Looking for Fairbanks hammer operating manual...

Nice, Justin. I wish our hammer had a foundation like that.

I'll get over to our shop today and get you some measurements. I'm thinking there are two diameters involved, but may find out otherwise.

Mike
 
Justin...

The "Y" piece (tightener pulley arm) does have two diameters. The tightener pulley pivot center is 9 1/2" from the center pivot point. The short arm where the brake/treadle linkage hooks in and adjusts is 5 1/2" from the center pivot. The distance between those two mounting points is 13". I fussed with this enough to know pretty surely those measurements are very close.

I don't know how to figure the angle between the two arms based on those numbers... someone does, though... has to do with radii and chord lengths... past that I'm lost. I can take the arm off and get close with the angle, push comes to shove.

Both the center pivot and tightener pulley are 3/4" thread, but they are not simple bolts. Bolt at linkage pivot is 1/2", with a shoulder length the thickness of the two linkage arms, plus the pivot thickness, plus a washer under the head, and there are enough threads for a standard nut and a thinner locking nut. I suppose there ought to be a washer on that side too, but...

The thickness at the pivot hole in the tightener arm is 1 1/16"... the thickness at center pivot is 1 1/4"... thickness at linkage pivot is 11/16".

Justin, I don't know if you have a tightener pulley or not, but it mounts to the back of the machine with a made mount. It's just visible in the first picture you posted for me. It's actually a relatively precision part, given it needs to hold the arm away from the machine the amount the pulley needs to be so it is centered under the drive pulley. It's threaded (3/4" I believe) on the frame end, has a substantial shoulder for the tightener pivot arm to butt against, then an axle section that is just longer than the center pivot is thick, and it has a big shoulder for a large diameter, thick washer, then a 3/4" threaded section for a nut that jambs the washer against the axle shoulder. This is what keeps the tightener arm vertical so the tolerances need to be minimal. Also, the axle and center pivot diameters need to be minimal. Also there is an oiling hole in the top of the center pivot to keep the axle lubed.

The mount for the tightener pulley is hard to describe and I don't have a camera available. It mounts hard and fast to that end of the tightener arm, but it is and axle, also and there is a grease zerk in the outboard end of the axle. Anyhow, there are multiple diameters, shoulders, grease channels, sloping shoulders to stops. If you don't already have one of these, I can take ours apart and get you hard measurements.

My brain wants to quit... holler about what you have, want, don't get, need more info on, etc.

Mike
 
Found this while emptying the coffee pot... http://www.calculator.net/triangle-calculator.html

The center pivot angle, given the two arm lengths of 9.5" and 5.5" with distance between arm ends of 13" is 117.653 degrees. Other two angles are 40.338 and 20.009 degrees.

Is that right ??? Well, it is if the measurements are right. As I said, I can take the arm off and maybe find the distances are a little different.

A thing about the short arm... This is an "A" and a "B" is bigger (taller, for sure, and with a larger diameter drive pulley, and a little larger base, and ???). The short arm (linkage side) on ours sets at a little above horizontal... that's where all the adjustments of treadle height, tightener pulley distance to belt (the closer it is, the more ability to take slack out) "averaged" out. BUT... little changes above and below horizontal still have the arm hole on a vertical line with treadle connector and brake connector... perfectly vertical ? No, I wouldn't bet that... but it looks vertical and straight through the connecting point. So... might be a person needed to run a vertical string through the treadle connection point and the brake connection point and then measure to the center of the frame for how long your short arm needed to be... maybe plumb bob down from brake arm pivot point (if that is an original part) and find both short arm length and where treadle connector is supposed to be. Yeah, I know... lots of "maybe's" and "if's"...

Mike

And one more thing... a 2:1 gear box reducer takes 1725 / 1750 rpm close to 900 rpm.
 
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This post is a lesson in old machinery HP requirements and specs.

In moving my hammer rather than having the motor hanging off the side and running to a jackshaft bolted to the frame and suspended above the hammer, I wanted to simplify things and make them more like the original motor powered configuration, with the motor and idler arm behind the hammer. It has been running fine for years with a 2hp 1725 rpm motor.

