PS, I understand that the ECU has to be controlled to wind the brakes out to change the pads, so perhaps it is a little more complicated than locost.
[Edited on 23/5/12 by HowardB]
OK so I've been on to VOSA and they've been really helpful, the general outcome being that there's two key requirements. The first is
to do with the activation of it, the second the actuation.
1) The switch to activate the brake must be protected from inadvertent use. Apparently, alternative to this is a system where the handbrake switch can
be activated but not de-activated when the ignition is off. I presume this is purely to prevent accidental/malicious release rather than to stop you
accidentally hitting the brake while driving.
2) The park brake must be held in the on position solely by mechanical means (hydraulic is not mechanical and any form of electric clamping must
failsafe to the braked/locked condition without power) - so any UK (EU?) type approved electric caliper such as those found on some Audis should do
the trick just fine as they meet the same requirements.
HTH
Interesting!
Controlling it would be a nightmare though. All cars have a dedicated park brake module for controlling EPB - don't think it's quite as
simple as having 12v to the caliper!
Ironically also one of the most likely things to fail on many VAG vehicles (the amount of times my colleague's VAG cars have refused to release
the EPB in the morning is getting ridiculous).
Never really looked to closely at the mechanics of the electrics in the actual caliper though so it might all be a bit easier?
sadly I have a VAG. Passat Estate to be precise, and I do not use the epb for anything, and certainly not in auto mode. It will not release, and has
on occasion caused the car to stall. It has been back to the robbers-main-dealer on a number of occasions. Having said that other colleagues have no
issues theirs,..
PS, I understand that the ECU has to be controlled to wind the brakes out to change the pads, so perhaps it is a little more complicated than
locost.
[Edited on 23/5/12 by HowardB]
We have them on some of the companies pool cars, but the thing i really dont understand is, whats wrong with a conventional cable. Its simple,
effective, reliable, cheap.
Daniel
quote:
Originally posted by dhutch
We have them on some of the companies pool cars, but the thing i really dont understand is, whats wrong with a conventional cable. Its simple, effective, reliable, cheap.
Daniel
A lever, ratchet, pair of cables, associated mounting points, associated lifespan of lubes, potential adjustment requirements etc are nowhere near as
simple as a switch, wire and a box of gubbins with some software to deal with control of the caliper? I think the locost brethren are still in an era
where electronics are a black art and a failure point, TBH this just isn't the case, less so if the person doing them has the time and patience
to do it as a personal project rather than lobbing them out to a deadline.
I'm considering buying a VAG caliper just to check out the interface - it won't be complex for a tiny micropro box. And the combined weights
of all parts are likely to be very similar.
quote:
If they got rid of all this crap then modern cars would hardly go wrong!!!!
quote:
PS, I understand that the ECU has to be controlled to wind the brakes out to change the pads, so perhaps it is a little more complicated than locost.
I've always been tempted to try and fiddle with some sort of linear-atuator for the trike. A simple switch would save me the hassle of trying to
cram a lever in the cockpit.
Surely it wouldn't have to produce much force to pull a single spot-caliper suitably tight on the rear disc of a 300kg vehicle???
The main problems I have with electric handbrake on tintops are:
1. If it fails its almost certainly return to dealer - how if its 'on'?. In the good old days when I ran cars from the 60/70s the handbrake
mechanism might seize, but you could almost always sort it for next to nothing rather than 'its the ECU mate, that £600' or the dedicated
controller box or the caliper. It almost certainly means taking the car to the main dealer when the pads need sorting too if you need a special ecu
mode to back the pads out(=£120 rather than £30).
2.My wife actually runs a fleet of cars. electronic failures are the most common fault by a long way, especially if its french. In my experience they
are the problems that are the most difficult to overcome at home, unless you are lucky and spot an obvious break in the wire or fallen off
connector.
3.A lingering fear that the brake will suddenly apply itself, or release itself. At my missus's they have had one car roll away in the carpark
(luckily its very shallow slope so no damage was done)
when the auto handbrake was active (Audi).
Regards
Hugh
almost man enough actuator linky... but not quite
Toyota uses electric park brake and everyone knows Toyotas don't break down!!!!
It seems to be the trend over the last ten years to overcomplicate everything to force motorists into the dealers clutches to be robbed blind. Soon there will be nothing that is customer servicable on a car. Fine if its a firms car, but what about the average joe who gets fleeced every time it goes wrong. Keep things simple in my view.
quote:
Originally posted by coyoteboy
A lever, ratchet, pair of cables, associated mounting points, associated lifespan of lubes, potential adjustment requirements etc are nowhere near as simple as a switch, wire and a box of gubbins with some software to deal with control of the caliper?
