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Alveprins

C41-16 Air-Hammer - oil leakage?

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Ok, so I am trying to figure out this new air-hammer I've bought from China.

 

Having absolutely no previous experience with air-hammers, I do not know if the following is to be expected, or not... So here it goes..

 

I am having some concerns about the oil consumption. I have no experience with these machines, but in my opinion - this seems a bit excessive. Have a look at the pics and video below:

beforeafter.jpg

 

This is how it looks before and after idling for 5 minutes.

 

also, here is a 10 sec video youtube of the cylinder idling. you can see the oil dripping off it and stuff:

https://youtu.be/dfuEzmvmxfg

 

Any input will be very much welcomed.

 

Sincerely, Alveprins.

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Its massively over oiling.

Is there anything in particular I am supposed to do about that? I have adjusted the oil reservoar to release approx. 3-4 drops of oil pr. minute.

 

Also - I had to open the top cover above the piston that generates the air pressure and manually fill about 200 grams of oil into it in order to have it run. Or else - there would be too much friction for the motor to run it.

I suppose this surprus of oil has then been forced into the chamber with the actual hammer piston, and that it is that oil we're seeing?

 

I had some troubleshooting with the manufacturer yesterday as the motor was unable to run the drivewheel. They told me to open the top cover of the back cylinder and fill in 200 grams of oil, screw it back on, run the drivewheel by hand for 4-5 turns - and then start. It then started just fine. However - if I turn it off and leave it for .. say - 45 minutes; I have trouble starting it again and need to fill oil directly onto the back piston and turn the wheel manually - lubricating the walls and what not - before starting it. If not - the motor will run the driwheel maybe a half turn, then stop, and then another half turn, and stop - and so on....

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As I said in one of your other posts, the motor is not big enough.

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As I said in one of your other posts, the motor is not big enough.

Hmm... Ok. I suppose I will buy another one... Unless someone else has insight that says otherwise ofc. ^_^

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put an ammeter on the existing motor when it is running in full working and see how it compares to the 9 amp on the plate, then monitor the motor temperature after a half hour or so running, then make your decision.

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If you didn't yet realize, John is the master of self-contained hammers. If he says it's so, you can bank on it. He has spent his entire life rebuilding the hammers these Chinese ones are based on and knows them better than anyone. He has also spent years selling and servicing the Chinese ones. Just so you know.

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If you didn't yet realize, John is the master of self-contained hammers. If he says it's so, you can bank on it. He has spent his entire life rebuilding the hammers these Chinese ones are based on and knows them better than anyone. He has also spent years selling and servicing the Chinese ones. Just so you know.

 

.... aaaand I just called a guy and ordered myself a 2.2kw motor. :lol:

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^^^^^ Well that clears everything up :blink:

 

Alan, thanks for the nice words, though would not consider myself a master on these things. The funny thing with hammers is you learn something, and then realise there is another 5 things you don't know yet !

 

For clarification I do sell 'Anyang' hammers in the UK, so you can take these comments as biased or not! Anyang are by far and away the best of the chinese C-41 hammers I have seen.

 

Anyang hammers cost a lot more at the 'factory gate' than C-41 air hammers from other manufactures. You cant look at a hammer being sold on Alibaba and assumed that's what all air hammers from China cost. The comment in another post about this hammer 'I did not want to pay for 2 hammers, and receive one' is valid to some extent, but the logical extensions is 'its got 4 wheels and shaped like a car' therefore its the same as that car.

 

This one might be a fine machine once it works properly, might be a bag of spanners, who knows. I do think you would be unwise, or very confident in your abilities not to value the experience of a reputable dealer though. Always the chance you will pay for one hammer, and get none.

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^^^^^ Well that clears everything up :blink:

 

...The comment in another post about this hammer 'I did not want to pay for 2 hammers, and receive one' is valid to some extent, but the logical extensions is 'its got 4 wheels and shaped like a car' therefore its the same as that car.

 

...I do think you would be unwise, or very confident in your abilities not to value the experience of a reputable dealer though. Always the chance you will pay for one hammer, and get none.

 

For me it boils down to economics really. My choices are: buy a hammer with somewhat of an uncertainty - or buy no hammer at all. I choose to take the risk.

If I buy a hammer that turns out not to work "too good" - I can always try to make it work. There is an AnYang and HeLi dealer here in Norway - but I'd be paying 3 times what I did for my current hammer. Which I would simply not be able to afford. So I took the risk. ^_^

 

And thanks to the incredibly valuable insight of yourself and others on this forum - I've gotten one step further in my troubleshooting.

