# On-site rotor balancing in Aveiro: we drive from Gaia, about 60 km away

> AXILINE has no office, no workshop and no staff in Aveiro. We have one base in Vila Nova de Gaia and a van with Balanset instruments, and it is about 60 km down to the Ria on the A1 or the A29. We come to your plant, measure vibration at the bearing housings and balance the rotor in its own bearings without dismantling it: tunnel kiln exhaust fan, process pump rotor, cork granulator, dust extraction fan, grinding spindle. Compared with Porto, what changes on a trip to Aveiro is not the technique — it is the economics of the visit. Which is why grouping machines is worth the effort.

**In short:** Yes, we travel to Aveiro and across the district: Ílhavo and Gafanha da Nazaré, Estarreja, Ovar, Murtosa, Águeda, Albergaria-a-Velha, Oliveira do Bairro, Vagos and Anadia. The base is in Vila Nova de Gaia, about 60 km away, and kilometres are counted from there along the actual road route. The first 20 km are included in the price, after that 0.60 EUR per kilometre, round trip. If the job runs longer than a day, a per diem of 140 EUR per day applies. The minimum invoice per visit is 500 EUR, and vibration diagnostics with a report, 300 EUR, is always billed per machine; balancing is added according to rotor size, from +250 EUR. All prices + VAT. At this distance, putting three or four machines into one visit is what makes the trip make sense. Send the machine type, speed, power or rotor mass and a few photos to WhatsApp +351 931 831 229, and we will tell you honestly whether balancing will help at all.

Source: https://axiline.pt/en/services/rotor-balancing-aveiro/  
Publisher: AXILINE · Vila Nova de Gaia, Portugal · +351 931 831 229 · axilinegeral@gmail.com

## One base in Gaia, no branch in Aveiro: what that means for you

We are a travelling service with a single base: Rua das Colectividades 76 R/C ET, 4430-625 Vila Nova de Gaia. There is no branch in Aveiro, no workshop by the Ria, no engineer already sitting in town. The van leaves Gaia in the morning, takes the A1 or the A29 and arrives at your gate. We say it up front because it changes two concrete things: what time we can realistically be on site, and how travel enters the invoice.

Kilometres are counted along the road route from Gaia to your address, not as a straight line on the map. The first 20 km are included in the price, after that it is 0.60 EUR per kilometre, round trip. We calculate the exact figure for your address and fix it in the quotation before we set off, so there is nothing to settle afterwards. If the work does not fit into one day — which happens with three or more machines, or when the shutdown window only opens at night — a per diem of 140 EUR per day is added.

From that follows the one rule that actually matters if you are in Aveiro: a 60 km trip is paid for once, no matter how many machines are waiting at the other end. The first machine carries the journey; the second and third only pay for the work.

- Municipalities covered on a typical trip to this area: Aveiro, Ílhavo and Gafanha da Nazaré, Estarreja, Ovar, Murtosa, Águeda, Albergaria-a-Velha, Oliveira do Bairro, Vagos, Anadia.
- Distance is counted along the road route from the base in Gaia, and the amount is written into the quotation before we travel.
- One or two machines normally fit into a single working day; beyond that, plan for two days and for the 140 EUR per day per diem.
- We keep no store in Aveiro. Correction weights, plate, bolts and fixing material travel with us in the van; parts specific to your machine, such as a bearing or a mechanical seal, have to be on site already.
- If the machine sits in an ATEX area, in a port terminal or inside a plant with access control, we need to know before the date is fixed — contractor clearance usually takes longer than the drive.

> The right question is not "what does the trip to Aveiro cost", but "how many machines can I have ready that day". A list of four rotors with complaints, even in different buildings of the same plant, turns an expensive journey into an efficient visit. If your company has only one machine, it is worth asking the neighbour on the next plot.

## The industry around the Ria and the machines it runs

Aveiro is not a smaller version of Porto. It is a different set of sectors, and each sector brings its own kind of rotor with its own way of going out of balance. Here is what we meet most often when we drive down.

