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Recommendations for Caster and Track

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#1 marinaldi

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Posted 17 June 2022 - 05:10 PM

Hi,  I'm in the processes of building my own ROR observatory and am wondering if anyone has recommendations on Casters and Tracks.  I found this site online and would like some input on whether this is a good product for the V-track and 4" Caster.

 

https://www.alekopro...-tracks-12-foot

 

Of course if you have other products that you think are better please don't hesitate to send info.

 

Thank you,  Mike

 

 



#2 texastrain11

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Posted 17 June 2022 - 05:29 PM

Mike,

 

  Also look into garage door tracks and rollers.  They do mount in a different manner, but there is no concern about uplift.  And, looking at these prices, comparable.

 

Jesse


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#3 speedster

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Posted 17 June 2022 - 06:23 PM

Amazon has same track as Aleko for about 25% less and 4 wheels are about $25.  12' track is actually two 6' pieces.  It's all 6' pieces which is fine.


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#4 Simply Peter

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Posted 17 June 2022 - 08:41 PM

I am getting ready to start a build (fall).  I bought ROR plans from Skyshed and they call out using garage door track and rollers. They recommend using heavy duty components.  The track and rollers do mount differently as mentioned earlier but I live in a high wind area and want to make sure I don't have to rescue my roof from the neighbors yard.  



#5 marinaldi

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Posted 18 June 2022 - 01:58 PM

I am getting ready to start a build (fall).  I bought ROR plans from Skyshed and they call out using garage door track and rollers. They recommend using heavy duty components.  The track and rollers do mount differently as mentioned earlier but I live in a high wind area and want to make sure I don't have to rescue my roof from the neighbors yard.  

Hi Peter,  Do you have a link to the heavy duty garage door style rollers and track? 

 

I was briefly looking at this

 

But If I wanted to stick to a V-track system I was hoping to find clamping systems to engage once the roof is moved on or off?  Something similar (or heavier duty) like 4 or more of these on the corners.  Four inside when the roof is closed and 4 on the outside when opened.   I'm not looking for this to be a remote DYI obs.   I'm curious if this would do the trick

 

Mike


Edited by marinaldi, 18 June 2022 - 02:13 PM.


#6 Broz22

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Posted 18 June 2022 - 06:32 PM

I used https://www.amazon.c...&psc=1(v-wheels) with aluminum v-track from fencesandgates.com on one side, and https://www.amazon.c...e?ie=UTF8&psc=1 (wheels) on the other side. Both run on the top of the beams. It's important not to use v-track on both sides if you go this way since the wheel side can move a little side-to-side to make up for any settling or variation in the distance between the beams. I used truck load-chain dogs to secure the roof on the inside (and nothing on the outside), but this is probably way overkill. Your hold-downs look like plenty short of a hurricane. For the posts on the outside beams I poured concrete into 12" diameter, 30" deep holes and set a j-bolt into the tops of these footers. then a nut and washer arrangement for the bottoms of the posts like attaching a pier to a concrete footer allows for vertical adjustments to level the beams. It really needed x cross-bracing across the posts as well as the little top braces shown in the plans to minimize parallelograming/side-to-side shaking as the roof opens and closes with the Aleko gate opener. If you are going to use a powered opener like this be sure to account for the mounting arrangements in your design (I used track along one side of the roof and mounted the Aleko on  a sturdy wooden pad bolted underneath one of the beams about 3' out from the shed). This and somewhat longer outside beams allows the roof to open several feet past the end wall to reduce the horizon obstruction to the west (the direction my roof opens. Be sure to look at Speedster's thread on pier engineering if you are going to pour a footer for your pier. I found his instructions really valuable, and he disagrees with the Skyshed instructions to run the sonotube down into the ground. He emphasizes that the footer concrete must be in contact with undisturbed earth on the bottom and sides of the hole. Wayne at Skyshed is great (his pier and top adapter plates work very well), but I don't think his idea of the sonotube outside the footer aiding in minimizing frost-heave motion is correct, at least for the lower 48.

John


Edited by Broz22, 19 June 2022 - 08:54 AM.