 

My over-oilage was simply a result of me pouring oil into the cylinder with the piston that generates the air pressure. Since my motor var under-dimensioned for the machine (considering Norwegian electricity is 50hz and not 60), the motor they supplied, and which I suspect was juuust strong enough to run the machine in China - was simply unable to do so in Norway - except when the piston was overoiled that is... :P

 

So - today I picked up a relatively new 2,2kw 3-phase motor. Slapped 4x condensators on that thing - and I will be receiving a starting-condensator in the mail once the guy from whom I bought the machine receives it.

And that is 2,2kw at 50hz... Quite the difference compared to the 1,5kw at 60hz Chinese motor. :lol:

 

So - I am hoping this will be the only issue, and that this will be it... But with my luck - there might very well be more issues... haha :rolleyes:

 

Anyhow, thank you for quick replies to my questions. Your insight into these machines are like I said earlier - of extreme value to me - especially when I am standing down in my basement - scrathcing my head - wondering what the hell just happened... ^_^

 

Sincerely, Alveprins.

Edited by Alveprins

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No problem with the advice, glad its helpful, I was just trying to make the point that not all hammers are created equal, and (in my opinion) a lot of the hammer manufacturers do not really have a clue what they are doing.

 

Regarding your motor. 'if' your hammer was ever tested it is most likely they will have used a 'shop' motor that is much larger, not the one they shipped with your hammer. If the hammer was set up to run 60hz it should run easier on 50 hz, as it will be going slower (= less current draw on the motor). To the best of my knowledge there is no real internal difference in a motor with 'x' no's of poles, it will just run about 20% quicker if you connect it to a 60 hz supply.

 

If your hammer was set up for 60hz the motor pulley is probably incorrect (to small). In your situation I would measure the flywheel diameter, and calculate the number of rpm I wanted (around 300 for a 16 kg hammer) , and work it back from there. I think yours sounded much slower than that from the short video you posted.

 

From memory I thing a 15kg anyang is going about 320 bpm (rpm). Anyang miss state the speed as 245 even on their own website. A little hammer need to be going 'quick quick' to give the ram enough velocity to forge effectively.

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If your hammer was set up for 60hz the motor pulley is probably incorrect (to small). In your situation I would measure the flywheel diameter, and calculate the number of rpm I wanted (around 300 for a 16 kg hammer) , and work it back from there. I think yours sounded much slower than that from the short video you posted.

 

From memory I thing a 15kg anyang is going about 320 bpm (rpm). Anyang miss state the speed as 245 even on their own website. A little hammer need to be going 'quick quick' to give the ram enough velocity to forge effectively.

I talked to the producer and asked if 300 beats pr. minute was ok, and was told it was too fast.

 

They state 250 beats pr. minute at 60 hz with their standard motor - which runs at 1730 rpm at 60 hz, or somewhere around 1430 or so at 50. My new motor is 2,2kw at 50hz, and the flywheel diameter is a few mm larger than the one they supplied. The guy which from whom I bought the motor said I'd quite possibly end up at around 240 beats pr. minute on the hammer. He has previously sold two 2.2kw motors to two other guys here in Norway - who were also going to use them for their forging hammers... :lol:

 

Anyhow, I mounted the new motor just hours ago, but it will not start under load. I need to receive my start capacitor first - which will most likely not happen until wednesday one week from now. :wacko: That is the drawback with running a 3 phase motor as a 1 phase on a 10 amp fuse... :P Four running capacitors and one start capacitor needed it seems... Just missing the last piece now... I hope...

 

In the meanwhile - I've forged some round stock rebar and reinforced the wooden foundation of my hammer. It is all screwed damn tight together now, and I assume it will be able to withstand rigorous pounding from the little 16kg hammer. ^_^ I guess I also have time to reconfigure my improvized belt grinder, and tidy up the rest of the forge... Got all sorts of crap all over the place atm... :lol:

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I disagree with the operating speed you have been told, but it is their hammer ! you can always try a larger motor pulley in the future, they are inexpensive.

 

Why did you not buy a single phase 2.2 kw motor ? they are very readily available.

 

I have just found this video of my own 15 kg hammer 'woody' on youtube :) you can see the speed they should run at to give a decent bit of work !

