Jump to content

Recommended Posts

the total weight of that hammer is listed at 265 kg. Seems kinda light!  Bolting was the right choice. Ever try to repair Chinese cast iron? It doesn't like it even if you follow all the normal protocols for cast iron. There's a lot of garbage in the iron.  You MIGHT take the bolt plates off and clean up the paint/junk around the cracks and epoxy (JB Weld) the plates to the clean cast iron before bolting permanently. That might help the longevity of the fix. I'm guessing the manufacturer didn't return any messages. 

  • Like 1
  • Haha 1
Link to post
Share on other sites
Posted (edited)

Sorry your hammers broken.

 

I remember when you got the hammer, and it did not work properly. It was basically a very low cost / low quality lump from the start. Its done well to last as long as it has, I suspect it is a re-badged Rufna hammer. You should contact the person you purchased it from and see if there is a claim on the frame. Negative publicity might force their hand a little.

 

The repair you have done will not last long, as the bending moment on the frame is still concentrated in the area where the frame is obviously weak. You have moved the load points out a couple of inches, but concentrated the load across some bolts. = same result again.

 

Probably the best chance of the hammer lasting long term is to run a couple of tie rods, down from the top cover, to the sow block, so they are in tension. This will minimise the load on the 'hinge' (crack in the frame). It will restrict your access to the dies, but you can probably rotate the dies 45 degrees so you work from the front of the hammer. (if you look at really big flypresses you will see they have, by original design, a tie rod from the top of the frame, to the bed, for this reason)

 

From my experience, any attempts at welding / brazing the crack will be a complete waste of time and money.

 

edit, I now see the crack runs around the back of the hammer, so tie rods wont work :( - You might be able to buy a new frame for not much money?

Edited by John N
redacted swear words
Link to post
Share on other sites
On 4/29/2020 at 9:06 AM, James Higson said:

I'd be a little careful with anything that needs you to heat the casting, especially building a fire around it. The ram casing has some pretty small tolerances and warps could bugger the whole lot. That said, my old hammer went through my workshop fire that destroyed everything and John Nicholson managed to get it up and running again!

 

My tuppence would be, bolt the living hell out of it as alan said. 

 

Little Sam was so far beyond economic repair its a miracle hes still going ! - I learnt a lot from that re-build, which will hold me in good stead when I start to re-build the poor little Woody!

  • Sad 1
Link to post
Share on other sites
11 hours ago, John N said:

 

Little Sam was so far beyond economic repair its a miracle hes still going ! - I learnt a lot from that re-build, which will hold me in good stead when I start to re-build the poor little Woody!

 

I was absolutely gobsmacked when sam said 'let's have a run down the forge, I've got something to show you' haha. Never expected the phoenix to arise! Good luck with woody, hope he also rises!

Link to post
Share on other sites
  • 1 month later...

It may be a little late for this, but this is one way we fix cracked cast iron cylinder heads and engine blocks. Works very well and is very strong. The pins actually pull each half together as you tighten them.

http://www.locknstitch.com/index.html

Edited by Paul Carter
Link to post
Share on other sites
On 6/25/2020 at 7:47 AM, Paul Carter said:

It may be a little late for this, but this is one way we fix cracked cast iron cylinder heads and engine blocks. Works very well and is very strong. The pins actually pull each half together as you tighten them.

http://www.locknstitch.com/index.html

These bolts look really interesting, however.. I am having difficulty beliving that these will actually hold over time.

Won't the material (cast iron) simply get destroyed inbetween the threads of these bolts - and simply disintegrate?

 

Link to post
Share on other sites
1 hour ago, Alveprins said:

believing that these will actually hold over time.

I was wondering the same thing, especially with the specific application to power hammers.  I will admit to having almost zero practical or book knowledge here, but using my intuitive knowledge, a efficient power hammer is supposed to/going to maximize(?) impact forces whereas it seems like an optimally efficient engine would be trying to minimize impact forces.  

Edited by billyO
Link to post
Share on other sites

They are actually very strong when stitched together. Granted a power hammer is a different kind of force from what happens in an engine, but consider this. over ten years ago I fixed the heads on a Ford 6.0 liter diesel engine. Those heads had 18 cracks between the pair. They were in the combustion chamber, exposed to a lot of heat and other forces we just cannot imagine. A diesel engine runs off of detonation which can be a very destructive force in a gas engine, yet those pins hold up just fine. I talked to the owner of that engine just a few weeks ago and he said it's still running strong. I have yet to see one of these pins fail. The way the threads are shaped, they pull the parts together tight.There again, not sure about the whole power hammer thing, but I bet they would work as good as about anything else in this situation which isn't good no matter how you look at it.

  • Like 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...