# On-site rotor balancing in Guimarães and Vila Nova de Famalicão > We have no workshop, no office and no staff in Guimarães or Famalicão. We have one base, in Vila Nova de Gaia, and about 60 km of motorway to the Ave valley. The engineer drives up from Gaia with the Balanset instruments, measures vibration on the bearing housings and balances the rotor in its own bearings: the stenter, the dyeing circulation pump, the plastics granulator, the dust-extraction fan all stay exactly where they are. At this distance the result is decided by planning, not by speed — a properly agreed shutdown window and, ideally, more than one machine waiting. **In short:** Yes, we travel to Guimarães and Vila Nova de Famalicão. It is roughly 60 km from our base in Vila Nova de Gaia via the A3 and A7 — Famalicão is slightly closer, Guimarães slightly further — and the trip fits comfortably into one working day. The travel rule is the same for everyone: the first 20 km from the base are included in the price, and beyond that it is 0.60 EUR per kilometre, round trip, counted along the real road route and fixed in the quote before we set off. Vibration diagnostics with a report costs 300 EUR per machine and is always billed; balancing is added according to rotor size, from +250 EUR for package S up to from +1200 EUR for XL. The minimum invoice per visit is 500 EUR, and if the job runs longer than a day a per diem of 140 EUR per day applies. All prices + VAT. That is exactly why, at this distance, we push for several machines in a single visit: the travel and the minimum are paid once, so the second and third machine cost far less per rotor than the first. Source: https://axiline.pt/en/services/rotor-balancing-guimaraes/ Publisher: AXILINE · Vila Nova de Gaia, Portugal · +351 931 831 229 · axilinegeral@gmail.com ## Sixty kilometres: what that changes in the price and in the planning It is about 60 km from the Gaia base to the Ave valley via the A3 and A7. In practice that means leaving in the morning and driving back at the end of the day, no overnight stay, provided the shutdown window has been agreed. What ruins that plan is not traffic on the A3 — it is arriving and then waiting two hours for the electrician who is still tied up on another line. Kilometres are counted along the actual road route from Rua das Colectividades 76 in Vila Nova de Gaia, not as a straight line on the map. The travel figure goes into the written quote before we leave: no arithmetic done on the shop floor, no surcharges appearing on the invoice. The per diem of 140 EUR per day only applies when the job runs beyond a single day — usually because the machine can only be stopped at the end of the night shift, or because there are enough machines to fill two consecutive days. On a one-day visit to Guimarães or Famalicão there is no per diem. - [x] Minimum invoice of 500 EUR per visit. For one small machine that means paying the minimum for a whole working day — legitimate, but expensive per rotor. - [x] The 300 EUR per machine for diagnostics is always billed, including when the conclusion is that balancing will not fix anything here. - [x] If your own fitter and welder attach the correction masses, that is included. If AXILINE does it: +150 EUR per rotor without welding, +400 EUR per rotor with welding. - [x] The 140 EUR per day per diem applies only to jobs running longer than a day, not to every trip. - [x] VAT at the applicable rate is added to all figures. - [x] The travel cost for your address is calculated and sent before the visit, not afterwards. | Item | Condition | Price + VAT | | --- | --- | --- | | Vibration diagnostics with report | per machine, always billed | 300 EUR | | Balancing, package S | up to 15 kW or up to 50 kg | +250 EUR | | Balancing, package M | 15–75 kW or 50–500 kg | +450 EUR | | Balancing, package L | 75–300 kW or 0.5–2 t | +700 EUR | | Balancing, package XL | over 2 t or high running speed | from +1200 EUR | | Mass fitting by AXILINE | without welding / with welding, per rotor | +150 / +400 EUR | | Travel | the first 20 km from the base are included | beyond that 0.60 EUR per km, round trip | | Per diem | only when the job runs longer than a day | 140 EUR per day | | Minimum invoice | per visit, whatever the number of machines | 500 EUR | > Plain arithmetic is why we keep pushing to group machines: travel, the minimum invoice and the time spent setting up the instruments are paid once per visit. Two stenters and a granulator on the same day cost far less per machine than three separate trips spread over a year. If your plant has only one problem machine, ask the unit next door — in the Ave valley the sites sit close enough together to share a trip. ## Textiles and finishing in the Ave valley: where the unbalance comes from Guimarães and Vila Nova de Famalicão sit at the centre of the Portuguese textile industry: spinning, weaving, knitting, dyeing, finishing and garment making, often inside the same fence. In vibration terms that translates into something very concrete: dozens of rotors running in fibre-laden air, in steam, at drying temperatures. Almost none of these rotors left the factory unbalanced — they became unbalanced in service. The mechanism is nearly always the same: material that sticks to the rotor unevenly, or wears off it unevenly. Loose fibre, oligomers and resins from the finishing bath, scale from process water, impeller erosion. So on these machines the useful question is not «is it balanced?» but «how long does it stay balanced?». ### Stenter frames and drying ovens Every chamber has its own circulation fan running at 150–200 °C. Loose fibre and