Eight parameters pressed into four rows
The parameter block on this listing holds four rows. Each row has two columns, and each column carries a different fact. What looks like a four-line specification is in reality eight separate statements, and the two halves of every row have nothing to do with each other.
This matters because a two-column parameter table is read as label and value. A buyer scanning it sees Model: GSB-26C on the left and Head :57*41*17cm on the right and concludes that the model's head measures 57 by 41 by 17 centimetres. That reading happens to be roughly right, but only by coincidence. On the next row it breaks down completely.
Untangling the rows: what is actually specified
Read each half of each row as its own statement and the eight facts separate cleanly.
| Row | Label column, as published | Value column, as published | What each half really is |
|---|---|---|---|
| 1 | Model: GSB-26C (inclined head machine to make shoes above size 36) | Head :57*41*17cm | Model statement and head envelope |
| 2 | Hook diameter: 2.6cm, including FRP foot base, | Motor :33*28.5*22cm | Hook diameter and motor envelope |
| 3 | Fine nylon thread: #21-26 stitches, | Platform :85*60*0.8cm | Thread range and platform footprint |
| 4 | Needle length: h: 0.25-1.5cm | Head :18KG; Motor :8KG; Table :15KG | Needle figure and all three weights |
So the record does contain real numbers: a head envelope, a motor envelope, a platform footprint, three masses, a hook diameter, a thread range and a needle figure. That is more than most listings on this site offer. The problem is not the quantity of data. The problem is which data is missing.
The label does not match the value
Row two is the clearest example. The label reads Hook diameter: 2.6cm, including FRP foot base, and the value reads Motor :33*28.5*22cm. A hook diameter and a motor envelope are different kinds of quantity in different units describing different assemblies. The comma at the end of the label suggests the original text continued into the value column before the table was flattened.
The practical consequence is that any automated price comparison or specification scrape of this page will produce nonsense. It will record a hook diameter of 2.6 cm and a motor of 33 by 28.5 by 22 centimetres, then attach both to whichever field it guesses. A human reader can untangle it; a feed cannot.
Manual or electric: only one version has numbers
The title offers the machine as manual or electric. The parameter block describes a motor, an 8 kg motor in a 33 by 28.5 by 22 cm housing. There is no row for the manual version at all: no crank length, no handwheel diameter, no statement of what is removed when the motor is deleted.
This is not a small omission for a repair shop. A manual machine and a motorised machine are different products with different throughput, different fatigue profiles and different price points. A buyer who wants the manual version is reading a specification written entirely for the other one.
The photographs show the electric arrangement: a small pulley on the motor driving a large flywheel by belt, with a foot pedal below. That is a step-down drive, which is the correct choice for a machine that needs torque at low speed rather than speed at low torque. What the photographs cannot tell you is the ratio, and the record does not either.
Cylinder bed is the feature, and no photograph shows it
The title says single needle cylinder bed. The cylinder is the whole reason this class of machine exists: a shoe is a closed volume, and to stitch its insole or its welt you have to put the stitching point inside the shoe. A flat bed cannot do that. A cylinder bed presents a narrow horizontal arm that the shoe slides over, so the needle works on material wrapped around the arm rather than resting on a table.
Now look at the eight images. Three are photographs of the machine, one is a business card, one is a payment and shipping banner, and the rest are a factory gate and a logistics graphic reused across the catalogue. In the three machine photographs the head is shown from the side and from the front, and in none of them is the cylinder presented as the subject. There is no close-up of the arm, no view down the arm, no shoe on the arm.
For a feature that defines the machine's category, that is a strange thing to leave unphotographed. It is also the reason the next two sections matter.
The size 36 floor, in millimetres
The model line says the machine is for shoes above size 36. European sizes are Paris points, where the size equals one and a half times the last length in centimetres, so a size can be converted directly.
| EU size | Last length | Foot length | Against the stated floor |
|---|---|---|---|
| 35 | 233.3 mm | 220.0 mm | Below the floor |
| 36 | 240.0 mm | 226.7 mm | The floor itself |
| 37 | 246.7 mm | 233.3 mm | One step above |
| 40 | 266.7 mm | 253.3 mm | Comfortably above |
| 42 | 280.0 mm | 266.7 mm | Comfortably above |
| 45 | 300.0 mm | 286.7 mm | Upper end of the range |
Size 36 is a last length of 240 mm and a foot length of about 227 mm. One Paris point is 6.67 mm, so the floor sits 6.67 mm below size 37 and 13.3 mm above size 35.