 

https://www.youtube.com/watch?v=hqLTedVoCQM

Edited by John N

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Unless you are running a rotary phase converter to generate the 3rd leg, you will never get 2.2kw power from a 3 phase 2.2kw motor on single phase power, at most you will get about 2/3rd of the rated power. A 2.2kw 3 phase motor running with a static phase converter on single phase power will only generate 1.5kw. You should have purchased a single phase motor, they're regularly available and will generate full power for you.

 

EDIT: and you would need a 4kw rotary phase converter to generate enough power to run a 3 phase 2.2kw motor on single phase.

Edited by Justin Mercier

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IME the best way of running a 3-phase motor on single-phase mains is with a Variable Frequency Drive.

 

Search for "2.2kw VFD" on ebay and you'll find plenty of HuanYang drives. Filter for buy now and sort by price+postage. Best to go advanced and limit location to somewhere that is not going to mean import charges. They are cheap drives but seem to work pretty well.

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Good point Tim! you could then play around to find the optimum b.p.m for the hammer :)

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IME the best way of running a 3-phase motor on single-phase mains is with a Variable Frequency Drive.

 

Search for "2.2kw VFD" on ebay and you'll find plenty of HuanYang drives. Filter for buy now and sort by price+postage. Best to go advanced and limit location to somewhere that is not going to mean import charges. They are cheap drives but seem to work pretty well.

 

I've had a look at one of them on e-bay just now. I have no idea how it works though. It lets you vary the speed of the spindle? Does in manipulate the frequency only?

 

Running the motor with a VFD will not avoid losing 1/3rd of the power due to running a 3 phase on 1 phase as according to Mr. Mercier, will it? Because I look at prices for those Variable Frequency Drives he mentioned in his post, and I could aaalmost get a new hammer for the price of one of those when including shipping...... :unsure:

 

EDIT: Will this do the trick I wonder? http://www.ebay.com/itm/301670636881

 

Also, I talked with the guy who sold me the motor, he tells me the effect loss is 8% the way I run it now with 4x running capacitors.

Either way, I talked with an electro engineer friend of mine, and he agreed that a VFD would be the best solution.

 

I am just waiting for a thumbs up from you guys on this VFD I found on e-bay and linked above - and I will put in an order immediately. In the meanwhile - I will have to run the hammer with start- and running capacitors. :rolleyes:

Edited by Alveprins

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That looks suitable, but in your situation I would put up a photograph of the new 3phase motor rating plate, and wait for Timgunn to have a look and pass opinion !

 

I would probably go for a 3kw drive, not for any sciency reason, but I am distrustful, and usually 'over spec' things. I don't think the cost will be much more for 3 kw drive over 2.2 kw

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A VFD supplied with single phase power will allow your 3-phase motor to run at it's full capacity. They are very different than what you have tired with the capacitors, or what a rotary phase converter does.

 

The capacitors you tried create a phase shift in the current going into some of the motor windings. They literally slow down the AC waveform going into one set of windings as compared to the others. This "Sort of" creates 3 different phases, but it is not very efficient or effective.

 

A rotary phase converter uses a small single phase motor to spin a 3 phase motor that has one set of phase windings connected to the single phase power. The motor then becomes a rotating transformer that creates the other two phase legs. (Note: I am oversimplifying the wiring on this) However, the driven motor in the phase converter needs to be considerably larger than the motor on your equipment since all of the power is coming in through one set of windings. (Again, over simplified)

 

A VFD takes the incoming power and charges a DC bus. (Basically, a big bank of capacitors sitting there holding DC voltage) Then that DC power bus is chopped up into an appropriate waveform to drive a 3-phase motor. The nice thing is that you get speed control for free since AC induction motors are speed controlled by frequency, not voltage.

 

As John mentioned, it does not hurt to get a drive that is slightly larger than your motor so that you are not maxing out the drive all the time.

 

 

Thanks for posting all this as you go through it. I have been considering the same path you are on for a while :)

Edited by Brian Dougherty

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That looks suitable, but in your situation I would put up a photograph of the new 3phase motor rating plate, and wait for Timgunn to have a look and pass opinion !

