Gradnja mig mag aparata za zavarivanje?

Pozdrav svima

Evo jednog clanka sa Kursa o zavarivanju.
Prakticni problemi i zastoji koje mogu da otklone rukovaoci (zavarivaci.)
Mozda ce nekome koristiti.

Problemi-Rešenja

1.Nema strujnog luka?
Pritiskom na okidač čuje se "škljocanje" u aparatu, ali strujni luk ne pokazuje čak ni na klešta za "masu". Mogući uzrok
Prespojena izolacija između unutrašnjeg i spoljašnjeg omotača dizne.

Dizna za usmeravanje gasa (majstorski naziv "šobe") sadrži košuljicu izolator koja može biti prespojena kapljicama metala. Potrebno je pažljivo pregledati diznu ako je potrebno i sa lupom i očistiti metalne komadiće.

2.Prilikom ukljičenja glavnog prekidača ne gori signalna sijalica i ne čuje se ventilator.

Nedostaje neka od faza u utičnici ( u utičnici mora postojati 3 x 380 V).

3.Pritiskom na taster za start čuje se uključenje kontaktora, ali pogon za vuču žice ne funkcioniše.

Izgoreo osigurač , zameniti ga istom vrednošću .
Proveriti da li je mehanizam za regulaciju sile između vučnih točkića postavljen u dobar položaj i da li je sila dovoljna (da ne dolazi do proklizavanja).
Proveriti da li je pretegnuta čelična matica na TRN-u.

4.Pritiskom na taster za start ništa se ne dešava.

Proveriti ispravnost poli-kabla (tastera za start).
Proveriti kontakte tastera za start na centralnom priključku i na konektoru poli-kabla.

5.Žica dotiče neravnomerno (u prekidima).

Proveriti kvalitet žice (da li je dobro kalibrisana i da li ima oksidacije po njoj).
Proveriti kanal na donjem vučnom točkiću.
Proveriti pritegnutost vučnih točkića (mehanizam za reguleciju sile).
Proveriti da li je pretegnuta čelična matica na TRN-u.
Proveriti crevo za dotok žice (bužir) u poli-kablu (može biti izlomljen.
Proveriti ispravnost dizne.

6.Prilikom zavarivanja ima se utisak da nedostaje snage (zvuk zavarivanja nije ujednačen i rezak).

Nedostaje jedna od faza u utičnici.

7.Var je penušav i porozan

Nedovoljna količina gasa koji dotiče.

8.Prilikom zavarivanja dolazi do čestih prekida (zvuk zavarivanja nije ujednačen i rezak).

Dotok žice ili napon nije dobro odabran (potrebno je povećati ili smanjiti dotok žice ili napona).

Marko, poziv tebi i svima koji budu isli u Essen... Jedan dan cu organizovati, za sve posetioce iz Srbije koji budu zeleli, posetu najvecoj fabrici elektroda i zica u Evropi, kao sto sam to uradio i 2005 god.

(...Necu reci i prozivodjacu najboljih zica i elektroda jer u to treba sami da se i Vi uverite koristeci njihove proizvode, ali ceo svet ih postuje kao lidere u svojoj oblasti...)

Radi se o firmi "Boehler Schweisstechnic Deutschland GmbH" koju cine brendovi UTP i T-PUT. Udaljena je oko sat vremena voznje autobusom od Essena, u gradu Hamm. O detaljima, ima vremena, sajam je u Septembru.

U medjuvremenu, ako je neko zainteresovan mogu mu poslati neke uzorke, a mogu ga i posetiti ako prolazim njegovim krajem.

Pozdrav svim clanovima.

Nov sam na ovom forumu ali mogu ponesto da dodam o zavarivanju MIG/MAG i TIG. Imam Varstroj 300 star preko 20 godina nema sta nisam sanjim zavario sluzi ko pravi sluga. Vario sam i aluminijcke camce samo sam trebao da u rukohvat stavim teflonski buzir i vari bez problema.debljina Al zice 1,2. Naravno sa argonom. Teflonski ulozak nisam vise ni izvadio iz rukohvata i glatko prolazi i obicna zica 0,6, 0,8.

