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if i can suggest popping over to here...
http://www.mig-welding.co.uk
You can pick up a lot of good help, *some* of those welds look ok, some look dodgy but all will most likely do the job.
You should not need to re-run a weld, what sort of gap are you bridging? Any more that a mm or so and you will struggle.
Have you got an auto-darkening mask. If it is set too dark you will not be able to see properly what you are doing. Also reflections from the back of the glass can make it difficult to see where the weld is going, I have a leather shroud on the back of mine to cut out reflections from the workshop lights.
cheers,
Rob
Dave - Thanks for the link, it was very helpful in clearing up some of my confusion. Gaps I would say so far have been ~1-2mm, although the rads make them look much bigger.
Rob - Thanks, think a good starting point for tomorrow would be to pick up a decent mask as so far I have been using the hand held mask that came with the welder.
A decent angle grinder will work wonders to the look of the weld:applause:
The mask will be 99% of your troubles - bin that hand-held POS, nobody uses them anymore. Get a reasonable auto-darkening helmet, around £45-50 but will be a life-changing purchase, set to about 10 or 11 on the scale to start with, fast reaction and MIG setting.Quote:
Originally Posted by examorph
Then make sure you have some decent welding gloves at least one on your left hand anyway (assuming right-handed), hold gun with right hand and steady the end with part of the left hand. This will improve appearance and quality no-end.
Watch more videos - MIG is pretty easy to get right, but you need to follow examples, take a few examples too as there are some crap videos out there that will steer you wrong.
2mm is a big gap, get it smaller if possible, if not then use a gentle weaving motion on the run to get the two parts to fuse fully, only do one run but make it a good or at least usable one. Don't forget, you are not just applying weld, you need to get the three parts - two components and the mig wire to become one solid item.
Grinder work will make you a decent grinder not a decent welder - again, get it right from the start, only going where you need a fit. Do a test on two similar parts then cut down the middle, you want that weld to be going most of the way through if not all.
Practice, practice, practice.
What gas are using ????
One other thing - cover up ALL bare skin - MIG will give you a sunburn like no other and very fast, i can get a burn in as little as 6" of welding at 160A and it stings like hell, main target is the left arm and chest if shirt is open collar.
I don't know how much you intend to weld after your build, but I found using disposable bottles expensive, especially when the regulator leaks:heart-borken:.
CO2 is not the best shield gas, Argon, Carbon Dioxide with a trace (2%) of Oxygen seems to give better results. I bought a Hobbyweld 15 cylinder with a decent regulator and I don't regret the money spent.
Weld spatter does not hurt - at first - so I echo the cover up. If you smell bacon when you are welding, you have spattered yersel. I don't wear socks and it ain't fun when it goes down the side of your shoe :sour:
Cheers,
Rob
Yes, CO2 will give a bit more spatter but a hotter, deeper weld, Hobbyweld 5 or 15 will be better but standard pub CO2 is sometimes easy to get ;)
Set you flow to about 8-10lpm no more.
Disposables suck very quickly, don't go there if at all possible.
Thanks for the advice guys, will check this out. Little more progress made today:
Ground down all the welds slightly and fully at any mating faces (does this weaken the welds?):
Attachment 17865Attachment 17866
Welds seemed to start getting a little bit neater:
Attachment 17864Attachment 17867
I am running on a small tank of CO2 which as per your comments isn't the best as its already ran out :ambivalence: I noticed it a long time after my welds started getting worse and thought it was just me welding horribly (although that would have been part of the reason :shame:)
Attachment 17869
The empty tank meant I was only able to get both sides done this week:
Attachment 17868
Will be back on it next weekend and hopefully have the full frame/gantry welded :courage:
No, grinding flush will not affect a good weld, but it needs to be a good weld ;)
Pictures 2 & 3 look much better, a steadier hand will improve it even more.
Ask the local friendly pub landlord, plain Co2 is what you need and they use lots of it, I started out on that and gave him £20 a go, needed to buy the right regulator but it was great for learning on.
Nah Co2 is too spattery buy 5% mix and you'll get much cleaner weld.
