If you are making a model of a vessel which has an operating stern ramp, or similar, it was almost certainly opened and closed by hydraulic cylinders. Did you know that you can purchase hydraulic systems of model size that will allow you to replicate the real thing? RC4WD sells equipment on their website at: http://store.rc4wd.com/.​ Their hydraulic cylinders come in lengths between 3.5" and 8.25", with an outside diameter of 1/2". The equipment is not cheap; the average price of a cylinder is US$90, with hydraulic tank, pump and controls in addition to that.

From Doug: Looking for wood strips or any other stuff for building? Check out www.modelerscentral.com.  When I purchased my mahogany  strips from them I received them in a week.
 
A good source for building materials.

Hydraulic systems

Hardware

Wood

Ths information previously appeared in our May 2016 newsletter.

Hansen Hobbies has LED’s, switches and electronics in their catalog. For example, you will find receiver-controlled switches here: Hansen Hobby switches

Solarbotics has, amongst others, low voltage, low speed, geared motors. You will find them here: Solarbotics geared motors. Solarbotics list Sayal Electronics as one of their distributors.

An 8-channel radio-controlled switch was also listed, but that supplier is, apparently, out of the business. A search on ebay for "8 channel remote control" will show up some similar items.

When you learn that you need some of those hard-to-find small screws, nuts and washers, two of the best suppliers are:

Micro-fasteners and Model Fixings

Micro-fasteners are in the USA and their stock is mainly imperial sizes, but they do have some metric hardware.

Model Fixings are in the UK and specialise in metric hardware. Their range also includes taps and dies, bearings, and O-rings. 

Hints and tips - Motors and switches

Doug has found a new supplier of cheap LED’s: http://lighthouseleds.com/
One interesting component that will be of value to model builders is a “20mA LED driver”. As described on their website: This simple device limits the current through itself to 20mA. When a voltage is applied (anywhere from 2 to 45V) it will actively adjust its own resistance to allow just 20mA (+/- 3mA) to pass through. This makes it a perfect replacement for current-limiting resistors in LED circuits, and you won't have to calculate resistor values or worry about a varying voltage source. 

LED prices seem to change with the weather. Apart from local suppliers such as Sayal and Nutech, other potential suppliers, who may be cheaper tomorrow are: http://www.componentshop.co.uk/. There are others.

LED's

Building tips - Component information and supply news