Roberta Design Features:

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0 height="100%"><tr> <td valign="top" height=90 BGCOLOR="#3399CC" TEXT="#080000"> <div> <FONT SIZE="5" COLOR="#000000" FACE="Arial" ><B>Sugar River Handknits</B></FONT><FONT SIZE="4" COLOR="#006633" FACE="Arial" ><B> </B></FONT><FONT SIZE="1" COLOR="#FF3300" FACE="Arial" > </FONT><FONT SIZE="1" COLOR="#CC0033" FACE="Arial" > </FONT><FONT SIZE="1" COLOR="#990000" FACE="Arial" ><B> |  </B></FONT><B>   </B><A HREF="index.htm" TARGET="_top" TITLE="Sugar River Handknits"><U><B>home</B></U></A></div> <div> <A HREF="id126.htm" TARGET="_top" TITLE="Price List"><U>Price List-</U></A>   |   <A HREF="id129.htm" TARGET="_top" TITLE="Ertoel Guarantee"><U>Ertoel Guarantee</U></A>   |   Roberta Design Features:</div> <div> Back to <A HREF="id128.htm" TARGET="_top" TITLE="Roberta Electronic Spinner"><U>Roberta Information</U></A></div> </td> </tr><tr> <td valign="top" height=390 BGCOLOR="#FFFBF0" TEXT="#080000"> <div> Roberta Design Features:</div> <div> The Irish brake design means that it is a single band type; bobbin lead, i.e.  The bobbin (or spool) is driven by the band and the flyer is  free turning.  This is the opposite to the scotch tension design - this being flyer led i.e. band drives the flyer and the bobbin is free turning.  Out of the three designs - i.e. double banded, scotch tension and Irish brake design, the latter is the most versatile and easiest to use.</div> <bR> <div> Double banded machines have both flyer and bobbin driven.  The speed of each is defined by the whorl  or pulley size that the band runs on.  The ratio between the 2 parts always remains the same, although some people can run their treadle wheels with loose bands, creating slip when holding back harder in the drafting.  Overall, the whole system is a very rigid system and the person needs to maintain an exact feed rate in relation to the speed of the machine to obtain a perfect even yarn, hence the desire to create slip with the bands, while the spinning person pauses in the drafting and holds back.  Some treadle wheels handle this well, but others do not.</div> <bR> <div> The single banded machines are more flexible, as the free turning part can be braked to run at different speeds to create different ratios .  The scotch tension has a friction brake cord over a groove in the end of the bobbin.  This is tensioned to created resistance in the wooden groove.  This is quite a good system although the tension cord needs to be notched up a little about every hour of spinning to keep the ratio the same. This is due to the growing diameter of the filling bobbin which gathers faster as it gets bigger.  You still need to keep a reasonably consistent feed rate in drafting, as once the bobbin is braked, the ratio to the flyer is set, making it more like the double banded machine, although some slip can be created on the bobbin brake cord when pausing in the drafting.</div> <bR> <div> The Irish brake design is the most versatile and the most variable.  The spinner can alter the type of yarn by three methods.  1.  Alter the speed of the motor (alters the speed of spinning indirectly only)   2. Alter the speed of the free turning flyer on the tension device. 3. Alter the hold-back to the machine when drafting (i.e. feed slower or faster against the pull.  </div> <bR> <div> * Consider this scenario:-  The motor is running quite quickly, driving the bobbin and pulling in the yarn.  If you hold back against this effect, the flyer will increase in speed to match the bobbin speed, because the yarn travels over it.  With the bobbin and flyer running at the same pace, no yarn can gather on the center of the bobbin, so you can keep holding the yarn in one place for a few minutes.  The twist effect will continue, due to the yarn being at right angles to the turning bobbin and additional twist will run out in the fibber now ready.  The effect is to self regulate the twist effort.  Obviously holding onto the yarn in the same spot for a few minutes would be excessive, but it illustrates the function.  If irregular drafting is happening, the flyer changes speed to suit, and the unevenness of twist will self regulate between the point of loading on the bobbin and the pinch fingers and on into the ready fiber .</div> <bR> <div> This 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 understand the design and why it occurs.</div> <bR> <div> The tension device is unique to the "Roberta".  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 fiber is felt, relevant to your pace of drafting.  Always start your spinning work with a reasonable motor speed level (see instructions).  Then alter your flyer tension if need be.  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.</div> <bR> <div> 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 optional on/off foot control being fitted.  This can be fitted quite simply at any time after your purchase.  When starting, the speed comes back immediately.  It does not matter if you do not match the speed as fast as the machine does, because of the self regulating free turning flyer, as previously described.</div> <bR> <div> The polypropylene bearings are very useful in the overall design.  The polypropylene bearings gives instant and full performance straight out of the box on arrival.  Of course we all read instructions before we run our new toy, don't we?  Aren't instructions for when you are in trouble?  We never consider reading the instructions first, after all, we are an expert in spinning aren't we?  Well, some people are like that anyway.</div> <bR> <bR> <bR> </td> </tr></table></body>