Need Help Mechanical double lid lifter

  • Thread starter cybertron
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In summary: The bottom part cannot be the motor as it would become too complex. The linkage would be the rods that connect to the left and right hand lids. And the top piece is the cam device that would be affixed to the left door.
  • #71
nvn,

That is a great animation! How did you make it? Can you give me the name of the software or a link?

If he can live with your design, it would be MUCH better than the rack and pinion system I devised. It is much simpler and could be easily motorized by making the B-C link a rack and connecting his gear motor through a right angle drive to a pinion meshed with the rack.

cybertron,

I'm confused... My understanding of the Structure Limits which you had shown in your sketch at post #53 are shown in PINK on the sketch attached below. Please edit this sketch to correct any errors I have made. Also, please confirm that the doors weigh 10 pounds each, for a total of 20 pounds.

Your latest sketch appears to allow the mechanism to be up to 3" high, is this true?

Now, for the question of how much force the motor and mechanism will need to deliver:

Look again at the sketch I attached to post #59. The force necessary to start opening one of the doors with the mechanism is represented by the arrow labled "total force on linkage". You will see that it is much longer than the line representing ~41 pounds. I have not calculated that force (it will depend on the final configuration of the mechanism and the size of the angle "theta" shown on the sketch), but I would expect it to be in the range of 100 pounds.

Since the motor will be moving BOTH doors at the same time, it will need to deliver twice the force; or about 200 pounds. Any spring or counterbalance system should be set up to make the effective weight of the doors as small as possible.
 

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  • #72
tyroman.

I will try and made both mechanisms to see which would work best for my project.

I don't know what you mean or indicating about post 53.

The doors do weight 10lbs each for a total of 20lbs. I did not install them they were already inplace.

How do i know each door weights 10lbs, I weighted both doors with a scale' and off there hinges and on there hinges.

These doors are made with 2peices of solid wood 1/2'' thick for both doors this wood is not the kind of wood you can buy at any home improvement store this wood is solid plank boards that they would of used 60+years ago before they had plywood as we do today.There in great condition i just planed each side down 1/16 of inch to get the original grain of the wood back so I could stain them.

tyroman:you did mention in post i think 55 or 56 if I can increase the height of the tubing this will increase the strenght and function of the rack and pinion system.So this is what i did to compensate for that in my last post.

Yes. its ture, I did increase the height of the tube with a 1-1/2'' spacer under the tube, so i looked closer at the doors how they sit and it wouldn't be a problem to do this, but I CANNOT go any higher then 1-1/2'' on the spacer.I will have to accommodate for that height with a vertical bend piece of tubing to attach to the doors since the doors will sit 3'' below the top of the shorter tubes but this is not a big fix or problem to change.

The Gearmotor I'm getting has a high torque ratio do to its very low RPMs AND GEARBOX it can lift 40lbs - 60lbs as i been told, even if I didn't use any springs this motor could lift both doors i would think. But that's not good on the motor.And you want to use half what the motor can lift so 30lbs would be right.
So by using one or two springs on each door will bring the mass of each door weight down to about 0.5lbs or 0lbs I'm thinging two 20lb holding springs would work.if not one larger spring.

tyroman:
How do you get 100lbs to 200lbs on the rack and pinion mechanism the motor is applying the force and the springs that's lifting the doors the rack and pinion is there to guide the door in the lifting. Mostly all the force I would think is placed on the motor when lifting the two door up. Please explain I'm trying to understand this.

NVN.

As I and tyroman stated what program did you use for that video was it Windows Movie Maker or some other program can you please name the software or a link to that program as tyroman suggested.
 
  • #73
nvn said:
I now revised the attached file in post 68; see the revised file. The linkage bars in the post 68 diagram are flat bars, not round rods. The purple sleeve (cup) is a separate part. It is a solid square bar, then you tap a blind hole along its centerline. The bottom of the cup has a rectangular hole, through which you insert linkage bar HB. Linkage bar HB must be free to slide to the left. I.e., linkage bar HB is not rigidly connected to the purple sleeve at H. I don't know if "linear motion" equipment manufacturers, etc., might have something like the purple sleeve you could buy. You will need to research all available parts and manufacturers on-line. If not available, then you can hire someone to machine some parts. No problem.

nvn. As for getting any kind of part customed machined would not be an option do to a small amount i want to construct this for. Is there any standard part you can implement in the mechanism design that would be easier to find. off the self of any hardware home improvement store. at the bottom of the revised drawing don't understand the part please explain. thank you.
 
  • #74
On linux, you can use octave, gnuplot, and ffmpeg. I don't know the details of how it works, since I didn't set it up; and I wouldn't have time to go into that. I don't know if it works on Windows or Macintosh.

cybertron, you will be the one who needs to do most of the on-line research to locate off-the-shelf parts, unless someone else here happens to find some parts for you. Also, I think there are individual machinists who will do small jobs. So don't give up before you have tried to contact them.
 