Certainly a lot of cars these days are having electrical faults but IME they're nothing you can't fix if you have a bit of electronics
knowledge, just like mechanical issues for people with mechanical knowledge. The equivalent of a rattle in a track rod end. Sometimes there's
major failures of whole components, these seem to be catastrophic (Large ECU failure) which will happen when you have millions produced, it's
just the laws of averages, most of the mechanical parts have had 50 years of knowledge put in to them. All the faults I've seen on french cars
are wire failures, that's due to poor design and poor materials for a cheaper car. And if you don't have to go to a dealer for the part, it
doesn't cost hundreds. But valid points all the same.
A locost setup of this sort would not require ECU diags to retract for pad changes, that's been specifically designed in for a reason.
As for accidental applications or removals - the former should be designed out of the electronics, the latter - that's a bit more complex as it
relies on sensing when enough force has been put on. I've never heard of one doing that TBH but I'd have to know the circumstances to give a
fair assessment.
quote:
Depends whats in the box of gubbins. In my experience said boxes are rairly cheap.
But I guess for your average punter that is a bit harder than attaching cables. But I never said this was everyones cup of
tea. rather than mess about with the electronic controls of VAG why not use the electro-mechanical systems as found on Jag S-types etc. Standard cable
h/brake calipers with an electric motor pulling the cable and simple switching.
Still prefer the control of a manual lever though.
quote:...or put another way, a few mechanical parts that are easy to inspect and maintain with basic tools and minimal knowledge
Originally posted by coyoteboy
A lever, ratchet, pair of cables, associated mounting points, associated lifespan of lubes, potential adjustment requirements etc are nowhere near as simple as a switch, wire and a box of gubbins with some software to deal with control of the caliper? I think the locost brethren are still in an era where electronics are a black art and a failure point
quote:I know several people that have had issues with the newer VAG calipers, either the electronics packing in or the caliper siezing up (admitedly these cars had done 70k+)
I'm considering buying a VAG caliper just to check out the interface - it won't be complex for a tiny micropro box. And the combined weights of all parts are likely to be very similar.
quote:I'm afraid I'm with fazerruss on this one, I recon cars peaked sometime in the 90's (ok not all models, but the best of them), when they just figured out how to stop them rusting in 5min, but before they had electric/electronic everythingquote:
If they got rid of all this crap then modern cars would hardly go wrong!!!!
Personally I've had 3 handbrake cables snap, one caliper seize on and replaced 2 other cables due to lube breakdown as they got higher milage. They almost always need adjustment for MOT man to be happy. Couple of wires and a switch sounds like heaven to me.
quote:I'm told that you can just take the motor off wind them back by hand with an allen key/torx bit (then the ECU re-sets itself when you start it up again
.....I understand that the ECU has to be controlled to wind the brakes out to change the pads, so perhaps it is a little more complicated than locost.
) quote:
rather than mess about with the electronic controls of VAG why not use the electro-mechanical systems as found on Jag S-types etc. Standard cable h/brake calipers with an electric motor pulling the cable and simple switching. Still prefer the control of a manual lever though.
quote:
handful of wires and a black box that you either throw away and replace (at a considerable cost) or need specalist tools and a knowledge of electronics to fix.....
quote:
I know several people that have had issues with the newer VAG calipers, either the electronics packing in or the caliper siezing up (admitedly these cars had done 70k+)
quote:
I don't like electonics much, but play around with odd things (MJ for the dax, home built pc's etc...) - but I just don't see the need for an eletronic hand brake if the mechanical one is an easy option
However I love
electronics and mechanical stuff (combining them is my career field!) so I'm not shy of trying this sort of thing. Sorry, Really don't see the need for an electric handbrake
More to go wrong and over complicated
We've been managing fine with cable operation for years so why re-invent the wheel ?
Mate had one on his Renault and absolutely hated the thing, it kept getting stuck and it was one of the main reasons
he got rid of it in the end
Each to his own though
[Edited on 23/5/12 by perksy]
Dear christ, if you're just going to bash it at least read the thread and realise what you've said has been said before. 
I'm not
asking for opinions, I'm offering info.
If you're building a mid-rear engined car with shift gubbins going backwards, a tunnel fuel tank and fully IRS rear end removing a bunch of
unpleasant looking and pesky cables is actually fairly handy.
