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brian Rupnow
06-27-2011, 10:46 AM
Last night I couldn't sleep. Rather than counting sheep (which doesn't work anyways) I started casting about for interesting things I could drive with some of my model engines. So far I have designed and posted the Slinky Machine, and it was a big hit. People also liked the Pumpjack oil pumping model which I designed, built, and posted.(although I haven't seen anyone else build one). Recently I built and posted the Bubble Machine, which is cute. I didn't post plans, because it was so simple that anyone could replicate it after seeing the pictures and video. Two lots down from my house they are digging the basement for a new house with a large excavator, and for half an hour I persued thoughts of building a working model of that, but gave up---Just too many motions to replicate. Then I thought ---"Hey---What about a pile driver." That one would be fairly simple. I'm thinking an aluminum column/tower with a small chain sprocket at the base and a nylon top shoe for the chain to slide around. The "sliding hammer" would be a section of mild steel rod with a nylon guide attached which slid up and down rails in one face of the column. The roller chain could have a rare earth magnet attached to it so that as the bottom sprocket rotated and the chain moved up the tower, the rare earth magnet would pull the sliding hammer to the top of the tower. Then when the chain passed over the top shoe, the magnet would be pulled away from the slide hammer and it would fall to the base of the tower on the guides, thus "driving" the piling. This motion would keep repeating itself. A small gear reduction unit would probably be needed at the bottom drive sprocket. I think this would make an interesting display and could be driven by an air, steam, or I.C. engine.---Anybody interested?----Brian

TGTool
06-27-2011, 10:55 AM
At the risk of piling on someone else's idea ...

Would a diesel pile driver be possible? Essentially a two stroke diesel cycle with a free piston firing at the bottom of each stroke.

brian Rupnow
06-27-2011, 11:12 AM
My son, all things are possible---But not on this small a scale model. The sliding weight wouldn't have enough mass to raise the deisel fuel to combustion temperature. The sliding weight in this case will only be a maximum diameter of 5/8" x about 3" long with a fall of 1 foot.

Weston Bye
06-27-2011, 11:53 AM
The sliding weight wouldn't have enough mass to raise the deisel fuel to combustion temperature.

So put a model airplane engine glow plug in the chamber and use glow fuel. Maybe the compression would be high enough for that.

Jaakko Fagerlund
06-27-2011, 12:15 PM
You just have to make a cylinder/piston small enough to get the required compression ;)

The pile driver idea sounds nice, would like to see one though I'm not so much in to building models but I do like to admire them and the workmanship. Especially loved that hit'n'miss you built Brian! :)

toyjeep73
06-27-2011, 01:31 PM
They make air hammers too. A lot of dock builders around here use them. We use the big deisel ones at work for concrete pile.

strokersix
06-27-2011, 01:44 PM
One problem with the pile drive diesel concept is the energy required to compress the gas in the cylinder subtracts from the energy available to drive the pile.

tdmidget
06-27-2011, 02:08 PM
Yall must be awfully young not to remember the Vulcan steam hammers.
Build this one:
http://www.rrpicturearchives.net/showPicture.aspx?id=1404135
I remember seeing this at work.

brian Rupnow
06-27-2011, 02:38 PM
I'm up to my Ying Yang in engines, both air and Internal Combustion types. I'm sure that many other model builders out there are the same as me. The nice thing about all of these other "contraptions" that I like to design and build, is that they can be driven by either type of engine, and make fantastic displays at county fairs, etcetera. Everybody likes to see their engines "doing something".---And yes, I am "awfull young"!!!!----I'll be 65 in 2 weeks. I do remember the steam trains from when I was a kid, but can't honestly say I ever remember seeing a steam hammer.