That is the number to hold on to, because it is the only quantified claim about what the machine can physically accept. Everything else about capacity is qualitative.
Hook diameter 2.6 cm, and what has to fit around it
The hook is the rotating basket under the needle plate that catches the thread and forms the lock stitch. Its diameter sets how much bobbin thread you can carry, and bobbin volume scales with the cube of the diameter for geometrically similar hooks.
| Hook diameter | Relative bobbin capacity | Where it is usually found |
|---|---|---|
| 20 mm | 1.00x | Domestic class |
| 22 mm | 1.33x | Light industrial |
| 26 mm | 2.20x | The lower end of industrial |
| 28 mm | 2.74x | Heavier industrial |
At 26 mm this is the lower end of the industrial range, roughly 2.20 times the bobbin capacity of a 20 mm domestic hook. It is a sensible choice for shoe repair, where seams are short and the machine spends more time being repositioned than running. It is not a large hook, and a shop that plans long continuous seams on thick leather will be changing bobbins often.
Why the cylinder diameter outranks every other number
The hook rotates inside the cylinder. That single geometric fact constrains the cylinder from the inside out: the cylinder's outside diameter must exceed the hook diameter by twice the wall thickness, whatever the wall is made of.
With a 26 mm hook, a 3 mm wall gives a cylinder of at least 32 mm, a 5 mm wall at least 36 mm, and an 8 mm wall at least 42 mm. All three are plausible for a cast or machined arm, and the difference between 32 and 42 mm is the difference between fitting a small shoe and not fitting it.
So the one dimension that decides whether a size 35 shoe will go on the machine is derived from the hook diameter and the wall thickness, and neither the wall thickness nor the resulting cylinder diameter appears anywhere in the record. The listing states a floor of size 36 and gives no measurement that would let a buyer verify it.
This is the first thing to ask for, and it is a question a seller can answer with a caliper in thirty seconds.
The platform cannot be 8 mm steel, and the weights prove it
The platform is given as 85 by 60 by 0.8 cm, and the table is given as 15 kg. Take the 0.8 cm as a thickness and check it against the stated mass.
| Material at 85 x 60 x 0.8 cm | Mass of the bare top | Verdict against a 15 kg table |
|---|---|---|
| Steel, 7,850 kg/m3 | 32.03 kg | Impossible: the top alone would double the table's stated mass |
| Aluminium, 2,700 kg/m3 | 11.02 kg | Possible, but leaves only 3.98 kg for the frame |
| MDF, 700 kg/m3 | 2.86 kg | Possible, leaves 12.14 kg for the frame |
| Plywood, 600 kg/m3 | 2.45 kg | Possible, leaves 12.55 kg for the frame |
A bare 8 mm steel plate at that footprint weighs 32.03 kg, which is more than double the entire table's stated 15 kg before any frame, legs or fasteners are added. The 0.8 cm therefore cannot be the thickness of a steel top. It is either the thickness of a board, or it is not a thickness at all but a frame dimension that has been flattened into the same field.
Two readings survive the arithmetic: an MDF or plywood top, which leaves roughly 12 kg for the frame, or a thin aluminium top, which leaves only 4 kg and is therefore tight. Either way the top is not steel, and a buyer who assumed a steel bench from the numbers alone would be wrong.
This is worth stating plainly because the head weighs 18 kg and it overhangs. All of that mass, plus the downward force of the stitch, lands on a board top of unspecified grade. Ask what the top is made of, and ask whether a steel sub-plate is available.
Forty-one kilograms, split three ways
The three masses sum to 41 kg, and the split is informative.
| Assembly | Mass | Share | Envelope |
|---|---|---|---|
| Head | 18 kg | 43.9% | 57 x 41 x 17 cm |
| Motor | 8 kg | 19.5% | 33 x 28.5 x 22 cm |
| Table | 15 kg | 36.6% | 85 x 60 x 0.8 cm |
| Total | 41 kg | 100% | 64,500 cm3 recorded |
The head is the single heaviest item at 43.9 percent, and it is the item that overhangs the bench. The motor at 19.5 percent hangs below the top on a bracket, which puts a second eccentric load on the same board. The table carries both.
Freight: 41 kg actual against 10.75 kg volumetric
Add the three recorded envelopes and you get 64,500 cm3, or 0.0645 m3. Against a 1:6000 air divisor that is 10.75 kg volumetric; against a 1:5000 express divisor it is 12.90 kg. Both are far below the 41 kg actual mass, so the shipment is charged on actual weight and the volumetric calculation is irrelevant.
