I'm going to write a guide for newblets like myself. It will basically be all the research I have done over the past few years made into a nice concise newblet's buying and probably building guide. No flying guide of course, because I still haven't got that down .
This is the type I built, and one of the most popular. Usually this type is dragged over templates to cut airfoils into wings. The bow looks kind of like an H. Usually one side is allowed to rotate and the other fixed, but some have both rotate and some have both mounted rigidly, relying on the material's elasticity for tensioning. Handheld bows can be anywhere from a few inches to several feet long. A small, one-handed bow is good for trimming and cutting. The 24" bow I built is a modest, even a bit small size for wing cutting. Tension can be provided by strings, turnbuckle(s), spring(s), or a combination of several. I used a spring and a turnbuckle and it works well.
2. Vertical Scroll
Vertical scroll cutters are mounted rigidly to a table or other surface, sometimes integrated into the cutter. They are good for cutting out pieces but useless for airfoil cutting. The simplest method is to take a handheld and bolt, strap, or otherwise attach it to a table. Some vertical cutters are purpose-built, and it shows. Often the top 'L' shaped section of the bow is not mounted directly to the bottom. These are almost as popular as handheld bows.
Posted by newblet27 |
Jul 04, 2008 @ 11:06 AM | 2,076 Views
I originally post this as a reply. I thought others might want to read it, so enjoy!
Basically there are three main types of battery in use. NiCd, NiMh, and LiPo. NiCd stands for Nickel-Cadmium, NiMh Nickel-Metal-Hydride and LiPo is Lithium Polymer. NiCd and NiMh batteries are generally grouped together. Both are durable and put out 1.2 volts per cell. NiMh has a higher energy density (more power for size and weight), doesn't suffer from 'memory effect', and is electrically less durable (doesn't tolerate under- and overcharging as well). NiCd is cheaper, tougher, and bad for the environment. Then there is LiPo. LiPo batteries are leagues ahead of Nixx (collective term for NiCd and NiMh) batteries. They produce 3.7 volts per cell. They have MUCH higher energy density, are lighter and smaller, and they don't have 'memory effect'. However LiPo batteries are not very tough and dangerous when damaged. Also LiPo batteries tend to catch fire when overcharged or charged improperly. They also tend to stop working when you discharge them too much. LiPo batteries are improving however; a modern LiPo is MUCH less likely to catch fire or die than one from three years ago. LiPo batteries are highly recommended by everyone; few still use Nixx batteries.
The type of battery you choose dictates the type of charger you need. Most modern LiPo batteries have a balancing tap for charging. This makes sure each cell is equal when charged with a balancer. While not...Continue Reading
The main purpose of a power supply is to reduce voltage to a usable level. There are secondary purposes as well. One is to isolate the hotwire from line voltage. Another is to vary the power for different wires and cutting conditions. So how is this accomplished? Usually with a transformer.
Here are three common types of power supply: Model Train Transformer
Model train transformers are used to power model trains (duh). The output voltage works well for hotwires. Older models are best as newer ones sometimes have current limiters. However wear and tear may be present. Dimmer/Transformer
This consists of a dimmer and a transformer. See Figure 1 for the basic circuit. The power comes from a regular wall plug (1) and is varied by the dimmer (2). It is then reduced to a lower voltage by a transformer (3). The output is (4). Dimmer/transformer power supplies work well but can be expensive. You have to buy a transformer which is not cheap. A dimmer is about $7. There are also usually other components. Router Speed Control/Transformer
Very similar to a Dimmer/Transformer but uses a router speed control instead. The router speed control is better for the inductive load and may be about the same price or more expensive. It does not fit into a standard electrical box like a dimmer.
The power supply I used is a dimmer/transformer. It is not as simple as the two-component one described above however. Look at Figure 2. (1) is the plug from the wall. Use a three prong plug so...Continue Reading
I've been aware of this feature for a while now but only just now have I decided to use it. I'll post build logs, flying experiences, and possibly a few rants and raves. But let me introduce myself first.
I'm relatively new to RC. I understand the theory quite well, but the flying not so well. I crash a lot. I like scratchbuilt foamies the best and after a lot of research and the construction of a hotwire (mini-article coming soon) am about to build my first. Currently I own a Wing Dragon (old 3ch version) and a $40 toy heli. My funds are quite limited and the availibility of FFF is nonexistant. I know those two facts are completely unrelated but I needed a sentance-finisher .