brian Rupnow
06-27-2011, 02:53 PM
Okay---We're off and running!!! I went over to Princess Auto this afternoon and bought two 16 tooth #35 pitch sprockets, a ten foot length of #35 pitch roller chain, (this may be the same as bicycle chain, I'm not sure), two master links, and three 3/4" diameter "rare earth magnets". for the princely sum of $25 including the hated 13% "harmonized sales tax". I'm going to have to be clever and build a mount for one of the rare earth magnets to attach to one of the master links, and have it so it will still roll around the sprocket without binding in any way.
http://i307.photobucket.com/albums/nn294/BrianRupnow/003-1.jpg

brian Rupnow
06-27-2011, 03:45 PM
Well, Ya gotta start somewhere, so first off we create a 3D model of the sprocket----
http://i307.photobucket.com/albums/nn294/BrianRupnow/16T35PRCSPROCKET.jpg

brian Rupnow
06-27-2011, 04:44 PM
The first thing I have to establish is how I'm going to mount the magnet to a link of the chain and still have the chain travel freely around the sprocket. I think I can make up a magnet mount to silver solder to an outer chain link and then epoxy the magnet to the mount---
http://i307.photobucket.com/albums/nn294/BrianRupnow/ASSYOFOUTERLINKANDMAGNETMOUNT.jpg

laddy
06-27-2011, 06:14 PM
Awesome!!!!!

Dave S.
06-27-2011, 06:25 PM
Brian

Here are a couple of photos of old donkey engine running apile driver.

http://i132.photobucket.com/albums/q3/Dave_Sohlstrom/skid2.jpg

http://i132.photobucket.com/albums/q3/Dave_Sohlstrom/skid1.jpg

Dave

brian Rupnow
06-27-2011, 06:51 PM
At a quick glance, I think a model somewhere in the range of 18 to 20" tall is where this may end up at. I may go to 2 magnets arranged equal distances apart on the chain, to double the number of "hits" in one complete revolution of the chain. The chain isn't going to be moving all that fast, but the 'hammer" will free-fall when released by the magnet.
http://i307.photobucket.com/albums/nn294/BrianRupnow/SPROCKETANDCHAINASSY.jpg

Dunc
06-28-2011, 08:15 AM
If you want to build a deck why not buy one of the fuel-cell powered (eg Paslode) shooters?

brian Rupnow
06-28-2011, 12:44 PM
Big Son of a Gun, isn't it. Of course, the chain will be driven thru one of my gear reduction units. This may end up being driven by my twin horizontal or perhaps even by one of my i.c. engines. P.S.--If the drawing is too small to see clearly, hold down control on your keyboard and tap the + sign
http://i307.photobucket.com/albums/nn294/BrianRupnow/ASSYOFCHAININHOUSING.jpg

brian Rupnow
06-28-2011, 04:53 PM
Here's a quick and nasty (Though dimensionally correct) model of the electric window regulator that I modified to make a first rate worm gear reducer. The ratio is about 60:1. I cut the electric motor housing in half, and inserted a bronze bushing inside the motor housing, then fabricated a 2" diameter pulley to fit on the motor shaft. The gear doesn't come off the output side (at least I don't think so yet) so I will have to lash up a direct drive coupling between it and the lower sprocket shaft on the pile driver housing. You can see this modification at
http://www.homemodelenginemachinist.com/index.php?topic=13507.30
http://i307.photobucket.com/albums/nn294/BrianRupnow/ELECTRICWINDOWREGULATOR-2.jpg
http://i307.photobucket.com/albums/nn294/BrianRupnow/ELECTRICWINDOWREGULATOR.jpg

brian Rupnow
07-21-2011, 11:56 AM
Okay--Suffice it to say that the majority of this thread got posted over at HMEM. The project was pretty straightforward, barring some issues that were my own fault when I heated up the "drop hammer" portion of the build and screwed up the magnetism of the two embedded magnets. This model pile driver requires more energy to run it than any of my model steam engines could produce, so I ended up powering it with my hit and miss i.C. engine. It was a project to kill some time, and although it does work the way I intended, it probably isn't something that most model builders would want to invest the time in making. At any rate, here is a video of a succesfull run. Please excuse the "fogging" in the last half of the video. The humidity was at about 95% in my garage when I took this, and it started to fog up the camera lens.---brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/th_PILEDRIVER-HIT-N-MISS.jpg (http://s307.photobucket.com/albums/nn294/BrianRupnow/?action=view&current=PILEDRIVER-HIT-N-MISS.mp4)

Peter.
07-21-2011, 12:07 PM
At the risk of piling on someone else's idea ...