[Edited on 23/5/12 by coyoteboy]
I have a new vauxhall Astra with a electric hand brake [ i hate it ] and i don't trust it
I wish the car had the old fashioned cable brake
Jacko
quote:
Originally posted by coyoteboy
This is exactly the same arrangement though, only the electronics (or rather electricals) are concentrated into one unit instead of two. All the VAG calipers contain are an electric motor, gearing to the back of the piston and a latching pin that prevents the caliper backing off when the power is removed. It's possibly the most simple electromechanical device you ever saw.
I'm quite tempted to fit one to my Fury. The lever is currently in an awkward place and takes space away from an already cramped passenger.
quote:
Originally posted by MikeRJ
So you have an electric motor and associated gearing in a lump of metal that can get smoking hot under hard use, and which also should be mak[e as light as possible? That doesn't seem like a clever idea.
quote:
There doesn't appear to be any difference in the construction of the sliders and the piston, so what makes you think these electric calipers will be less prone to seizing than normal cable operated ones?
Nobody is addressing the main issue and sole purpose of existence of handbrakes.
Can you do handbrake turns with them?
quote:
Originally posted by whitestu
Nobody is addressing the main issue and sole purpose of existence of handbrakes.
Can you do handbrake turns with them?
quote:
Originally posted by whitestu
Nobody is addressing the main issue and sole purpose of existence of handbrakes.
Can you do handbrake turns with them?
quote:
Originally posted by whitestu
Nobody is addressing the main issue and sole purpose of existence of handbrakes.
Can you do handbrake turns with them?
quote:
Originally posted by whitestu
Nobody is addressing the main issue and sole purpose of existence of handbrakes.
Can you do handbrake turns with them?
quote:
Originally posted by whitestu
Nobody is addressing the main issue and sole purpose of existence of handbrakes.
Can you do handbrake turns with them?
quote:
Originally posted by whitestu
Nobody is addressing the main issue and sole purpose of existence of handbrakes.
Can you do handbrake turns with them?
I don't get all the negative views here. If you have packaging issues then, just like the OEMs, an electric solution makes a lot of sense. If you
don't, stick with the lever like the majority of mass produced cars still do. The info given is very useful and I can assure that what VOSA are
looking for is a far cry from the level of failsafes that type approval requires.
The comments above are all the same kind of stuff that would have been said when hydraulic brakes started to take over from rod linkages; discs
superceded drums; electric starter motors were introduced; etc etc. Fuel injection is another example: yes, when it goes wrong it can be expensive and
potentially difficult to diagnose, but most modern cars go their entire lives without missing a single beat. I'm running a 1994 Volvo engine on
its original ECU and sensors in the MK; 18 years old and it has never needed tuning or adjusting in any way, just oil and filters periodically.
I digress a little, but do we want to go back to 3000 mile services involving valve adjustment, brake shoe adjustment and points / spark plug gapping
amongst countless other items? Yes, the 500+ quid bill if / when something goes wrong is hard to swallow, but you've saved that many times over
in the life of the car compared to the maintenance costs of the old technology that seems so loved by some! I admit this logic is not really relevant
in the EPB debate, but the principle of rejecting new technology rather than learning about it holds true.
I don't get all the negative views here. If you have packaging issues then, just like the OEMs, an electric solution makes a lot of sense. If you
don't, stick with the lever like the majority of mass produced cars still do. The info given is very useful and I can assure that what VOSA are
looking for is a far cry from the level of failsafes that type approval requires.
The comments above are all the same kind of stuff that would have been said when hydraulic brakes started to take over from rod linkages; discs
superceded drums; electric starter motors were introduced; etc etc. Fuel injection is another example: yes, when it goes wrong it can be expensive and
potentially difficult to diagnose, but most modern cars go their entire lives without missing a single beat. I'm running a 1994 Volvo engine on
its original ECU and sensors in the MK; 18 years old and it has never needed tuning or adjusting in any way, just oil and filters periodically.
I digress a little, but do we want to go back to 3000 mile services involving valve adjustment, brake shoe adjustment and points / spark plug gapping
amongst countless other items? Yes, the 500+ quid bill if / when something goes wrong is hard to swallow, but you've saved that many times over
in the life of the car compared to the maintenance costs of the old technology that seems so loved by some! I admit this logic is not really relevant
in the EPB debate, but the principle of rejecting new technology rather than learning about it holds true.
I don't get all the negative views here. If you have packaging issues then, just like the OEMs, an electric solution makes a lot of sense. If you
don't, stick with the lever like the majority of mass produced cars still do. The info given is very useful and I can assure that what VOSA are
looking for is a far cry from the level of failsafes that type approval requires.
