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March 12, 2016 / apexprecitech

Apex Load Enhancing Spacer for P3-1 Top Arm

Ever thought of a simplest of a solution for some really baffling and complicated job ? Well, here it is.

Apex Precitech was committed to improve the pneumatically loaded P 3-1 top loading arm. Apex Precitech published an article  <here>  regarding the full construction of the P 3-1 top arm.  This top arm is the maximum populated one in the international level and its simplicity and ease of operation still overrule its rejection. The problem areas in these top arms are reduction of loads over period time and  inability to raise the loads despite increase of air pressure.

With the advent of compact spinning and with many frames getting converted to handle compact drafts, the spinners are facing a crisis of sorts with inadequacy of loads in these top arms. It is to be noted that compact front rollers are also loaded from the top arm. The load starved top arm is powerless to handle this issue.

Spring load conversion of the top arm failed miserably and another viable solution was badly needed.

The Solution

We  always were intrigued by the enhancement of loads with the slight lifting of the pressure lever of the top arm. In fact the spinning siders place a small cotton wad and then press the lever thereby creating a gap between the anvil and the lever.  This lifting was never uniform and created excess loads which led to wear of the bottom roll bearings and the rubber cots.

We analyzed this further and found that the L shaped loading fulcrum of the top arm has a curvature inside which the idling roller of of the top arm sits upon the final pressing of the lever. This is where the inadequacy of engagement takes place once the pressure hose inside the arm bar even slightly loses its elasticity. The resultant ‘play’ developed leads to lowered engagement force experienced at the bottom roller.

When we insert a spacer into the pressure lever as shown, the fulcrum is noaded at the curvature but at the preceding slope which immediately tightens the fulcrum against the pressure hose. The loads are now consistent and steady. This gives life into even discarded hoses saving money and  time. Many anxious spinners who once thoughts of replacing the frame itself due to this, can be relieved now.

The Product ” Apex Load Enhancing Spacer”

The spacer is shown here. It has five components. The U shaped housing, the metal washer which prevents from biting of the sharp bottom edge of the pressure lever, a top cover and a screw. The nut is embedded in the housing itself.

spacerspacer with washer

spacer final

Once this assembly is fastened onto the Top Arm , the results are sure and consistent. Our 4.5 mm spacer has uniformly created a 4.5 Kilogram increase in the fron roller load. This further means an additional 4.5 kilo load increase in the back roller and  1.5 kilo increase in the middle roller load. A total of 10.5 kilogram per top arm!!!

Now , the spinner has the joyous problem of plenty. As a 6 to 17 kilogram is enough for the normal spinning process, he can now reduce the air pressure !!!

For compact spinning processes, the front roller load needs 21 to 22 kilograms. This spacer is capable of generating that load easily. This is a very low priced product and a boon to all spinners. I appeal them to use this to increse productivity, increase quality, decrease down time and increase smiles all around.

The following video demonstrates the spacer


March 12, 2016 / apexprecitech


For long the saddle setting in the P 3-1 top arm continued to be laborious. The handheld setting gauge of yore allowed for a limited turnout due to the holding of the gauge in one hand and snapping it on to the saddle with the other.  usually a team of five technical  persons do this job of removing the saddle loosening the saddle screws, snapping into the setting gauge, tightening and removing and reassembly back  into the top arm. Setting the field length is another job using vernier calipers. Usually the job takes 5 to 6 hours to to set a 1000 spindle ring spinning frame.  The machine is stopped during the period.

The New Solution 

Apex has introduced a portable table mounted setting device designed to take on all the above jobs  with much ease and accomplishes them at one third of the labour and time.



The above picture shows how the machine is constructed. The salient features are

  1.  Vernier caliper fitted slidable, lockable saddle heads. Two vernier scales take care of the front (finisher draft zone)  and back (break draft zone).
  2. Wheels fitted at both ends enable smooth sliding of the heads varying the distance which can be locked at any desired point with an accuracy of 0.01 mm.
  3. This device empoys the slip on fitting of the saddle shafts into the saddle instead of snap fitting . The present method takes care of the fingers of the operators. Earlier, the snapping makes the fingers tired and every chance was there in getting tender skin getting squeezed into the saddle spaces.
  4. The rigid fitting of the heavy device means , the opertaor does not handle the gauge and concentrates only on the saddle.
  5. Usually a team of two people can handle this job at a time. One for removing and the other for unscrewing , setting and tightening the saddle.
  6. The machine need not be stopped as the team targets one top arm at a time. The siders can be called in once a dozen top arms are set. (one arm bar length).

The following video will further demonstrate the usefulness of the device.


