Electronic Hood Cover Release

Moderators: theelanman, dapinky, Specky, clemo, Nige, Sy V, Dave Eds, DaveT, Elanlover, muley, Enright, algirdas, nitroman, GeoffSmith

Electronic Hood Cover Release

Postby dapinky » Sun 10.05.2015, 22:27

Okay, I know this project won’t necessarily interest everyone, and many would consider it severely over-complicating an adequate system – but for those of us who like to see what can be done to make life that little bit easier, here goes….


Well, having tried a few weeks ago to get the hood cover (tonneau cover) to release with an electrical system which ended in abject failure due to the required pull on the cable being far in excess of the solenoid I had purchased (burned it out on the first attempt), I re-visited it today with a different mind-set.

The OE cable works well enough, but does require a good pull (on my car anyway!) to release the 2 catches. This is due in main to the release system whereby 1 cable operates 2 catches via a pair of levers inside the catch holder brackets.

I frequently needed to push down on the cover to take pressure off the catches whilst pulling the cable – not always an easy task to reach everything whilst applying enough force to the cable to work the mechanism.

The actual catches are exactly the same as the boot catch - but using 2 of them – and as the boot opens easily with a solenoid, it couldn’t be that hard to make it all work….

Once you take the plastic cover off (2 small self-tapping screws) it is apparent that the metal rods from the leverage mechanism work in an inefficient plane (90 degrees from the cable movement), and therefore an awful lot of force is required to get the required movement at the catch.

The actual mechanism doesn’t need much force at all to operate; it just needs to be applied in the right direction.

It took a bit of thought (about leverage principles), but wasn’t at all difficult to achieve.

I needed to purchase 2 bicycle cables (I went for stainless steel Teflon coated gear cables, as they are thinner than brake cables which makes the crimping a bit easier, but brake cable would also work), I still had an unused solenoid from my earlier purchase of 2, some suitable bolts and some 10mm aluminium plate left over from my seat brackets so nothing else to be bought. As Halfords currently have Universal gear cables for £1.99 each it wasn’t a hugely expensive project.

6.JPG


Firstly, I had to route the cables – easy on the drivers (right) side, but a little harder on the left as the petrol tank is right below the bracket. I drilled a 10mm hole at the bottom right-side of the steel bracket and job done.

I made up some cable-end brackets from the aluminium plate – each one was made from a bit 10mm x 15mm x 40mm (approx.), and as they can’t be seen the exact size/finish is fairly irrelevant, as long as it does the job. A simple case of drilling a 2mm hole through the width (15mm) of the metal, then opening the hole out to 6mm for 10mm depth. Then a couple of 5mm holes across the other face for the fixing bolts.

2.jpg
3.jpg


2 are the same, and the 3rd is similar, but with 2 holes next to each other, approx. 10mm apart (2 cables).

Fix the 2 aluminium cable ends to the inside of the current brackets, angled slightly away from vertical, so the cables run in a straight line between where they enter the bracket and where the release catch fits (obviously, they fit with the 6mm hole downwards!).

Push the inner cable through the sleeve and fit the end of the sleeve into your aluminium block (probably easiest to do these bits before actually finally bolting the blocks to the bracket!). Then loop the cable through the end hole in the lever at the back of the catch (again, easiest to remove them first, and take the metal rod out of hole!!) Crimp the wire loop (I used standard blue wiring crimps, but removed the insulation to leave the metal bit) – again, it is obvious that you need to have fed the crimp over the cable before forming the loop, but I’ll state the obvious anyway.

1.jpg


Feed the cable so that it is all running freely and snug in the blocks, then refit the catches and tighten up the bolts holding the blocks to the brackets.

I fitted the solenoid to a piece of steel plate which I had lying around, and cut it to the right size to fit where I wanted to mount it, but you can fit it wherever you want. It needs to be on a plate to give suitable rigidity to the system, as the other aluminium block mounts to the same plate, and without it, you would have to engineer some way for the solenoid to actually operate the cable, not just pull the whole lot!