Za pocetak toliko.

TIG Welder 180 Amp (Home Built)
This project is a collaberative effort between myself and my old friend Will Coetzee and is built around TTL and CMOS logic to keep it simple, repeatable and easy to trouble shoot.

We purposely did not use a micro to control it because most folks don't have the capacity or experience to work with or program those devices.
We chose to use through hole components also because the average person doen't have suitable facilities at home to build with SMT parts as antistatic work surface, stereo microscope and proper soldering station would be required at minimum.
All the information I have currently available is on this page ! At the present time we are both very busy with family and work and will get back to the project to complete the detailed information as soon as possible.

Please DO NOT email asking for parts lists, Gerber files, ...I have none done up yet and as for PC boards, we are not selling kits or parts.

The welder as presented requires you to supply a simple basic AC Arc (stick) welder, this provides the AC voltage at whatever suitable current range you elect to purchase and our controller as described will give full control of the weld current be it AC or DC. More details and specs added at the end of the article.
Test PCB on Vector board

Top close-up of Front panel Front Panel lower portion close-up
Frequency counter
Finished Foot Peddle control with geared potentiometer and Opto switch.
Basic Arc Start components in case
Bridge Diode IGBT Cooling Tower
Partially Wired Arc Start Unit
Home made Spark Gap unit, Current Limiting resistor and Resonating Capacitor
Completed and buttoned up Arc Start unit
Folding Ferrite (6 pcs used as core material to improve coupling
This page details the design, construction and fun involved with building my version of a modern TIG welder with 180 Amp capacity and all the features of present day state of the art TIG machines at a fraction of the cost.

The project started out as an excercise in frustration. As I'm sure you are aware if you are reading this there is little real in depth information available on the web detailing the design of welders.
Lots of block diagram and generalisation......but no real substance, probably because the welding companies don't want anyone to see how simple it really is to produce a TIG unit with real world capability.

After over a year of searching out what was required I finally ended up going to component manufacturers application sheets and found more there than was generally available from welder companies.

Many modern welder front panel's were looked at and many dozens of spec sheets studied to gain a list of requirements, then it was simply a case of reproducing those function's simply and cheaply.
The descision was made early on to build using descrete I/C's for three main reasons. Firstly they are easy and cheap to obtain for anyone wanting to copy the design.
Secondly Microprocessors are great and simplify things a geat deal but one has to have programming knowledge and the equipment neccesary to actually get the firmware into the chip....not everyone has either.
And thirdly if fault finding is required descrete TTL and CMOS is far easier to troubleshoot with average home type test equipment (VOM, Freguency Counter, Oscilloscope etc)

My list of functions was growing longer by the day so I started to construct a basic (Alpha) test bed, a small alloy chassis with three controls and a littlel piece of Vector board, it soon became clear this was too restrictive to accomplish all the functionality I had envisioned so a larger (Beta) version was embarked upon, it has a hinged front panel to allow easy access for adding parts as I went along.
I have put a picture so you can see the crude but functional test bed Beta unit......yes I know its crude but remember its only a test bed !