It is a labour saving, time saving and accurate device which is necessary for quality conscious and cost conscious spinning mills.

January 28, 2016 / apexprecitech

Apex Top Arm Load Gauge now totally “compact spinning”compatible

The Apex Top Arm Load Gauge has got better. Recently we added a new feature by which our gauge has become the first to measure the loads in the compacting rollers of compact spinning drafting.

We experimented with Suessen Elite compact spinning drafting. So far , we had only given arbors to measure the second roller which is actually held in the saddle. But, this present arbor is in fact, as assembly of a normal top roller and the plastic casing from the original compact dtafting. See the picture below.

This assembly was held in the arbor of a Suessen Elite drafting, and the arm pressed to exert load. We got the loads from 5 to 6 kilograms as anticipated by us. This was when the front roller load was about 25 kilograms.  See the below picture.


September 24, 2012 / apexprecitech


A Study on the power consumed in the drafting apparatus of a Ring Spinning Frame using pneumatic arm loading.


Prepared by J Venkatasubramanian, Research Engineer, Apex Precitech., Coimbatore

The objective is to find the load consumed for excess/ deficit loading of the bottom rollers by the loading arm of a pneumatically loaded drafting system. Another objective is to calculate the actual cost of such an increase for a mill.

The Rieter/ Lakshmi Rieter type of drafting with their current P 3-1 top arm is taken for analysis. Assumed is that one complete ring frame has 1008 spindles and the mill has 25,000 spindles.

The standard motor capacity is 45 KW and the percentage load consumed in the drafting is taken as 25 % i.e., 11.25 KW. (The remaining 75% will be towards  the spindle drive)

It is known from studies on P 3-1 top arms that the loading pattern from front to back roller of the drafting is as follows

Front- 16 kg       Middle- 12 Kg     Back 16 Kg.

For an optimum performance in cotton spinning conditions technicians keep these values. Also, at the recommended air pressure of 1.6 bar, only these values are recorded using Apex Top Arm Load Gauges. This means  a total load of 44 Kg for one top arm.


Total number of top arms – 504

Load per arm – 44 Kg

Total drafting Load – 44 X 504 =  22,176 Kg

Power consumed for one full machine = 11,000 watts

(11,000 watts are consumed by an exertion of 22,176 Kg.)

Therefore , for one Kg , the load consumed is   = 11,250 / 22,176 = 0.507 watts

The P 3-1 top arm is centrally pneumatically loaded and the increase of air pressure fed into the machine will result in the increase of top arm loads in all the top arms. Another feature in the P3-1 top arm is that the increase of one kilogram of the front roller in the standard pin setting of the P3-1 top arm will result increase in other rollers too. The ratio of inmcrease  (front: middle: back ) is 1 : 0.5 : 1

Hence, if we assume the front roller is loaded in excess of 1 kg (over the normal of 16 Kg) the loading pattern will be like 17 :12.5 : 17. The increase in load will be 2.5 Kg total. For 504 top arms the excess load applied  = 2.5X 504 = 1,260.00 Kilograms.

Since   we arrived at the power consumed per kilo as 0.507 watts, the total power for 1,260 Kilos of excess loading will be

= 1,260 X 0.507 = 638.82 watts.

For 24 hour running of the machine, the power consumed will be = 24 x 638.82

= 15,331.68 watts= 15.33 KW

Converting into energy units for  24 hour running consumed will be 15.33  kilowatt hour (units)

Calculating for 25000 spindles (25 machines)  the excess energy consumed per day  will work out to be            = 25 x 15.33 = 383.25 units

For 365 days the calculation will be = 1,39,886.25 units

Considering Rs 7.00 as an average cost of a unit as in Tamil Nadu the Rupee equivalent of the excess energy consumed is                                             = 1,30,886.25 x 7

=  9,79,203.75 Rupees per annum.


Since this cost is for unit increase of load , i.e., by 1 kilogram, for any further increase , the cost can be got by multiplying by the factor. For example , for 1.5 kilogram increase, the cost can be simply  1.5 multiplied by 9,79,203.75.

This can be used as an empirical method to calculate the costs for any increase or decrease of air pressure.

March 6, 2012 / apexprecitech

Lakshmi Rieter P 3-1 Top Arm Loading Details

The Rieter P 3-1 is easily the largest populated spinning top arm in the world today. I had already written about this top arm in a separate post. see the article <here>

This is a pneumatically loaded top arm with the benefit that even upon regrinding of the top roller, the load applied remains the same. The load is transmitted to the top arm via a fulcrum loading point.

