# Jacobs Ladder---



## Brian Rupnow (Nov 29, 2011)

The krazy klockwork machine is finished, and I'm not about to start something new right away, But-----A goodly portion of my 46 years in design engineering has been spent designing material handling projects. One of the more intriguing elevator type devices, to elevate either round rod or pipe sideways out of a full bin and to "singulate" them is called a "Jacobs Ladder". It works on the principal of a moving staircase. Imagine, if you will, 3 very very narrow flights of stairs, on which the treads tip in a bit towards the staircase, while the risers are vertical. In this case, say the outer two flights of stairs were cut from 1/4" plate, the inner flight cut from 1/2" plate, and all 3 set in very close proximity to each other---maybe .030" to .040" apart. The two outer flights are stationary, while the center flight of stairs "orbits". The orbit carries this center flight up the height of one riser plus perhaps 1/16", and then the orbit causes it to "sink back" between the two outer flights, complete its orbit, and once again rise up between the two outer flights and repeat---over and over again, as in continuosly. The tread area in the center flight would have a slight concavity running along it, put in by a v or ball nosed mill. Now, if a person had a supply of 3/4" or 1" diameter wooden or aluminum balls (I think steel balls would be too heavy)---and if they were "funneled" towards the foot of the stairs---. The moving center flight would pick up a ball, carry it upward, and deposit it on the next higher tread of the two outer flights. On its next orbit, it would move this ball up to the next step, while simultaneously picking up another ball. This would keep happening untill all the treads were full of balls, and they started to fall off the top step---where they would be funneled back to the base to start their journey over again. Wow!!! What a neat piece of animation that would be---especially if the orbiting mechanism was driven by a small steam or gasoline engine. In a "real world" application, for example lifting 48" long pipes out of a bin, there would be a Jacobs Ladder at each end, but for a demo unit using balls, only one ladder would be required.---Surely bears thinking about, doesn't it!!!


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## larry1 (Nov 29, 2011)

Brian, This sounds great, please give a go.  larry


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## swilliams (Nov 29, 2011)

sounds very cool Brian. 


If you really want to go off the deep end, perhaps you could make a steam engine wind up a falling ball clock? :big:
http://www.timeonthenet.com/ball_clocks.html

Cheers
Steve


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## nsfr1206 (Nov 29, 2011)

Looking forward to seeing it!


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## tel (Nov 30, 2011)

You've got my attention as well!


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## Ken I (Nov 30, 2011)

I built something similar for feeding shockabsorber rods into a centreless grinder (crib of Cincinnatti original IIRC) consisted of alternating stationary and mobile "stairtreads" each cycle would cause the rods to progress up the staircase and eventually onto a conveyor.

The original was crank driven - this one pneumatic - boring industrial stuff.

Ken


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## Brian Rupnow (Nov 30, 2011)

Yes Ken, thats the one. Same principal but with the moving portion orbiting on an eccentric instead of driven by a cylinder.


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## Brian Rupnow (Nov 30, 2011)

A teaser---Only had time for this much tonight. Have the mechanism to move the center staircase in mind, and if it works i should be able to animate it and post a video----


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## Gordon (Dec 1, 2011)

If I understand you correctly I think you are talking about something similar to a walking beam conveyor except moving vertically instead of horizontally. True?


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## Brian Rupnow (Dec 1, 2011)

Gordon  said:
			
		

> If I understand you correctly I think you are talking about something similar to a walking beam conveyor except moving vertically instead of horizontally. True?


true


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## Brian Rupnow (Dec 1, 2011)

This is it, and it works really well, just as I had imagined it would. The two orange colored arms must rotate in tandem to give the desired effect, and though I can drag it around on my model, I can't quite figure out how to mate the two orange arms so that they continuously rotate in tandem. (My software is capable of doing it, its just that I don't know how to do it untill I've talked to my Solidworks service provider. I thought it would be the "Gear Mate" function, but it doesn't want to work for me tonight.) In real life, the two arms would have to be on a pair of sprockets connected with a small roller chain. Once I get the mate thing figured out, I will be able to animate it and make a short video of it operating.


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## Blogwitch (Dec 1, 2011)

Brian,

To get them to work together just requires a conrod between the two offset parts of the 'cams'. Extend the pins that are attached to the centre stairway, and put the conrod to join the two. Just like drive rods on loco wheels.

But you will need to drive just one from the opposite side the 'cams' are on.

John


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## Brian Rupnow (Dec 1, 2011)

That doesn't work John, without some kind of flywheel effect. When the driving wheel passes "over center", the driven wheel wants to stop and rotate backwards.


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## woodnut (Dec 1, 2011)

This is what I like about this site. 
Someone is always building something different AND showing now they did it rather than keeping it a secret.

Your Krazy Klockwork Mechanism was as fun to watch run as it was to watch you build, I am sure this will just as great.

My only complaint is I am spending too much time on the computer and not enough time building my own projects.  ;D

Thanks Brian!!

John


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## Blogwitch (Dec 1, 2011)

I understand where you are coming from Brian, but I have seen the method I described used in a few places, and not on 'light' work either.

There are plans about that use that method, instead of gears, for making a set of sheet metal rollers. 

As long as centres of the bearing holes for the two shafts are exactly the same as the centrers of the two holes in the conrod, then things should be OK.


John


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## Brian Rupnow (Dec 1, 2011)

John---I certainly can't argue with you. A thousand steam trains can't be wrong!!! I just can't get it to work in my software.