Also 90% of the time where people go wrong with Mig is the wire speed is too slow and they travel too slow dumping more heat than needed into steel and giving raised welds.
Preparation is key so nice ground fillets on edges and with well setup machine then you'll run perfectly flat welds in no time. No grinding Required.
Yes, spattery a bit more but if you can get it, its far cheaper than any pro mix and great for practising on. A little spatter on a job like this is not really that crucial i feel, I never had that much that it was a pain - its not like chalk and cheese.
+1 on the wire feed, this must be set right first off, as you said, too low will give a weld but damn, things will get hot and can lead to a large heat affected zone and distortion etc which can easily be avoided.
Current is pretty easy, if this is like 4mm box then any hobby welder in the 150-180A range will likely be on full-tilt, but getting the wire feed and motion speed right takes a little practice.
I started using CO2 only and it seemed cheaper, but its not. Once you swallow the pill and rent big Argon mix bottle you will wonder why you have not done it on first place. Not to speak of that i need not clean additionally the job. And believe me, it took me all day only cleaning spatter, when i welded my machine.
But to make things easier:
-brush parts around with oil prior to welding. As i said i use olive oil. So the spatter will not stick to the oiled part.
-dip the clean Mig gun every 10 min into the oil while welding. That will help keep it clean all day.
Thanks guys. I am looking into buying in some aluminium plate now and saw that Smith Metals was recommended on here. As they are local, think it might be worth checking with them also. They have a few options for aluminium tooling plate on their website: http://www.smithmetal.com/aluminium-tooling-plate.htm
What option would you guys recommend, would it be the the KASTAL or would any of them do the job?
Hi guys, been a while as life seems to keep getting in the way!! Some progress so far:
Had the frame and gantry welded up and cut back down over 3 times in attempt of getting it all lined up with minimal distortion, but finally got there in the end! (I hope)
Attachment 18164Attachment 18165Attachment 18166
Aluminium also came in, so started work on the Z-Axis. Think I slipped a bit with the blue...:
Attachment 18162Attachment 18163
Think its now finally time to start looking into the epoxy leveling on the X axis, only thing is getting it up to temperature (I think Dean mentioned 20C for 3 days at least). Other than waiting for the sun to come out (if ever), I think my only other choice is to stick it in the shed with an electric heater. What do you guys think?
If i ever get to that stage i intend to use Raychem Winterguard
http://www.traceheating-cables.co.uk/wintergard.html
I have it installed on my water pipes(Caravan) and it produces a uniform heating of the covered pipe ect, same principle as weld preheating but a lot lower temperature. No idea of the cost but i have some left over from doing the caravan plumbing.
Regards
Mike
I think you will be OK at 18C but it will take longer for the cure. In any case leave it to cure for at least 7 Days.Quote:
Think its now finally time to start looking into the epoxy leveling on the X axis, only thing is getting it up to temperature (I think Dean mentioned 20C for 3 days at least). Other than waiting for the sun to come out (if ever), I think my only other choice is to stick it in the shed with an electric heater. What do you guys think?
When you pour it make a test strip as well say 150mm x 40mm x5mm then after about 4 days check the test strip to see if it will bend or snap. If it snaps ie. very brittle then it is cured.
In the link is a temperature chart.
http://www.westsystem.com/ss/cold-temperature-bonding/
Hi all, this ones been on and off the back-burner too many times now but some progress had been made! Thanks again to Dean and Clive for helping me out with many things including the epoxy leveling and rail binding issues :encouragement:
So far, managed to do the leveling using West System Extra Slow cure epoxy:
Attachment 19428Attachment 19432
Got the aluminium cut:
Attachment 19429Attachment 19430
Z Axis assembled:
Attachment 19431
and some of the mechanical assembly done:
Attachment 19426Attachment 19427
Still got the X Axis ball-screws to sort out, some shimming to do on the Y-Axis screw and paint the frame. Will Hammerite be ok for painting the frame?
In the mean time, I guess its time to start looking into that witchcraft they call 'electrics' :barbershop_quartet_
Nice to see it coming together keep up the good work. Let us know what you intend to buy before actually parting with hard earned dosh re the electrics. Don't forget to make adjustments in the motor mounts etc.