From the arm the load is individually transmitted via an arrangement of loading pins. This is simply placement of the pivot positions of the front and middle rollers in one set and the back roller alone as another set. The pin positions can be in three positions and the position will decide the intensity of load in that region.

For example, if the pin is inserted in the last pair of holes, the loading will be more on the back roller than the front.

The figure will explain the construction. The points ‘m’ and ‘n ‘ determine the load sharing ratio between the front middle and back rollers.


The top arm load of P 3- 1 is front 16  Kg, middle- 12 Kg, back- 16 Kg. The hexagonal arm bar houses a lengthy hose which exert load on the top arm on a bent lever. The advantages are that even after regrinding of the rubber roller (cots) the top arm load does not diminish.  This is due to  the fact that the area of the hose and the pressure remain constant and as a result, the load is also constant.

Despite its many advantages, the top arm is found to give erratic load readings because of following reasons.

1. Weakening of the hose material.

2. Leakage in the air line/ hose

3. Play developing in the key joints where load is transmitted.

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Our contact address:

APEX PRECITECH, No; 2/36  , Sri Ambal Nagar, Vilankurichy, Coimbatore- 641 035, India ; Tel: 0091 422 2667026  , 0091 98430 35014   email:

April 12, 2010 / apexprecitech


Textile technicians the world over are aware of the original contributions that the name ‘Suessen’ brought into the Industry. They were the originators of the first plate spring loaded top arm with individual load adjustments.

A decade back, Suessen again pleasantly surprised everyone with their “Elite Compact spinning system”. The technology was revolutionary. With the help of a driving  front roller running over an oval tube, a compacting zone was created. In this zone, a porous apron in fact runs between the runner and the tube. The tube is connected to vacuum and this vacuum is applied to the travelling fibres in the form of a calculated slot. The fibres are aligned on a central axis by the action of the vacuum and this compacted strand is then gripped by the roller and twisted and spun in the same manner using the ring and traveller thereafter.

Millions of spindles are now retrofitted with Elite Compact system and they continue to produce excellent standard of compact yarn.

Well, we at Apex saw a great opportunity for us in Elite compacting systems. We knew that drafting load setting in such systems are an absolute must. Further, a fourth roller meant that it shared (or took away) some of the load of the second roller. Hence, the second roller load has to be increased to avoid undrafted fibres. Instead of the usual 14 Kg for the second roller, 18 Kg gave excellent results with some clients.

The clients continue to use the gauge at every regrinding of the rubber cots since loads may vary then. More and more spinners around the world are buying and using the gauges to have a first hand knowledge of what is going on in the compact spinning draftings.

Some clients have argued that they have seen no immediate benefits arising out of using the Apex Top Arm Load Gauge. We pointed out that these machines were new . Just after a year, the same customers have told us that the Top Arm Load Gauge is an indispensable tool in their mill. They have also confided that this gauge is more helpful in diagnosis of the drafting since ruling out problems in drafting loads helps them to analyze other areas.

To read more about our gauge click the following link

<<Apex Top Arm Load Gauge>>

If you liked this article, and would like to leave a comment click <here>

J Venkatasubramanian

March 20, 2010 / apexprecitech

RoCoS Compact spinning and Apex Drafting load gauges

RoCoS was launched  by Rotorcraft AG amidst great expectations. Till then compact spinning was conceivable by pneumatic suction only. It was upto RoCoS to demonstrate a neat, decisive mechanical set up to compact the spun yarn. This means an enormous power saving over conventional pneumatic suction type condensing mechanisms.

RoCoS is an ingenious development over the conventional drafting for spinning. By adding an extra roller running at the same speed as the front top roller, a new passage area for the yarn fibres is set up. These fibres pass through a mechanical guide like condenser made of ceramic material. This condenses the fibres which are then clamped by the newly introduced front roller and twisted by usual means by the ring + traveller mechanism.

(pictures from the official website of M/s Rotorcraft AG)

RoCoS and Importance of Top Arm Loads:

Since, the newly created roller shares the same saddle as the second roller, correct load setting of these two rollers are of utmost importance. Almost every spinner who has installed RoCoS in his mill has seen benefit from regular load setting.

RoCoS is installed in both SKF PK 225, (also pk 2025), and P3-1 draftings. In all of these draftings, correct load setting is important. The front saddle load has to be increased so as to compensate for the load sharing with the front idler roller.

Apex has been at the forefront in drafting load measurement and is a proud supplier of many Top Arm Load Gauges to Rotorcraft over the past six years.

To see a write up on our Apex Top Arm Load Gauge , click on this below link

Apex Top Arm Load Gauge

If you liked this article, please leave a comment by clicking on this <link>


March 17, 2010 / apexprecitech


The textile machinery major Suessen, has continuously introduced breakthrough design features in Ring spinning and Roving top arms. Suessen was the first to introduce the plate spring for loading the arms.