The original spec called for 350 BPM, driven by a 900 RPM motor. 900 RPM motors are getting few and far between these days, because all the extra windings for slow speed cost a lot more money to make, but I found myself a huge baldor 2hp 900rpm motor. The original design for the motor driven hammers was just direct drive, motor to hammer with the tension arm and idler attached to the treadle. The drive pulley on the hammer is 13 inches, so I needed a 5 inch drive pulley for my motor. I made myself a crowned drive pulley, fabricated a new motor mount, got a new belt, and just yesterday fabricated the new tension / idle arm and linkage.

pulley7.jpg

pulley11.jpg


tensionarm.jpg


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Everything looks like it should work just great, right? ... Not quite...

Here's a look at how the hammer was originally set up with the 2hp motor that I was using. Take careful note of what I have eliminated...
DSCN2140.JPG


I removed more than 60 pounds of rotating weight, and the result is that the innertial energy stored in the top shaft as a flywheel effect is gone. When I step on the treadle, if I step hard, it just stops the motor dead, if I step slowly it will start hammer moving and then pick up speed and I can step down harder, and it works fine. The old literature gives weights of the hammer with and without motor, and as a result. The originally fitted motor for this machine weighed almost FIVE HUNDRED POUNDS, so even though the horse power rating is the same, it weighed 5 times as much as the motor I've got on it now, and had effectively several hundred pounds more rotating mass, it was it's own flywheel. In talking with another owner of a slack belt clutch Fairbanks power hammer, he said he obtained his with a 5hp motor, and it would do the same as mine is doing right now, bog down and stall the motor if he stepped down on the treadle hard from a stop. He instead ran a line shaft with several large heavy pulleys off of a 3hp motor, and it now runs great, and picks up instantly. Even though the literature says "2hp" needed to run the hammer, the old machine literature is talking about line shaft HP, and those line shafts have a huge amount of stored energy in them which allows that energy to transfer into the stopped hammer for the initial lift needed to pick up the 100+ pound head and start the two massive discs on the hammer spinning. The real lesson here is that the rated HP to run a machine does not necessarily equate to the power needed to START that machine. Modern technology is wonderful, but there were some distinct advantages to the old lineshafts, and ginormous motors.

As much as I wanted to simplify things and get away from having jackshafts and whatnot... it looks like I'm going to have to build a shaft system with some mass just to store the energy needed for the initial start of the hammer. This design has been recommended to me, just throwing a heavy flywheel on the back of the shaft opposite the drive pulley, just like on Mike's model A. I should be able to keep using the same 900rpm 2hp motor which I purchased, and the pulley which I made, but I'm going to have to hit mcmaster or something up and buy myself some 1 1/8 shafting, some pillow blocks, and some V belts and fabricate a shaft which I can drive at a 1:1 ratio with a pair of 4 inch double V pulleys that I already own.

DSC00988.JPG


I just ordered parts from McMaster to build a new jackshaft similar to the one pictured above on Mike's machine. I also have a 50lb flywheel which will fit on the end of the jackshaft that I can add to give it some real momentum. The shaft will be 1.125 to match the pulley I made, and the 4 inch double Vbelt pulleys I already own, so I can drive the shaft 1:1, the flywheel has an inner diameter of 1.165 so I may have to slip some 20thou shim stock in it before I tighten down the set screws. It's an old 22inch diameter 3 step pulley from a treadle lathe, which made its way into my house while I was restoring an 1880s barnes velocipede lathe. It wasnt the right size shaft size for the lathe, but I'm glad I held onto it now. I know it's good at 300rpm, but I'll have to be careful and see if it's still good at 900 rpm

flywheel.jpg
 
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Jesus dude. This thing is really putting you through your paces, much more than my 50# LG rebuild did me. Though I did have to pour babbit. Good luck! Staying tuned.
 
Justin,

I thought maybe you had died. Should have known you were just busy. Our hammer is right on the edge of failure in pick up with a geared-down 3hp 1150 rpm Baldor.

I don't understand fly wheels. Is it weight? Is it diameter? Is it weight to diameter? Or ???

I'm really looking forward to seeing/hearing the evolution of this, Justin. I know it's "extra", but if you can make the time, you'd be famous with me.

Mike

PS... I'll try to get a picture of our original (mouse chewed insulation... WAY out motor bushings... not within my understanding or skills to save) "A" (50 pound) motor. "Big 'ol girl" is a serious understatement.
 
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Salem Straub said:
Jesus dude. This thing is really putting you through your paces, much more than my 50# LG rebuild did me. Though I did have to pour babbit. Good luck! Staying tuned.
Click to expand...

As I see it (whether I understand, or not), Salem, is a Little Giant treadle movement picks up a light load... relatively speaking... and it picks it up with a fly wheel. Look at the turning mass motor-side of the wooden clutch. With an LG, anything that turns that unloaded mass is okie doakie. On a Fairbanks, there is a lot of to-be-turned mass out in front of the pick up.

Mike

PS... Would you be disposed to passing learned knowledge on re-babbiting an LG? Friend has a broke-dick 25 that really ought to be sharing rent.
 
To quote monty python, "I'm not dead yet!" Just been very very busy =) With a flywheel (or line shafting) you have a tremendous amount of energy stored as rotational momentum, when you apply the clutch (slack belt clutch for these Fairbanks hammers) if you have a flywheel that momentum is going to keep the drive pulley spinning and allow it to pick up and start the mass of the hammer head, crank plate, shaft, and rear pulley, which for a 75# fairbanks is substantially more than 75 pounds. In fact, weighing the head and arms and top die of my hammer it's well over 100lbs just for the ram (even though its only a '75 lb hammer' these hammers are WAY heavier built than say a little giant), and then the pulley, crank, and crank plate are probably another hundred. It takes a lot of energy to get that mass moving. Cars have flywheels as well, to store the rotational energy of the engine to allow it to not stall out the engine when you let out the clutch, and keeps the engine running smooth as the cylinders fire. A flywheel stores energy by picking up speed, and releases the energy when it slows down. In the powerhammer drive-train that energy is transferred by the belt to the top shaft to do the initial pickup of the hammer head.

McMaster managed to get me the shaft and pillowblocks that I ordered to me today, so I started planning out the reconfiguration.

I was originally looking around my parts bin for a big hinge to hang under the mount that I already had fabricated, but then I thought of something better. I have a motor mount plate already which is pre-drilled with the holes to fit a variety of motor frames, and rather than attaching that to a giant hinge... I'm going to run a pair of angle iron bars across and bolt those to the current frame and then I can hang 4 bars of 3/8 all thread and run them through the motor mount plate, which can then be hung directly below. This will allow me to use both the weight of the motor for belt tension, as well as locking the position there and allowing for adjustments when the belts stretch. In addition this makes it so that I'm not tied to any particular motor, as the base plate will mount almost any motor, and with the shaft above it, if I swap to a 1750 rpm motor for example, I need to just double the pulley size on the shaft, and then I can adjust the motor height to keep the pulley fitting . I'm using an H type pulley hub on the shaft so that if I do swap motors it will be simple to swap out the jackshaft pulley and retain 900rpm on the drive pulley.

Measuring the center height of the pulley position, I need to put 3 inch riser blocks under the pillow blocks to match the same location for the drive pulley, which gives me plenty of clearance under the jackshaft to put some angle iron across the top for suspending the motor mount plate. I'll then cut the angle iron at the top short, letting the pulleys on the motor and the jackshaft hang just past the end of the mount, and then just beside that that I will mount the flywheel. I want the the pillow block as close to the flywheel as I can, and I may end up adding a foot underneath there to help support the weight too.

plan.jpg
 
I just re-did the pulley math for how the hammer WAS running with the old setup, and it was actually set up to run QUITE a bit slower than the rated max BPM, and a lot slower than I thought that it was running. There was a 5 inch pulley on the 2hp motor hanging off the side, this ran to a 12 inch pulley on the top shaft, the drive pulley on the topshaft was only 3.5 inches in diameter. With a 1750rpm motor that means the top shaft was rotating at 730 RPM, and then with a small pulley at 730RPM going to the 13 inch pulley on the hammer, the hammer was only running at 200bpm, which was actually quite comfortable. I may just stick a 6.75 inch pulley on the counter-shaft instead of doing a 1:1 ratio with the pulleys, to slow the counter shaft down to 533 rpm (and slow down the speed that I'd be spinning that big flywheel to a safer level) 533rpm on the 5 inch drive pulley would get me to 205 BPM for the hammer, right around where it was previously.
 
