move the opposite way. (I realise this is a simplified version of events). I reckon, and I've no real in-depth knowledge of this, that some sort of variable sliding resistor (like you get in a scalextric hand throttle) in fact, two of them one in the x axis and one in the y axis, could be used to move two actuators on the rear gearbox. It's not as beautiful as a mechanical linkage or as elegant but doing it with electronics means no engine movement or crash damage will affect it. It's perhaps a more modern solution?

I could never be arsed to sit and make something like that work, but I'm sure it would.

_________________
samfieldhouse wrote:
What I like about I2F is that there is no pretence of democracy.


February 24th, 2013, 8:47 pm
Profile
Firing on 1-2 Spark
User avatar

Joined: November 8th, 2009, 5:42 pm
Posts: 2847
Location: NL
Post Re: Double-engine question
1-2-shift.......

_________________
Russell wrote:
Hi Geo,
you've been one of the sites biggest attractions in recent years.
Russ


February 24th, 2013, 8:57 pm
Profile WWW
Firing on 1-2 Spark
User avatar

Joined: November 8th, 2009, 5:42 pm
Posts: 2847
Location: NL
Post Re: Double-engine question
So youv'e got me there. 3 double pneumatic cilinders, each for one slider in the gearbox and and a controller of mine would do.
Controller sends current to lpg valves 6 pieces, little programming if then else and hey presto
automatic gearbox.......

Shit Russel I'm lost again.....

_________________
Russell wrote:
Hi Geo,
you've been one of the sites biggest attractions in recent years.
Russ


February 24th, 2013, 9:03 pm
Profile WWW
Firing on two.
User avatar

Joined: November 29th, 2008, 10:05 pm
Posts: 9259
Location: West Sussex, U.K.
Post Re: Double-engine question
I'm not clever enough to think about moving the selector rods independently but that would be much better than my idea which was to simply use the 'sender' at a fixed point on the front box and use the actuators on the same point on the rear box.

_________________
samfieldhouse wrote:
What I like about I2F is that there is no pretence of democracy.


February 24th, 2013, 9:13 pm
Profile
Display posts from previous:  Sort by  
Reply to topic   [ 40 posts ]  Go to page Previous  1, 2, 3, 4

Who is online

Users browsing this forum: No registered users and 109 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group.
Designed by STSoftware for PTF.