Looking good! I used Hammerite on mine - worked well.Quote:
Originally Posted by examorph
Thanks Joe, did you just do the single coat or did you have to go over it a few times?
Also, thank you for all the info in your build log, it has been a great help for both me and I bet many other members on this forum! I look forward to seeing your electronics come together as I am planning on a very similar setup and your schematics have already answered many of my questions! Did you use AutoCAD for these?
I think it needed two coats but I didn't bother taking the mill scale off - just went straight over the steel.Quote:
Originally Posted by examorph
Be careful copying my schematic as it is yet to be proofed by the gurus!! I use Archicad...
After much hair pulling I think I have finally started getting my head around some of this electronics! Please could you guys cast your eyes over the attached schematic for me to ensure I don't see any of this rumored 'magic smoke' come from the electronics, or worse yet...my head?! :barbershop_quartet_
Most of its based on a circuit diagram Dean posted for another user a while back and connections based on various instruction manuals and confirmed against Joe's schematics. Some things I was unsure about were things like daisy chaining some of the wires (eg at the fuses/terminal blocks), if connecting shield wire earths in series on the limits was OK and if the alarm terminals on the drives only applied if using a safety relay?
Also, I know you recommended 6.1Nm NEMA 34 for the X axis but would I be OK going with the 8.7Nm instead as per Joe's build? As this would let me buy all motors from one supplier (CNC4YOU). Thanks.
Schematics
Forgot to mention, would the below enclosure setup be OK? I think I read somewhere that 600 x 900 was the typical recommended size for enclosure so will look for this, does anyone have any recommended suppliers please?
Schematics
Also, will this do for the drives: https://www.aliexpress.com/item/New-...2-5560f2d46d31
Or does anyone again have any alternative recommended supplier? Thanks!
That was probably from me, 6x9 isn't as common a size and so was more an approximation (and a typo), adequate airflow is important to me and I think should be considered by others, plus working in an enclosure should be a pleasure not a chore.Quote:
Originally Posted by examorph
6x8x3 would meet the needs of most I think: http://uk.rs-online.com/web/c/enclos...ng/enclosures/
Try and keep all power cables away from communication cables as best you can, use cable trunking to define 'zones' and then group components in each zone :thumsup:
Will look at this properly for you later but see one thing I'd change. Use contactor rather than relay contact for turning on transformer. Still use relay for safety but have turn it on contacter which is better suited to high current.
Also what kind of limit switch are you using.? On quick look if Proximity then think you have them wired wrong. If Prox what type NPN or PNP.?
Thanks Dean, they are NPN proximity switches, I think you recommended these for another user http://www.ebay.co.uk/itm/1417817891...c=1&rmvSB=trueQuote:
Originally Posted by JAZZCNC
Another thing I noticed I had cocked up on was showing them as "limits" on the diagram, they are actually homes and I was planning on using soft limits within Mach3, will get the drawings updated showing this and the contactor. Thanks
EDIT: Is it also worth running the VFD through the same contactor as the transformer or should I keep that one running through the relay?
Ok had good look and only see few things would change.
First home or limits makes no difference to how wired and you had it wrong. See pic how to wire Npn correctly.
Now if you have the switch travel with the axis and sense target you can have one switch work has home and limits for that Axis. Just few settings inside mach3.
Regards the VFD then yes it would be better run thru contactor than Relay contact.
However personally I wouldn't Kill power to VFD just sending it stop signal is enough IMO. While strictly it's safer to Kill power it's also pain in the arse waiting for VFD to power up just because you put machine in Reset mode. It's personal thing really but IME it's more trouble than it's worth and spindle being forced into stopping is safe enough at DIY level. The Controller will also drop the Spindle output so stops anyway when E-stop occurs.
Next I would control the Water pump using the VFD on board Relay. This way the pump only comes on when spindle is spinning.
Fuse sizes for drives are too large. 5A is more than enough.
Edit: Noticed on pic forgot to change input numbers but you should get the picture.