The 2 cable inners loop through the solenoid bar and crimp to each other (that makes more sense if you see the picture). You need to adjust the amount of inner cable so that the catches operate within the movement of the solenoid, then do up the crimps, trim the cable length and move on.

4.jpg


Arguably, the plate with the solenoid could just be left lying anywhere, but you need to make the cable runs as smooth as possible, so I mounted it to the roll hoop side mounting – it is easy enough to fit in the same location if you haven’t got LGM hoops fitted :D .

5.jpg


Wiring was simple as I already had a solenoid in that area for the fuel filler cap release so there was a fused supply right next to it, but assuming that you haven’t got that, it’s easy to run a fused (4 Amp) supply direct from the battery (which is only a foot away) to the green wire on the solenoid. The blue wire I extended and ran through the bulkhead (between the hood frame mounting and the B post cover, no drilling or cutting required to that part) and used the push button which I had previously utilised for the boot release (which has since been adapted to release from the key fob, so the switch was somewhat redundant). It is a standard Saab boot release switch (any push-to-connect switch will do) mounted on the B post trim, just above and inboard of the old pull cable location.

7.JPG
It’s an old pic of my old car, but I can’t be bothered to take another pic which would show the same switch in the same location


The other side of the switch just goes to earth.

That’s all there was to it, and the solenoid is plenty strong enough to pull 2 cables and release the 2 catches when it is aligned properly – the only really fiddly part was getting the inner cable lengths correct, and that only took about 3 minutes. I suppose that if you engineered the system slightly differently you could incorporate a couple of cable adjuster sleeves, but I didn’t think it was necessary. I might change my mind as and when the cables settle and/or stretch and I need to re-crimp the wires a bit tighter, whereas a simple twist of an adjuster would make it an easy process.

There is a potential problem with the whole system – if the battery is flat (or the fuse blows), or the solenoid burns out, then you can’t open the cover – and sods law states that it will happen just as it starts to rain and you want the lid on, but all is not lost.

I’m sure that you could either leave the original bars in place so that the OE cable pull remains (but I didn’t), or you can easily reach over the rear bulkhead to the catches (even with roll hoops fitted). As such, I drilled a 10mm hole in the middle of the plastic cover and fitted a rubber grommet. In event of a failure, simply remove the grommet and you can see the wires/catches and a quick tug of the wire, or poke of the lever with a small screwdriver will easily release the catches.

Having also (a while ago) replaced the fuel filler release with a cable/solenoid system, I have been able to remove the 2 cables from the door frames, and the remaining holes can be either filled & painted, fitted with a rubber grommet, or an M8 bolt with a nut on the back.

It all looks a lot tidier, and I can open the cover easily – even if I need to press lightly down to take the pressure off the catches it is so much easier to press a convenient button than pull a cable the wrong way!

It is obviously easier to do if you can remove the plastic liner tray, but it is possible with it still in situ (but you need to remove the right-side end cover to access the wheelarch space to stick the solenoid down there :roll: )
Dave

Just the one now, but this one's mine! - and it will be finished eventually..... - but also temporary custodian of a project until it is finished enough for Angie to drive it

go on - click this link - you know you want to!
User avatar
dapinky
LEC Administrator
 
Posts: 10000
Joined: Sun 15.10.2006, 12:54
Location: As far west as you can get in West Wales before you become Irish (Pembroke Dock).