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## rleete (Dec 1, 2011)

Brian, I believe if you linear pattern the arms (instead of inserting separate copies), they will rotate together.

Hope that works for ya.


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## Brian Rupnow (Dec 2, 2011)

This is it---Very short and a bit too fast, but it lets you see what happens.


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## archer3d (Dec 3, 2011)

Looks like a great mechanism, but I just cant figure out how you will control the top of the moving ladder, Will just have to wait


tom


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## Brian Rupnow (Dec 3, 2011)

archer3d  said:
			
		

> Looks like a great mechanism, but I just cant figure out how you will control the top of the moving ladder, Will just have to wait
> 
> 
> tom


Thats why there are two pivot points down at the bottom. That keeps the top of the ladder travelling in a fixed circular path. I could have just as easily put one of the pivots up at the top, but then the balls wouldn't have been able to fall off,


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## Brian Rupnow (Dec 4, 2011)

I went over to Barrie's hobby shop on Saturday morning, hoping to find a small roller chain and sprocket set-up. Sadly, they don't have anything like that. I know from when I built the pile-driver, that the only sprockets available to me in town are small bicycle sprockets, and thats just too big for this project. I'm not sure what to do now. This would have made a nice small project with a lot of eye appeal and not too many parts, but as of now I'm kind of stuck!!!


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## Brian Rupnow (Dec 4, 2011)

The model engine Gods have smiled on me once again!!! A gentleman known as Duffy out of Quebec has offered to send me a pair of sprockets and some chain out of a 1950's era printer. So---The project still lives, and will be christened "THE DUFFY" in his honour.


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## Brian Rupnow (Dec 5, 2011)

This gets more and more interesting as I dig my way into the design. I realized last night that I didn't need to have the center flight of stairs extend down below the two outer staircases. I can achieve the same "orbiting" by moving the axis of the pivot arms up and into the position shown. This makes a much more compact assembly, easier to fabricate and much more eye appealing. The pivot arms clear the spacers between the two outer flights, and the bearing support off to one side clears everything. Now with sprockets to tie the two shafts together, and a pulley on the end of the highest shaft we are starting to get somewhere.


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## Brian Rupnow (Dec 6, 2011)

Thank you everyone for the great suggestions. I really like Evans cam concept. I'm not going to use it, but it is a really great idea. I have rethought the big "windows" in the sides of the outer staircases, in favour of two 2" dia holes in the near side staircase only for the "arms". I have added in a 4 1/4" dia pulley, which is as large as I can go without hiding some of the stair treads with it. I have added a 2 1/2" x 1/2" x 10" baseplate. I have to sneak Duffys sprockets and chain in behind that pulley yet. I also have to figure out some way to make a track for the wooden balls to follow around from the top discharge point to the bottom step to let them recirculate. My current thinking is two bent 3/16" rods running side by side to form a "ball track".


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## lee9966 (Dec 6, 2011)

That's really cool!

The balls can do some roller coaster action on the way back, gravity defying curves, or a loop.

Lee


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## mklotz (Dec 6, 2011)

LeeScrounger  said:
			
		

> The balls can do some roller coaster action on the way back, gravity defying curves, or a loop.



Better yet, the balls can roll down a ramp and activate the lever arm on Brian's previously built escapement device, thereby producing a totally useless, albeit entertaining, bit of chewing gum for the eyes.


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## Brian Rupnow (Dec 6, 2011)

The ball return has me somewhat concerned. I don't want the model to take up a lot of real estate, so big sweeping curves of parallel round rod is not a particularly great option. Although the total drop is not dimensioned on the drawing, its only about a 4 1/2" total drop from the top step to the bottom step. I would like the balls to fall off the end of the top step, circle around a full 360 degrees and enter at the front of the bottom step. The best alternate I can think of at the moment is to have a short vertical section of 1" thinwall tube about 2 1/2" long on the left-hand side of the stairs, which the ball falls straight down through, but then I'm not sure what to do with it after it falls down thru the tube. I can't afford to have any level spots in the return system---it must all slope downhill. This kind of thing does not lend itself to a "machining" solution. Its a problem.---I can get my balls up, but I' not sure how to get them down!!! ;D ;D ;D


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## bearcar1 (Dec 6, 2011)

Hi Brian, a great number of ways for the ball to be returned to the bottom of the chute can be imagined of course. It occurred to me, in a Rube Goldberg style, that a set of stair steps that have treads tilted in opposite directions could be utilized. The ball, after its initial lift would exit out onto the top step of the stairway and would then be forced to roll to the other end of the step where it would then would have to travel back the opposite direction until it met the end of that step and so on and so forth until it reached the bottom step and would again begin its journey back up Duffy's lift. The board game "Mousetrap" has such a contraption built into its action if you have ever seen it in action. 

BC1
Jim


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## Brian Rupnow (Dec 6, 2011)

Bearcar---Thats a great idea!! It just entails far more work than I wanted to get into. I'm liking the idea of a vertical tube as stated earlier, then a parallel track made of round rods with only a slight downhill slope and a 180 degree turn at the discharge end. I have to be carefull that the balls don't bounce off the track or roll so fast that centifugal force causes them to jump off the rails. Thats why I was thinking of dropping them down a section of tube, to get rid of most of the vertical difference. A peice of 1" clear rigid plexi tube would be great for that.