Would a diesel pile driver be possible? Essentially a two stroke diesel cycle with a free piston firing at the bottom of each stroke.

As far as I know, there have been full-size working ones that do just that. An old guy I worked with once told me a story of how they used to start one with a spoonful of ether until one shift boss poured way too much in one day and blew the piston clean out of the top.

Weston Bye
07-21-2011, 12:58 PM
They're called Pile Hammers. I remember seeing one on a bridge project. The piston was visible bobbing out the top of the device with a puff of black smoke out the side exhaust port. The piston would fall down, then bob up again and another blast of smoke. Seems like the cycle time was around a second per stroke.

DFMiller
07-21-2011, 01:31 PM
Brian,
That's really cool.
I enjoyed the video.
Whats HMEM?
Thanks
Dave

brian Rupnow
07-21-2011, 02:19 PM
Brian,
That's really cool.
I enjoyed the video.
Whats HMEM?
Thanks
Dave

http://www.homemodelenginemachinist.com/index.php?topic=14887.0

Black Forest
07-22-2011, 01:35 AM
Build that thing a little bigger Brian and you could use it to set fence posts.

Richard Wilson
07-22-2011, 04:19 AM
As far as I know, there have been full-size working ones that do just that. An old guy I worked with once told me a story of how they used to start one with a spoonful of ether until one shift boss poured way too much in one day and blew the piston clean out of the top.
Yes, this was a very common type of piling hammer back in the 1970s, but I haven't seen one used for good few years now, mainly superceded by hydraulic drop hammers or vibro pile drivers. They were a good hammer, once you'd got them started, and yes, ether was the favourite to get them going, but even so, it could take a while, especially on a cold morning. I'm partially deaf, and I put that down to too many years spent in close proximity to these beasts, nobody gave us ear defenders back then, cotton wool plugs were all that was available.

richard

John Stevenson
07-22-2011, 03:16 PM
Brian,
It would work with a sprag on the chain and that way it would not allow the driver to fall until the sprag had gone over the top sprocket.

Did you used to have these things over there ?

http://www.berm.co.nz/cgi-bin/video/play.cgi?XnnvH5_Y0Eo

Awesome things if you could keep your feet out the way.

Bought a job lot of 25 of these, all worn out and broken at a sale, everyone thought I was mad but they had the same BTH magneto on them that the racing bikes had.

brian Rupnow
07-22-2011, 03:54 PM
Brian,
It would work with a sprag on the chain and that way it would not allow the driver to fall until the sprag had gone over the top sprocket.

Did you used to have these things over there ?

http://www.berm.co.nz/cgi-bin/video/play.cgi?XnnvH5_Y0Eo

Awesome things if you could keep your feet out the way.

Bought a job lot of 25 of these, all worn out and broken at a sale, everyone thought I was mad but they had the same BTH magneto on them that the racing bikes had.

Sir John---I haven't seen the small rammers that are in the link, but I have seen many of the diesel type pile drivers.---Brian

Mcgyver
07-22-2011, 09:27 PM
Brian

Here are a couple of photos of old donkey engine running apile driver.


Dave, great pics, thanks for putting them up. Not knowing much about pile drivers, is basically the donkey engine raises a weight up the mast and then lets her go? It would make a great model

There's probably one or to OHSA infringements there. :D

Pete F
07-23-2011, 01:09 AM
Very nice! Hooking up two projects like that must be very satisfying.

Would it rebound less if you put some lead shot in the pile (or whatever the thing that drops is called)?


-Pete

brian Rupnow
07-23-2011, 08:50 AM
Very nice! Hooking up two projects like that must be very satisfying.

Would it rebound less if you put some lead shot in the pile (or whatever the thing that drops is called)?


-Pete
It probably would rebound less, kind of like a dead blow hammer.