oligomers from the finishing chemistry bake onto the blades unevenly, and the unbalance changes over weeks, not years. We measure with the machine hot, at its real operating regime, and only fit the masses once the casing has cooled enough to work safely. Magnetic masses here serve only as trial masses and come off before the run. ### Hydro-extractors and centrifuges The basket spins with wet load distributed by hand, and that load unbalance cannot be corrected with masses: it returns on every cycle. What can be balanced is the empty rotating assembly — basket, shaft and pulley. If the machine shakes with an empty basket, there is work for us; if it only shakes with a badly loaded basket, the problem is in the process and we say so instead of selling a balancing job. ### Dyehouse circulation pumps Jets, jiggers and autoclaves run high-flow centrifugal pumps almost continuously. The impeller suffers erosion and scale from the bath, and unbalance creeps in slowly, disguised as «the pump is noisier than it used to be». Worth measuring before deciding: unbalance, cavitation and a bearing at the end of its life sound alike to the ear and look nothing alike in the spectrum. ### Fibre extraction and filtration Extraction fans in spinning and weaving, filter units, cyclones. The air carries fibre continuously: one part of the impeller clogs while the other wears away. These rotors are easy to balance, but the result lasts exactly until the next fouling cycle. If cleaning is not organised, balancing is an expensive sticking plaster. ### Compressed air, vacuum and the dyehouse effluent plant Air-jet looms live on compressed air, and dyeing comes with its own effluent treatment plant: aeration blowers, pumps, decanter centrifuges and dewatering units. These machines sit in closed rooms where nobody stands, so the vibration is noticed late. In exchange they are grouped together — the ideal case for doing three or four rotors in one trip. > We do not publish plant names or case numbers, here or on any other page. If you want to know whether we have handled a machine like yours, describe the equipment on the phone and you will get a straight answer. ## Cutlery and metalworking in Guimarães: wheels, polishing and extraction Guimarães and the surrounding municipalities keep an unusual concentration of cutlery makers and light metalworking: cutting and stamping, heat treatment, sharpening, polishing, plating. Vibration here has a signature of its own — it shows up first in the surface quality of the part and only later in the bearings. An unbalanced spindle or grinding wheel leaves a visible mark on steel long before it heats up a bearing. This is also the sector where the honest answer is most often «this is not a balancing job». A worn or loaded grinding wheel needs dressing, not masses; a buffing wheel at the end of its life needs replacing. We measure first so as not to sell the wrong work. ### Grinding and sharpening wheels A wheel loses mass unevenly as it wears and soaks up coolant unevenly when it is left standing wet. Wheel unbalance is small in grams and large in effect, because the running speed is high. It is handled together with dressing: first the surface is trued, then the wheel is balanced — done in the reverse order, it does not hold. ### Polishing and brushing Cloth mops, felt wheels and wire brushes run fast and wear down within a single shift. Here balancing makes sense on the shaft, the pulleys and the polisher's motor; the consumable itself is simply replaced. When the operator says «the machine suddenly jumped», material has usually come off the wheel, and that shows in a measurement within two minutes. ### Spindles, shafts and belt drives A lot of useful machinery in this region is twenty or thirty years old and belt-driven. Buckled pulleys, badly seated taper bushes and worn couplings all produce vibration at running frequency, just as unbalance does, and are told apart by phase. We check this before proposing masses, because a bent pulley is not cured by balancing the rotor afterwards. ### Dust extraction and furnace fans Grinding and polishing dust extraction, scrubbers, circulation fans in heat-treatment furnaces. Metallic dust is abrasive and heavy: it wears one side of the impeller and builds up on the other. In furnaces temperature is added, with the thermal bow of the shaft that comes with it. These are machines nobody looks after until they stop. > On machine tools the balance quality grade matters more than in ventilation: a spindle calls for a tighter class than an extraction fan. The applicable class and current edition of ISO 21940 should be checked for the specific rotor type — the rules differ for rigid and flexible rotors. ## Plastics and injection moulding in Famalicão: granulators, blowers and cooling towers Vila Nova de Famalicão and the axis down to Trofa and Santo Tirso concentrate injection moulding, extrusion, compounding and technical components, a good share of them for the automotive supply chain. It is a younger machine park than the textile one, but it runs a type of rotor that goes out of balance abruptly rather than gradually: knife rotors. The practical difference matters. On a textile fan, unbalance grows every week, a little at a time. On a plastics granulator it stays stable for months and then changes in one step, on the day the knife set is reground or replaced. So in these plants the right moment to call us is usually straight after work on the rotor, not once the vibration is already destroying bearings. ### Granulators and purge shredders A knife rotor, counter-knives and a set that gets reground several