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## Brian Rupnow (Dec 6, 2011)

And where, short of making them myself, do I get a dozen 3/4" dia. wooden balls?????????


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## Brian Rupnow (Dec 6, 2011)

Nevermind---I did a quick online search and found all kinds of sources. now what do I do with the other 88 wooden balls????
http://www.woodparts.ca/WOODTURNINGS-BALL.HTML


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## Brian Rupnow (Dec 6, 2011)

I may have part of the answer. Like many men my age I take a plethora of age related medications. Nothing serious, just old man stuff, arthritis etc. Anyways---the pill bottles are a clear plastic 1" in diameter x 3" long.--Might make the perfect vertical tube for the returning balls. As it is I currently use them to hold a wide assortment of small taps, dies, set screws, etc. in my little machine shop. Might as well use them on my toys too!!!


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## Brian Rupnow (Dec 6, 2011)

mklotz  said:
			
		

> Better yet, the balls can roll down a ramp and activate the lever arm on Brian's previously built escapement device, thereby producing a totally useless, albeit entertaining, bit of chewing gum for the eyes.


Marv---I truly hope that wan't a shot. None of this hobby stuff I build is truly usefull. Its all eye candy. Of course, I will agree, some of it is more "eye candy" than others. ;D ;D


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## mklotz (Dec 7, 2011)

Not a shot at all, Brian. I like your mechanisms and was just trying to puzzle out a way to tie the ladder together with your recent escapement device. Like so many others, I'm fascinated with devices that do nothing except show off the ingenuity of mechanical design.


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## tel (Dec 7, 2011)

... and somewhere in the cycle it would be good to see the ball trip a single cycle of the slinky machines as it goes past. ;D


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## bearcar1 (Dec 7, 2011)

I can see it all now 8)

[ame=http://www.youtube.com/watch?v=k1sP_bRheP8&feature=related]http://www.youtube.com/watch?v=k1sP_bRheP8&feature=related[/ame]

Ones imagination is boundless

BC1
Jim


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## Blogwitch (Dec 7, 2011)

Two parallel wire rods are perfectly good enough for balls to roll down, say 1/8" copper coated gas welding rod. Dirt cheap, and you will have enough to play around with for ages.

If you have them feeding into a plastic cereal bowl at the bottom, you could have a never ending supply of balls.

John


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## agmachado (Dec 7, 2011)

Hi Brian,

I was reading the comments of this topic and I immediately thought of a soundtrack for this project...

[ame=http://www.youtube.com/watch?v=LHSaK78d9b8]Rush - Jacbos Ladder[/ame]

I do not know if you like this style of music ... but that's okay!

I like your projects and again thanks for sharing them with us.

:bow:

Best Regards,

Alexandre


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## Brian Rupnow (Dec 7, 2011)

bearcar1  said:
			
		

> I can see it all now 8)
> 
> http://www.youtube.com/watch?v=k1sP_bRheP8&feature=related
> 
> ...


Just watched the vido----HOLY COW!!!


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## Brian Rupnow (Dec 7, 2011)

Waiting for wife to get home from work, so figured I could fill in some time---


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## Brian Rupnow (Dec 7, 2011)

Wife's home, supper is et, Jeapardy is coming on.


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## kcmillin (Dec 7, 2011)

This is a really cool mechanism Brian!

 or should I say, "What is, A Cool Mechanism!" 

I am curious to know how you are going to machine acute angles on the stairs?

Kel


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## Brian Rupnow (Dec 7, 2011)

Kel--I thought of that myself----Thats why, in the upper right hand corner of the drawing, I make reference to "non critical" and "saw/filing". I don't really know of any other way myself. However, as long as both sets of outer stairs are identical, it won't be a real problem. There is plenty of "play" in the way this thing will work. I have my software drawing template set to 3 decimal places---This assumes that whoever has enough moxy to attempt making something like this will know which dimensions must be held to a high accuracy and which can be "close" and still function. For me to do it any other way creates too much hassle when creating the drawings. In a real world "work" situation, where accuracy costs $$$$ I would take the time to change the number of decimal places and implied accuracy.


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## kcmillin (Dec 7, 2011)

Thanks Brian. I scrolled the image and now I see the note. ;D

I know what you mean about tolerance being expensive. My new job, which I love BTW, has me reading prints much like I did when building engines, except for the dimension tolerance. I now know what .63 is supposed to be :big:

Kel


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## chuck foster (Dec 7, 2011)

Alexandre that music you suggested is perfect (rush is my favorite band) some good canadian music for a good canadian gizzmo :big:

what do you think brian ?

chuck


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## tel (Dec 8, 2011)

No need to machine an acute angle for the stairs, an ordinary end mill, cutting at 90° will work fine provided the stairs are oriented at a slight tilt (5°?) from the vertical and horizontal plane - ie once your square edges are established, lean the workpiece into the cutter.


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## Brian Rupnow (Dec 8, 2011)

Just a pair of quickies tonight, because I'm very tired.


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## Brian Rupnow (Dec 9, 2011)

Tonight I was going to post a drawing of the center section of stairs, but on closer examination I decided there is no way to build what I had designed, at least without going to a lot of grief. So---tomorrow I will experiment with the 5/8" dia ball nosed cutter I bought while building the popcorn engine, and depending on what results I get, will post a drawing "after the fact".


