Advantages and disadvantages of horizontal hook machines
Mid-priced machines have a shuttle device, located horizontally. This design has a number of advantages.
- Due to the lack of a bobbin case, the lower thread is very easy to thread.
- Through a transparent window on the needle plate, made of plastic, you can see how much thread is left on the bobbin, what color they are. This makes it possible to wind the thread on the bobbin on time and not wait until at the most inopportune moment, when there are still a few stitches to sew, it ends.
- Machines with a horizontal hook have a wider range of stitch length and width: length. up to 4.5 mm, stitch width zigzag. up to 7 mm.
- Most often, machines with a horizontal hook are much quieter than the vertical, because the vibration is less.
But there are disadvantages to the horizontal hook. These include such as:
- shuttle works only with standard threads;
- there are difficulties in adjusting the machine‘s bobbin thread settings;
- The shuttle requires careful handling, strict adherence to the instructions, and can fail quickly if these are not followed.
Horizontal hook device has a rotary principle of operation, that is, the carriage of the shuttle rotates 360 °, due to which the machine has reduced vibration and is almost silent. It is easier to thread the bobbin because it does not have a bobbin cap, and the plastic plate allows you to check the remaining thread on the bobbin. Zigzag stitch can be made with a width of more than 5 mm.
Some models of Janome, Brother, Bernette sewing machines are equipped with a horizontal hook.
How to adjust the thread tension in a sewing machine. a few practical tips and how-to’s
Setting up the sewing machine will go without problems if you familiarize yourself with the basic rules of operation of the device and follow them. Exact requirements are described in the manual for each model. But there are basic recommendations that will help sort out the different machines:
Need to know the construction of the machine
- you must not pull the fabric when the sewing process itself takes place;
- It is necessary to timely lubricate the mechanisms with the means that are recommended in the instructions;
- It is important to dress the machine in the correct sequence.
Important! Not all machines require lubrication.
Sewing machine needs to be cleaned
Most older models have an adjustment dial in the same place as the bobbin changes. Tooth lift is not a random value, it varies depending on the selected fabric, its density. The teeth should protrude more if the fabric is thick and dense, but if thin, a barely perceptible lift is sufficient.
Important: if the machine is used for embroidery, it is necessary to completely hide the combs.
Basic rules for sewing machine settings
Every sewing machine is first adjusted at assembly. Factory setting is for medium-density fabrics. Before you start, always read the instructions for use for the chosen model and take into account the characteristics of the fabric and threads used. The adjustment process for different models differ mainly in used regulators and their location. Significant differences in how to configure the sewing machine Janome from the adjustment of a sewing machine Brother or other manufacturer is not. In computer models, some settings are made electronically adjusting.
Setting up a sewing machine consists of changing the following parameters:
- choice of type, length and width of stitching;
- adjusting the thread tension;
- adjusting the presser foot pressure;
- Adjusting the hook sewing machine;
- Elimination of problems with the pedal.
Separately, it is worth noting the need to adjust the sewing machine after a long downtime.
Sewing machine shuttle adjustment
Sewing machine. it is an indispensable accessory of modern life. Sewing machine hook. one of the most vulnerable to damage parts of a mechanical or electrical appliance. Adjusting the hook sewing machine industrial or domestic type depends on a certain level of knowledge of the owner of the device or a professional adjuster.
The sewing machine always comes with an instruction manual, which indicates the class, type, brand and functions, as well as recommendations on sewing machine maintenance and replacement of consumable parts. Maintenance of the product should be entrusted to a professional adjuster, which guarantees the longevity of use, prevention of many minor errors in the device. Owners of a sewing machine adjustment hook will not be a problem, as the procedure is simple and requires operations according to user recommendations. Mistakes in the application of the stitch on the fabric in the form of a loop of the upper thread on the wrong side of the material, breaking off loops, skipping stitches due to clogging of small parts of the machine’s shuttle stroke.
Be sure to check the needle bar, in which the needle must be inserted as far as it will go, with the long groove towards the needle thread guide and securely fastened. Needle bobbin wobbling in the needle holders will cause the needle to warp.
Depending on the type and type of fabric, choose a needle number and then a thread number. Usually the Janome sewing machine instructions show a table of matching fabrics and needle and thread numbers. When sewing thick fabrics, needles that are too thin will break and thin thread will tear. Conversely, thick needles and thread will tear the material at the stitching point. Watch the condition of the needle: a blunt needle causes skipped stitches, foreign knocks, fabric being pulled into the hole of the needle plate, fabric tearing. Crooked and rusty needles are not allowed. Upper and lower thread must be from the same bobbin.
What is a bobbin?
This is such a small bobbin for winding thread on it to create the bottom of the machine stitch. The thread on the bobbin is called the bobbin thread. The thread is wound onto the bobbin automatically (only the old Soviet style machines need to do it differently). Then the bobbin has to be inserted into the bobbin case into the hook. And the hook can be horizontal or vertical.
Horizontal or Vertical: Which Shuttle is Better?
