Woodturning Safety – What To Look For In A Sawbuck

Woodturning is a very safe part of the woodworking family of arts and crafts, however it uses power tools and sharp edges and carries a certain amount of risk. One of the areas of woodturning which has its own dangers is rough wood preparation, particularly in the area of faceplate work. A few simple rules and especially the use of an appropriate sawbuck will make the work much safer.

The most common form of faceplate for most people is bowl turning and most bowl blanks are cut from the log in undried or green form. This is almost forced on the turner as blanks thick enough to use for turning a bowl are very difficult to find unchecked and then very expensive when found. Cutting one’s own with a chainsaw quickly pays the cost of the chainsaw and its upkeep.

While a course in chainsaw safety should be undertaken by everyone who lans on the use of one, there are a couple of rules that every woodturner needs to know and follow. Note that most bowl blanks will start with a log longer than it needs to be so that a shorter one is cut from it and then sliced in two.

First of all, never cut logs to length in the pile. They need to be placed in a sawbuck so that the end of the log to be cut projects out of the buck and will fall away from the log when it is cut. This prevents kickback from the chainsaw. For in stance a ten inch long piece may be cut from a ten inch diameter but six foot long log to make ten inch bowls.

Second is to prevent the sides of the short log from jamming when slicing it down the center. The shorter log must be sliced with the chainsaw into two bowl blanks. This particular cut is peculiar to woodturners and requires a unique sawbuck. Most sawbucks are made of a couple of sets of legs made from two by fours in the shape of an X connected with a couple of crosspieces. While this is good for cutting to length, when the shorter log is cut lengthwise the X’s allow the pieces to slide down and grab the saw bar causing kickback that projects the saw at the sawyer’s head. This is both frightening and dangerous.

What is needed is a sawbuck that holds the log securely to prevent rolling and yet allows the two separated sides to fall away safely, releasing the chainsaw bar. One simple way to achieve this is to make a channel from two by fours. The log rests in the channel securing it from rolling but the width of the channel is narrow enough to allow the pieces to fall to safety. All that is now needed is a set of secure legs which hold the sawbuck at waist height or a bit below for comfort in the work.

Safety needs to be first and foremost when using a chainsaw. A good sawbuck easily made adds a great deal to the safety and enjoyment of woodturning wood preparation.

Safety First Baby Monitor Reviews

Parents appreciate the peace of mind and freedom of movement provided by baby monitors. Their little one can sleep peacefully in the crib while Mom and Dad take care of chores around the house. The parents can monitor the baby from another room and know immediately when Baby needs them. One product group of monitors is the Safety First baby monitor line. Their monitors include those that monitor sounds and also some that include a camera component for visual monitoring.

The Safety 1st Crystal Clear Baby Monitor and the Safety 1st Glow and Grow Baby Monitor are the more economical models. Both models offer two channels at 49MHz with low battery indicators and volume control. Both the parent and baby units in these models operate on batteries with AC adapters also included. They are both offered only in white. There are several variations between the models also. The Crystal Clear model includes a belt clip on the portable parent unit and an intercom talk back feature. Its signal has a range of up to 600 feet. In contrast, the Glow and Grow model provides a digital reading of the nursery’s temperature. It also has a tap on night light that automatically shuts off in fifteen minutes, which is handy for night time diaper changes. Its signal range is up to 400 feet away. Both receive good parent ratings for clear signal and great range. There seems to be some quality control issues, however, since some units are reported as having a lot of static while most others transmit very clearly.

The medium priced models the company makes are the Safety 1st Safe-Glow Nursery Monitor, the 1st Glow and Go Duo Monitor, the Sound View Monitor and the Comfort Zone Digital Baby Monitor. All operate on nine volt batteries with energy saving AC adapters included. All have low battery and power on indicators and only come in white. All have a portable parent unit with belt clip, but the Glow and Go Duo and the Safe-Glow models offer an additional parent unit as well. The first 3 models operate on two channels at 49 MHz at a range from up to four to six hundred feet. The Comfort Zone Digital is the only model with an alarm that signals if the nursery temperature falls outside the range parents have set for it. It also has 2.4 GHz of digital technology offering 14 channels at up to 900 feet. The Sound View, Glow and Go and Safe-Glow units have a soft glowing tap on night light with a fifteen minute automatic cut off period.

Parent reviews of these four models are mostly positive. There again appears to be inconsistency in production of the models. Some work very well from the start while others do not and need to be replaced. Some parents state the units “eat up batteries” as they only last a few hours sometimes in the parent unit. The nursery temperature measurements tend to be higher than the actual temperature of the room.