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## Brian Rupnow (Dec 10, 2011)

Let the games begin!!!! Went down to my favourite metal supplier and got all the plate to make the Jacobs Ladder for $5.00. thought I was really smart, so went up to Canadian tire and bought a 2" bi-metal hole saw and an arbor for it. All the money I gained on the price of aluminum was soon lost at canadian Tire-----the holesaw cost $18.99 and the friggin' arbor cost $28.99. Oh well, what the heck, I'm working every day, earning real money.


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## Brian Rupnow (Dec 10, 2011)

First step--Print out center staircase at 1:1 scale, cut it out, glue it to poster cardboard. I don't usually recomend doing this, but on a part where the only two critical things are the hole centers, it is perfectly acceptable.


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## Brian Rupnow (Dec 10, 2011)

Cut out cardboard, tape it firmly to the peice of aluminum to be cut, which has been coated with Dykem, and scribe around it. if the pattern has two "square" edges, take time to align them with the edges of the aluminum before taping it in place.


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## Brian Rupnow (Dec 10, 2011)

Go nuts with bandsaw----


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## Brian Rupnow (Dec 10, 2011)

Well. that seemed to work out very well.


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## Brian Rupnow (Dec 10, 2011)

This is one of those times when I absolutely can not afford to have the center axis of the holes to be out of square with the staircase, causing it to "orbit". I don't really trust my "Tilt a whirl" vice, because the moving jaw kicks up a bit when it is tightened. When its critical, as in this case, I clamp the part being drilled to the table with a couple of 1/2" square unground lath tools for stand-offs so as not to drill into the mill table. I am going to use 5/16" shoulder bolts to connect the center staircase to the eliptical arms. This will mean that regardless of what it says in the drawing of the outer staircases, they will both need a pair of 2" diameter holes in them---To clear the rotating eliptical arms on one side and to clear the heads of the shoulder bolts on the other side.


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## Brian Rupnow (Dec 10, 2011)

Well there!!! Thats my Saturday morning accounted for. Hope the outer staircases go as well.


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## Brian Rupnow (Dec 10, 2011)

And more of the same---Only this time its the outer staircases. No words of wisdom to offer up here, except that you'll notice I did screw the two peices of plate together BEFORE sawing them out, to keep them exactly the same.


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## Jeremy_BP (Dec 10, 2011)

Looking good, and moving fast as always. The animation is nice, but I really just can't wait to see it actually go. How about driving this off the krazy klockwork mechanism?


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## Brian Rupnow (Dec 10, 2011)

The crazy clockwork mechanism ended up being "dedicated".---That is to say, it was attached directly to the base of the popcorn engine and driven by meshing gears. I don't generally do that, as I like to drive my "toys" with a belt drive so that they can be driven by any engine. I MIGHT drive this off the Overcrank Single that appears in my avatar.


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## Brian Rupnow (Dec 10, 2011)

Well---I'm impressed!!!! The holesaw works great. I did this out on my big old 16 speed drill press in my main garage. The little mill I've got starts popping fuses at anything bigger than a 1/2" drill, and those tiny glassfuses are over $3.00 each. This has been a good days progress.


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## Brian Rupnow (Dec 11, 2011)

Now that I know my method works, I feel safe posting the drawing.


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## Brian Rupnow (Dec 11, 2011)

Lew Hartwick just emailed me and asked if I owned stock in the layout dye company, and made me laugh.---Reminds me of a very funny story. The year I was 17 an older fellow in my small town asked me if I would paint his mothers house white for $100 if he supplied the paint. It was a small house, and I really needed the money so I said yes. The son lived out of town a few miles, but he had to drive in and out of town twice a day, and his mothers house was right on the main corner in town, so every time he came in or out of town he would see me there painting. Now I have to admit, I had never painted a house before, but it was an old previously unpainted clapboard house, and it sucked up paint like a sponge. I think I painted that damn house about 4 times before it quit soaking up paint. I didn't want to waste any good clothes, so I just wore the same old clothes for a week straight through, and by the time I was done, everything I was wearing was painted white, including my old work shoes and my hair. Finally I was finished, and Rene' came to inspect the job. He walked all around, looked up, down, and in all the crooks and crannies, pulled out a $100 bill (The first one I had ever seen), and pronounced it a job well done.--Then he asked me--"By the way, how did that paint taste?" somewhat taken aback, I asked what he meant. He said---The first dozen times I drove by the house, I thought you were using a brush, but the last dozen times I drove by, it looked like maybe you were drinking the paint and p1ssing it on!!!! ;D ;D ;D


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## seagar (Dec 11, 2011)

Another karma to you Brian.This is great ,you never stop to amaze and educate me .Thank you.

Ian (seagar)


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## Brian Rupnow (Dec 11, 2011)

2 drawings to finish off the weekend. I have all my platework finished except for these two pieces.


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## Brian Rupnow (Dec 11, 2011)

As in all the things I design, there is a bit of"design evolution" happening here. Basically, I decided to put the 2" dia holes in both outer staircases, and the counterbored holes will be in the "near side" outer staircase only, with clearance holes in the spacers and threaded #5-40 holes in the far side staircase only. This is because I had to thread them anyway to bolt the two sections of outer stairs together while sawing them out and shaping them. I will update the outer staircase drawing later this week.