The hook is one of the main mechanisms of a sewing machine. That is why customers pay close attention to the hook when choosing a machine. So which one is better: the usual vertical or modern horizontal hook? Let’s find out together.
The vertical hook
The principle of its operation is based on the reciprocating motion of the shuttle crescent. This is also the first technical problem. The pusher has to move the shuttle at high speed in the opposite direction to the original speed. That is, the needle moves up and down, and the shuttle goes half a turn in one direction and half a turn in the other. The movement is reversed, putting a lot of strain and wear on the mechanisms that drive the hook. As wear increases, the noise produced by the device increases proportionally. Also the pusher plate of the shuttle is subject to wear due to the constant shock loads.
Now for the hook itself. The half-moon is precisely matched to the hook stroke housing, and the hook rubs against the housing as it moves. Due to the fact that users VERY rarely clean and lubricate the hook (although it is recommended to do it at least every 4-6 hours of the machine), both elements of the system quickly wear out. This leads to increased knocking and eventually to skips or regular needle failures.
Replacing the hook crescent will cost a pretty penny, replacing the hook body is even more expensive. To get a perfect result, you need to change everything at once. And taking into account that we are talking about inexpensive machines, the expediency of such work tends to zero.
Now about reliability and durability. If you use the sewing machine intensively for 3-5 years without quality service, the system will work out to a critical stage. Another problem with the vertical shuttle is. When the hook removes thread from the needle, the gap between the hook and the needle plays an important role. So, the design of the vertical hook initially accepts the backlash of the hook crescent in all planes. As a result the clearance between the hook and the needle is not constant. over, this oscillation only increases during operation.
Another problem is related to the mechanism that drives the pendulum shuttle. The most common is the crescent pinion, which is always made of plastic.
The problem is that without proper maintenance this pinion is under a lot of stress. And if the shuttle system gets jammed by dirt or just by thread entanglement, it bites and breaks. The gear itself is inexpensive, but the process of replacing it is quite complicated and requires adjustment of the hook‘s momentum.
The other downsides of the vertical shuttle are quite obvious:
So, let me summarize. The vertical pendulum shuttle has not changed since the production of the old Podol machines. It is noisy (and the sound increases during operation) and reliability is not much. Failure of almost any element will be a headache for the mechanic.
The principle of its operation becomes as clear as possible on the video clip, which was shot by many favorite Discovery Channel. a very clear video.
However, there are a few things I should dwell on in more detail. First: the shuttle is made entirely of metal, including the worm gears of the torque transmission (there are exceptions, but these are isolated cases). Only the bobbin insert is made of plastic and replaces the bobbin case.
The main advantage of the horizontal rotary hook is that it always runs in the same direction during operation. This system eliminates shock loading from the transmission gears and almost eliminates wear. As a result. the quiet, even operation of the mechanism for the entire period of operation of the sewing machine without additional vibration. In this system, only the hook axle is lubricated every six months. This is usually done at the service center during machine maintenance.
There is still the bobbin capsule to deal with. During normal machine operation this element is rigidly secured by stops. A needle can hit it only if the stops are dislodged or deformed. This is only the result of improper user action. For example, if the thread is incorrectly threaded or if the machine shaft is rotated the wrong way round, the thread may become tangled in the hook. If the shaft is twisted violently, the stopper can bend and the bobbin can turn.
If a similar situation arises in a machine with a vertical shuttle, the user could break the plastic gears of the shuttle drive. and that is a completely different repair. Using any sewing machine with a vertical, as well as a horizontal hook, requires you to follow the instructions in the Instruction Manual exactly.
Even if your missteps caused damage to the horizontal hook bobbin insert, all you have to do is replace it with a new one.
So the conclusion is obvious. The horizontal hook is quieter, more reliable, easier and cheaper to operate. It has a maximum width of 7 mm which is very useful for sewing buttonholes, because they are practically useless if they are less than 6 mm wide.
And finally, some myths about shuttles
Myth 1. The vertical shuttle is made entirely of metal, but the horizontal one is made of plastic, so it’s more reliable.
This is completely wrong. the horizontal shuttle is completely made of metal. And thanks to the rotary motion, the horizontal hook is much more reliable.
Myth 2. You can adjust the thread tension in a vertical hook, but not in a horizontal.
Completely incorrect: the thread tension is adjusted on the bobbin capsule in the same way as in the upright. But that’s not all: due to the rotary motion, machines equipped with a horizontal hook are much less sensitive to threads. That is almost no need to change the tension of the hook thread.
Myth 3. Horizontal hook machines don’t sew well on heavy fabrics.
A horizontal hook works just as well with heavy fabrics as a vertical hook: just remember to use a thicker needle. What’s more, most horizontal hook machines are equipped with a better advancement system, making the machines sew even better on dense fabrics.
Myth 4. The bobbin insert wears out quickly and is very expensive.
Properly operated, bobbin inserts last as long without wear as a classic bobbin case. We have machines that have been in service for over 20 years with the original bobbin capsule.
