Bonnet Hinges and Bonnet Stays

[John Dolphin]

Would anyone be able to put some photos of Jupiter Bonnet Hinges and Bonnet Stays on the gallery?

I need to have both fabricated for my car so if anyone else is in need let me know and I'll investigate getting a small run done.

Thanks.

[Amy]

I'm pretty certain that we have pictures of both of these as we had problems with both when doing my Jupiter... Will dig them out and link them. If you've the energy have a dig through the SC rebuild album on the gallery as that's where they'll be.

If you're getting bonnet struts made, we may well be interested as despite several days of the team's time the left hand strut is still broken

Amy.

[Leo Bolter]

Hi all . .

I need to have both fabricated for my car so if anyone else is in need let me know and I'll investigate getting a small run done.

Before doing the production as mentioned above, please check with JCC of NZ Spares for the availability of bonnet hinges (if for a Jupiter). I'm sure I had made a pattern for them to be cast many years ago and the Spares guys took the patterns over. They were available to be cast in bronze or aluminium. Mine were cast in bronze as they would be considered to be more robust. The originals had been alloy and showed multiple signs of being welded over the years.

JCC of NZ Spares are contactable by e-mail The address can be found by Googling for the Jowett Car Club of New Zealand web site and getting there via the "Contacts" tab.

I believe ALL door hinges, Jupiter and Javelin, as well as the above mentioned bonnet hinges, plus the spare wheel clamp for the Jupiter, are either available off the shelf or as patterns ready to have cast to order from NZ. Currently I could be wrong, but do check for yourselves.

BTW, Roughly speaking . . . . UK Pound 1.00 = $NZ 2.00 at the moment . .

Leo.

[John Dolphin]

Thank Amy & Leo for the replies.

I have sent a note off to the NZ club spares contact regarding the bonnet hinges. All I have of the original hinges are two 3" stubs that were bolted to the bonnet frame. Both hinges appear to have broken in the same place.

Regarding the bonnet stays I have an 8" length of the inner tube with the clevis to fix to the bonnet frame. I don't have the lower tube or the latching mechanism so any photos, diagrams or measurements would be most appreciated. I'll have a good look through the SC rebuild album and see if I can find the pics.

Thanks,

John Dolphin
E3SA 887

[Amy]

John, I've had a look through the pictures and it looks like one of the few things we don't have pictures of is the bonnet hinges or struts, sorry! Let us know if we can help with getting measurements of the struts.

Amy.

[Leo Bolter]

Hi John.

Here's some images of my Jupiter's bonnet stays to go on with. I believe they are "as original".

I'll work on sketching the component bits with included dimensions tonight (or tomorrow . . . depending on how my health lets me feel

You'll notice that they will allow the lift of the bonnet to near the maximum when extended. This shows by the chafe mark on the paint . . . The top clevis is threaded for 1/4 B.S.F. on one side (the "in" side), while there's a 1/4 unthreaded hole on the "out" side (to take the through bolt which has the necessary locknut). The brass nuts and the short tube involved in the latching mechanism actually have a rather coarse thread (and unknown to me at this stage, as I have no thread-gauge here), but it's not a thing that could be called critical (unless one is extremely pedantic regarding originality). The latching gear is inclined inward at 55 degrees to the bottom mounting holes and of course need to be made for the right and left hand sides. This angle gives a sweeping curve to the pull cable if it's made the right length and it also falls nicely to hand when it needs to be pulled! My stays didn't have springs in them when I got the wreck, so I didn't know they originally had them. When I found out I never bothered to find any, but I had fleetingly contemplated looking into using gas struts . . but didn't go down that path. It "wouldn't have been cricket"!

EDITED 9:00pm today: I just remembered that there's a short (1.5inch long), fairly soft spring in the bottom of the outer tube in my set-up. That exerts a little upward pressure on the inner tube when the bonnet is right down. It takes up any tendency for the mounts/pins/bolts and the tubes from rattling.

EDITED once more: IMPORTANT. Please refer to my posts of Monday, 2nd April, 2012 for changes in dimensions

Anyway . . it'll all be revealed in the sketches I'll post in the next day or so . . .


The RH Latch Assembly


The RH Bonnet Stay Dismantled


The Lower Ends of the Tubes and the Latch Slot


The Top Ends of the Tubes and the Latching Gear


The Pull Cable Attachment Nut and Soldered On Ferrule (the cable is a inner and outer Bowden Cable with the inner nominally the same length as the outer (plus the bit that goes through each of the ferrules, of course) The nut shown here screws onto the threaded end of the latching pin, shown above.

EDITED again . . this time at 11:50pm today.



I'm sorry about the poor sketch . . . my drawing hand has a mind of it's own these days Please let me know if there's any dimension missing or not clear.