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## Brian Rupnow (Dec 11, 2011)

Gotta make a note to myself---Maybe paste it on my forehead!!! Don't push so damn hard on the scriber. I like my scribed lines to show up really good, so I push really hard on the scriber to make the lines really visible against the Dykem layout dye background. Then after all the layout dye is washed off with methyl alcohol, I have these big deep grooves to sand/polish out, and it takes forever. Maybe if I post about it, I'll remember for next time-----


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## bearcar1 (Dec 11, 2011)

I know what you mean Brian, there's nothing more satisfiying busting walnuts with a sledge hammer. :big: I too soon learned that a gentle touch is all that's required doing lay out work using dye, just enough to make the mark visible. 'Cept where there is to be a hole drilled, then I get a bit ham fisted at the line intersects, but that is only because I still manually find and drill holes the old fashioned way. ;D

Duffy's lift is coming along quite nicely BTW

BC1
Jim


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## Brian Rupnow (Dec 12, 2011)

Drilling the spacers for between the outer staircases.---Ya gotta love those little machinists jacks. I didn't even know there was such things till heard about them on this forum.


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## Brian Rupnow (Dec 12, 2011)

Time for a teaser shot.---Its a trick. Those are 1" balls, not 3/4". but you get the idea. I didn't have any 5/8" plate to make the bearing stand with, so I used a piece of reclained 1/2" plate----thats why there is an extra hole in the plate. i will probably make up a 1/16" spacer to set between it and the staircase it is bolted to.


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## Brian Rupnow (Dec 12, 2011)

The center section of staircase was heavier than I felt comfortable with, so a series of 1" dia. holes took away some of the weight.


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## larry1 (Dec 12, 2011)

Brian, Looking great, keep up the good work. larry


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## Brian Rupnow (Dec 13, 2011)

It makes me so happy when one of my projects gets mature enough to stand up all by itself!!! (Man, I've been around my latest grand kid too much!) Got the baseplate finished tonight and the spacer that fits in behind the bearing stand. Next thing to tackle will be the eliptical arms I guess, then I can't do much untill Duffys sprockets show up in my mailbox.


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## Brian Rupnow (Dec 14, 2011)

WOOHOO!!!!! Duffys sprockets arrived in the mail today. Thank you Duffy!!! Thank you, thank you, thank you!!! I made up the two eccentric arms tonight from brass and "posed" them with the sprockets and chain for tonights picture. I will model the sprockets and add them into my assembly, and figure out my shafts next. The sprocket bores were just slightly undersize from .1875, and I suspect that in their previous lives were press fitted onto 3/16" diameter shafts. Duffy said they are out of a 1950's era printer, so I doubt they were metric. I put them in my lathe and ran a 3/16" reamer thru the bores, and will add a #5-40 set screw to each hub. Since the original plan was to have 5/16" shafts, and thats what my eccentric arms and bearings are set up for, I may put a 5/16" bore in the 4 1/2" drive pulley and mount the sprockets outboard of the pulley.---I'll have to model it up and see what it looks like. I don't dare open the sprocket bores out to 5/16" as they are two piece construction and would fall apart if I took that much out of them.


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## Brian Rupnow (Dec 14, 2011)

Naw, It'd just look too goofy with the sprockets outside the pulley. I'll make the pulley with a 3/16" bore and set it up like this.


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## nsfr1206 (Dec 14, 2011)

Looks great!


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## Path (Dec 14, 2011)

Wow really neat!  


Pat H


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## Brian Rupnow (Dec 15, 2011)

I was haunted by my old friend insomnia last night, so I popped out of bed at some ungodly hour this morning and bored one of the sprockets out to 1/4" with no consequent disasters. I'll use that one on the upper shaft so I can keep the pulley bore at 1/4". The one on the bottom shaft can stay at 3/16" bore, because there is not nearly so much overhung load on the shaft.


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## Brian Rupnow (Dec 16, 2011)

No post last night, as I had a "command appearance" at number 1 Grand daughters Christmas concert. I did however find a source for 3/4" diameter wooden hardwood balls in Guelph, Ontario, and was able to buy 12 balls for $12. I also ordered a pair of 5/16" dia. x 1/2" long shoulder bolts which will be used to hold the center (moving) staircase to the eccentric arms. Tomorrow morning I hope to finish the shafts, and may even get to test run this critter!!!----Brian


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## Brian Rupnow (Dec 16, 2011)

Cowabunga Roy!!! I think its going to work!!! I held the chain tight by hand and rotated it thru one complete revolution, and it seems to do exactly what I expected it to. I'm going to have to do some serious shortening of the chain, and I will probably have to but a 'take-up' idler on it to keep any slack out of the chain, but I think its going to be great. I couldn't wait 4 days for my shoulder bolts to come in, so I made up my own for "try-out' purposes. If I find time tomorrow. I'll make up a pulley and shorten up the chain, and MAYBE we'll get a first run video made up. I will only be able to use "pretend" balls, and like migrating lemmings, they will all jump off the cliff into the sea because I don't have my return ramp made up yet, but I'm feeling good about the progress.