Re: Electronic Hood Cover Release

Postby HJ2 » Mon 11.05.2015, 07:47

Very creative and thought ahead (rubber grommet in case of failure) :D
Hoping to see a cable operated all electrical hood soon (Like the BMW Z3) :lol:
If you always do what you always did, you always get what you always got
User avatar
HJ2
Wodan - God of the Low Lands
 
Posts: 4380
Joined: Fri 06.06.2008, 10:54
Location: Delft, the Netherlands

Re: Electronic Hood Cover Release

Postby Jamie N » Mon 11.05.2015, 09:55

Nice wee project Dave, top marks for inventiveness :bowdown: . What about adding in another part to the setup which actuates 2 hydraulic pistons to lift the hood cover straight after release followed by automatic closure. 8)
Monaco S2 #406

https://youtu.be/MGiyiIFjUew Rubbery stuff.
User avatar
Jamie N
Seal God
 
Posts: 1175
Joined: Wed 21.12.2005, 18:49
Location: Sunny Fife.

Re: Electronic Hood Cover Release

Postby dapinky » Mon 11.05.2015, 10:05

Jamie N wrote:..... What about adding in another part to the setup which actuates 2 hydraulic pistons to lift the hood cover straight after release followed by automatic closure. 8)


I was actually looking at whether a pair of hydraulic struts could be mounted to hold the lid open anyway, and decided that there isn't enough clearance between the hood and the lid to allow them to operate - as such, a pair of hydraulic pistons would be even more difficult to mount (but, no doubt, possible).
Dave

Just the one now, but this one's mine! - and it will be finished eventually..... - but also temporary custodian of a project until it is finished enough for Angie to drive it

go on - click this link - you know you want to!
User avatar
dapinky
LEC Administrator
 
Posts: 10000
Joined: Sun 15.10.2006, 12:54
Location: As far west as you can get in West Wales before you become Irish (Pembroke Dock).

Re: Electronic Hood Cover Release

Postby Elanlover » Mon 11.05.2015, 12:14

Dave, I've had a solenoid operated tonneau cover release for several years now. Not as critical for UK based cars but for FED cars having to run around to the passenger's side to grab the release is a real pain. I've had 3 tries at this project with ever increasing sizes of solenoids. the latest is a 40lb model which just releases the cable - most of the time. It has to be perfectly aligned, the tension just right, etc. Its a real pain and not satisfactory at all. Very interested in your solution here as I took a quick look at something similar a couple of years ago but never dug deeper. Do you have any better pics? I'm having trouble visualizing your solution but its early in the morning here and I may need some more tea before I read it again. :-D

P.S. I left the original cable in place so I could operate the manual release if needed - which is more often than not.
I do whatever my Rice Crispies tell me to do
User avatar
Elanlover
Moderator
 
Posts: 3498
Joined: Fri 05.08.2005, 19:11
Location: The Great White North

Re: Electronic Hood Cover Release

Postby cliff » Mon 11.05.2015, 12:54

Very good Dave, just what I need, more project creep. :lol:

My hood cover would not release and turned out to be the cable seized between the 2 catches. Lack of lubrication in this area could be a reason for difficulty opening the cover.

viewtopic.php?f=37&t=23004&p=290189#p290189
91 Lotus Elan SE Turbo
03 MG TF 135 Sprint (Partner's)
15 Renault Megane Coupe

If you can't be a good example, then you might as well be a terrible warning
User avatar
cliff
God
 
Posts: 800
Joined: Mon 17.01.2011, 18:39
Location: Preveza Greece / Scunthorpe UK

Re: Electronic Hood Cover Release

Postby dapinky » Mon 11.05.2015, 14:00

cliff wrote:Very good Dave, just what I need, more project creep......



Well, in that case, I'll not publish the details of my other project yet.

..... but I happen to know that it was something you were looking at a while ago....


...... and I've now got a 'simple' instalation which works a treat :wink:
Dave

Just the one now, but this one's mine! - and it will be finished eventually..... - but also temporary custodian of a project until it is finished enough for Angie to drive it

go on - click this link - you know you want to!
User avatar
dapinky
LEC Administrator
 
Posts: 10000
Joined: Sun 15.10.2006, 12:54
Location: As far west as you can get in West Wales before you become Irish (Pembroke Dock).

Re: Electronic Hood Cover Release

Postby dapinky » Mon 11.05.2015, 14:04

Blair,

I've got it all put back together again at the moment - what bits do you need clarifying, and I'll see what I can do.