### Ceramics, porcelain and glass

The cluster running from Aveiro and Ílhavo up to Ovar and Águeda turns spray dryers, ball mills, mixers, presses, exhaust fans on tunnel kilns and fast-cooling zones, and the whole dust extraction chain with cyclones. These rotors live in abrasive dust at high temperature: blades lose metal on the leading edges and pick up deposit on the back at the same time.

### Pulp and paper

Refiners, pulpers, vacuum pumps, blowers, dryer hood fans, boiler induced-draught fans, wood chippers and debarking drums. The process runs continuously and the window for test runs is narrow, so the right date is nearly always the planned shutdown, booked weeks ahead.

### Cork

Granulators and shredders, hammer mills, densimetric tables, dryers and, above all, extraction fans with cyclones. Here the problem is not only imbalance: it is combustible dust. Weight fixing has to be planned without welding — bolted on, or by removing metal.

### Estarreja chemicals

Process pumps, blowers, agitators, compressors, cooling tower fans. Technically these are rotors like any other; what changes is access. ATEX zones, work permits, contractor safety induction and a permanent escort set the calendar far more than our own diary does.

### Moulds and metalworking

Along the Oliveira de Azeméis, Vale de Cambra and Águeda belt: machine tool spindles, grinding wheels, drive pulleys and couplings, weld fume and oil mist extraction. On these machines vibration shows up in the surface finish before it shows up on an instrument — the complaint usually comes from quality, not from maintenance.

### Port of Aveiro and the Ria shoreline

Dust extraction on bulk terminals, conveyor drums and drives, pumps, compressors and condenser fans in industrial refrigeration, blowers on aeration tanks at treatment plants and in aquaculture. The common factor is salt-laden air: corrosion eats metal wherever it likes, and never symmetrically.

> We do not publish company names or case studies with numbers. If you want to know whether we have worked on a machine like yours, describe the equipment on the phone — we will answer honestly, including when the answer is no.

## Why these rotors lose their balance here

Imbalance is not born with the machine; it develops in service. Around Aveiro certain causes repeat that you barely see inland or in a city centre, and they are worth recognising before you call us — they often explain why vibration came back soon after a previous balancing job.

- Abrasive wear with simultaneous build-up, typical of ceramics: slip and spray-dried powder stick to one part of the blades while wearing another. The rotor loses mass on one side and gains it on the other at the same time, and the result drifts from week to week.
- Operating temperature: a kiln fan balanced cold can vibrate again when hot. We measure with the machine at settled thermal conditions, not in the first minutes after start-up.
- Fibre and pitch in paper: they build up in uneven layers on vacuum pump rotors and dryer fans, then break away in lumps. The level jumps from one shift to the next with nothing having been touched.
- A new set of hammers or knives in cork granulators and wood chippers: replacement parts rarely match each other piece by piece in mass, and the imbalance shows up in the very first shift after the change.
- Cork and wood dust: light, but it settles in a thick layer on extraction fan blades. This is the case where cleaning the rotor before balancing is no formality — without it, the weights last until the next build-up.
- Salt-laden air off the Ria and the port: pitting corrosion on roof fans, condensers and cooling towers. Metal lost to corrosion is never symmetrical, and the effect accumulates year after year.
- Recent work: a new impeller, a reground shaft, a rewound rotor, a coupling half taken off and refitted, a blade repaired by welding. After any of these, the factory balance no longer exists.

> One point of language that saves wasted work: imbalance is one cause of vibration, misalignment is a different cause, and shaft alignment is the corrective action that deals with that second cause. They are not interchangeable. Weights on a rotor never correct misalignment, and perfect alignment does not remove imbalance.

## What a trip to Aveiro costs

The price of the work depends on rotor size, not on the brand of the machine and not on distance. Distance is charged separately, under the travel rule. VAT at the statutory rate is added to every figure below.