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## Brian Rupnow (Dec 17, 2011)

This morning I'm making a 4" dia. pulley, because thats the largest stock I have. However, I have found a real "caveat" in my design. Even with Duffys chain connecting the two shafts, unless it is pulled painfully tight, the non driven shaft still wants to turn and rotate the wrong direction when the driven shaft passes over "top dead center". I hadn't realy expected this. I think I see a way to add a second "link" between the two shafts, offset the same amount as my eccentric arms, but out of phase to them by 90 degrees, on the outside of the pulley. If that is the case, Duffys chain may become redundant. I'm learning as I go along here, so will keep you posted.----Brian


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## Brian Rupnow (Dec 17, 2011)

I built a pulley this morning, and here you can see that the center staircase had paused halfway thru its "lift" mode and lifted one of the 1" balls up, getting ready to carry it up to the next step. I'm still not 100% sure that this will work with only a chain and not a second link arm, but I bet I'll know before the weekend is over. Gotta go now and take a load of dry firewoood over to a friends house. I just got a gas fireplace in last week, and its wonderfull.--


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## Brian Rupnow (Dec 17, 2011)

I am really surprised about the "delicacy" of timing between the two shafts. Even the slightest bit of slack in the chain, and the non-driven shaft wants to flip around and travel backwards, locking up the mechanism. Tomorrow morning I am going to but an outboard link between the two shafts 90 degrees out of phase with the center staircase. That will absolutely keep things from getting "out of time",and may do away with the necessity of having a chain and sprockets. I am learning new stuff here. In 46 years of designing just about every conceivable type of industrial machinery, I haven't ran across something quite like this. It is reminding me more and more of the solid links between drive wheels and non drive wheels on steam trains. John Bogstandard tried to explain this to me in a much earlier post, but I didn't understand what he was getting at, however it is becoming clearer as I progress.


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## tel (Dec 17, 2011)

And then, of course, the situation may well change when it is running under power and inertia is tending to push the driven wheel 'forward' as well. 

Meanwhile I'm still thinking gears, with an idle wheel space - but heeeey! I _like_ cutting gears!


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## rleete (Dec 17, 2011)

tel  said:
			
		

> but heeeey! I _like_ cutting gears!



And here I thought I was weird.


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## tel (Dec 18, 2011)

rleete  said:
			
		

> And here I thought I was weird.



I find it very ... erm .... _therapeutic! _


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## Brian Rupnow (Dec 18, 2011)

Well, at this point in the game, all I have to report is a complete and total FAIL!!!!! I got up early this morning and made the modifications to add a second arm on the outside of the pulley. I even took the inner staircase, the bearing support, and the added link which all have to have identical hole centers and put dowels through all 3 at the same time to convince myself that I hadn't machined something wrong. The net result of adding the second link was that it locked things up tighter than ever. I am somewhat bumfoozeled at this point, so will take a break from this and read for the afternoon. My next plan is to remove the second link, go back to the chain and sprockets, and open the lower hole in the staircase out to .030 oversize. Maybe if I engineer a bit of "float" into the system it won't lock up like it currently does when all the holes are a "reamed fit"


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## GailInNM (Dec 18, 2011)

Brian,
On model locomotives, it has been a rather standard practice to elongate the holes in the rods to correct or any position errors and for quartering errors. Quartering is the setting of the cranks at exactly 90 degrees to each other. Either error will cause things to lock up. It is not a bad a practice as it seems as neither rod is contributing any thing when a line between the rod ends passes through an axle. Actually quite a bit of slop can be introduced this way and it is not evident. Even making the rod end holes oversize rather than elongating does not show up.
Gail in NM


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## coopertje (Dec 18, 2011)

Brian, first of all compliments for your build, very interesting!

I am not sure if I start to repeat Gail, but maybe the problem is not the exact fit but the fact that the 2 levers operating the inner staircase travel the exact same way during the rotation. I believe that if you give them an offset (turn on a little CW and the other one a little CCW) they will never line up and most likely not stall anymore. If the offset is kept reasonable it probably will not be visible in the movement of the inner case.

Good luck and hang in Jeroen


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## Brian Rupnow (Dec 18, 2011)

I'm going to make this statement while firmly grasping my wooden chair, but the oversize hole in one end of the staircase SEEMS to have gotten rid of the bind. I think that with a swing arm chain tensioner, the problem may be solved.


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## rleete (Dec 18, 2011)

I'm interested in seeing what you have in mind for a tensioner system. Torsion spring? Gas pressure piston? How are you determining the force neccesary to maintain tension, without putting too much drag on the system?


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## Brian Rupnow (Dec 19, 2011)

It works!!!!---BUT---The trick is going to be slowing it down enough. I had a 1.5" pulley on the mill to test drive it with, and the moving center staircase wanted to run at warp speed. I kept putting the 1" steel ball on it and then slowly advancing the mill speed from zero to see it elevate the ball. The device wouldn't run at all, then would take off and bounce that friggin steel bearing ball around like a ping pong ball. I didn't have my chain tensioner on a spring loaded swing arm, just had it bolted onto the bearing support, but that isn't going to do it. The sprockets are not perfectly concentric to the hub bores, and the load imposed by the center staircase varies quite a bit through its 360 degrees of travel, causing the chain to "whip" and jump sprocket teeth, which of course threw things out of time and caused it to lock up repeatedly. At any rate, it works. all I have to do is slow it down a lot.


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## Brian Rupnow (Dec 19, 2011)

And I know how I'm going to do it. In the foreground of the attached picture is the pump that I built a couple of years ago, and I am going to reclaim the timing belt pulley from it. In the background is a gear reducer system that I had on the Doodlebug, which has the mating timing pulley on it, as well as a pair of nylon meshing gears. I am going to "reclaim" these components and build them into the Jacobs Ladder, to get it running at a more manageable speed.