Added four new pictures and nine PDF links for the finished Arc Starter Unit.
I have recently replaced the Arc Start circuit after considerable experimentation I deduced that the Flyback Transformer was simply too loosely coupled to deliver the required power to the heavy current coupling transformer (Yes, some of you told me that but I had to try myself and see Anyway a neon sign transformer was procured, as was a commercial spark gap and door knob cap, I tried building a cap (2500pf at 30Kv) and it had huge losses in the dielectric and the home built spark gap (made with machine tool tungsten carbide tips) also was not the best so I went with used locally available commercial units (the price was right With the new circuit which is taken from a welder handbook, the spark gap / cap primary winding increases the dangerous and unsafe frequency from 60Hz (coming out of the Neon trans) to around 1Mhz at the primary of the coupling transformer. I had a few iterations of the coupling unit too, found it didn't have enough coupling in its initial forms, so I added some ferrite cores taken from those folding split ferrite units, chucked 6 into the centre of the core of the coil, (4 would do !). I'm using 6 turns of 15Kv wire for the primary winding and 18 turns of welding cable for the secondary, closely wound on top of the sec winding. This circuit works really well with lots of power at a good (safe / skin effect) frequency, I have touched it to make sure The arc is about 6mm long and very strong. The final circuit uses a 2200pf doorknob capacitor with a rating of 15Kv, I rebuilt the commercial spark gap assembly as it was only intended to start arc lamps, I increased the heat sinking capabilities of the device considerably, also added a 3.9 ohm wire wound resistor to limit the current in the circuit. The choice of this resistor is somewhat critical !! I found that the white or grey square bodied ceramic types are best as they apparently add little inductance to the circuit, while the older green or black round bodied units upset the ballance of the circuit by adding way too much inductance caused by the wire wound nature of their construction. !
- Complete System Drawing
- Control Panel Drawing
- Arc Starter / Stabilizer Drawing
- Frequency Counter Drawing
- Timing Circuitry Drawing
- Controller Drawing
- System Power Supplies Drawing
- 100 Amp Power Stage Drawing
- 200 Amp Power Stage Drawing
Here are a couple of the PCB Layouts finished so far in PDF format.
- PCB Bottom view
- Top view mirrored
- Control board bottom
- Control board mirrored

Some of you have asked which IGBT's I used ? Well, the reason the numbers were left off the diagrams was that it was deemed best to leave the device selection up to the builder and availability in his or her particular area.
Just for interest the devices used in the Alpa test version of the unit were IRG4PC40F (600v 27amp, these will handle 49 amps in pulsed mode ! 4 pieces were parralleled for each section of the H bridge.
I later switched to a higher current device G30N60B3D which is good for 600v 60amp (220amp pulsed). Also used was an ultra fast switching diode to protect the device junctions part number: MUR1540 (600v 15a)
The other question that comes up in emails quite often is the Current Sensor, A three wire Honeywell device with a split core that slips over the welding cable was used, part number: CSLA1GF.
Finally the foot peddle opto sensor is a GP1A05, This I feel is more reliable than mechanical microswitches.
********************************************************************************************************** Note on specifications for the welder that many folks are asking about, hope this list help answer your questions.

1/ AC-DC welding variable via two thumbwheel switches from 1% (all Negative) right through full range of AC to 99% (all Positive) These are connected via J4 Con24.
AC frequencies available from 15 to 400 Hz
2/ Pulse Frequencies fully variable from .3 to 10 Hz This does away with having to pulse the foot peddle on thin materials.
3/ Variable control for Maximum Welding Current available to the Foot peddle control.
4/ Variable Start Current (period of higher current available (higher than starting foot peddle position, IE. max setting on front panel control) for short time heating of thick materials)
5/ Variable Start time for above.
6/ Variable End Current (Crater).
7/ Variable End Current time.
8/ Variable Gas Start time.
9/ Variable Gas End time (Dwell).
10/ HF Arc Start.
11/ Opto Interupter / Potentiometer foot peddle current control.
The arc Start can be easily switched off when not needed and an auto off position will be added when time permits.
12/ The basic unit documented here still needs a Buzz Box AC Arc Welder to supply the welding current.
13/ One question that has come up a couple of times it relative to timing in the "H" bridge, the leads of the H bridge sections must be kept as close to identical to each other as possible so the timing remains the same for each half....IE/ if the halves get swithed on together due to messed up timing caused by excessive capacitance of long leads then there will be a problem possibly damaging one or both set of IGBT's, this is a normal situation with all H bridge circuits and does need to watched for.
Hope this helps clarify things a bit guy's.
Thanks for all your interest, sorry if I'm a bit slow sometimes replying but the shear quantity of email enquiries is sometimes overwhelming............Dave
***************************************************************************************************************