Myth 5. Manufacturers save money by installing a horizontal hook.
This is completely wrong. the horizontal hook was originally installed only in the most expensive models of sewing machines. And today it is still in the most expensive models.
It’s not for nothing that all top brand luxury sewing machines are equipped with a rotary hook system. Most people prefer the horizontal shuttle because of its obvious ease of use, high reliability, and unpretentious adjustability. The largest companies, such as Brother and Toyota, completely abandon pendulum shuttles, and even the most basic models are equipped with horizontal rotary shuttles. And for the users it is reliability, low maintenance and maximum ease of use.
Takase Motoshi R&D Center Engineer domestic sewing machines
In the previous section were given basic concepts about the main types of sewing machine faults and how to fix them. The task of the second part is to bring the repair technician closer to the practical implementation of the repair. Practice has shown that in order to clarify a malfunction in a machine and.To eliminate it, you have to deal with one or more units, disassemble, adjust and reassemble them. It’s impossible to do without some knowledge.
The entire mechanism of a straight-stitch sewing machine is divided into 12 parts (with some reservations they also apply to a zigzag sewing machine). Parts are grouped together in a particular assembly group according to certain characteristics. One or more malfunctions, most often encountered during repair, include one group of parts. In other words, all kinds of faults are grouped together, and a certain group of parts is involved in rectifying them. This is how the component groups of a particular subassembly have been determined.
The task is to replace the fixed pin connection of the shaft with a crank on the adjustable with two screws. To do this remove the machine from its hinges, remove the manual drive. In the connection between the shaft 1 of the shuttle pusher and the crank 4, loosen the set screw and knock out pin 3 (Fig. 33) with the needle up. For convenience place the machine on your lap with the bottom of the platform up.
How to adjust sewing machine hook timing
Remove the hook stroke housing, knock out the pusher shaft and hammer the pin into the hole on the shaft. Cut off the protruding end of the pin and file it flush with the shaft so that the crank can be pressed onto the shaft with an easy-to-press fit. On the crank, thread the hole near the set screw with an M4 thread. Put a headless screw with a length of 4 mm. Check the leaf spring on the pusher. Its ends must fit tightly on the pusher!
Fig. 33. Crank shaft node hook (machine 2M cl. PMZ):
|1. shuttle shaft;||5. rocker arms of the small shaft;|
|2. platform housing flange;||6. crank slide in the rocker;|
|3. conical pin (press out side);||7. Small shaft with a rocker arm ,|
The needle runs from the plane of rotation of the hook at a distance of more than 0.1 mm (sometimes this distance is 2 mm). In this case there is a skip stitches in the stitching.
The needle is too close to the plane of rotation of the hook (distance 0.1 mm, sometimes it is equal to minus 0.5 mm). An emergency situation is created and can occur:
a) friction on the wall of the needle hole, thread chafing and thread breakage;
b) impact on the foot, needle plate, hook, bobbin case;
c) there is no gap between the needle and the hook (see “stitching”); c) there is no gap between the needle and the hook. п. 4);
d) the type of needle does not fit the machine, etc.
b) pulling on the material in the stitch from right to left and left to right, the needle hits the thread of the fabric and pulls it in the form of loops down;
c) skipping stitches in the stitching. Needle blunted by a light blow on the needle plate, hook, foot, button, etc. п.
The needle is the wrong type of needle for which the machine is adjusted.
In this case, the seamstresses refer to the lack of the right needle. But this reason is unfounded. For example, machine is adjusted on a needle of domestic production. The gap between the hook and needle is set 0.1 mm. After a needle breakage, an Indian needle was supplied, which has a thinner bulb than the domestic needle, with a more sheared baldness. The gap between the needle and hook becomes less than 0.1 mm.
The needle is positioned above the required level (pin stop is missing).
Faulty needle (eye at an angle to the flats and other types of defects).
b) upper thread breakage. The needle was supplied without prior verification.
Fig. 34. Needle position in the hook of LADA machine T-238 cl.:
|a. wrong;||b. correct position (after repair);|
|1. hook spout;|
|2. wide shelf;|
b) Remove the thread-righting plate;
c) anneal the zone of plate holes on the fire, annealing time 2 min. Do not burn the working area!
d) use a round file to enlarge the hole 2mm towards the blunt end of the bobbin case (see. fig. 11);
e) saw off the right side of the hook block by 2 mm, t. е. The stop screw comes out of the bobbin case latch and moves its handle back about 0,3 mm;
The plastic locking ring does not provide zero-playback movement of the hook in the vertical plane.
a) Change the plastic ring if the machine has not been used much;
The stop screw is coming out of the bobbin case latch, about 0.3 mm from its handle.
The bobbin case latch handle is angled.
b) upper thread looping in the stitch;
bobbin case is placed in the hook. The knob is loose (not pressed firmly against the knob).
b) upper thread winding on the bobbin case;
c) the bobbin case pops out of the hook;
The cylindrical spring of the bobbin case has weakened so much that the latch handle is not pressed tightly against it.