times over its life. Every regrind removes mass, and rarely the same amount from every knife. The rotor is usually hardened steel, so welding masses on is out of the question: correction is by bolted masses in the positions provided, or by calculated metal removal. Before measuring, the rotor has to be clean of melted plastic — balancing dirt achieves nothing. ### Blowers and pneumatic granulate conveying Side-channel blowers, extraction impellers and vacuum pumps serving virgin and regrind conveying. They run continuously, sit in service galleries and nobody hears them. By the time they are heard there is already bearing clearance on top of the unbalance, and then the correct order is diagnostics first, masses second. ### Cooling towers and chillers Axial fans with long blades on a large diameter, permanent humidity, scale and corrosion on the blade edges, an adjustable blade pitch. This rotor is sensitive to small masses and needs small steps and patience. It is also worth checking the spread of blade pitch angles: one blade out of pitch imitates unbalance and cannot be corrected with weight. ### Extrusion, blow moulding and line cooling Cooling fans on extrusion and blow-moulding lines, moulding fume extraction, drives and pulleys on haul-off lines. These machines are tied to product quality: a wobble in the cooling shows up in wall thickness and surface finish, so vibration gets noticed earlier here than on other equipment. > If your machine is not on this list, that is not a refusal. The conditions are the same for any rotor: a stable operating speed, access to the correction plane — the place on the rotor where the mass is fitted — and a confirmed dominance of the 1x component, the vibration at running frequency. ## When it is not unbalance: what we see most often in these plants Not every vibration is solved with masses, and this region has one structural factor that turns up regularly: a lot of production installed in old mill buildings, extended in stages, with machines on upper floors, mezzanines and steel structures added later. A floor slab or a platform in resonance produces high readings with a perfectly balanced rotor, and masses change nothing. The second case is misalignment: the shafts of two coupled machines do not sit on the same axis. Misalignment is a cause of vibration; the corrective action is called shaft alignment and it is a different job from balancing, done with different instruments. It is not corrected with masses on the rotor, and confusing the two costs a full day of pointless test runs. The third is mechanical and mundane: soft foot — the imperfect seating of the machine's foot on its frame — loose hold-down bolts, slack in the bearing housings, badly tensioned belts, a degraded foundation. These causes spoil any balancing job, however well calculated, and are checked before any test run. - [x] Vibration dominated by the 1x component at running frequency, with a stable phase: that is the portrait of unbalance, and balancing works. - [x] A strong component at twice running speed with a high axial level: points to misalignment — the answer is shaft alignment, not masses on the rotor. - [x] A level that spikes at one speed and disappears at another: resonance of the structure, the platform or the ductwork, common on the upper floors of old buildings. - [x] High-frequency energy, a rising noise floor, a bearing running hot: bearing damage, which is replaced — balancing on top of it achieves nothing. - [x] Vibration that changes when a bolt is tightened or a hand rests on the base: fixing, soft foot or foundation. - [x] Amplitude that jumps suddenly with no change of regime: material shed from the impeller or a broken knife — check mechanically before measuring. > If, in the first half hour on site, the numbers say the 1x component is not dominant, you hear that then and there, not in a report a week later. The 300 EUR per machine for diagnostics is still billed, because the work was done — but you leave with a diagnosis instead of masses stuck onto a problem that did not exist. The applicable part and edition of ISO 20816 and ISO 13373 should be checked for each specific machine type. ## What a day in Guimarães or Famalicão looks like 1. **Leaving Gaia and getting through the gate** — We leave Vila Nova de Gaia with time to spare to arrive at the agreed hour, via the A3 and A7. Site entry, passes, safety briefing and a walk round the machines on the list. If work permits and area barriers still need sorting out, this is where the first hour is either lost or won. 2. **Baseline measurement on every machine of the day** — Before touching any rotor we measure: overall level and 1x component with phase at each bearing, in the same directions, with the machine at its normal operating regime. That round sets the order of the day and shows whether some machine on the list is not a balancing case after all. 3. **Mechanical checks and test runs** — Tightening fixings, checking for soft foot and clearance, cleaning the correction plane. Then the trial mass and the runs: at least three per rotor. This is the part that needs your shutdown window and someone from maintenance on hand. 4. **Calculation, mass fitting and check measurement** — The software calculates the correction by the influence coefficient method and splits the mass across the available blade or hole positions. Once the mass is fitted, the measurement is repeated at the same points, in the same directions and at the same regime — only then are the before and after numbers comparable. 