 

I would probably go for a 3kw drive, not for any sciency reason, but I am distrustful, and usually 'over spec' things. I don't think the cost will be much more for 3 kw drive over 2.2 kw

Ok... So I suppose I will put in the extra 10 USD and get the 3kw drive instead... haha :lol:

 

Anyhow, motor specs pic - and a profile of the machine for the heck of it:

 

Motor specs:

motor specs.jpg

Machine in it's current condition:

air hammer.jpg

 

I will be making an extended foot pedal for it today I think... I've forged half of it allready... 16mm rebar... haha! ;)

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A VFD supplied with single phase power will allow your 3-phase motor to run at it's full capacity. As John mentioned, it does not hurt to get a drive that is slightly larger than your motor so that you are not maxing out the drive all the time.

 

Thanks for posting all this as you go through it. I have been considering the same path you are on for a while :)

Alright... I will over-spec it to be sure then. ^_^

 

Threads like these might just save someone else in the future from making the same mistakes. So I guess this far - if you order a machine like this - order it with a 2,2kw motor that runs at that effect at 50 or 60hz depending on where you live - and for the love of Odin - just order a 3kw VFD at the same time so you have it by the time the machine arrives! ... :lol:

 

OR - order from a reputable source and trustworthy brand... ;) - unless you're a cheap'o like myself.... :lol:

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OR - order from a reputable source and trustworthy brand... ;) - unless you're a cheap'o like myself.... :lol:

 

Ordering from someone who can provide proper support is certainly the right thing to do most of the time. I suspect that if I were honest, it would even be the least expensive thing to do all the time. However, it is much easier from me to spend $6k over a period of 3 years to make a tool work than it is for me to spend $5k in one whack. (I'm not defending this very foolish trait of mine) As a result, I have a shop full of machine tools that were once basket cases. Now, after spending tons of time and money, they are nice tools.

 

Lets just say that I sympathize with your plight :)

 

BTW, I went back and edited my last post while you were typing and added some explanation the differences between a VFD and phase converter.

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Looking at the photo of the motor rating plate, it's rated as a 2.2 kW motor at 50 Hz and as a 2.5 kW motor at 60Hz, so you'll want the 3 kW VFD to allow the possibility of running to 60 Hz. You'll need to connect in Delta, but I assume you are already running in Delta on the capacitors.

 

The speed you can actually run to will probably depend on the current draw and you won't know the speed/current relationship until you actually run it.

 

I had some brief hands-on experience of a Chinese hammer on a HuanYang VFD when I helped set the VFD up, It worked, but I don't honestly know how well it has held up since.

 

If you can get your hands on one, an optical (laser) tachometer is a very useful thing to have when setting things up: Stick a bit of reflective tape on the top die and you can read out the BPM directly. They cost around 10 Euros/bucks from China on ebay, but the delivery time might be a problem. If you know anyone into RC aircraft or drones, it's worth asking them if they have one you can borrow.

 

Note that the VFD will need protecting from metal dust, especially if there is grinding done in the vicinity.

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Looking at the photo of the motor rating plate, it's rated as a 2.2 kW motor at 50 Hz and as a 2.5 kW motor at 60Hz, so you'll want the 3 kW VFD to allow the possibility of running to 60 Hz. You'll need to connect in Delta, but I assume you are already running in Delta on the capacitors.

 

The speed you can actually run to will probably depend on the current draw and you won't know the speed/current relationship until you actually run it.

 

I had some brief hands-on experience of a Chinese hammer on a HuanYang VFD when I helped set the VFD up, It worked, but I don't honestly know how well it has held up since.

 

If you can get your hands on one, an optical (laser) tachometer is a very useful thing to have when setting things up: Stick a bit of reflective tape on the top die and you can read out the BPM directly. They cost around 10 Euros/bucks from China on ebay, but the delivery time might be a problem. If you know anyone into RC aircraft or drones, it's worth asking them if they have one you can borrow.

 

Note that the VFD will need protecting from metal dust, especially if there is grinding done in the vicinity.

Thanks man!

 

About the protection from metal dust... There will be ALLOT of metal dust in the vicinity... Like a Sahara sandstorm... I grind and do everything in that small room.

Will it be sufficient to "seal" the unit with tape and whatnot, or should I build a cabinet around it with a door that can be closed? Sort of - like a medical cabinet... kind of... ?

 

EDIT: Just ordered this: http://www.ebay.com/itm/272246644199:D

Edited by Alveprins

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Tim, to the best of my knowledge the 25kg we put on the Huang Yang drive 2 or 3 years ago is still going strong. The enclosure did cost double what the drive did though !

 

I made expensive blue fireworks from 2 VFD's with grinding dust (and they were a lot more expensive than the HY drives at the time ! ) I thought they would be OK taped up in plastic bags.....

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