Newsletter Articles 2003


Selected articles from 2003


DESIGN FEATURES IN SPINNING WHEELS (June 2003)

There are three basic designs - Double Banded, Scotch Tension and Irish Brake.

Double banded machines have both the flyer and the bobbin driven. The speed of each, is determined by the whorl or pulley size, on which each drive band runs. The ratio between these two parts is fixed. One being slower or faster than the other. Overall, this system is a very rigid.

Some people do run their treadle wheels with loose drive bands, creating a slipping effect on the pulleys (or whorls). This slipping will occur when hesitating in the drafting. The effect overcomes the rigid nature of the two driven parts. It allows some measure of irregular drafting without affecting the quality of yarn making. Some treadle wheels can handle this well, but others do not. With Double Banded spinning wheels, the person normally needs to maintain an exact feed and drafting rate, relevant to the treadling rate, to obtain a perfectly even yarn.

The single banded machines are more flexible, as the free turning part can be braked to run at different speeds to create many varied and different ratios . There are two types of single banded spinning wheels, depending on which part has the brake. The Irish Brake system has a free turning flyer with a cord acting as a brake, The Scotch Tension system has a cord restricting the free turning bobbin and acts as a brake. These two systems are often referred to as bobbin led or flyer led ( Leading meaning the driven part).

The Scotch Tension (flyer led) has a friction brake cord in a groove at the end of the bobbin. This is tensioned to create a drag in the wooden groove. This is quite a good system, although the tension cord needs to be pulled tighter frequently , to make the bobbin slow down, to keep the ratio the same. This is due to the growing diameter of the filling bobbin, which gathers in faster as the filled diameter increases. You still need to keep a consistent feed rate in drafting, to match the flyer speed. With the bobbin being braked, the ratio to the flyer is set.

The speed of the flyer, on any type of spinning wheel, determines the pull in rate. With the driven flyer, the speed of drafting must match the speed of the flyer otherwise unevenness of the yarn will occur. For most experienced people, this is quite acceptable, changing and matching both speeds as they do their spinning.

The Irish Brake design is the most versatile and the most variable. This is because it is largely self regulating, with no constant changing of the bobbin brake tension , as occurs with the Scotch Tension system. Also there is no need to match drafting rates to the speed of a driven flyer as occurs in the Scotch tension design. The Irish brake system is the same system as used in modern mills today. The only variation is they have their bobbins mounted vertical instead of horizontal.

The Irish Brake system (bobbin driven) can alter the type of yarn by three methods.

  1. Alter the speed of the driven bobbin. This affects the twist rate only.
  2. Alter the natural speed of the free turning flyer on the tension device, by setting the brake tension. This alters the draw in rate.
  3. Alter the hold-back to the spinner when drafting (i.e. feed in slower or faster against the pull.)

Consider this scenario:- The bobbin is running quite quickly, pulling in the yarn, across the free turning flyer. If you hold back against this effect, the flyer will increase in speed to match the bobbin speed, because the yarn is travelling over it. (It will overcome any tension effect on the brake cord.) With the bobbin and flyer now running at the same pace, no yarn can gather on the centre of the bobbin, so you can keep holding the yarn in one place for a couple of minutes if you wanted, and the yarn would not break. The twist effect will continue and the yarn will curl up. This is due to the yarn being at right angles to the turning bobbin. This additional twist can be dissipated in a long draw, when you are ready. The effect is to self regulate the excess twist. Obviously holding onto the yarn in the same spot for a couple of minutes would be excessive, but it illustrates the function. If irregular drafting is happening, because of difficult fibre, the flyer will change speed to suit what is happening and any unevenness of the twist, will self regulate between the point of loading on the bobbin and the pinch fingers.

Out of the three designs - i.e. double banded, scotch tension and Irish brake design, the latter is the most versatile and easiest to get good results, even with irregular drafting.

There has always been a little bit of bias against the bobbin led design. This was because of the traditional leather bearings that are normally used. They can create a fairly strong draw in, if they are not properly lubricated with vaseline or grease. Light sewing machine type oil is ineffective in the leather bearings to give the flyer absolute free turning. As the flyer speed determines the pull in rate, without good lubrication, the free turning flyer will run slower ( the same effect as applying the brake cord). The pull in, then may be excessive for the type of yarn wanted.

Spinning cotton or short fibre could not be handled. Also the making of a soft fluffy type yarn can become difficult. The adjustment on the tension cord on the flyer can then only alter the draw in rate from a medium pull in, to a heavy pull in rate. If the flyer is lubricated well and is absolutely free turning, a very light pull in would occur. ( no brake tension applied.) In this situation you can regulate the draw in rate from next to nothing, right up to as strong as you wish. Unfortunately this impact of lubrication on the Irish Brake design ( bobbin led ) is not fully understood by most people. They then would proceed to experiment with the tension device, making things worse for themselves.