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#7 marinaldi

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Posted 18 June 2022 - 11:59 PM

I used https://www.amazon.c...&psc=1(v-wheels) with aluminum v-track from fencesandgates.com on one side, and https://www.amazon.c...e?ie=UTF8&psc=1 (wheels) on the other side. Both run on the top of the beams. It's important not to use v-track on both sides if you go this way since the wheel side can move a little side-to-side to make up for any settling or variation in the distance between the beams. I used truck load-chain dogs to secure the roof on the inside (and nothing on the outside), but this is probably way overkill. Your hold-downs look like plenty short of a hurricane. For the posts on the outside beams I poured concrete into 12" diameter, 30" deep holes and set a j-bolt into the tops of these footers. then a nut and washer arrangement for the bottoms of the posts like attaching a pier to a concrete footer allows for vertical adjustments to level the beams. It really needed x cross-bracing across the posts as well as the little top braces shown in the plans to minimize parallelograming/side-to-side shaking as the roof opens and closes with the Aleko gate opener. If you are going to use a powered opener like this be sure to account for the mounting arrangements in your design (I used track along one side of the roof and mounted the Aleko on  a sturdy wooden pad bolted underneat one of the beams about 3' out from the shed). This and somewhat longer outside beams allows the roof to open several feet past the end wall to reduce the horizon obstruction to the west (the direction my roof opens. Be sure to look at Speedster's thread on pier engineering if you are going to pour a footer for your pier. I found his instructions really valuable, and he disagrees with the Skyshed instructions to run the sonotube down into the ground. He emphasizes that the footer concrete must be in contact with undisturbed earth on the bottom and sides of the hole. Wayne as Skyshed is great (his pier and top adapter plates work very well), but I don't think his idea of the sonotube outside the footer aiding in minimizing frost-heave motion is correct, at least for the lower 48.

John

Thank you John!!  These are invaluable recommendations.  So if I understand correctly you have v-track on one side only.  Do you have a flat metal surface on the other side or are you running on top of the wood?  I understand my latches look cheap but they were more to convey the idea.  I think if I used these specific ones I'd probably use 8 evenly spread inside.  But I'll look into the truck load chain dogs.    I was planning on running my sonotube onto dobies.  So they'l bee 2-3" from the bare earth.  

 

Mike



#8 Broz22

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Posted 19 June 2022 - 07:14 AM

I just run the wheels down the approximate center of the beam on the one side. The rubber wheels are a little taller that the v-track and metal wheels, but don't seem to cause any problems. I could have fixed this if I had thought ahead and padded the top plate and beam on the v-track side by an extra inch or so under the track.The top-plate of the shed (which is at the same level s the beams) is a doubled 2x6 since I used 2x6 framing for the shed, probably not necessary, but overconstruction runs in the family. My grandfather built his house with railroad tie studs (maybe 12x12s?) on 16" centers. They almost touch! Anyway, I built up the beams of a stack of 3 standard 2x4's laminated then coated with West epoxy to avoid any twisting. This also provides a nice hard surface for the wheels to run on. The posts are built up similarly. The posts and beams do require  painting with good exterior paint to protect the expoxy coating from UV, but the very stable epoxy-coated wood makes the paint very durable, there is no chance of water penetration, rot or warping. The beams  are tied into the top plate of the shed by making the top layer of the beam 5 1/2" longer and leaving a matching gap in the top plate of the walls facing the beams. These are epoxied and screwed together tieing the whole structure together nicely, and helping resist racking due to the off-center forces generated by having the opener on one side of the roof. I struggled with how to mount the Aleko opener to avoid either having to mount the motor upside down on the inside of the shed with the track running between the center of the two beams or having a hole in the gable end of the roof to allow the roof to pass over the motor. So I put the whole mess on one side. This avoids all of those problems and allows mounting the motor right-side up on the outside of one of the beams, but means you need to deal with racking forces in the roof and beam structure as well as assuring that you can line up the track (or chain) on the roof with the motor gear while providing clearance between edge of the metal roof and the motor during opening. I ended up having to trim a few eights of an inch off the end of some of the roofing where it would have scraped the motor during opening. I reduced the racking of the roof by placing triangular plywood gussets under the corners of the roof.  That helped a lot in stiffening everything up, and worked well in conjunction with the x crossbracing between the outer 2 posts. The inner pair (I used 2 sets because my beams are about 14' long) could probaby also use the cross-bracing, but I wanted to minimize the obstructions in the area. All of this coupled with the v-tracks/wheels on one side, and hard rubber roller wheels on the other resulted in a roof that I could move fairly easily by hand, although it probably weighs about 1500 lbs. The Aleko is nice though, and helps a lot with my bad back.

