Results 1 to 13 of 13

Thread: 32 GRP cab to frame advise required

  1. #1

    32 GRP cab to frame advise required

    Seeking advice, again!! I am thinking of ways to mount the 32 Model B pickup GRP cab to the frame. If I lay 3mm thick webbing on the frame and bolt the cab to the frame using grade 8.8 m8 bolts into rubber rivnuts. The flange of the rivnuts is also 3mm so if holes are made in the webbing it will all sit at the same height. Is this solution feasible and if so how many bolts would you fit each side?
    Many thanks in advance for your help.


    Sent from my iPad using Tapatalk

  2. #2
    NSRA member
    Join Date
    Jun 2003
    Posts
    4,657
    Images
    2
    32 coupe and roadster have i think 6 per side including the 2 in the firewall.

    M8 sounds a bit skinny. 7/16 is stock and that's what I've used. M10 sounds more like it.

    My glass roadster has bolts through large / thick washers (or steel frame mounting points), through the glass, through the webbing and into welded inserts / nuts in the frame. Locking washers / locktite. Snug tight but not mashing the 'glass!

    Not sure about rubber rivnuts (or steel ones for that matter!). Not sure that kind of flexibility is necessary / desirable, but I'm talking about boxed / stiff frame.

    Chris
    Bumper sticker - This is an historic vehicle and only has three speeds....... if you don't like this one you sure as hell won't like the others.

  3. #3
    Quote Originally Posted by Happydaze View Post
    32 coupe and roadster have i think 6 per side including the 2 in the firewall.

    M8 sounds a bit skinny. 7/16 is stock and that's what I've used. M10 sounds more like it.

    My glass roadster has bolts through large / thick washers (or steel frame mounting points), through the glass, through the webbing and into welded inserts / nuts in the frame. Locking washers / locktite. Snug tight but not mashing the 'glass!

    Not sure about rubber rivnuts (or steel ones for that matter!). Not sure that kind of flexibility is necessary / desirable, but I'm talking about boxed / stiff frame.

    Chris
    Hi Chris, thank you for your advise very much appreciated. My frame is boxed so I will now go for m10 mild steel inserts/bungs.


    Sent from my iPad using Tapatalk

  4. #4
    NSRA member rem's Avatar
    Join Date
    Jun 2003
    Posts
    7,341
    Images
    1
    I agree with Chris, M10 or M12 would be my choice if using metric fasteners. The construction and thickness of the floor is also important as that is all that will be holding the cab, the seats and the driver/passenger onto the chassis!
    Sent from my Kitchen Table using a little box full of smoke and dangerous radio waves


    Shine is Fine

  5. #5
    Quote Originally Posted by rem View Post
    I agree with Chris, M10 or M12 would be my choice if using metric fasteners. The construction and thickness of the floor is also important as that is all that will be holding the cab, the seats and the driver/passenger onto the chassis!
    Hi, noted. The proposed floor will be constructed as follows:
    A sheet metal floor will be made with relevant beads to give some strength. The sheet metal will only be used as a mold. The cab will sit on this and the grp laid up. Two layers of 450 gsm, the beads will be filled with 3mm coremat, another layer of 3 mm corematt laid on top then a further 2 layers of 450gsm. I emailed Tribute Automotive who made the 32 GRP cab and he stated this should be fine.
    Always welcome any feedback - many thanks.


    Sent from my iPad using Tapatalk

  6. #6
    NSRA member
    Join Date
    Jun 2003
    Posts
    4,657
    Images
    2
    So there's no flange already moulded with the body to fix through to the chassis?

    Chris
    Bumper sticker - This is an historic vehicle and only has three speeds....... if you don't like this one you sure as hell won't like the others.

  7. #7
    Quote Originally Posted by Happydaze View Post
    So there's no flange already moulded with the body to fix through to the chassis?

    Chris
    Hi Chris, no there is no flange. It’s just straight down as sketch.


    Sent from my iPad using Tapatalk

  8. #8
    NSRA member
    Join Date
    Oct 2003
    Posts
    192
    Does the body have any framing/stiffening or is it just a glass shell? It could be worth building an inner steel frame (including an outer perimeter floor frame to bolt through to the chassis) that you can mount seats/steering column/ pedals etc to. Would also offer some protection in the event of a crash. Just make sure the body is shimmed square to the chassis (door gaps) before you start, in case it's twisted.

  9. #9
    Quote Originally Posted by Pete Rodder View Post
    Does the body have any framing/stiffening or is it just a glass shell? It could be worth building an inner steel frame (including an outer perimeter floor frame to bolt through to the chassis) that you can mount seats/steering column/ pedals etc to. Would also offer some protection in the event of a crash. Just make sure the body is shimmed square to the chassis (door gaps) before you start, in case it's twisted.
    Hi Pete, thank you for your response and useful advice which I will take on board. I do plan to have a steel inner structure to brace the GRP cab, door fittings etc. I will also be installing a tight fitting roll cage made for ROPT510 tubing which will bolt through to additional supports on the frame rails. I hope at the end it will be as safe as one can make it.
    Many thanks.


    Sent from my iPad using Tapatalk

  10. #10
    NSRA member yellacar's Avatar
    Join Date
    Oct 2005
    Posts
    541
    Use 600 gram instead of 450, When i used to lay up Fiberglas body,s for show cars we used 1 layer 450 then 1 600 then core matt then another 600.

    hope this helps Ian.
    Member of the Long Roof society

  11. #11
    Quote Originally Posted by yellacar View Post
    Use 600 gram instead of 450, When i used to lay up Fiberglas body,s for show cars we used 1 layer 450 then 1 600 then core matt then another 600.

    hope this helps Ian.
    Hi Ian, so in my example is replace the 3 layers of 450 with 600 apart from the first one.
    Thank you for your advice, very much appreciated.


    Sent from my iPad using Tapatalk

  12. #12
    NSRA member yellacar's Avatar
    Join Date
    Oct 2005
    Posts
    541
    Yes 450,600,core matt,600,600, should be super strong.

    Cheers ian.
    Member of the Long Roof society

  13. #13
    Quote Originally Posted by yellacar View Post
    Yes 450,600,core matt,600,600, should be super strong.

    Cheers ian.
    Hi Ian, many thanks. Stay safe


    Sent from my iPhone using Tapatalk

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •