Jump to content

Japanese power hammer build - "Jingle bells"


Recommended Posts

So I have build me a power hammer, the mechanism runs quite well, its about 40# hammer weight and 7" travel. The sabot is wagon wheel axle, which was originally 500#, that took some to get into my workshop by hand. Now its still about 330# and the lower plate is 250#. The pillar is from two cut CO2 bottles packed with sand.    I am using a pallet wagon 80 mm rubber wheel on the motor, that will turn the big cast iron one and give me 7,5X down ratio thus about 188 bpm from 1410 on primary. I am fitting the 1,1 kw motor now and I need to do the lower step on lever. I cannot bend a tube of the diameter I would like, but I can cut and weld profile.  How would you do it? The sketch of the step on lever is the picture in colours.  I have offset the railroad track dies to be able to draw long piecesnex to the main pillar.

 

 

image000000 (1).jpg

image000000.jpg

image000001.jpg

image000002.jpg

image000003.jpg

šlapka.jpg

šabota.jpg

  • Like 2
Link to post
Share on other sites

So I have put the step lever into place, old torsion bar on the side does the movement. Its now set high, because I dont have primary wheel for the motor and the brake (wooden block) on the oposite of the motor mount is also not mounted.  This should be almost horizontal on idle and should not take more than 1,5 cm to engage.

image000006.jpg

image000005.jpg

  • Like 2
Link to post
Share on other sites

This is a really cool build, for knife forging these japanese hammers look like they are super efficient.

I don't know if the hammer is running full speed in the video above, but from what I've seen, these hammers normally go really fast.

Link to post
Share on other sites
Posted (edited)
7 minutes ago, Pieter-Paul Derks said:

This is a really cool build, for knife forging these japanese hammers look like they are super efficient.

I don't know if the hammer is running full speed in the video above, but from what I've seen, these hammers normally go really fast.

 

The primary wheel on the motor is 63 mm. I can change that easy to 75.  The motor is 1410 and the secondary pulley is 600 mm.  Thus I think what we see is about 148 bpm.   With a 75 mm primary this would go 176.  The primary wheel are 4 hockey pucks :D  but I used "junior" size for the test run It can also be adapted to 80 mm pallet wagon wheel, with that it would be at 188 bpm.   I also probably need to cut about 30-40 mm from the ram, but that is easy job. The brake is now not yet installed.   This is literary first run without no adjustments whatsoever.

Edited by Jaro Petrina
Link to post
Share on other sites
1 hour ago, Sam Salvati said:

Looks powerful! Adjust for 25-50mm space between the dies at rest and it will really whip!

 

Exactly!  These mechanical hammers need space between the dies. This allows the spring to put some extra force into the blow.  My 22kg hammer has about 50mm between the dies at rest, and it will snap with great force.

Link to post
Share on other sites
3 hours ago, Sam Salvati said:

Looks powerful! Adjust for 25-50mm space between the dies at rest and it will really whip!

 

OK, I shall do that!   I have now shortened the lever from the pedal, it gives me some control, I cna slow down etc... altough not as well ason something like air hammer.

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

 

Exactly!  These mechanical hammers need space between the dies. This allows the spring to put some extra force into the blow.  My 22kg hammer has about 50mm between the dies at rest, and it will snap with great force.

 

 

This one has 20 kg ram (incl. die)

Link to post
Share on other sites
  • 1 month later...
On 1/6/2021 at 1:01 AM, Sam Salvati said:

I cannot wait to see more. Finally something good!

 

 

So I have reset the crankshaft for a 100 mm stroke, also its now somehow higher as there are welded block under the bearings (which are SnCu bronze). I need to turn a different main gear for the motor, the one I have is too small I think.  Then the ram is going to be upgraded with settable ram guides. I think in about week or two I have the final version running.

 

Edited by Jaro Petrina
typo
Link to post
Share on other sites
  • 4 weeks later...

Getting there. I have radically reworked the concept of the ram. Also changed the secondary drive wheel for a conventional tire, because it gives far better traction.

image000000 (1).jpg

image000000.jpg

  • Like 2
Link to post
Share on other sites
  • 2 weeks later...

I need to drill and thread the connecting plate from connecting rod to the spring, because, overworked I am I drilled one by accident using too big a drill. And then I need to make the bones, I will not using the leather strap to hang the ram on. Getting there.

dily na buchar.jpg

sestava beranu.jpg

  • Like 1
Link to post
Share on other sites

If you do, be sure to add lock nuts outside the threaded part.  In English we call that a turnbuckle.  Take it apart and thread a plain nut onto the rod so it is outside the adjusting part.  Then when you have the spanner tightened as you want, tighten the extra nuts.  This will prevent the spanner from getting loose during use.

 

A simpler way to make it adjustable might be like on my hammer:

Alan's Star 3.jpg

 

You still have four nuts to tighten or loosen, but you don't have the added complexity of the turnbuckle. I am sure you can figure out a way to do it in a similar fashion.

Link to post
Share on other sites

In English we call that a turnbuckle.     Its called "contra"  here.  I shall do that.  I need to turn my spring left to right now, because, its not perfectly even and when I was assembling the whole thing first time it was the other way around. Which means the sabot is off. :D   This needs bit of tinkering.  It would be done, was I not so tired.

Link to post
Share on other sites
Posted (edited)

It starting to look like quite nice machine altough more like a little giant. I must disasemble this on tommorow and drill grease holes into the bones in the inner part so that they face up. I have mistakenly drilled them from the end and there is no room for terminal in the middle. It is really easy to set up now and it has good "whoop" feel.  On tommorow I shal setup the guides vertically and weld the guides platen to the body of the machine. Looks like I will have about 7,5  (3") opening between the dies at the low crank position. I dont think the spanner will get loose, the central nut is quite massive. 

image000000 (2).jpg

image000000 (1).jpg

image000000.jpg

Edited by Jaro Petrina
Spelling
  • Like 2
Link to post
Share on other sites
Posted (edited)

So I got it operational. 

It really hits hard.  It stands now on 4 pieces of wood not bigger than my palm, so I need to put something underneath. Also There are few small things to finish:

 

1) electric switch for the motor

2) To weld reinforcement on the square tube profile that is holding the guide assembly in its place

3) Cast the counterweight from lead and screw it on the back of the crank

4) Setup spanner for the pedal - the long shaft that is pulling motor needs to be adjustable. I m gonna use the same spanner like on the bones, just bigger diameter

5) Once the pedal is set I will also mount the wheel brake, so once I get my foot from pedal, the brake will stop the main wheel

6) Paint job - now what colour scheme I should go for ??? Hm......

 

Some TTD

Motor - 1,1 kW

Crank 100 mm

Opening of dies 70 mm at the low crank position

Weight of the ram  22 kg or close to 50#

Tools made from railroad track head

Total weight about 550 kg or 1200#

Weight of the sabot 170 kg or around, but on a 110 kg steel platethat would be all 600# or more

The column is from cut off CO2 Bottles and it is filled with sand

All joints and axles can be greased by handpump.

It beats at 190/min  with this wheel or around 3/sec.  I have feeling it could have been bit faster.

 

 

 

 

 

 

Edited by Jaro Petrina
just clarification
  • Like 4
Link to post
Share on other sites

Awesome!  I agree, could be a little bit faster, but it looks like you tuned the ram/spring ratio very well indeed. B)

  • Like 1
Link to post
Share on other sites

might I ask what was wrong with using a belt strapped ram?

all I could see was that it looked kinda loose?

yea just found this

here you can see how tight the straps are

 

Link to post
Share on other sites

The problem was that the hose I used was kind of ruberry and I couldnt locate such a good leather belt. Second problem was that to get it tight I would need an asisstance of another person and the jig to compress/preset the spring. Taking all that in account I just changed my thinking and construction of the machine. I was able to do the spring setup with the metal spanners basically using nothing but a ruler and took me whole 10 minutes. They are easy to turn by hand up to the tension that is on the video.   Also, from the prototype I have went up with the weight of the ram from about 13 kg to 22 kg and doubled the spring stack. But it hits with lots of authority now.  Thirdly I couldnt get a good setup with the guide I had. With this one its really easy.....

Link to post
Share on other sites
  • 2 weeks later...

Jaro, first off- amazing build! Second- how did you bend your leaf springs? 
thanks!!! 

  • Like 1
Link to post
Share on other sites

Many thanks Chris.  There is a chap who did springs for my offroad truck, so I just asked him if his bending machine can do this and he made me whole spring at very affordable price. Its relativelly short i think he used strips that werent long enough for a car.  I judged the thickness from pictures of different hammers I found online.

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...