PS, The solenoid I am using (sucessfully) is a 4Kg one - so sustantially less than your 40Lbs - which only emphasises my abject failure to start with, and the extra force required if using the original cable/lever system.
Dave

Just the one now, but this one's mine! - and it will be finished eventually..... - but also temporary custodian of a project until it is finished enough for Angie to drive it

go on - click this link - you know you want to!
User avatar
dapinky
LEC Administrator
 
Posts: 10000
Joined: Sun 15.10.2006, 12:54
Location: As far west as you can get in West Wales before you become Irish (Pembroke Dock).

Re: Electronic Hood Cover Release

Postby Elanlover » Mon 11.05.2015, 14:13

I'll pull the latches apart today and have a look to refresh my memory. Perhaps it will all become clearer when I can see the parts we're talking about. I've never liked using the 40lb solenoid. Its heavy, loud and draws a lot of amps when activated.
I do whatever my Rice Crispies tell me to do
User avatar
Elanlover
Moderator
 
Posts: 3498
Joined: Fri 05.08.2005, 19:11
Location: The Great White North

Re: Electronic Hood Cover Release

Postby dapinky » Mon 11.05.2015, 14:20

Blair,

If you simply remove the 2 self-tappers on the plastic shroud and lift it up and off the catch to have a look at the current system (look down inside the brackets, and you'll see the rods i removed - the cables run pretty well where the rods were, but obviously exit the bracket before the OE cable entry point), then it should all become crystal!

Unfortunately, when i get into these projects, I end up getting far to engrosed in what I'm doing and forget to photograph everything - then I'm left with pics of the end result (which often show nothing useful) and images which are taken from funny angles and don't tell the whole story well.....

.... add to that my 'writing style' and I can see how it may be difficult to follow.

(But knowing the sort of projects you have accomplished, this one is relatively simple and would be easy once you appreciate how i did it)
Dave

Just the one now, but this one's mine! - and it will be finished eventually..... - but also temporary custodian of a project until it is finished enough for Angie to drive it

go on - click this link - you know you want to!
User avatar
dapinky
LEC Administrator
 
Posts: 10000
Joined: Sun 15.10.2006, 12:54
Location: As far west as you can get in West Wales before you become Irish (Pembroke Dock).

Re: Electronic Hood Cover Release

Postby Elanlover » Mon 11.05.2015, 14:43

dapinky wrote:................Unfortunately, when i get into these projects, I end up getting far to engrosed in what I'm doing and forget to photograph everything - then I'm left with pics of the end result (which often show nothing useful) and images which are taken from funny angles and don't tell the whole story well........


There's a club for that - of which I am President. Unfortunately, as membership requires documenting the application process with pictures, there's only one member.
I do whatever my Rice Crispies tell me to do
User avatar
Elanlover
Moderator
 
Posts: 3498
Joined: Fri 05.08.2005, 19:11
Location: The Great White North

Re: Electronic Hood Cover Release

Postby cliff » Mon 11.05.2015, 20:54

dapinky wrote:
cliff wrote:Very good Dave, just what I need, more project creep......



Well, in that case, I'll not publish the details of my other project yet.

..... but I happen to know that it was something you were looking at a while ago....


...... and I've now got a 'simple' instalation which works a treat :wink:


Waiting in rapt anticipation. :P
91 Lotus Elan SE Turbo
03 MG TF 135 Sprint (Partner's)
15 Renault Megane Coupe

If you can't be a good example, then you might as well be a terrible warning
User avatar
cliff
God
 
Posts: 800
Joined: Mon 17.01.2011, 18:39
Location: Preveza Greece / Scunthorpe UK

Re: Electronic Hood Cover Release

Postby Elanlover » Tue 12.05.2015, 14:00

Alright my dear David, I've had a good look at the release mechanism today and I follow your machinations about 1/3rd of the way. :-D

My original design was relatively simple. I attached a secondary cable to the primary cable with wire clamps. I drilled a small hole in the metal frame which holds the latch, ran some bicycle brake cable through it and attached the end to the primary cable (which is bare after it enters the frame and attaches to the pulling lever). So, when the solenoid activated it actually pulled the original cable allowing me to leave the manual operation intact. However, as I mentioned, it requires a huge solenoid to pull it and even then it works intermittently.