- [x] The 300 EUR vibration diagnostics is always billed, per machine, even when the job goes on to balancing. It is not an optional extra: it is the measurement without which nobody knows what to correct.
- [x] A small machine with balancing — 300 + 250 — already clears the minimum invoice. A single diagnostics visit on its own, 300 EUR, falls below the minimum and is invoiced at 500 EUR.
- [x] Travel is calculated to your address along the road route and fixed in the quotation before we leave Gaia.
- [x] The 140 EUR per diem only applies when the job genuinely runs past one day. A normal Aveiro visit with one or two machines does not include it.
- [x] If your own fitters and welder do the mass fitting, it is included in the price. With our specialists it is +150 EUR per rotor without welding, or +400 EUR per rotor with welding.
- [x] We also sell the instruments: Balanset-1A at 1975 EUR + VAT and the OEM version at 1735 EUR + VAT, if you would rather do the measuring with your own people.

| 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 | above 2 t or high 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 | after that 0.60 EUR per km, round trip |
| Per diem | when the job runs longer than a day | 140 EUR per day |
| Minimum invoice per visit | any trip | 500 EUR |

> Do the arithmetic backwards before you call. On a 60 km trip, three machines in one visit split the journey three ways while each keeps its own price for the work. That is why we push for the machine list before fixing a date — it is not cross-selling, it is the only way to keep the distance out of your invoice.

## What a working day in Aveiro looks like

A visit 60 km out is not organised like a visit in Porto. There is no going back in the afternoon for a tool, and no splitting the job into two short passes. So the day is planned backwards: we measure everything first, then decide the order.

1. **Before the date: machine list and permits** — You send the type of each machine, its speed, power or rotor mass, photos of the bearing housings and of access to the correction plane, and the address. In parallel, the slow items get started: contractor clearance, work permit, hot work authorisation if welding is needed, an escort for ATEX areas. We send the quotation with the travel amount already calculated.
2. **Arrival and measurement of the whole list** — The first thing we do on site is not balancing: it is measuring every machine on the list, at the bearing housings, with the machine at operating conditions. That is the only way to see which ones genuinely have a dominant 1x component — vibration at rotational frequency — and which have a different problem. A machine that made the list can drop off it at this stage.
3. **Balancing in order of priority** — Trial run with a test weight, calculation by influence coefficients, weight fitted, check measurement at the same points and the same operating conditions. We take on the machine that is hardest to stop first, so that if the day gets tight, what slips is the least critical item.
4. **Closing the day with numbers** — Before and after values, at the same points, in the same direction and at the same operating conditions. Whatever the weights did not solve is written down with a concrete next step: shaft alignment, bearing replacement, structural stiffness, impeller cleaning. You hear this on site, not a week later.

> If the only shutdown window is at night, on a Sunday, or inside the planned general shutdown, say so in your first message. It is not an obstacle, but it decides whether the visit fits into one day or becomes two — and that difference is what brings in the 140 EUR per diem, or keeps it out. Contact: WhatsApp +351 931 831 229, axilinegeral@gmail.com.

## What to prepare before we arrive

Preparation costs you an hour and decides whether the day yields two machines or four. In this region three points fail more often than the rest: cleaning the rotor, fixing weights in a combustible dust atmosphere, and access authorisations.

- [x] Secure a window in which each machine can be stopped and started at least three times in a row at operating speed.
- [x] Clean deposits off the rotor before we arrive: slip and spray-dried powder in ceramics, fibre and pitch in paper, dust on cork and wood extraction fans. Balancing a dirty rotor means paying to have the job repeated.
- [x] Check access to the correction plane — a hatch that opens, a removable cover, a window in the casing. If there is no access, say so beforehand: it changes the work plan and sometimes the answer.
- [x] Prepare surfaces for the sensors at the bearing housings: smooth clean metal, no loose paint and no corrosion crust. On equipment exposed to salt air this is the point that delays measurement most.
- [x] Leave a spot for the reflective mark on the shaft or pulley, with a clear line of sight for the laser phase sensor, and a 220 V socket near the machine.
- [x] If the machine stands in a combustible dust atmosphere — cork, wood, grain — plan the correction without welding: weights bolted into existing holes, or metal removed by drilling. Tell us in advance, because it changes the tools we bring.
- [x] Sort out the authorisations: contractor clearance, work permit, hot work authorisation, an escort in classified areas, area cordoning and start-up lockout. Site safety requirements take priority over our plan for the day.
- [x] Tighten and check the fixing of the feet, the baseframe and the foundation. A soft foot — one machine foot not seating properly on the frame — ruins the result more reliably than any calculation error.
- [x] Put together the full list of candidate machines on site, including ones in another building. It is the single decision that most affects the cost per machine on a trip of this distance.

