Wednesday, September 24, 2014

Safety First when it comes to casters.

"An ounce of prevention is worth a pound of cure." Caster wheels that are incorrect for the floor surface can pose the risk of serious injury. Even brand new chairs can cause problems as they are routinely equipped with hard wheel casters suitable for carpeting. For chairs to roll safely, use hard wheels on carpeted floors, and soft wheels on chairmats and hard floor surfaces. Many new chairs are equipped with hard wheel casters for use on carpeted surfaces only. Hard wheels skate and slide on hard floor surfaces. For safe rolling on chairmats, and all hard floor surfaces, soft wheel casters should be used. Soft wheels provide traction and prevent sliding. Just as tires must have the proper tread for safe driving performance on dry pavement as well as slick or snow-covered roadways, chair movement depends on wheels that provide appropriate traction on hard and soft surfaces.
Hard floor surfaces require soft wheel casters or the chair will be subject to dangerously rapid movement. Many new chairs are equipped with hard wheel casters for use on carpeted surfaces only. Hard wheels skate and slide on hard floor surfaces. For safe rolling on chairmats, and all hard floor surfaces, soft wheel casters should be used. Soft wheels provide traction and prevent sliding. Spinning out of control while the user is seated or rolling away when the user rises, and then tries to resume a seat are other examples of what can happen if hard wheel casters are used on hard floor surfaces. In addition, injury due to falling is an obvious risk. A more insidious problem is the muscle strain that can result from constant efforts to keep the chair in place or trying to roll with an improper caster.

The requirements for carpeted floor surfaces is just the opposite. Hard wheel casters are necessary for the chair to glide smoothly across the carpet. If, instead, the caster grips the carpeting and the user tugs back and forth to move the chair, it can topple over. Even if this hazard is avoided, such constant exertion can result in strain and injury.

The use of the proper caster for the intended use is extremely important from a safety standpoint. Also take into consideration that the use of an improper caster can result in damage to the floor that it is rolling on. Hard wheels can scratch and damage wood floors and soft wheels can damage carpet fibers.
Choosing the proper caster is a Win - Win situation!!
Excerpts of the above were provided with permission by Master Caster in their flyer titled "Accidents Happen"

Monday, September 22, 2014

Stemless Casters for Steelcase & Welded Stem Chair Bases

Steelcase and some others, build their chairs just the opposite of most chair manufacturers. Instead of attaching the stem to the caster, they decided to attach the stem to the chair and then designed a caster body to fit the stem on the chair. A normal caster has the stem attached to the caster and then the caster assembly is inserted into a hole in the base of the chair.

There are many caster manufacturers in the world. There is no standard on how to attach the caster stem to the caster body. Each manufacturer does it differently. Therefore, the body from Caster Company A will not fit the body of Caster Company B. This can present a problem when trying to find a replacement should your caster break. Sometimes when a caster breaks, it will break away from the stem. When this happens, it may appear that the stem of the caster is permanently attached to the chair base. You must look carefully to determine whether it is. If you can turn the stem with pliers, it will come out. If it will not turn, you must look further.


Do you know if you really need a stemless caster? See NeedCasters.com for one on the best explanations along with photos.

http://www.needcasters.com/stemless-casters.htm 




Monday, September 15, 2014

How to "snug up" your CASTER sockets.

Plastic Sockets
 
Over time sockets can wear out. How fast they wear out depends on how well they were installed. If a socket is loosely installed into the hole in the furniture, it will wobble when ever the object is moved. If this is a chair, that will happen often. As the socket moves, it not only deforms itself but will start to deform the hole that it is in if it is in wood. Look at your caster installation occasionally to check for loose sockets. If you find that they are getting loose, here is a tip. Use some vinyl electrical tape to tighten them up. A turn or two of tape around a plastic socket might be all that is needed. This same tip will work on a new socket installation. If the hole is worn and your new socket seems to be loose, tighten it up with electrical tape.

Metal Sockets

 
Metal sockets that are used in wood furniture have a tendency to loosen up quickly. This is due to the fact that the hole where the socket is installed is not filled with material. Both the socket and the stem of the caster do not totally fill the hole. There is space around the socket. With movement, the metal socket loosens and will start to elongate the hole. To stop this from happening, use silicon sealer ( bath tub caulk ). Remove the sockets, apply some silicon sealer around the socket and into the bottom of the hole. Install the sockets and the casters while the silicon is wet. Do not use the chair until the silicon hardens. The voids in the holes should now be filled and the casters and the sockets should not wobble.


If you need new shocks, check out our selection at NeedCasters.com

 http://www.needcasters.com/caster-sockets-hardware.htm

Wednesday, September 3, 2014

Proper Chair Caster Installation

If you are replacing casters that have been working on your chairs or furniture simply measure the attaching device ( stem or plate ) using the methods shown on our website. But if you are building a project or thinking about putting casters on a chair or furniture that currently does not have casters, be careful. A caster is a wonderful invention. It allows you to move things very easily but it relies on one geometric principle. It MUST be installed "perpendicular" to the floor. That means it has to be on a right angle to the floor. Why? So it can rotate in a circle around its attachment. If it is mounted on any angle, it will be forced into one position and it will NEVER swivel. Look at the photos shown. One chair would be a good candidate for casters and the other would not. One chair has straight legs and the other has legs that come down on an angle. You could probably install casters on the straight legged chair but never on the curved or angled leg chair. So how can you check the angel? You can use a "square" or if you don't have a square, use a cereal box or any other box in the kitchen. If the legs are straight, they will be parallel with the edges of the box and if they are not parallel on all sides, don't try to put casters on the chair.

Here is another tip. If your current casters do not swivel well, check to see if they are perpendicular to the floor. Make sure that the chair legs have not bent or maybe a socket is defective and now the caster is on an angle which would make swiveling difficult. Don't assume that you have a defective caster as it might be a bad socket or a bent leg and even if you replace the caster, you will still have the same issue.


Here are the 2 images. The 1st one could be a good candidate for casters as the legs are large and perpendicular to the floor. Casters could be installed by removing the glides on the bottom of each leg and drilling a "straight" hole into the leg to install a socket. The size and type of socket would depend on the thickness of the leg and/or the type of stem to be used on your caster.


This 2nd photo shows chairs that should not have casters installed. If you look closely, the front legs seem to be straight and perpendicular to the floor. However, the rear legs are curved backwards and are not perpendicular to the floor. This chair would NOT be a good candidate for casters.



For more information on how to choose the right caster or replacement caster, go to our short course on how to proceed. http://www.needcasters.com/how-to-measure-for-new-casters.htm