Its vintage UT 200 and UT 600 series of  top arms have proved beyond doubt that plate springs are by no means inferior to helical compression springs (as promoted by SKF) .  Suessen’s technological uniqueness further improved with the HP-A 310/320 top arms finally culminating in the spectacular ” Suessen ELITE” compact spinning system.

The HP-A top arm is a rigid top arm for ring spinning. The front roller is loaded at 16 Kg which is  shiftable to 12 Kg by turning a nut.  The middle apron roller and the rear roller are loaded at 14 Kg each.

When retrofitted with Elite compact spinning system, the front roller is set at 23 Kg and shiftable to 17 Kg.

Apex has always been a favourite with spinners when it came to top arm load measurement. Suessen top arms are no exception. We were approved by Suessen and their Indian counterparts are insisting on checking with Apex Top Arm Load Gauges in all their installations.

To view the full article on our Apex Top Arm Load Gauge please click on this <link>

If you find the above article useful and would like to comment on it, please click this <link>


March 16, 2010 / apexprecitech


Rieter P3-1 is perhaps the most widely distributed top arm in the spinning industry today. It is a simple top arm to work with but a little complex to understand in its intricacies.

This top arm is supplied by both Lakshmi Machine Works Ltd and Rieter Textile Systems in their Ring Frames. Rieter considers this top arm so effective that the same arm is used in Rieter’s flagship ” ComforSpin” compact spinning frames with slight modifications.

This top arm is pneumatically loaded. A long hose runs through the hollow hexagonal arm bar that also doubles as a housing for this pressure hose. This hose is pressurized to around 1.4 to 1.8 bar to get desired loads at the rollers.

The top arm is loaded from the fulcrum. The fulcrum is loaded by the expanding hose inside the arm bar. When the arm engages with this fulcrum, the load is transmitted to the arm area.

In this area, there is a bridge which divides the applied load to the combines front and second rollers and to the third rollers. The division of load is varied by shifting the pivoting distance of division by simply altering the position of a locating pin. This is an ingenious setup whereby simply by changing the position of the pin, loading ratio is changed.

The load transmitted to the first and second roller is through another bridge which again splits the load between the fron and second (apron) rollers, Here again three pin positions are given by which the ratio of loading between them can be changed.

The recommended load setting values for cotton spinning in the P3-1 top arm is like this

As always, Apex Top Arm Load Gauges were the first   to measure the top arm loads in P3-1 successfully and accurately from the very beginning.  We were initially discouraged by the spinners in the measurement of P 3-1 saying this was a pneumatic system and measurement was not at all necessary even after cots regrinding.

But experience is a better teacher. When we demonstrated the possible variations with worker neglect, pneumatic hose wear, and top arm general wear, spinners quickly understood its value. One defective top arm can play as a black sheep and spoil the quality of a lot. Variations of even 5 to 10 % in top arm loads can alter CSP and USTER values. Yarn appearance is directly affected by variations in top arm loads.

Also one idle top arm is a potential loss to  the mill. The gauge may be small but its indispensability to a spinning mill is undisputed. Now, mills are buying these gauges right at the project stage.

You can read more about our Apex Top Arm Load Gauge (with video  demonstration) by clicking on this <link>

If you have found this article useful and would like to comment on it , please click on this <link>

J Venkatasubramanian

March 16, 2010 / apexprecitech


Trutzschler draw frames have always fascinated everyone with their original features. Everytime they announced a model, a novel idea would definitely be in there.

click on photo to enlarge

TD 03 is no exception. Built over the earlier HSR series platform, these machines display one extraordinary, never before tried feature. The loading arm is laterally positioned in them instead of the right over top design of the loading arm. In other words, the top arm is designed like a hinged door. Look at the following picture

click on photo to enlarge

This is a four over three roller drafting. The first roll is a guide roll for the web coming out of the drafting and usually is loaded at 15 kgs/end. This roller is seen in the picture with an inclined angle of loading in the front. The remaining three rollers are loaded at 30 Kg/end. The loading is pneumatic and the load is separate for each roller.  This means there is separate air supply to load each roller and each is individually variable.

Apex Draw Frame Load Gauges are eminently suited for measuring the loads in TD 03 machines. In fact, we have come out with a special gauge for TD 03 in view of its restrictions in the drafting space.

Look at the article for a description of Apex Draw Frame Load Gauge by clicking on this <link>

If you liked the above article and find it useful, you can leave a  comment by clicking on this <link>

J Venkatasubramanian