That is good news for the buyer and worth knowing before requesting a quote, because a freight forwarder quoting on volume alone would produce a number 3.8 times too low and then revise it.
One caveat: the three envelopes are the machine's own dimensions, not a shipping carton. A crated head for export will be larger than 57 by 41 by 17 cm, and the crating can add both mass and volume. Treat 41 kg as a floor for the freight estimate, not a final figure.
The drive you can see, and the numbers you cannot
The photographs show the belt run clearly: motor pulley low and to one side, flywheel high and central, belt crossing between them, foot pedal connected below. That is a reduction drive, and the flywheel's inertia is what carries the needle through a thick seam without stalling.
What is absent is every number that would let you predict behaviour. No motor power. No voltage. No phase. No motor speed. No pulley diameters, so no ratio. No stitch rate. No stitch length range.
For comparison, a 2-pole motor at 2,800 rpm behind a 3:1 step-down turns the shaft at about 933 rpm. That arithmetic is available to anyone, but it needs two inputs the record does not supply, so it stays a hypothetical. A buyer cannot size the electrical supply, cannot estimate throughput, and cannot compare two quotations on any performance basis.
What the record does not contain
Collected in one place, the gaps are: cylinder outside diameter; cylinder length; platform material and true thickness; motor power, voltage and phase; motor speed and pulley ratio; stitch length range; stitch rate; needle system code; thread diameter in millimetres; the manual version's specification; machine colour and finish; and any statement of what the FRP foot base mentioned in row two actually is.
That last item deserves a note. The label in row two reads including FRP foot base. FRP is fibre-reinforced plastic, and a foot base in that material would be a real feature: light, and immune to the water that a shoe repair bench sees. But it appears once, inside a label, attached to a hook diameter, and never again. Whether it is part of the machine, part of the packaging, or a leftover from an earlier version of the text is not stated.
What to measure before ordering
Four measurements on the machine you are replacing, or on the shoes you intend to repair, settle most of the ambiguity.
- The smallest shoe you actually need to repair. Measure its internal width at the waist. If your work is mostly size 36 to 40, the stated floor is adequate. If you regularly see size 34 or 35, the cylinder diameter becomes the deciding number and you must have it in writing.
- The cylinder diameter on any machine you can inspect. A caliper across the arm, taken at the free end. This is the number the listing omits and the number that governs the size floor.
- The bench top under your existing machine. Thickness and material. If it is steel, the replacement's board top will feel different and may need a sub-plate.
- Your electrical supply. Single or three phase, and the rating of the circuit. The record gives no motor data, so the motor has to be confirmed against your supply before the order, not after arrival.
What to put in the request for quotation
Ten items turn this record into a purchasable specification.
| Item to confirm | Why it decides the purchase |
|---|---|
| Cylinder outside diameter, measured with a caliper | Sets the smallest shoe that will go on; the record never states it |
| Cylinder length from the head to the free end | Decides how far into a shoe you can reach |
| Platform construction: board or steel, and its actual thickness | The stated 0.8 cm cannot be an 8 mm steel top given a 15 kg table |
| Motor power, voltage and phase | None of the three appears anywhere in the record |
| Motor speed and pulley ratio | Together they set shaft rpm; the photographs show a belt step-down but no numbers |
| Stitch length range and stitch rate | Neither is stated, so cycle time cannot be estimated before purchase |
| Needle system and needle length, stated as a system code | The recorded 0.25-1.5 cm is ambiguous and matches no standard needle designation |
| Thread size against a published ticket number | #21-26 is given without a ticket system, so the diameter in millimetres is unknown |
| Manual version: what is supplied and what is removed | The title offers manual or electric; only the electric version carries numbers |
| Spare hook and bobbin, quoted as line items | A 2.6 cm hook is the consumable that wears first on leather |
How this record differs from the TK-26C article
This listing and the TK-26C listing carry byte-identical parameter rows. Both name GSB-26C in the model line, and both give the same hook, thread, needle and mass figures. They are two listings for one machine, not two machines.
The earlier article on this site covered the TK-26C record from the purchasing side: the model code conflict between TK-26C and GSB-26C, the manual and electric configurations, the consumables, the incoming inspection plan and the RFQ checklist. This article deliberately does not repeat that ground. It works from the geometry instead: what a cylinder bed is for, what the size 36 floor means in millimetres, how the hook diameter constrains the cylinder from the inside, and how the stated masses rule out a steel bench top.
If you are choosing between this machine and another model, read the TK-26C procurement guide first. If you have already decided on this class of machine and need to check it will fit your work, the geometry above is the part that decides it.
Frequently asked questions
What does cylinder bed mean on a shoe repairing machine?
The stitching point sits on the end of a narrow horizontal arm instead of on a flat table. The shoe slides over the arm, so the needle can reach the insole and welt from inside a closed shoe. A flat bed cannot stitch inside a shoe, which is why repair machines of this type are cylinder bed.
The machine says shoes above size 36. How big is that?
European sizes are Paris points, where the size equals one and a half times the last length in centimetres. Size 36 is a last of 240 mm and a foot of about 227 mm. One size step is 6.67 mm, so the floor sits 6.67 mm below size 37.
Why is the cylinder diameter so important if it is not listed?
Because it sets the smallest shoe that will physically go on the arm, and it is constrained from inside by the hook. With a 26 mm hook, the cylinder is at least 32 mm across with a 3 mm wall and at least 42 mm with an 8 mm wall. The listing states a size floor but gives no measurement to verify it.
Is the hook diameter of 2.6 cm large or small?
It is the lower end of the industrial range. A 26 mm hook carries about 2.20 times the bobbin thread of a 20 mm domestic hook, and about 80 percent of a 28 mm hook. For short repair seams that is fine; for long continuous seams on thick leather you will change bobbins often.
Can the platform really be 8 mm steel?
No. An 85 by 60 cm plate at 8 mm in steel weighs 32.03 kg, more than double the 15 kg stated for the whole table including its frame. The 0.8 cm is either a board thickness or a frame dimension. Ask which, and ask for a steel sub-plate if the head's 18 kg overhang worries you.
What is the FRP foot base mentioned in the parameter row?
Fibre-reinforced plastic. It appears once, inside the label of row two, attached to the hook diameter, and never again in the record. Whether it is part of the machine or a leftover from earlier text is not stated, so treat it as an open question rather than a feature.
Is this the same machine as the TK-26C listing?
The parameter rows are byte-identical and both name GSB-26C, so they are two listings for one machine. The purchasing side of that record, including the model code conflict and the inspection plan, is covered in the separate TK-26C procurement guide on this site.
Frequently asked questions
- What does cylinder bed mean on a shoe repairing machine?
- The stitching point sits on the end of a narrow horizontal arm instead of on a flat table. The shoe slides over the arm, so the needle can reach the insole and welt from inside a closed shoe. A flat bed cannot stitch inside a shoe, which is why repair machines of this type are cylinder bed.
- The machine says shoes above size 36. How big is that?
- European sizes are Paris points, where the size equals one and a half times the last length in centimetres. Size 36 is a last of 240 mm and a foot of about 227 mm. One size step is 6.67 mm, so the floor sits 6.67 mm below size 37.
- Why is the cylinder diameter so important if it is not listed?
- Because it sets the smallest shoe that will physically go on the arm, and it is constrained from inside by the hook. With a 26 mm hook, the cylinder is at least 32 mm across with a 3 mm wall and at least 42 mm with an 8 mm wall. The listing states a size floor but gives no measurement to verify it.
- Is the hook diameter of 2.6 cm large or small?
- It is the lower end of the industrial range. A 26 mm hook carries about 2.20 times the bobbin thread of a 20 mm domestic hook, and about 80 percent of a 28 mm hook. For short repair seams that is fine; for long continuous seams on thick leather you will change bobbins often.
- Can the platform really be 8 mm steel?
- No. An 85 by 60 cm plate at 8 mm in steel weighs 32.03 kg, more than double the 15 kg stated for the whole table including its frame. The 0.8 cm is either a board thickness or a frame dimension. Ask which, and ask for a steel sub-plate if the head's 18 kg overhang worries you.
- What is the FRP foot base mentioned in the parameter row?
- Fibre-reinforced plastic. It appears once, inside the label of row two, attached to the hook diameter, and never again in the record. Whether it is part of the machine or a leftover from earlier text is not stated, so treat it as an open question rather than a feature.
- Is this the same machine as the TK-26C listing?
- The parameter rows are byte-identical and both name GSB-26C, so they are two listings for one machine. The purchasing side of that record, including the model code conflict and the inspection plan, is covered in the separate TK-26C procurement guide on this site.