[Leo Bolter]

My last post was edited twice
Leo

[PJGD]

John,

I am in need of both bonnet hinges and bonnet stays also. I could be interested if you plan to get a small batch made.

I have made drawings of the hinges (as original, and a strengthened version) and put them in my Gallery here: TOPIC

[John Dolphin]

Leo,

Thanks for your photos and sketch. I should be able to work with them. I have one quick question though, what is the AF measurement of the brass nut?

Philip,

I'll let you know if I hear anything back from the NZ club regarding the remanufactured hinges. In the meantime I'll have a look at your drawings.

I'll look into the costs of getting the struts made, it'll probably be in the New Year now before I get on to it.

Cheers,

John Dolphin
E3SA 887

[Leo Bolter]

Hi Philip et al.

You have used your considerable skills once again and made some great CAD drawings of the hinges . . . with the great plan to add the extra web to strengthen any patterns made in the future, either for casting, or fabrication if that is decided upon.

Regarding the bonnet stays. A thought did occur to me . . . . I wondered if you might be interested in converting my dreadful sketch to a CAD, Phil? It could then be something that would be more useful in the future and for archiving . . . What do you think?

Also, while on the subject of bonnet stays, Neil Moore said (when I phoned him tonight re. bonnet hinges) that he has a couple or so of sets of stays already in stock* . . . The bonnet hinges are not presently in stock, but they should be available early in the new year. They'll be ready to go and fully machined. One thing that is an advantage with them being "out of stock" is that you guys will be able to make a choice of the material they are cast in when your order is placed ! He said a VERY rough guesstimate of the cost of the bonnet hinges would be $NZ50.00 each, plus freight. But, this could be a bit out as he hasn't had casting done for some time . . .

John.
Neil says that the answer to you message is typed and ready to go, tomorrow . . . it has to be sent from Denise's office as they have no computer at home. The brass nut is 7/8" AF and 3/4" long and of course has a 5/16" hole for the latch pin (plunger) to pass through. I see the JOAC Spare Parts list, lists the bonnet plunger springs (# 53215) and the stay support springs (# 53208) (available to members only).

Cheers to all.

* No price was discussed, but I imagine freight could be reduced considerably if all that can, get together and order as one.

[PJGD]

Leo,

Yes, I can convert your excellent bonnet stay sketch into CAD format in the near future; it won't be immediate though, my CAD computer is down at present.

Philip

[John Dolphin]

Hi Philip,

I have had a reply from Neil of the NZ Club spares section and he has confirmed that they are out of stock of bonnet hinges and he will investigate getting some made in the New Year.

I also asked about the price & availability of the bonnet struts but I am still waiting to hear back. I'll post another note when I have further news.

Cheers,

John Dolphin
E3SA 887

[Leo Bolter]

HELP . . please!

Way back on Wednesday Dec 01, 2010 I said:

My stays didn't have springs in them when I got the wreck, so I didn't know they originally had them. When I found out I never bothered to find any . . . ."

Well, lately I have been finding that the bonnet on my Jupiter is becoming increasingly heavy (I think the aluminium is gradually turning to lead!), so I bought a set of springs for the stays from JOAC Spares. I thought I'd do the 5 minute job of fitting them about 3 hours ago . . . . Although it was not going to be "Rocket Science", I now find that "I have a problem, Huston!". IMPORTANTLY this possibly means that there could end up to be something amiss if anyone makes a set using the dimensions that I found on my stays.

The stays work perfectly as drawn when there's no helper springs installed (just a short anti-rattle one in the bottom of the outer tube, as mentioned previously).

Here's what I found when I tried to install the "proper" springs. Please refer to the two images below.

The first gives a overall "picture".
The second shows the gruesome facts. Dimension "A" is the helper spring length when fully compressed. (200mm) and dimension "B" is the room available (55mm) when the inner tube is fully down, i.e. when the bonnet is lowered . . . . accordingly 200 won't go into 55!

Something is dreadfully wrong! . . . any ideas, anyone. Perhaps someone who has these springs in use could take some dimensions of their stays, and post them here so that if there is a problem with what I've published it can be corrected before new stays get made.

My apologies for the poor images . . . (cellphone!).
Embarrassingly . . .
Leo

[Jack]

Hi Leo,

From memory of assembling ours, I think the spring needs to go inside both tubes - it is not dimension B that you are trying to get it into, it is pretty much the full length of the bottom half.

Jack.

[Forumadmin]

My grey cells are thinking hard as I/we had similar problems, but only in that the last couple of inches would not close.
The two springs are sequential and as Jack says fit inside the inner tube as well as extending in the outer tube. The problem we had was with the angles of the pins holding the end stops and some fouling where the tubes had been welded. Be very careful fitting the springs as you do not want to spear yourself or the car. I made a safety wire just in case!