For anyone needing more information please:Contact Me
Page Last Modified: 8 September 2006

Auuuuuu Demian sad su tu dva problema, prvo treba naučiti Engleski pa tek onda se upustiti u pravljenje aparata, još kaže For anyone needing more information please:Contact Me (svima kojima je potrebno više informacija, molim kontaktirajte me) samo ne znam koga tebe ili autora teksta koji je objavljen 8. septembra 2006 :hh :hh :hh

Demian
I speak English language very fluently but
nije reč o meni nego o ljudima koji posećuju ovaj sajt a ne moraju da znaju Engleski, pa ako već nadješ neki interesantan tekst uloži malo napora pa ga i prevedi da i ostalima bude dostupan.

Reko da malo vratim temu u život..
Posle skoro 6 meseci povremenog rada na aparatu, najzad sam priveo sve kraju, treba još malo šminke i sl. al to može da ceka.
Stroj je isproban, vario sam limove od 0,6 mm do 2 - 2,5 mm. Nisam baš nešto naročito zadovoljan kako izgledaju varovi, ali treba malo vremena da se uverim da je do aparata, a ne do varioca .
Evo kako izgleda skalamerija i neka slika vara, mada se varovi ne vide najbolje jer je slikano noću

по варовима на слици мала је ампеража и пуно жице.зато вар изгледа "набацан" а не "уливен". :bye2

већ ћеш се уверзирати,у сваком случају скидам капу :bye2

Hvala maradona, nadam se da ce biti bolje

@zmaj
Pazi kad su televizori ostali na broju
Kutija je od starog elektro ormana, samo dubina nije odgovarala pa je sa zadnje strane prošireno za 15 - ak cm. A gornja kutija je orginal od REL aparata ( kupljenog na bubanj potoku za 2500 din )
A to da je i više nego što sam očekivao - jeste, skoro sam pokušavao da zavarim nešto slične debljine ( 2 mm ) sa hobi aparatom od "140 " ampera i bilo je mnogo grdje, samo napljuje, nagomila... nije bilo šanse da var drži nešto. Tako da sam za manje para nego što koštaju kineski i sl. škart aparati, dobi nešto u šata se isplati uložiti još para i da se dobije ozbiljna mašina ( mislim na neki ozbiljniji trafo i prigušnicu )

Da opišem još neka revolucionarna rešenja
Prigušnica je namotana od AL lima - flaha 20x2mm, a za izolaciju sam koristio kuhinjski papir za pečenje Jezgro je od nekog starog trafoa

Nosač za kalem je brezon M12, ušrafljen za lim sa jedne strane, pa onda idu redom distanceri (šajbne, stari ležajevi, deo od neke pumpe za vodu... i sl. ). Na brezonu se šrafovima priteže kalem, a promenom razmaka šrafova može da se koristi i manji i veći kalem, ispod šrafa sa spoljne strane sam stavio neki stari ležaj, kao od točka bicikla, on obezbedjuje da se prilikom okretanja kalema ne otpuštaju šrafovi za pritezanje.

Ispravljačke diode su razne od po 35 - 40 A, a ima ih po 3 - 4 kom na ploči. Ploče su napravljene od Al lima od 0.6 ili 0.8 mm po 3 sloja na ploči. Ploče sa diodama su učvršćene na traku od bakelita, pa bakelit za kućište

Ozbiljnije komponente nisam hteo da budžima, tako da sam ponešto i kupiio, priključak za pištolj, pištolj i crevo od 4m, ventil za gas, pogon za žicu i ploču za elektroniku kupio od Ljube pa uradio po njegovom "receptu" ( šljaka odlično).

To bi bilo to otprilike.