Justin,

Thanks for making the time Justine. I can't keep up with your understanding without studying it, but I love learning about new stuff... =]

When I think about 350 bpm and whacking something, I, mentally, transfer to 5.833 whacks per second. I know the hammer won't actually reach max BPM, but still... So how, my brain asks, is one preforming calculated whacking at machine gun firing rates? I think your reduced BPM isn't going to get in the way of anything.

Mike
 
Mike Krall said:
PS... Would you be disposed to passing learned knowledge on re-babbiting an LG? Friend has a broke-dick 25 that really ought to be sharing rent.
Click to expand...

Mainly I had never considered the extent to which the clutch pulley on an LG serves also as a flywheel, I think.

Mike, here's a link to my WIP thread on rebuilding my hammer, babbitt included. If your friend wants to talk babbitt, tell him to get ahold of me... my phone number is at my website.
 
Just got back from reading your Rebuild WIP... Nice, Salem. Thanks for doing it. It will help when/if we get the friend into his 25# rebuild.

Mike
 
Swapped motors to my 3hp 1750rpm TECO Westinghouse motor, I think it runs a little bit faster than it should be, in timing it it looks like it's running about 220 bpm, when it was running at 200 bpm. With the 900rpm motor there was a lot more belt slip and it was only running around 160bpm actual head speed. What I think I am going to do is get myself a KBAC-29 10001 VFD which will run the 3hp TECO Westinghouse motor I've got on it now, and then I can slow it down a tad without having to change anything from the current setup. In fact I also would not need to use the rotary phase converter and switch on the side of the hammer, as I could directly wire the motor to the start/stop switch on the VFD.

This video is terrible, the lighting was bad and the camera wouldn't focus, and it's mostly staring at my butt, but you can see it's running a bit faster than 200bpm although it may be fine.

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IMG_2102.JPG

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[video=youtube;kng4zE4Jh1g]https://www.youtube.com/watch?v=kng4zE4Jh1g[/video]
https://www.youtube.com/watch?v=kng4zE4Jh1g
 
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That's a nice set up, Justin.

Boy do I wish our hammer picked up as nicely as yours does. I'm going to work on our adjustable hammer guide gibs one of these days. I tried to set it the way Sid told me to, but maybe I got it too tight. It would be nice if that was the fix as it is relatively easy to do.

Nice little Christmas present you sent me with this post, Justin. Thanks.

Mike
 
Been looking at your photos more since I posted. Are those original dies, Justin? I built ours from the catalog photos and from pics Sid and Keri have on their web site. Looking at yours, the draw section looks a lot more "serious" for drawing than ours... wonder if you find yours is good/bad/indifferent?

Mike
 
They are not the original dies, they're a bit aggressive drawing, the previous owner made a lot of blacksmith's tongs with the hammer and used the aggressive dies for drawing the reins out. I like them because the drawing if off to the side so that I can still use the center of the dies without the transition point from drawing to flat being right in the middle like most dies.

In talking with a few other people with fairbanks hammers, what I think that I am going to do is take the faceplate off and sit it on a milling machine and mill off the area behind the bolts so that it bolts up tight, and then use brass shims between the faceplate and frame to put the required space needed, and when it wears more, I can just remove shims instead of having to re-mill the face plate.

Here's a much better quality video I just took.


[video=youtube;a4J3F0WOvtE]https://www.youtube.com/watch?v=a4J3F0WOvtE[/video]
 
Yup, better video... =] That is a NICE hammer, Justin.

So you feel the dividing line between flat and draw on the dies really ought to be off-center of the hammer block? What do you see as the advantage of that?

I get the mill/add shims idea... brilliant!

You mention yapping with other Fairbanks owners. Is any of that yapping in the public realm? I'd like to go there and learn stuff, if it is.

Mike
 
This chat was on the new england blacksmith's mailing list, and on a phonecall with Richard Spreda from Stowesmith.com who owns a B model fairbanks himself. I'm trying to think of the best way now to fix the brake ring. I may forge a piece of barstock about the same thickness as the brake to replace the missing part, and have a welder weld it together for me (i'm a lousy welder and I dont want it to just break again hehe)
 
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