Kudos to you for looking at the actual mechanics of how the lever operates the latch as I can now see that its not very efficient as you've pointed out. So, I've followed you this far but I have to admit that I'm a bit lost after this. I'm not sure exactly where you've run and attached your cable, how your plates work (and where they are attached), etc. I'm sure its just me not comprehending but could you explain the plates, attachment points, cable routing and how they've changed the physics of the lever operation??? Pretty please???

One thing I have noticed while pulling on the wire ("the" wire not "my" wire) operating the lever for a good 20 minutes is that the metal rod that sits between the latch and a lever at the bottom of the metal frame is very inefficient. I see it moving around a lot in its mounting points which serves to vary the amount of force applied to the latch. Also, because its rigid it can't flex to suit the changing position it goes through as the lever moves. I'm wondering if a simply solution might be to replace the rod with a piece of crimped wire that has some flex?????

EDIT:

Just looked over your pics again and it seems that these "plates" are bolted to the inside of the frame that holds the latch and are just under the latch itself. Correct? Now what?
I do whatever my Rice Crispies tell me to do
User avatar
Elanlover
Moderator
 
Posts: 3498
Joined: Fri 05.08.2005, 19:11
Location: The Great White North

Re: Electronic Hood Cover Release

Postby dapinky » Tue 12.05.2015, 18:34

Blair,

Yes. the plates are bolted to the inside of the frames, about half-way along - the exact position isn't too important, but you need to leave enough room for the actual lever to move full travel without hitting it!

3.jpg


The plates themselves are simple - these pics are from the 'type 1' version which is still in the garage - I drilled the 6mm hole a bit too deep so didn't use it - but it's okay to show the principle...

10.jpg

11.jpg


The picture shows the end nipple still on the cable - you could just keep that in place and feed the cable through the hole in the lever where the current rod goes - it means that you won't have to worry about any 'loops' or 'crimps' inside the bracket/frame - but i only thought of that after I'd cut it :bonk:

If you align the cable with the current rod run (but exiting the bracket just above the current cable entry point) it is about as smooth a run as you can get it.

The cables just run along the bulkhead behind the plastic liner/cover, behind the battery and into the space above the wheelarch.

Obviously, you need to trim them to the right length - but don't go so short that there are any sharp bends in the cable - then attach them to whatever bit of spare metal you have lying around (well, not ANY bit of metal - a piece of railway line may not be suitable :D ) with a similar aluminium bracket drilled for 2 adjacent cables - then fit to the solenoid - job done.

Does that help?

I'll try and take some more pics tomorrow if you need them - but the car is put away for the night at the moment.
Dave

Just the one now, but this one's mine! - and it will be finished eventually..... - but also temporary custodian of a project until it is finished enough for Angie to drive it

go on - click this link - you know you want to!
User avatar
dapinky
LEC Administrator
 
Posts: 10000
Joined: Sun 15.10.2006, 12:54
Location: As far west as you can get in West Wales before you become Irish (Pembroke Dock).

