Announcement

Collapse
No announcement yet.

Toyota 88C suggestions for the future

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Toyota 88C suggestions for the future

    Finally got around to working on one. Maurizio, the body mount design is a problem on this car; I couldn't find any threads about them, so:

    1. Both of the car's body mounting tubes were cracked. I had to ream out a pair of thick styrene tubes to fit over the body mounting tubes.

    2. The front screw was just too short to thread into the tube more than about one or one-and-a-half levels of the thread, and I had to substitute another screw - a long one from Scalextric. I wouldn't be surprised if the problem was the cause of the cracked front tube, because someone in China really overdid the force needed in the assembly.

    3. The rear tube does double-duty for the wing mount, and the tube I used to reinforce it makes the wing assembly stronger, but you had locating ribs on the rear mount, and I had to cut them away.

    Maybe consider either making the tubes wider and stronger, or add reinforcing tubes to your aftermarket parts list. The diameter of the Slot.it mounting tubes is often much smaller than just about any others that I've seen, and they don't match up to the available brass or styrene tube diameters (Imperial or Metric).

  • #2
    Personally I own 5 Toyotas and have never had a problem. But aftermarket parts would be a good idea for those that are unlucky enough to have problems.

    Comment


    • #3
      Did yours have the short partially-threaded flat-head screws and washers for the body-to-chassis attachments? Mine did, which I think allowed the assembler to break the posts.

      Glad you like the idea of the post reinforcements. The Slot Car Corner tubes have threaded inserts on brass tubes, but the diameter of the inserts and the tubes are too large for the Slot.it posts.

      Comment


      • #4
        Yes if I remember rightly all had the flat head screws with washers. I could be wrong but my thinking was that the washers were there to stop the assembler from overtightening and causing damage. I remove all washers and change to a finer thread screw, but that's just personal preference.

        I have had a body post on a Slot.it Nissan break due to high speed impact. Otherwise I've been quite lucky. In saying that, the Nissan body sits unused so if Slot.it put out a repair kit I'd happily purchase it.

        Comment


        • #5
          I could be wrong but my thinking was that the washers were there to stop the assembler from overtightening and causing damage.
          I don't think so!

          Comment


          • #6
            Yes, yes!


            Originally posted by slot.it View Post
            Hi and thanks for pointing this out.
            We need the washers so that the chassis will not be cracked by excessive screw torque applied during assembly - and if the screw was longer, then with no washer it may actually interfere with the inside of the car.
            Actually what has probably happened is that the screws were overtightened, and stripped the plastic in the motor mount (see above for a reason ). Removing washers, you are using the part of the motor pod that is still good... Glad to see that this cures the issue!
            Actually there may be a further explanation for all of this - in order to avoid breakage of chassis mounts when used with the 2.2 metric screws, we've made the hole slightly larger, which means that in production, some care must be applied when assembling the chassis and motor mount, to avoid stripping the screw holder...

            Comment


            • #7
              Thanks for that info from Maurizio - makes sense, not surprisingly - but I still reckon it reduces the possible friction between the screw head and the body post when the car is being run slightly loose. Your results may vary.

              Comment


              • #8
                It seems to me that the larger post hole and the shorter screw (threaded for only a little bit) puts more stress on the top of the very thin tube, washer or not, not less stress! The plastic ends up being weaker and more prone to damage from the metal screw, because there is less material able to withstand the forces of assembly, use, disassembly, and reuse. A washer makes it easier to turn the last few rotations of a screw that might otherwise catch on the surface of the material through which it passes, and spreads out the stress from the screw cap. It doesn't let the threaded portion of the screw go down as far as it would if there was no washer, but I don't think it changes an overly aggressive assembler's actions at the end of the travel distance of the screw. Actually, I think the opposite is true. On my car, the posts were not only cracked, but the front post was stripped out.

                The washer is extremely thin, and doesn't make much of a difference in a "regular" screw's depth of penetration into the tub; granted, a washer under a flat-head screw will limit the depth a bit more than if the screw had a cheese-head or button head, but the shank of the screws used by Slot.it isn't that long, especially when compared to other manufacturer's body attachment screws. On the Toyota, the threaded portion of the screw shank extends only a very little bit past the chassis' mounting hole, something like two sections of thread, which further stresses the tiny part of the thin plastic post that's attached to the screw. So the chassis is attached to the body only by a very small area where there's any plastic-to-metal interface, and that reduces the amount of material able to resist the stresses of repeated attachment and use. A ham-handed assembler is going to be more likely to damage the body post if there's only a tiny area where the screw and post come together.

                The washer may make the chassis hole (not the body post) less likely to be damaged, it might make for less friction in lateral movement of the body on the chassis, but alone I don't think it's going to reduce the possibility of damage to the post. And if the unthreaded portion of the screw shank actually extends into the body post, that will likely further damage the threads the screw cut into the plastic post.

                And, finally, it seems that the flat-head screw engages less of the driver tip than the button-head screws, so the assembler is likely to use more force pushing down on the screw to get it to rotate without the driver tip camming out. The recesses in the flat-head Slot.it screws are not as deep as those in the older screws, and the recesses in flat-head screws tend to be softer than those in button head screws.
                Last edited by JML; 07-17-2013, 12:38 PM.

                Comment

                Working...
                X