I wanted to be able to mount my SLR Photolenses with webcam on top of the LX200 but when I looked how much a commercially available piggy back rail would cost I was shocked :-{
I talked it over with my good friend Matthias Meijer who produced this sketch:

I gave it a good thought and then hurried to the DIY shop where I bought the following material (total costs Euro 35):

• 2 aluminium handles (used for drawers etc.)
  Note: make sure they are not of cast aluminium, because those will break when you try to bend them.
• 1 aluminium tube 2cm x 4cm, length 1 metre
• 2 black plastic plugs for a nice finish of the tube
• 1aluminium U-shaped strip 2cm x 2cm, length 1 metre
• 2 small pieces of 18mm plywood: 4cm x 8,1cm (the DIY shop did the cutting for me :o)
• 2 small pieces of 4mm hard plastic ("Trespa"): 4cm x 8,1cm (the DIY shop did the cutting for me :o)
• some M6 bolts, nuts and wing nuts
• some felt with self adhesive back

With the above material I made a Piggy Back Rail with adjustable Sliders.
Note: guess how am I going to make a Balance Rail :o)
And of course this Piggy Back Rail is interchangeable with my LX200 Heavy Duty Piggy Back Rail for Autoguiding

I bent the drawer handles so that they followed the curve of the OTA so that I could attach then to the OTA using the original LX200 bolts.

Here is how I did the bending:

• First I exactly measured the distance between the bolts on the OTA (10,2 mm if I remember correctly)
• Then to the DIY store(s), armed with a calliper
• Searching ... searching till I found 2 handles with the correct price, the correct (bendable !!!) material and the holes more or less where I wanted them
• I took a piece of paper and the front cap of the OTA to draw a half circle which I could use to compare my bending progress
• I bent the handle by hand: clamped them in my Workmate and used a piece of metal tube to apply the appropriate force
• After that: checked with the circle on paper till I got it right (the OTA cap I had put back where it belongs)
• Then with the calliper I set out the 10.2 mm and drilled/widened holes for the OTA bolts
• Then tried it out on the OTA: a perfect match the first time! Happy !

	The complete Piggy Back Rail with sliders: steady as a rock! Note: it is nice that all my LX200 Piggy Back Rails can also be mounted on my Astro-3 (Lidl) mount: yes, I like to be able to use my equipment in multiple configurations.
	Using pliers I changed the shape of the drawer handles so that the holes match the bolts of the LX200 OTA. I drilled matching holes through the aluminium tube and drawer handle and used M6 bolts and wingnuts to fasten; by undoing the wingnuts I can remove the piggy back rail while the handles remain fastened to the OTA. The nylon caps make a nice finishing touch. The top of the sliders are made of 18mm plywood: 4cm x 8,1cm: the extra millimetre is to provide extra play so that the slider does not get stuck on the piggy back rail. The bottom is made from 4mm hard plastic ("Trespa"): 4cm x 8,1cm and the U-shaped aluminum strip acts as connection between top and bottom. The slider is bolted with 2 M6 bolts and wingnuts; inside the U-shaped piece is also an M6 nut so that I can swap the top for one with e.g. a ring mount. To protect the paint of the OTA the very bottom of the slider is finished with a layer of felt. I am planning to put 3-point ring mounts on top of the sliders but I have not yet decided about the size I need.
	I used a left-over piece of hard plastic to make a platform between the two sliders and mounted my Witty slow motion controller on it. Using the knobs I can make very small up/down/left/right movements.
	Here is my SC3 webcam with 135mm SLR Photolens on top of the Witty. It might seem not very stable and top-heavy but in fact it is quite doable: with the same setup I have made many succesfull long time exposures as my images demonstrate; see for example this image of M31 Meanwhile I have added a Viewfinder.

Here follows a list of all my Home Made LX200 based Piggy Back Rails:
Heavy duty Piggy Back Rail
Balance Rail
Piggy Back for WO ZS 80 ED APO
Piggy Back for Filterwheel + SLR Photolens