Re: Electronic Hood Cover Release

Postby Elanlover » Tue 12.05.2015, 18:49

Thanks Dave, I think I am getting a better sense of what you've done now. I was probably a put confused as its hard not to think about it in terms of what I had already done myself - easier to visualize if nothing but the stock operation and pieces are in place. Let me see if I've got this right. Starting from the latch itself you have:

1) run a new cable FROM EACH latch - different from the stock setup (and my Frankenstein version) which uses one long cable to pull both levers simultaneously
2) you've run the cables at a slight angle from the latch downwards and secured that position by using a plate on each "frame" (metal that holds the latches) to guide the cables
3) once the cables exit your guide plate they are inside the plastic casing (common to most bicycle brake cables) which allows them to turn the near 90 degree angle necessary to run out of the frame to your solenoid
4) you've connected both individual cables to the solenoid

Does this sound right?
I do whatever my Rice Crispies tell me to do
User avatar
Elanlover
Moderator
 
Posts: 3498
Joined: Fri 05.08.2005, 19:11
Location: The Great White North

Re: Electronic Hood Cover Release

Postby dapinky » Tue 12.05.2015, 19:35

Blair,

I do believe, Sir, that we have an understanding!

(sounds about right)
Dave

Just the one now, but this one's mine! - and it will be finished eventually..... - but also temporary custodian of a project until it is finished enough for Angie to drive it

go on - click this link - you know you want to!
User avatar
dapinky
LEC Administrator
 
Posts: 10000
Joined: Sun 15.10.2006, 12:54
Location: As far west as you can get in West Wales before you become Irish (Pembroke Dock).

Re: Electronic Hood Cover Release

Postby Elanlover » Tue 12.05.2015, 19:40

Excellent. I will attempt a prototype post haste! Do you feel the 10lb solenoid you are using does the job adequately or has just enough force to work? I ask only because I have a couple of solenoids lying around including a 10lb and 20lb one I can use. I might try connecting to the second hole on the latch instead of the main one used by the rod. That way I'll still be able to use the manual release if need be.

Thanks Dave!
I do whatever my Rice Crispies tell me to do
User avatar
Elanlover
Moderator
 
Posts: 3498
Joined: Fri 05.08.2005, 19:11
Location: The Great White North

Re: Electronic Hood Cover Release

Postby dapinky » Tue 12.05.2015, 19:44

The solenoid has enough oomph to do the job, but how marginal it may be is another issue - I have no method of determining the force used to open the catches.

If you are going to use the other holes, you may need more pulling power due to the leverage being less (obviously it will need less travel, but it will need more force).

With the angle of pull, it probably won't make a lot of difference (the 2 holes are in a similar plane of movement), but I just wanted to give it the best possible chance of doing the job without stressing the solenoid.
Dave

Just the one now, but this one's mine! - and it will be finished eventually..... - but also temporary custodian of a project until it is finished enough for Angie to drive it

go on - click this link - you know you want to!
User avatar
dapinky
LEC Administrator
 
Posts: 10000
Joined: Sun 15.10.2006, 12:54
Location: As far west as you can get in West Wales before you become Irish (Pembroke Dock).

Re: Electronic Hood Cover Release

Postby GeoffSmith » Tue 12.05.2015, 19:57

Having looked at the boot lock a couple of years ago, I realised that there is quite a lot of stiction, but once that is overcome not a lot of force is needed.

My (WIP) solution was to use a very petite 6V solenoid driven from a capacitor charged to 24V by a DC-DC converter. The 24V provides a huge force to overcome the stiction and the capacitor soon discharges so the solenoid doesn't burn out even if it sticks.
Calypso Red S2 #417

USB ElanScan interfaces - £60 incl. UK P&P & £65 incl. ROW P&P
User avatar
GeoffSmith
Kitty Fiddler
 
Posts: 15577
Joined: Fri 03.02.2006, 21:57
Location: S2#417 in Tytherington, Gloucestershire

Re: Electronic Hood Cover Release

Postby maz_r » Tue 12.05.2015, 20:00

Or (and I may be divergent from the plan a bit here), is there some reason you can't use 2 solenoids - one for each catch?
There are 10 kinds of people in the world; those that understand binary.....
User avatar
maz_r
Binary Bodger
 
Posts: 739
Joined: Sun 05.07.2009, 20:36
Location: Solihull, West Midlands

Next

Return to Projects - Other (Minor)

Who is online

Users browsing this forum: No registered users and 4 guests