## When balancing is not the answer — and we say so before leaving Gaia

Balancing reduces one thing only: the 1x component, vibration at the rotor's rotational frequency. If the level that bothers you comes from somewhere else, a 60 km trip with test weights is a day wasted on both sides. That is why we ask for numbers and photos before booking, and why we always start with measurement.

The situations that most often turn up here dressed as imbalance: misalignment in motor-pump sets reassembled after a repair, structural resonance on extraction fans with long ducting and light platforms, degraded bearings in continuously running machines, cavitation and off-duty-point operation in process pumps, and loose fixings after years of vibration.

- Vibration that changes with flow or with valve position: that is hydraulics, not imbalance. Weights will not remove it.
- Vibration that appears only in one speed band on a variable-speed drive: suspect resonance. It is treated with stiffness or with the operating regime, not with mass.
- Vibration at twice rotational frequency with a pronounced axial phase: that points to misalignment, and the corrective action is shaft alignment.
- Broadband noise and heat at the bearing housing: that points to the bearing, and balancing a rotor on a degraded bearing only postpones the failure.
- A level that drops and returns within days: look for uneven build-up on the rotor before looking for inherent imbalance.

> The standards framework we work to is ISO: ISO 21940 for balance quality and tolerances, ISO 20816 for evaluating vibration levels on the machine, ISO 13373 for condition monitoring and diagnostics by vibration measurement, and ISO 281 for bearing life. Which part and edition apply depends on the machine type and must be checked case by case — we always record before and after values under identical conditions, without fitting the result to a convenient line in a table.

## Frequently asked questions

**Do you have a team in Aveiro? How fast can you get here?**

We do not. AXILINE has a single base, in Vila Nova de Gaia at Rua das Colectividades 76 R/C ET, and drives out to the customer. Gaia to Aveiro is about 60 km on the A1 or A29 — a short drive in time, but a trip that shows up on the invoice: the first 20 km are included in the price, after that 0.60 EUR per kilometre, round trip, counted along the road route. We do not promise "we'll be there in two hours": we set the date around your shutdown window, which is almost always the deciding factor.

**Is it worth calling you out for a single machine?**

It is possible and we do it, but you should know the arithmetic. The minimum invoice per visit is 500 EUR, vibration diagnostics with a report is 300 EUR per machine and always billed, and balancing is added by rotor size: +250 EUR for package S, +450 for M, +700 for L and from +1200 for XL, all + VAT, plus travel. A small machine with balancing already clears the minimum. At this distance, though, the difference between one and three machines in the same visit is not three times the price: the journey is paid for once. If you have only one rotor, it is worth asking the plant next door.

**We work with cork dust and cannot weld. Can you still correct the rotor?**

Yes, and it is the normal scenario in the region's cork and wood plants. The correction weight does not have to be welded: it can be bolted into existing holes or at fixed blade positions, or the correction can be made by removing metal with a drill. Tell us before the visit, because it changes the tools and material we load into the van. If your own fitters do the work it is included in the price; if we do it, it is +150 EUR per rotor without welding and +400 EUR per rotor with welding, + VAT. Hot work in a classified area always needs your authorisation, arranged in advance.

**Our line only stops during the planned shutdown. How does that work?**

That is the usual situation in paper, ceramics and the Estarreja chemical plants, and it is the best time to call us in. Book weeks ahead, gather every machine with a vibration complaint into one day — even across different buildings — and we arrive set up to measure all of them as soon as we are through the gate. If the list does not fit into one working day it becomes two, and the 140 EUR per day per diem applies. We also work night and weekend windows when they are agreed in advance: what does not work is deciding that on the day.

**If the vibration comes back, will you return to Aveiro? Is it cheaper?**

We will, and the work itself is faster, because we keep the influence coefficients for your machine — exactly how that rotor responds to a fitted weight. On a second visit that means trim balancing: one run to measure, calculation of the additional weight, fitting, and a check run, with no repeat of the trial runs. What is not cheaper is the road: a return is a new trip, under the same rule of 20 km included and 0.60 EUR per kilometre, round trip. That is why we prefer to confirm the result the same day, with the machine hot and under load, rather than come back a second time.