Thanks Dean, drawings almost updated but I am still struggling with figuring out how to wire the water pump direct to the VFD on board Relay :dejection:
Also, after searching many posts I noticed that most people seem to be using a pump ran off of mains voltage instead of 24VDC as shown, so would something like this be more suitable? http://www.ebay.co.uk/itm/2000-L-H-W...3D390532181450
If so, how would I wire it direct to the VFD so that it has mains supply only when spindles running please? Thanks.
If using a small mains pump, as i do, use a separate relay to control it from the vfd.
The vfd has a relay - you need to set the parameter which turns this on when the vfd is in the 'run' condition.
Next, feed this relay a 24v supply to the 'com' or common contact, then from the 'n/o' or normally open contact you go to the +(if marked) terminal on your pump relay, the - terminal then goes back to your 24v supply.
Now you have a separate relay which turns on with the vfd. The relay will have common and normally open contacts - feed a fused live supply (1A or 2A fuse) into the common, then normally open to your pump, other pump lead back to neutral.
That should be it :)
The reason i would do this is for isolation - i don't like having 240v mains anywhere near the logic side of the vfd terminals.
Exactly like dave says but here's pretty pic just in case. Don't forget to change VFD param.
If you do end up using 24Vdc pump you can Dump the Extra Relay just run 0Vdc thru FA FB terminals straight to pump.
Thanks for all the help guys, this makes things so much more clear! If I understand this right, would using terminals FB & FC have the same result for 250VAC? Sorry if its a daft question as i'm clueless when it comes to electronics!!
Please if you get the chance could you give the updated schematics a final once over? Only additional thing I changed further to the suggestions was earthing the Spindle to the VFD rather than star point as I guess will make wiring easier.
I noticed that AliExpress have a sale going on Friday, so would I be OK going ahead and buying the below whilst the deals are on?
3x - https://www.aliexpress.com/item/New-...2-5560f2d46d31
1x - https://www.aliexpress.com/item/Wate...a-7162575c4107
I already have a 80mm spindle clamp but sale price seems to beat all eBay offers I can find for just the spindle/VFD alone :greedy_dollars:
Schematics
While the manual mentions KA & KB I think you'll find there isn't any terminals with those markings. Well not on any I've fitted anyways.Quote:
Originally Posted by examorph
The manual is confusing and I think wrong. On most I've fitted FB is Common and FA =NO with FC=NC manual shows it other way round I think.
The 3A/240Vac 3A/30Vdc are the ratings of both contacts and not for one set like what manual leads you to think.
Just wire it like shown and it will work.
They seem fine to me make sure the VFD is the one in the picture as sometimes they send a different one out.Quote:
I noticed that AliExpress have a sale going on Friday, so would I be OK going ahead and buying the below whilst the deals are on?
3x - https://www.aliexpress.com/item/New-...2-5560f2d46d31
1x - https://www.aliexpress.com/item/Wate...a-7162575c4107
Ok few small details.Quote:
Originally Posted by examorph
The Green wire you have coming off Stepper B (-) I'm hoping is representing Shield going to earth and your not actually taking B(-) to earth.? If correct still only earth at the Controller end not the Stepper end.
Don't need 24V to outputs 0-3 because your not using any. Your only using the onboard Relay which is output 4 and doesn't need 24V.
Fans can get away with sharing fuse. I use 2 x 12v wired in series because are cheaper and easier to find.
With the 24V for Controller I/O save your self some wire and jumper between the Pins. Don't need to run separate wire to each pin. (See pic)
Don't forget to send Earth to Machine Frame.
Attachment 19571
http://m.ebay.co.uk/itm/170746857178Quote:
Originally Posted by examorph
£180
Lee that looks to me to be the cheaper VFD
Yes it will the the same like i got, how Dean said not original huanyang..
Išsiųsta naudojantis SM-G900F Tapatalk 4 Lt
But still usable nonetheless :thumsup:
Everyone loves a cheap copy of a cheap Chinese drive! What a mine field! What do you guys think of these: https://www.ebay.co.uk/itm/131841763367
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2.2kw is £222
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