Custom Body Mounting

[HO RacePro]

It seems that the most frustrating part of assembling a scratch car comes when trying to mount the body. I'm talking about a body that was either from a static model kit, or one where the mounting posts simply do not match up with any useful mounting points on the custom chassis. The problem is getting the heights of the mounting posts right. The best I have been able to do is glue in mounting posts that are too long, and carefully trim them down, a bit at a time, until the body sits properly. Or close enough to properly that I can give it up and live with it.

It doesn't help to have good measuring tools -- the clearances are too close. I've never found a good way to weasel one in to get a decent measurement.

You wouldn't believe how much time I've spent trying to dream up a proper way to do this.

Does anyone have a splendid trick to make this job simple, once and done?

Ed Bianchi

[williamg]

I too do the same thing.
I JB weld a long post in then trim down to fit testing along the way.

I've also used Balsa wood blocks and shim with balsa or brass to fit.

[RichD]

It is best to put a foot on each post, posts that are just glued to the body are likely to break loose. I cut out a .5X.5 inch piece of ABS and drill a hole in the center to match the OD of the tubing.

[32lbking]

Ed, you didn't say whether you were attaching the body posts to the body, or the chassis before cutting. A lot of guys screw the posts [slightly longer than needed] to the chassis.
First place the body over the chassis [without body posts] on a flat surface. Use shims under the sides of the body until you get the desired height above the chassis. Measure the distance from surface to body [ height of the shims].
Then place the body on the chassis with the slightly long posts screwed to the chassis. Measure the distance from surface to body.
Subtract the height of the shims from this measurement. The result is the amount that you cut off the body posts.
After cutting posts to proper height use a drop of superglue on top of the posts. Quickly adjust the body, left to right and front to back before the glue dries.
After the glue is dry, unscrew the body screws and put a filet of epoxy or JB Weld around the posts to strengthen the joint to the body and let dry.
Randy

[bdsharp]

I haven't done this enough to perfect the procedure, but here goes:

Two pieces of telescoping brass tube, each about 75% of your estimate of the final post length. The ID of one tube should allow you thread in a mounting screw. Slightly deform the other piece to create a friction fit. Screw the assembly to the chassis, and slide the length to what you know is too long. Lower the body to the desired height, compressing the tubes. Remove the body and cut your mounting post to the same length.

[HO RacePro]

Randy, I like your system. I'm going to try it.

Next time that is. Today I spent a couple hours just trying to fit two mounting posts in the front of a body. I thought I had a good way to do it. Didn't. How could I be off by 100 thousandths? I was. Added shims.

I need to install another two mounts in the back of that same car. I'll try your method and report back.

Oh, and Rich... I have custom-printed posts that attach to a wider, separate foot using a ball-and-socket joint. That setup has been pretty successful as far as conforming to the different contours in the undersides of bodies, and it does help reinforce the posts.

Ed Bianchi

[one32]

HELLO MR BIANCHI I SENT YOU A PM

[slothead]

I'm Leary of using super glue for a job like this - it always hardens before I have things just the way I want them. Yes, I know you can get super glue with different curing times in seconds (don't know what I have).

JB Weld is my go to glue/epoxy for anything I want time to adjust before it hardens.

[32lbking]

slothead, something I have found that extends the working time of liquid superglue is to use more than required [if you would normally use 1 drop for a joint use 3-4 drops and it will give a little more working time]. Definitely not for every job, but works for some.
Randy

[slothead]

Thanks Randy - I'll try that.

[Fathead59]

I was thinking about using a washer and JB weld . With the washer I was thinking of a bigger foot print for the post .