John



#9 Broz22

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Posted 19 June 2022 - 09:05 AM

As far as the sonotube and dobies, you might be better off just using a 6" section or so from the ground-level up to make a neat base for your pier (if you are using one). J-bolts for the pier should be set into the wet concrete when you finish the pour I made a plywood pattern to set over the bolts like Wayne suggests to get proper spacing of the pier bolts. I poured a slab after making the pier footer to make a flush slab, but if you do this, wrap some styrofoam or other spacer wrap around your footer to isolate it from the slab. You may wish to make a rebar cage to set into the hole prior to the pour as per Speedster. If you do this make sure to use dobies to keep the rebar up from the bottom to reduce water penetration leading to corrosion and expansion of the rebar. Similarly the rebar cage should be a couple of inches in from the edges of the hole. Speedster's book is worth it to really understand the issues with concrete and footers. It is really hard to change any of this afterwards if you are not happy, so it is worth the tie to study it thoroughly before you start pouring concrete.

John


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#10 marinaldi

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Posted 19 June 2022 - 11:06 AM

As far as the sonotube and dobies, you might be better off just using a 6" section or so from the ground-level up to make a neat base for your pier (if you are using one). J-bolts for the pier should be set into the wet concrete when you finish the pour I made a plywood pattern to set over the bolts like Wayne suggests to get proper spacing of the pier bolts. I poured a slab after making the pier footer to make a flush slab, but if you do this, wrap some styrofoam or other spacer wrap around your footer to isolate it from the slab. You may wish to make a rebar cage to set into the hole prior to the pour as per Speedster. If you do this make sure to use dobies to keep the rebar up from the bottom to reduce water penetration leading to corrosion and expansion of the rebar. Similarly the rebar cage should be a couple of inches in from the edges of the hole. Speedster's book is worth it to really understand the issues with concrete and footers. It is really hard to change any of this afterwards if you are not happy, so it is worth the tie to study it thoroughly before you start pouring concrete.

John

Can you send a link to the hard rubber wheels you're using?  The two links you sent in your initial response were to the same metal grooved wheels.  Also, if you have the link of the truck load-chain dogs that would be very useful.

 

In terms of my pier I went (or am going) overboard.  I dug a 3'x3'x3' hole in the middle of my obs room (yes that's a cubic yard of concrete).  The sono tube will sit in the middle of that hunk of rock.  I decided to send the sono tube 2.75' into the 3' deep concrete cube.  The slab will be vibrationally isolated from the cubic concrete pier.  I got this manic idea from an observatory built by a friend of an old neighbor.  He had a much bigger observatory and scope (don't recall the size).  But he dug an 8'x8'x8' (19 cu yds !!) pier that held a larger concrete and steel scope pier.  He was a much more serious AstroPhotographer with a Bortle 1-2 dark sky property.  

 

Thanks again for your detailed descriptions! 

 

Mike



#11 Broz22

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Posted 19 June 2022 - 01:19 PM

Wow, it sounds like you came from the same school of construction as my grandfather. As far as wheels, I used these:

Casoter 2 Inch Black Low Gravity Center Nylon Caster, 32mm Extra Width Hi-Temp Nylon Wheel Top Plate Rigid No Brake Heavy Duty Double Ball Bearing Caster, 2700Lbs Total Load Capacity 4-Pack

I think the proper link is:

https://www.amazon.c...e?ie=UTF8&psc=1

 

They are very heavy duty and have worked well so far in summer and winter temps. If you need any photos of my construction details I'd be happy to upload them.

John


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#12 Broz22

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Posted 19 June 2022 - 03:54 PM

I forgot the lever tie-downs:

https://www.amazon.c...e?ie=UTF8&psc=1

 

As I said, these are probably overkill, but certainly work. I just put eye hooks in the roof corners and the studs near them. I only tie it down if we are expecting winds or I head out on travel.

John


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#13 marinaldi

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Posted 19 June 2022 - 11:47 PM

Wow, it sounds like you came from the same school of construction as my grandfather. As far as wheels, I used these:

Casoter 2 Inch Black Low Gravity Center Nylon Caster, 32mm Extra Width Hi-Temp Nylon Wheel Top Plate Rigid No Brake Heavy Duty Double Ball Bearing Caster, 2700Lbs Total Load Capacity 4-Pack

I think the proper link is:

https://www.amazon.c...e?ie=UTF8&psc=1

 

They are very heavy duty and have worked well so far in summer and winter temps. If you need any photos of my construction details I'd be happy to upload them.