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## Brian Rupnow (Dec 19, 2011)

My dozen wooden balls showed up in the mail today. Good quality and a very fast turn around. In spite of all the crude remarks that I thought of before posting this picture, I'm going to be the good clean living boy my 91 year old mother expects me to be and say nothing, just post the picture.


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## rleete (Dec 20, 2011)

What? You've lost so many marbles that you had to go buy wooden replacements?


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## Brian Rupnow (Dec 22, 2011)

I was right at the point of giving up on this project. It kept locking up, the balls kept falling off when they were almost to the top----it was ugly!!! I was setting here thinking "What haven't I tried, that might have some positive effect on the way things worked." The only obvious thing was to try the pulley on the lower shaft, so just for a giggle, I did.---and EUREKA!!!! It made a big difference in smoothness of operation and how the balls stayed on the operating ladder. With all the gears, timing belts, etcetera, it is starting to take on a Rube Goldberg/Steampunk appearance, and I like that!!! Time is at a premium right now, but once we get thru christmas I will be hooking this up to my overcrank single engine and beginning to take a serious look at a ball return. Merry Christmas everyone, thanks for looking.---Brian


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## Path (Dec 23, 2011)

*Merry Christmas and a Happy New Year to you and your family. * 

Looking forward to seeing your finished ladder. :big:

Pat


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## Brian Rupnow (Dec 23, 2011)

Here we are guys. Large as life and twice as ugly!!! First succesful run!!!


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## Harold Lee (Dec 23, 2011)

Now that is cool!!!!!! That would be a good stress buster, watching that while having a cup of coffee. Glad you persisted on it.

LOVE IT BRIAN!!!!

Harold


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## lee9966 (Dec 23, 2011)

Very nice Brian. I love watching as you solve design puzzles, very educational.

Lee


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## 90LX_Notch (Dec 23, 2011)

Brian,

That is very cool. I like it very much.

Bob


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## larry1 (Dec 23, 2011)

Brian, As usual great job, Thank you. larry


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## Brian Rupnow (Dec 23, 2011)

Thanks guys. Your positive comments mean a lot to me. Now that it actually works, I can clean it up a bit and start work on a return ball track.---Brian


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## AussieJimG (Dec 23, 2011)

Thank you Brian, an educational journey all the way. Can't wait to see what you will do next.

Jim


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## Ken I (Dec 24, 2011)

Brian, a novel idea taken to conclusion (well almost) - just love it.

Thanks for taking the time to share that.

Ken


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## steamer (Dec 24, 2011)

That's pretty cool Brian! I like the adjustable mill/right hand turn belt drive!  :bow:

Dave


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## archer3d (Dec 24, 2011)

Lookin great Brian Thm:

tom


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## SBWHART (Dec 24, 2011)

Bin following this adventure along Brian very interesting and looking good.

Stew


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## Ramon (Dec 24, 2011)

Hi Brian, 
I have to confess this is not my kind of project but I have been following it from the beginning and have enjoyed watching it grow. I admire your ingenuity and the thought that you have put in as well as the excellent way you have presented it. Looking forward to it's further development.

Have a good break and Best Wishes for the coming year

Ramon


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## Path (Dec 24, 2011)

Great video ... steady as she goes. 

Reminds me of someone 


Pat


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## nsfr1206 (Dec 24, 2011)

Cool, cool, cool Brian!! Have a Merry Christmas! David


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## Captain Jerry (Dec 24, 2011)

Brian

A very interesting mechanism and a lot of lessons learned. The problems with the connecting link reversing would have trapped me too and the simple solution of an elongated hole at one end is a good one to remember. The trouble that you had with the chain links jumping and the fix of moving the drive to the bottom shaft had me puzzled. I had to have an explanation for the improvement so I spent some time thinking. (what's that burning smell?) Here is my theory, others may think differently.

When you were driving the top sprocket, the top chain pulls tight and any slack in the chain causes the bottom side to droop away from the sprocket, reducing the effective number of sprocket teeth engaged allowing the chain to climb out.

When you drive the bottom sprocket, the bottom chain is pulled tight and the slack in the top chain droops to the inside of the loop, increasing the wrap on the the drive sprocket.

The key here is not the fact that one sprocket is higher than the other. The critical factor is that the droop in the chain must be on the top where it closes the loop and not on the bottom where it opens the loop.

If there are any different theories out there, speak up! I like to have a reason for things like this.

Jerry


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## Brian Rupnow (Dec 24, 2011)

Shows your thinking Jerry. The fact that I removed one link from the chain was a big help too. ;D ;D


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## Brian Rupnow (Dec 26, 2011)

Christmas is over, all the relatives have returned home, and I got to play in my shop a bit this afternon. The Jacobs ladder runs successfuly when driven by my "Overcrank Single" air/steam engine. I however, am having a very difficult time getting am "in focus" movie of it. My camera instructions say to hold the button half way down to let the auto focus work before pushing it all the way down to take a picture. That seems to work fine for still shots, but doesn't seem to work worth a darn when I'm making a video. I will talk to the Cannon camera people when the holidays are over and get that sorted out. I may try the Jacobs Ladder with my horizontal twin engine tomorrow and see if the action smooths out any--its a bit jerky when driven by the Overcrank Single. At any tate, another milestone has been reached, as I now know that one of my air/steam engines has enough power to run things.


