leaf springs

[retroguy]

I'm gonna try scratch build leaf springs,any tutorials...

[jeffs396]

Hey Michael, here's a good photo tutorial from an offroad modeling friend, but you can use it for whatever project you're working on, just change the dimensions:

http://public.fotki.com/modeljeeper/models/working_leaf_suspension/

[roadhawg]

From my own clubs website.............

http://www.mountainmodelers.org/2009/11/creating-realistic-springs/

[Dr. Cranky]

Use the search engine, there should be a couple. I've seen a couple, I think.

[retroguy]

Thanks guys,great info...

[Art Anderson]

Here is a tutorial I created back in 2006 on how to make leaf springs. These were made for the rear springs of a still-unfinished 1920 Oldsmobile Truck, but the principal is the same, all leaf springs are made in essentially the same way:

Part 1: Making spring leaves

This is an easy step. Keep in mind that spring leaves are progressively shorter, from the main leaf to the final one. One thing to do, that makes the strip styrene into well-defined spring leaves, is to "chamfer" the edges of the styrene strip first. This can be done by adzing (scraping) the edges of the strip (all 4 of them) to round off them, so that when stacked in a spring, you can readily see each leaf. Real spring leaves are rounded slightly on their edges as well, so this is a "realism" step.

For main leaves, I prefer .030" Evergreen styrene strip, however wide the leaf needs to be, for structural strength. I realize that .030", scaling out to 3/4 inch in scale, is too thick for exact scale fidelity, but sometimes, strength is the issue in scratchbuilding. All the other leaves are .020" thick.

This spring will be one of two rear spring for a 1:25 scale 1922 Oldsmobile 1-ton truck, so an 8-leaf spring was decided upon. Notice that all 8 spring leaves were cut at the same time, to get two of each leaf exactly the same length.

[Art Anderson]

Tapering the ends of the leaves

Spring leaves are almost always tapered (as in this unit) or rounded in manufacturing, which aids them in sliding against each other, without binding, and reducing wear. I do this by stacking each pair of identical leaves together, and slicing off the corners of the ends. The trick here is to make them look as uniform as you can, again for a realistic look.

[Art Anderson]

Getting the curvature of the spring

Leaf springs, by their very nature, are curved, when not mounted in a chassis, with the weight of the empty vehicle pressing them out to a lesser curve, but they are still curved. A template is needed here, to give a uniform curve to both leaf springs. Finding a template for making this curvature is pretty simple; common household bottles and packaging generally can give approximately the curve you need. In this case, an empty deodorant stick case works. Small liquor flasks also work, as do dishwashing detergent bottles, numerous glass bottles--in short, look around, keep your eyes open--as you just never know where you will find something that has the curve you want for parts like these!

[Art Anderson]

Building the spring

I start this process by giving each spring leaf a curve. This is done by drawing the leaf between my thumb and forefinger, against my fingernail to force a bit of pre-curvature into each leaf. This makes them lay down, one against the other, as they get stacked together, without seriously trying to "spring" apart.

The leaves are laid, one at a time, first onto the main leaf which is taped at its ends to the template. Each successively shorter leaf is then laid on, with Tenax 7R liquid cement applied with a small brush, letting "capillary action" wick the cement into the space between the leaves. You don't want to have to press the leaves together, as that can squeeze melted plastic out from between the leaves, so check the curve of each leaf before applying it, making sure each one lays down cleanly.

Here you can see the first spring completely assembled. Once dry, I will take it off the deodorant package, trim the ends of the main leaf to length, add the eylet to one end, a scratchbuilt shackle to the other end, and it will be all done!

Time elapsed to make this spring? About 45 minutes!

[Art Anderson]

Completed!

The springs are now completed. Eyes have been added to each end of the spring, and on one end, a "forged steel" shackle has been added as well. .020" holes were drilled into the spring eyes on the inner side of the springs, with .020" brass rod stock glued in place with CA glue, to act as locating pins for positive assembly to a chassis (in this case, a 1920 Oldsmobile 1-ton truck chassis.

[Art Anderson]

I hope this helps in understanding at least one way to scratchbuild a leaf spring. The ideas and techniques I've shown here are not entirely my own--I watched Chris Etzel do leaf springs this way for his now legendary 1920's Indianapolis race cars. Just keep in mind the dimensions of the springs you want to model, and when doing a pair of leaf springs, be sure to make two of each leaf, so that you have identical springs from one side to the other of your model.

If you can't find a common household bottle or other ready-made object having the curvature you need, you can always carve the shape from a piece of basswood, which is readily available at most large craft stores, such as Michael's or Hobby Lobby, even a lot of LHS's have the stuff as well. Just remember, it's a simple template you want, not high tech tooling.

Also, since I made this tutorial in 2006, Tenax 7R has gone away, but there are very similar liquid cements out there, the best being either Ambroid, or if you have an industrial plastics supply house in your city, WeldOn #3 (which I highly recommend, as it comes in larger quantities at very inexpensive prices.

Art

[misterNNL]

Art,I need to build a rear buggy style spring for a model TT Ford wrecker I have underway on my bench.Since the worm gear drive rear end is considerably taller than the standard T rear end I need to build one with a double curve to nestle into the frame rear cross member and clear the worm drive housing.Have you ever built that type and do you have any tutorial photos of the process?Thanks.....Tom