John

Thanks again!  I'd love to see some pics of how you did the track/caster and the motor setup.  Any pics that you think maybe useful are much appreciated.

 

Mike



#14 speedster

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Posted 19 June 2022 - 11:52 PM

Putting sonotube into your 3x3x3 footing is working against you.  3x3x3 pours against the dirt (no forms) and the sonotube sits on top.  All can be poured in a single pour.

 

Hold down can be one pin, between the wheel locations, on each side.  Pin can go through an ear on the wall and then into the roof.  Similar ear at the open position so you can pin it open if you want. 

 

Sonotube doesn't help reduce frost heave.  Skin friction on sonotube is plenty high for the soil to grab it.

 

Best of luck with your build!


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#15 Broz22

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Posted 20 June 2022 - 08:11 AM

Speedster,

  The tie-down pins sound a lot better than the chain-dogs. I'm going to look at changing over. And thanks for all of the help with the pier-footer/pier. There seems to be near zero deflection and vibration. The L-350 reports short-period tracking errors of a few tenths of an arc-second.

John



#16 archer1960

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Posted 20 June 2022 - 10:22 AM

Speedster,

  The tie-down pins sound a lot better than the chain-dogs. I'm going to look at changing over. And thanks for all of the help with the pier-footer/pier. There seems to be near zero deflection and vibration. The L-350 reports short-period tracking errors of a few tenths of an arc-second.

John

The mount won't detect movement of the pier unless you're guiding. PWI only reports what the encoders detect.



#17 marinaldi

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Posted 20 June 2022 - 10:47 AM

Putting sonotube into your 3x3x3 footing is working against you.  3x3x3 pours against the dirt (no forms) and the sonotube sits on top.  All can be poured in a single pour.

 

Hold down can be one pin, between the wheel locations, on each side.  Pin can go through an ear on the wall and then into the roof.  Similar ear at the open position so you can pin it open if you want. 

 

Sonotube doesn't help reduce frost heave.  Skin friction on sonotube is plenty high for the soil to grab it.

 

Best of luck with your build!

Hi speedster,  Thanks for you input.  I don't understand how the embedded sonotube is working against me.  I'm planning on pouring everything at once.  Are you implying that having a layer of sonotube paper "skin" between the cubic pier concrete and the sonotube enclosed concrete is problematic?  Also,  I'm not worried about frost heave as I live in Northern California and the air temp very rarely gets below 32 for more than 5-6 hours. 

 

Mike 



#18 marinaldi

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Posted 20 June 2022 - 10:51 AM

Speedster,

  The tie-down pins sound a lot better than the chain-dogs. I'm going to look at changing over. And thanks for all of the help with the pier-footer/pier. There seems to be near zero deflection and vibration. The L-350 reports short-period tracking errors of a few tenths of an arc-second.

John

Hi Speedster/John,  Can you send a link to the tie down pins?  I've looked at this on Amazon but I'm getting marine tie downs mainly.  

 

Thanks, Mike



#19 archer1960

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Posted 20 June 2022 - 05:10 PM

Hi speedster,  Thanks for you input.  I don't understand how the embedded sonotube is working against me.  I'm planning on pouring everything at once.  Are you implying that having a layer of sonotube paper "skin" between the cubic pier concrete and the sonotube enclosed concrete is problematic?  Also,  I'm not worried about frost heave as I live in Northern California and the air temp very rarely gets below 32 for more than 5-6 hours. 

 

Mike 

You don't want sonotube or anything else between your block of concrete and the concrete of the pier; you want that all to be one solid piece of concrete to the maximum extent possible. It's ok if the concrete comes up a couple inches around the bottom of the sonotube as you're pouring it (it's hard to prevent that completely), but leaving sonotube in the block (or empty space where it used to be) is going to weaken your pier.


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#20 speedster

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Posted 20 June 2022 - 11:46 PM

A pinned connection is super simple when you see it but may not be the easiest thing to explain.  It's something akin to this pic below.  There is a pin that goes through an ear (tab, plate, whatever you want to call it) and then goes into the roof like, in this pic, the pin goes through the trailer side wall and then into the ramp.  Pin can have safety clips, knobs, and various configurations.  To secure the dome, PODs use a threaded bolt through the dome lip and into a threaded insert in the wall. Same principal for a ROR.