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## dgjessing (Dec 26, 2011)

I love it! You sir, are an inspiration :bow:


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## Brian Rupnow (Dec 27, 2011)

Success!!! I have figured out the mystery of my camera (Read the instruction booklet) and changed engine over to my Horizontal Twin to run the Jacobs ladder. Its working real slick now. And yes, you will hear me contradict myself---I can't honestly remember if it was 3 or 4 years ago that I built my horizontal twin engine---(I say both in the video). Now I can start work on my ball return track.


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## Brian Rupnow (Dec 30, 2011)

Slowly, and not too surely, my ball return is progressing. I'm making it up as I go along here, but this first leg of the return track seems to work okay.---At least any balls dropped in at the top end do fall cleanly and quickly out through the hole in the side. ;D ;D


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## Brian Rupnow (Dec 30, 2011)

Its not very often that I think I'd like a power feed on my mill table, but it would have been nice to have one today!!! I'm building the second part of my return ball track, and that slot is about 10" long x 1/4" deep x 3/4" wide. I feed .030" on the vertical axis bfore each cut, and deepen it another .030" when I reverse directions, so I'm cutting while travelling both ways. With a 3/8" end mill, daamn, thats a lot of cranking!!!!


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## chuck foster (Dec 30, 2011)

i know it is too late now but you should try a roughing end mill, you would have been able to cut that slot in 2 passes.

i tried a roughing end mill for the first time about a month ago and man oh man do they cut 
i had a 1/2" roughing end mill in my mill and took a cut .250" deep (in aluminum), the cutter was spinning 1800 rpm's and 
as fast as i could crank the work into the cutter it just kept cutting. 
the swarf was just flying.

just a thought.............all be it a late thought

chuck


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## Brian Rupnow (Dec 30, 2011)

Rotary tables are a GOOD thing to have!!!!


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## Brian Rupnow (Dec 30, 2011)

And yes, the ball does return all the way to the first step!!! Now, to build a few brackets to hang my ramp on-----


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## rake60 (Dec 30, 2011)

Looks GREAT Brian! :bow:

Rick


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## Harold Lee (Dec 30, 2011)

I can hardly wait Brian..... You've got the clamps on.... fire it up already!!!!

Harold


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## Brian Rupnow (Dec 30, 2011)

chuck foster  said:
			
		

> i know it is too late now but you should try a roughing end mill, you would have been able to cut that slot in 2 passes.
> 
> i tried a roughing end mill for the first time about a month ago and man oh man do they cut
> i had a 1/2" roughing end mill in my mill and took a cut .250" deep (in aluminum), the cutter was spinning 1800 rpm's and
> ...



Chuck---I don't think my little BusyBee mill has enough power to run a roughing cutter.


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## chuck foster (Dec 30, 2011)

brian you will be surprised how well a smaller mill will handle a roughing cutter, i only have a sieg sx3 and it is just a small bench top mill.

this is the supplier i use for end mill's  http://accusizetools.ca/ 
the 1/2" cutter i used is only $10.00

give it a try and i think you will be surprised how well they work in aluminum..................i have not tried one in steel yet.

chuck


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## Brian Rupnow (Jan 1, 2012)

YES!!!! Old age and treachery triumph once again!!!! The balls go up, the balls roll down, all that remains to be done is a good video. Just when I thought I was all finished, the balls proceeded to roll down the ramp so damned fast that they "Jumped the track" at the bottom curve just like the freight train in the old movies. However, a bit of a retaining wall on the bottom curve, and all was well.----Video to foollow----After I've had my afternoon nap.


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## Brian Rupnow (Jan 1, 2012)

Well, there we have it guys. Another succesful, totally useless peice of mechanical wizardry. Its not terribly difficult to build, but it certainly does have "eye appeal" when operating. If anyone decides they would like to build one of these to run with an Elmer Verbourg sized engine, I recomend building it at 1/2 the scale of the drawings I posted. Did I learn anything new when building this?---Well, yes, I learned how difficult it must be for model train builders to build the links that run between wheels on the engine and get them to operate without binding and locking up. I learned that no matter how many times you clamp a ball track in place and roll balls down it to establish the correct angle, it can still surprise you after all the holes are tapped and things are bolted, not clamped into place. In hind sight, I think perhaps it would have worked better with steel balls instead of wooden balls, but the fact that it works as well as it does pleases me. Thanks guys, for looking and following my thread, and for your positive comments. Happy New Year-----Brian


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## lee9966 (Jan 1, 2012)

Looks good and works good, congratulations! My favorite part is the fact that it does nothing but look interesting.

Lee


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## AussieJimG (Jan 1, 2012)

A great machine and much more difficult to make than I thought it would be when you first proposed it. It is a tribute to your imagination, ingenuity and persistence.

Thanks for the ride Brian and Happy 2012

Jim


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## Ken I (Jan 2, 2012)

Well done - I'm a great fan of interesting things with no real purpose - like my head - a mine of useless information.

Ken


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## archer3d (Jan 2, 2012)

An excellent job well done Brian. Your persistence to work through a project is admirable. thank you

archer3d


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## Brian Rupnow (Jan 2, 2012)

Nothing new on the machinery itself, but I have been playing with my cameara today, to see why I get such beautiful still shots but such marginal results with videos. Finally resorted to "Restore Defaults" because it yielded such great results when I bought it new. This seems to have greatly improved the video function, so I may well have unknowingly changed a setting on the camera at some point while using it. At any rate, here is a much clearer video.----Brian


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## swilliams (Jan 2, 2012)

Very nice Brian. I enjoyed seeing a project that went off the beaten track

Steve


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