After many years of practical research, and studying new and old designs in spinning equipment, we believe that the one and only disadvantage in the Irish Brake design has now been eliminated. We have done this while still maintaining all of its advantages over the other 2 basic spinning wheel designs. We have been using a special polymer product for flyer bearings on our Irish Brake design,since 1995. It has many characteristics the same as the traditional leather, i.e. bends easy, will not crack and maintains its shape. The big difference is that it reduces the friction, allowing the flyer to run very freely. In theory, these new type of support bearings do not require any lubrication with the steel parts, however I still advise people to still use the vaseline to get maximum life. The tension device still works the same but now gives a range of pull in rates from next to nothing to strong. To achieve the strongest pull in {rarely needed} wipe off the vaseline from these special flyer bearings.

With this improvement now featured in the Roberta electronic spinner, it makes it the most technically advanced and user friendly hand spinner available in the world. Great for the beginner, as well as the production spinner. Makes thin lace yarn through to rug yarn, from any type of fibre, without any changes or modifications. The large jumbo bobbins are very suitable for the Roberta spinner {with the Irish Brake bobbin led system }as the increasing loading diameter of the jumbo bobbin does not have to be constantly adjusted as would occur on the Scotch Tension system. {note:- standard or regular size bobbins are still available}

The tension device for the flyer is unique to the "Roberta".electronic spinner The nylon running in the groove of the steel orifice piece creates little or no friction. The resistance (created by the spring) is transferred to the flyer bearing surface, inside the hole. As this is lubricated, the easy surface enables the speed of the flyer to remain absolutely the same for days of use. When experimenting with the adjustment, take it in very small doses starting with no tension first. Ease the tension on a little, until the right pull-in of fibre is felt, relevant to your pace of drafting. Always start your spinning work with a reasonable motor speed level. {creates the twist rate} Then alter your flyer tension to give the exact pull in rate. Once your tension is set on the flyer, there may no need to alter it again, regardless of how the diameter of the bobbins grows. {which is a necessity with the scotch brake or flyer led system}

After a while you will know exactly where the slow/fast knob should be, and it can be left at that position all the time. Alterations to the speed knob will only affect the rate of twist.

What I have descibed with the Roberta electronic spinner sounds very technical, but many spinners who get their hands on a "Roberta" say immediately. "this is great". When asked why, they cannot quite explain. They just know that they have the flexibility in their hands and do not really understand the design and why it occurs.

Stopping and starting on the switch is easy. Take your free hand behind your pinch fingers to operate the switch. The machine stops instantly - no run on like a treadle wheel. If you are a person who likes to keep both hands in place at all times, you can consider the inexpensive and optional pause control . Use your elbow, thigh or foot to pause the spinner. Very comfortable to use. This can be fitted quite simply at any time if you already own a Roberta electronic spinner. When re-starting again, the bobbin speed comes back immediately, but this does not matter if you are not matching this speed, because of the self regulating free turning flyer, as previously described.

The special bearings are very useful in the overall design. Traditionally leather has been used (we did use it on the "Roberta" for 17 years). Some minor problems have occurred with people not appreciating the design and forgetting to lubricate the leather bearings, or either, using the wrong lubricant i.e. sewing machine oil. The latter soaks away rapidly in new leather and is useless. The effect was undue resistance in the hole causing a slower turning flyer, giving a stronger and more direct pull to the bobbin. Until the leather bearings had settled down (about 8 hours use) the full versatility of the "Roberta" could not be realised. By this time, some people who did not appreciate the design, or the instructions given, had decided they did not like it. Now the special bearings gives instant and full performance straight out of the box on arrival.

It is important to read the operating instructions with the new Roberta spinner to get a full understanding of its ability. We never consider reading the instructions first, after all, we are an expert in spinning aren't we? Of course, we all read instructions before we run our new toy, don't we? Aren't instructions for when you are in trouble? Well, some people are like that anyway.

I trust this technical information, will allow you to experiment, and achieve the maximum potential the Irish brake design can give. Should you have any question about getting the most your spinning wheel do not hesitate to contact the undersigned.

Ian G Spark

Manager/Proprietor for Ertoel Wheels

 

ERTOEL WHEELS
Specialists in: ELECTRONIC SPINNERS AND CARDING MACHINES (Hand and Electric)

"The best spinning equipment available at a reasonable price"

Factory 7/45 Vinter Ave, Croydon, Victoria, 3136
Fax and Phone (03) 9725 6253 E mail:- crowng@connexus.net.au

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