5. **Closing the day and what is left over** — Before leaving we go through the figures for each machine and say plainly what has not been solved: a machine that needs a new bearing, a fan that needs cleaning before balancing is worth doing, a coupling that needs alignment. We keep the influence coefficients, which makes a second visit much faster. > If the only possible shutdown is at the end of the night shift or at the weekend, that works perfectly well — it is planned in advance. If the list of machines does not fit into one day, the per diem of 140 EUR per day is added, stated in the quote and not at the end. ## How to prepare a visit at this distance Preparation is worth more here than on a short trip. At a plant in Porto, one missing condition means coming back next week; at 60 km it means losing the day. The list below is what we ask for before leaving Gaia. - [x] Send the list of candidate machines with type, power or rotor mass, operating speed and drive type. At three or four machines the visit starts to make economic sense. - [x] Photographs of the whole machine, the bearing housings and the access to the correction plane. A short video of the machine running says more than a written description. - [x] Agree in writing the window in which each machine can be stopped and started several times in a row: at least three runs per rotor. - [x] Secure access to the correction plane — inspection door, removable cover or an opening in the shell. Without access the work plan is a different one, and it is better to know beforehand. - [x] Prepare clean bare-metal surfaces on the bearing housings for the vibration sensors, and a spot on the shaft or pulley for the reflective mark, with a clear line of sight for the phase sensor. - [x] Clean visibly fouled impellers in advance — stenters, fibre extraction, granulators with melted plastic on the rotor. Balancing dirt is money lost on the next cycle. - [x] Check fixings, feet and foundation, and deal with obvious clearance before we arrive. - [x] Decide who fits the correction masses: with your own fitter and welder it is included; with ours, +150 EUR per rotor without welding or +400 EUR with welding. - [x] Arrange passes, work permits, start-up lockout and area barriers. Your plant's safety rules take priority over our schedule. > Phone and WhatsApp: +351 931 831 229. Email: axilinegeral@gmail.com. Instagram: @axiline.pt. Base: Rua das Colectividades 76 R/C ET, 4430-625 Vila Nova de Gaia. Send photographs and a short video on WhatsApp — when preparing a trip to Guimarães or Famalicão, it is the fastest way to establish whether the journey is justified. ## Frequently asked questions **Do you have a workshop or a team in Guimarães or Famalicão?** No. AXILINE has a single base, in Vila Nova de Gaia, at Rua das Colectividades 76 R/C ET. There is no branch, no workshop and no resident technician in the Ave valley: the engineer drives out of Gaia and covers the roughly 60 km via the A3 and A7. We would rather say that plainly than advertise an address that does not exist. In practice it changes little for you — the distance fits into one working day, and the travel cost is calculated and sent before we set off. **How much does travel to Guimarães or Vila Nova de Famalicão cost?** The rule is the same across the country: the first 20 km from the base are included in the price and, beyond that, 0.60 EUR per kilometre, round trip. We count along the real road route from Gaia to your address, not the straight line on the map, and we send the figure in the quote before the visit. Famalicão is slightly closer and Guimarães slightly further, and that difference shows in the quote. There are no hidden surcharges for urgency, tolls or parking. **Is it worth calling you out for a single machine?** It is, but it is expensive per rotor, and it is fair to say so up front. The minimum invoice per visit is 500 EUR, vibration diagnostics is 300 EUR per machine, and travel is added on top — all of it paid once, whether we come for one machine or four. At this distance the sensible pattern is to gather several machines into the same shutdown: the stenters and the extraction in the finishing department, the granulators and blowers in moulding, or even machines belonging to a neighbouring company on the same industrial estate. From the second machine onwards, the cost per rotor drops sharply. **We can only stop at the weekend or on the night shift. Is that possible?** It is, and in textiles and plastics it is the normal case. The condition is agreeing the window in advance, because balancing needs repeated runs up to operating speed — at least three per rotor — and the schedule cannot depend on an improvised stop. If the job runs longer than a day, for example a night shutdown continuing the following morning, the per diem of 140 EUR per day is added and stated in the quote from the start. Planned shutdowns, summer ones included, are the best moment to group several machines together. **We balanced our stenter fan and a few months later it was vibrating again. Why?** Because balancing corrects the state of the rotor on the day it is done, and on these machines the rotor changes by itself. In a stenter, oligomers and fibre deposit unevenly on the blades again; in spinning extraction, one part of the impeller clogs while the other wears; in a granulator, the next knife regrind removes mass once more. That is not a failure of the balancing, it is the process doing what it does. The practical answer is to organise rotor cleaning before balancing and to build the measurement into the maintenance plan: with your machine's influence coefficients on file, the next check is considerably faster than the first.