 

Embedding your sonotube down to 3" off the bottom of the foundation is not going to fall over or anything drastic.  The paper is of no structural value so what you are doing is isolating the pier from the foundation except for the 3" of concrete at the bottom of the hole.  It's not that it won't work.  It's just that it's working against you in terms of performance.

 

I just mentioned frost heave because someone above mentioned that someone else mentioned that sonotube helped with frost heave.  Unfortunately, it doesn't.

 

Regarding heavy duty garage door tracks:  nothing wrong with heavy-duty anything but have you seen garage doors in your area blown off the walls?  These are likely on standard duty hardware.  Your ROR may have less wind loading than a garage door.  Designing for high wind is not too tough.  It's what's in the wind that makes things interesting.  A 150mph wind is one thing but a hit by a 1,000 pound palm tree traveling 150mph in that wind is a whole different challenge to survive.

 

Screenshot 2022-06-20 232057.jpg


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#21 Broz22

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Posted 21 June 2022 - 08:53 AM

Mike, if you are looking for pins to implement something like what Speedster has shown above, you could look at regular lawn tractor hitch pins like:

https://www.amazon.c...,aps,221&sr=8-6

 

I'll post some pictures later of construction steps that I used based very loosely on Skyshed plans. I ended up making it 11'x12', and using 1 course of block connected to rebar pins set every couple of feet in the slab, and then filling the web holes where the pins are and also allows for jbolts in the same webs to tie down the bottom plate (pressure treated)  of the wall framing. This all makes for a nice (permanent) foundation for a shed that is set up a bit from ground level to prevent rot as well as providing a strong connection to tie down the shed. It all depends on how sturdy and permanent you want the shed to be (and how much effort and $ you are willing to put into it).

John


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#22 t-ara-fan

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Posted 21 June 2022 - 03:43 PM

 

Casoter 2 Inch Black Low Gravity Center Nylon Caster, 32mm Extra Width Hi-Temp Nylon Wheel
 

Some say*  that steel wheels have lower rolling resistance than nylon or rubber.  My roll-off is 12'x18', so less rolling resistance the better.

 

*trains, for example.


Edited by t-ara-fan, 21 June 2022 - 03:46 PM.

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#23 Broz22

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Posted 21 June 2022 - 06:33 PM

You are probably right, but I suspect that steel wheels would work better with a perfectly flat track (like railroads), A flat steel strip along the top wall plate and roll-off beam would probably work well with steel wheels. The steel v-wheels on the v-track side run smoothly.  I will say that my 11'x12' very heavy roof (overthickness metal roofing and a LOT of framing including siding on the gable ends) rolls pretty easily. I went with the Aleko gate opener because I have a bad back and don't like pushing on things over my head. The Aleko does force me to ensure that the scope is parked before I close the roof, and that the tie-downs are taken off before I open it. This has made me hesitant to use the remote opener that reaches the shed from from the house since I need to check these things visually before I move the roof.

John


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#24 greenstars3

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Posted 22 June 2022 - 12:45 PM

What ever system you chose, use more wheels than the minimum

I have my RoR set up with metal V casters from Graingers and set them on inverted angle iron welded to some 1/4 inch flat steel

The flat steel is not really straight so snap a chalk line before welding

I use 3 4 inch wheels per side and pull the 12 x12 ft roof open by hand (wheels were rated for 16000 lbs each and have grease fittings)

the roof is secured when closed with chains and boomers (like the ones used to secure loads on trucks)

Be sure to use string lines to align the tracks and keep them parallel during construction and your roof will not bind up 

 

Robert



#25 marinaldi

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Posted 23 June 2022 - 02:01 PM

What ever system you chose, use more wheels than the minimum

I have my RoR set up with metal V casters from Graingers and set them on inverted angle iron welded to some 1/4 inch flat steel

The flat steel is not really straight so snap a chalk line before welding

I use 3 4 inch wheels per side and pull the 12 x12 ft roof open by hand (wheels were rated for 16000 lbs each and have grease fittings)

the roof is secured when closed with chains and boomers (like the ones used to secure loads on trucks)

Be sure to use string lines to align the tracks and keep them parallel during construction and your roof will not bind up 

 

Robert

Thanks Robert.   I believe the idea (spoken of above) of only using V tracks and wheels on one side and good hard rubber wheels with no track on the other side is a great way to prevent any roof binding.  Better to deal with a 1D problem instead of a 2D situation.  


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