The comments above are all the same kind of stuff that would have been said when hydraulic brakes started to take over from rod linkages; discs
superceded drums; electric starter motors were introduced; etc etc. Fuel injection is another example: yes, when it goes wrong it can be expensive and
potentially difficult to diagnose, but most modern cars go their entire lives without missing a single beat. I'm running a 1994 Volvo engine on
its original ECU and sensors in the MK; 18 years old and it has never needed tuning or adjusting in any way, just oil and filters periodically.
I digress a little, but do we want to go back to 3000 mile services involving valve adjustment, brake shoe adjustment and points / spark plug gapping
amongst countless other items? Yes, the 500+ quid bill if / when something goes wrong is hard to swallow, but you've saved that many times over
in the life of the car compared to the maintenance costs of the old technology that seems so loved by some! I admit this logic is not really relevant
in the EPB debate, but the principle of rejecting new technology rather than learning about it holds true.
Why not have a linear actuator like the one above pressing on the arm of a master cylinder to move a hydraulic caliper ...
quote:
Originally posted by mad4x4
Why not have a linear actuator like the one above pressing on the arm of a master cylinder to move a hydraulic caliper ...
quote:
Originally posted by mad4x4
Why not have a linear actuator like the one above pressing on the arm of a master cylinder to move a hydraulic caliper ...
quote:
Originally posted by iank
quote:
Originally posted by mad4x4
Why not have a linear actuator like the one above pressing on the arm of a master cylinder to move a hydraulic caliper ...
... (Might be legal for an MSVA'ed trike though)
quote:
Originally posted by JeffHs
Toyota uses electric park brake and everyone knows Toyotas don't break down!!!!
Ford use the simplest system an electrically driven screw jack pulls on the cable. To meet regulations the jack is designed with worm drive so
it "overhauls" ie internal friction id desined to be high so friction holds it on and it has to be electrically driven backwards
to release tension from the cable
Still it is absolutely pointless extra complication.
Oh 'eck
I quite surprised how negative this threads gone, (although my own post earlier reads more negatively than I thoght when I typed it). I can see the
reason for fitting one if the packaging works, and can imagine it is pretty reliable if you take away the 'auto' gubbings, and have a on/off
switch (preferably with some decent cover to stop accidental activation!). I can't imagine using one myself for reasons mentioned before, and
because it seems like a load of extra efforst/cost (unless you stripped the donor and had al the bits anyway), but then I'm building a self
designed midi as my first 'kit', and no one would recommend that either. So thanks for posting the info and drawing, and best of luck - I
will be interested to hear how you get on with it. Remember the reason for doing something a particular way on one of these cars doesn't have to
be any more that 'because I fancy it that way...'
Regards
Hugh
quote:
Originally posted by britishtrident
Still it is absolutely pointless extra complication.
) hughpinder - cheers for the slightly more positive note!
britishtrident - I don't see it as much, if any, extra complication as there's nothing complicated about it, but each to his own.
I fully recognise the tiny increase in unsprung mass (which is avoided by the mono-point system but which really is more of a complexity issue as
you're keeping half of the original components AND adding electronics. I don't recognise the heat problem, nor the control problem.
You've swapped a lever and ratchet and two cables for two motors, two gears and two locking pins. Sure electric motors fail, but primarily with
use - not going to be seen much on a kit. The locking pins are the likely failure point IMO, they'll be spring assisted and disengaged
electronically. Sliding joint in a thermally fluctuating location is probably the point that causes most failures on these and I think that's
borne out by evidence - people claiming they either release when not expected (spring not pushed it home properly) or don't release (pin jammed
or wire broken maybe). Neither of these is catastrophic and a quick strip and diag would solve the issue but in dealership/OEM situations it's
just not financially viable - quicker to replace the whole caliper.
I guess my position is "I don't see electronics as bad or a complication" which is a personal point of view based on my experience and
work. It seems I've struck a nerve here, plenty of folk seem almost agressively against the idea. Maybe it's contrary to the locost
principles the site tends to follow, but I don't think so. Unless you think you need to run the OEM electronics to get it to work, but I
don't.
Strange to see plenty of folk build, modify and tune their own megasquirts (ECU), fit tiny microelectronic injection solenoids (same as locking pins
in caliper) and motors (pumps) and don't consider it a complication instead of just just whapping on carbs.
As for handbrake turns - I see no problem with that option other than not being able to control the force application too easily with a button.
It'd be fairly easy to modify the control system to provide a non-locking adjustable force solution though!
[Edited on 24/5/12 by coyoteboy]