Na kraju da dodam i malo o ekonomiji poduhvata, za sve one koji razmišljaju da urade nešto slično ). Kada se sabere vreme potrebno za izradu, mozganje kako šta nabudžiti, kupovinu svih delova po maloprodajnim cenama, pa onda uzmete u obzir uštedu koju ste ostvarili... sve to sumirate i dodje otprilike da ste satom rada štedeli 5 din, a satom razmišljanja u najbolju ruku dinar.
Znači upustiti se u nešto slično radi uštede je čisto gubljenje vremena i totalno neisplativo! Bolje zovite Ljubu i pustite da to profesionalac uradi za Vas.

Ali... ako ste entuzijasta i uživate u izmišljanju tople vode i konstruisanju šerpe u kojoj će te da je ugrejete ( ja sam sve to što sam pobrojao :roll:)... onda se sigurno isplati upuštati se u sličnu ludost.
A tek osećaj kad čuješ TAK, zalepi sklopka i krene da pršti prvi put... neznam koliko bi mogao da vredi taj osećaj, al sigurno jeste vredan svog onog truda

evo još neke slike, ali opet telefonom i noću slikano
al slikaću aparatom jedan dan i postaviti da se lepše vidi skalamerija

Baš sam Vas udavio ovaj put

p.s. Samo da se još jednom zahvalim Ljubi i svima koji su svojim savetima doprineli da realizujem ovaj "poduhvat"

Obavezno stavi kondezator.isprobano na mom aparatu,daje mnogo bolji var.

Mislim da to nece moci, posto taj inverter daje mnogo vece napone nego sto treba za Co2, ovde ima jedan clan koji pravi aparate pa sacekaj malo mozda ce ti on odgovoriti tacno dali moze ili nemoze
Mislim da je jedino resenje u tvom slucaju da uzmes trofazni trafo

pozdrav
Marko

Evo da se i ja malo prikljucim.Procitao sam sve postove na ovom forumu,mnogo guglao,ali i dalje je proracun transformatora za mig-mag misterija.Pitanje je jednostavno,dal su i strucnjaci iz esaba,fronijusa,varstroja seli i izracunali sve potrebne podatke za transformator i iz prvog pokusaja dobili sta su hteli,ili su se ipak mucili i eksperimentalno dolazili do odredjenih karakteristika transformatora.Ako je ipak ovo drugo,onda nam nista ne preostaje nego da odmah odustanemo,jer nam cak i pravi podatci od recimo esabovog aparata nece pomoci,posto verovatno necemo pronaci trafo limove istih karakteristika,pa nam ni karakteristika transformatora koji sami "napravimo" nece biti ista.Imam i dosta pitanja da postavim,kao na primer dal se moze uhvatiti nekakva relacija struja zavarivanja-napon,i recimo koji to parametar utice na "tvrdocu"karakteristike transformatora?I jos nesto,kako to REL transformator ima veliko rasipanje,a mig-mag ga nema?

Prilikom rasklapanja REL transformatora imao sam prilike da vidim da je na krajevima "E" limova,odnosno na mestu gde se naslanja "I"lim postavljen izolacioni materijal (fiber) koji povecava rastojanje izmadju trafo-limova,odnosno narusava idealan magnetni tok.Jedino ako je to razlog tzv. rasipanja.U tom slucaju,po mom misljenju dovoljno je ukloniti tu prepreku i malo doraditi sekundar,odnosno odmotati koji navojak da bi se smanjio izlazni napon i eto nas blizu resenja.Voleo bih da neko prokomentarise ovo moje misljenje,posto stvarno imam zelju da napravim dobar co2.Da jos nesto napomenem,kupio sam disk "NAPRAVI SAM CO2",ali nisam siguran da su podatci na disku bas najbolji.Naravno,sve je dobro objasnjeno osim transformatora i prigusnice.Inace imam co2 rucne izrade koji sam kupio,trofazni je i ima tiristorsku regulaciju,ima tackasto varenje,ali ja hocu da ga licno napravim i da bude bar 250A :tup Bas sam se zainatio!!!

za tcvijovic
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