The final Safety 1st baby monitor models are the Prism and the True View Color Video Monitors. These are the most expensive models of the product line because they include color video cameras as the baby units. The Prism comes in black and the True View in white. Both have 2.4 GHz of digital technology which run on batteries with AC adapters included. Each can be set on table tops or wall mounted. Other common features are sound lights, volume and brightness controls, adaptable viewing angles and a signal range of up to 350 feet. The True View model includes low battery and on/off warning signals with an out of range indicator and auto channel selector. The Prism, on the other hand, offers a remote zoom feature, is voice activated and includes a date and time display. It also monitors the temperature in the nursery.

The Truth About 4.9 GHz for Citywide CCTV Systems

So you are going to use 4.9GHz huh!

I often ask myself this question when designing a citywide surveillance solution. My experience working with 4.9 in various deployments has not been the most pleasant. The obvious answer for me is NO, and Sometimes. Let me explain what I mean by this statement.

In comparison 4.9 GHz as well as 5 GHz frequencies have the least amount of utilization than 2.4GHz. Most private homes and small businesses use 2.4Ghz predominantly because hardware for 4.9 and 5.0Ghz was reserved for enterprise specialized hardware and applications. Over the last 5 years I have seen an increase in the use of 5 GHz and 4.9, mostly because the hardware has become more accessible. 4.9 GHz is reserved for public safety, fire and.gov (dot gov) applications so the hardware for this frequency is still out of reach of the general public.

So if the hardware is not readily accessible to everyone then shouldn’t 4.9 be pretty much open? The short answer to this question is yes, it should be but it’s not. Here is the problem with 4.9 GHz. Before I get into my explanation I need to explain the structure of the frequency. I will start with the 5 GHz first.

Lest Start with the easy stuff 5 GHz

I am going to attempt to keep this topic very modest. A frequency like 5 GHz is actually referring to a group of numbers that are in the five thousand megahertz (5000Mhz) range of the radio frequency spectrum. These numbers are known as channels. Channels on a wireless signal work pretty much the same as the general concept of channels on a TV. For example on your TV each channel takes you to a different program. You don’t know what’s on the other channels until you turn to it. It is total isolated from other channels. In Wireless the concept is the same. Channels represent a unique frequency, but just like a TV everyone has access to the same available channels.

The 5 GHz frequency band is comprised of four bands. These bands are 5.1 GHz, 5.3 GHz, 5.4 GHz and 5.8 GHz. Combined the bands have a total of 24 channels with each channel at 20 MHz bandwidth. This means that 24 channels on the 5 GHz frequency band has a bandwidth (Big Pipe) of 20MHz each. This makes the 5 GHz band very suitable for video over wireless.

But 4.9 GHz Also has 20 MHz, right?

On the other hand 4.9 GHz has very little similarities to 5 GHz. First difference is 4.9 GHz is the public safety band. Meaning it is a license band and only to be utilize by public safety agencies. You must apply on the FCC website if you are not public safety but wish to use the frequency. Here is what really confines the usability of 4.9 GHz for building an entire video wireless network. You may not understand the hertz and bertz and so forth just pay close attention to the number. Numbers don’t lie. The 4.9 GHz band is limited to 50 MHz with only 2 standard, independent channels of 20 MHz. Let’s compare this to the 5 GHz that has 24 channels at 20 MHz each. See the similarities, I think not.

So how do you deploy a citywide CCTV system using 4.9 GHz when it is limited to only 2 channels at 20 MHz? The only option is alternating your frequency, which translates to a very short game of Tic, Tac, Toe, to avoid causing yourself a complicated troubleshooting session. Eventually you will step on yourself, which is a very technical term meaning create your own interference.

OK, so should I use 4.9 in my design?

The reason 4.9 GHz, in my opinion, is not suitable for a citywide CCTV system is the lack of independent 20 MHz channels. What the FCC has done to the 4.9 GHz band is to stretch it out to allow more than two systems to utilize it. The band is fragmented in to smaller pieces. You can select to use 20 MHz (Default), 10 MHz or 5 MHz channels. The 10 MHz band allows for four (4) independent channels and the 5 MHz band allows for 10 independent channels. So what’s the problem, it appears we have plenty of channels to work with! Wrong. All it takes is for someone else, not you, to be utilizing the 20 MHz channel. Which if you recall is the full spectrum of the 10 MHz and 5 MHz channels. 4.9 GHz uses a smoking mirror technique to appear to have more available channels to operate on than it really has. The technique is referred to as channel fragmentation.

In a citywide CCTV deployment 4.9 GHz has its place. An experienced consultant, designer or integrator should have a strong background in wireless deployments and building networks. Only with experience will they know to best utilize the 4.9 GHz band.