  • #75
nvn said:
On linux, you can use octave, gnuplot, and ffmpeg. I don't know the details of how it works, since I didn't set it up; and I wouldn't have time to go into that. I don't know if it works on Windows or Macintosh.

cybertron, you will be the one who needs to do most of the on-line research to locate off-the-shelf parts, unless someone else here happens to find some parts for you. Also, I think there are individual machinists who will do small jobs. So don't give up before you have tried to contact them.

I throught you might of had some other standard part for that part that will be connected to the flate stock that i could get at an hardware store. And yes i will be doing the on-line rearching which I have been doing. But the part that connects to the bar is i think a custom made part that will properly be hard to locate.Yes i will contact some machinists in my area but I do know a one item custom part can get expensive to forge.

No I'm not going to give up?

As for the flate bar what do you think i would need in size and thickness because you didn't state this.
I did find some on-line Alumimum or steel, sizes 1'',1/2,3/4'' 5/8'' wide and for the thickness 0.05'' 3/16'' or 1/8''.what would be the way to go. As for connecting the bar together, I do have some ideas.

In post 68 in the drawing what is that part in the low bottom right.please explain.

What is a program I can use for Windows like the one in the video, I don't use Mac which i think those programs work in.
 
  • #76
infsup said:
Another alternative if your current project is over budget, is an inverse trans-axle. The motor is placed at the bottom center, attached to it is a parallel gear (at 0dg.) A second gear placed perpendicular to the right of the first gear. The main gear turns counter clockwise. The second gear turns a screw, where a third one (gear and screw) is placed parallel (facing the opposite direction). Both screws turn the same direction perpendicular to the motor or drive shaft, to form the main axle. Attached to each axle is a cable that pulls each door open or closed, both at the same rate and in equal and opposite directions. To be more specific the two main axels are attached, such that the counter clockwise drive rotates both axles clockwise, pulling the doors open.

This might not work do to the space that the motor must be place in.
Can you show a 3d drawing of this alternative option.

All suggestions, ideas, and help is greatly appreciated. thank you.
 
  • #77
cybertron (paraphrasing) said:
As for the flat bar, what do you think I would need in size and thickness? ... In your post 68 drawing, what is that part in the lower, right-hand corner? I don't understand the part. Please explain.

cybertron: Don't worry about sizes just yet. You are not ready to select stock sizes. The view shown in the lower, right-hand corner of my post 68 diagram is a bottom view of the linkage bars shown above it in the side view. This gives you two views (side view and bottom view) of the connection at point B. All of my parts (in the post 68 and post 14 diagrams) are inside the square tubes, except for a portion of linkage bar AB, which passes through slots in the long and short square tubes, as stated in post 39. The motor in post 68 is also outside. Unlabeled views on a drawing are called orthographic views (orthographic projections).
 
  • #78
cybertron,

In your post #72 you say;

"I don't know what you mean or indicating about post 53."

Here is what I mean...
In your post #53 you attached a sketch titled;
"End on view area to work.png 1.PNG"
On that sketch you have the following notes;
"This area is what I have to work with."
Next to that note is a long line with arrows at each end. It is labled;
"18" long space is length of the 18" tube".
Another shorter line with arrows at each end is labled;
" 2" space"

Also look at your post #56 where you say;
"Yes the mechanism and motor that I use must fit in the 2''x18'' limited space."

Now look at the "Plan view B.PNG" sketch I attached to my post #71. The only space on that sketch which is not PINK is the 2"x18" space between the mechanism and the wall. What I need you to do is either confirm or correct my understanding that no part of the mechanism or motor can be in the PINK space shown on "Plan view B.PNG" attached to my post #71.
 
  • #79
The image I posted in post 60 was grossly simplified, because it has the pins (points A and D) collinear with the hinge and square tube face. In reality, these two pins are offset from the square tube face. Now that I am taking a quick look at the actual configuration, with accurate dimensions and accurate pin offsets, I am currently unable to get both doors to open to the same angle at the same time using the post 14 design. If there is a solution that makes both doors open at the same rate and to the same angle, I have not been able to find it, in a matter of minutes, using the asymmetric post 14 concept.

I am starting to think we may be required to use a symmetric design.
 
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  • #80
tyroman said:
cybertron,

In your post #72 you say;

"I don't know what you mean or indicating about post 53."

Here is what I mean...
In your post #53 you attached a sketch titled;
"End on view area to work.png 1.PNG"
On that sketch you have the following notes;
"This area is what I have to work with."
Next to that note is a long line with arrows at each end. It is labled;
"18" long space is length of the 18" tube".
Another shorter line with arrows at each end is labled;
" 2" space"

Also look at your post #56 where you say;
"Yes the mechanism and motor that I use must fit in the 2''x18'' limited space."

Now look at the "Plan view B.PNG" sketch I attached to my post #71. The only space on that sketch which is not PINK is the 2"x18" space between the mechanism and the wall. What I need you to do is either confirm or correct my understanding that no part of the mechanism or motor can be in the PINK space shown on "Plan view B.PNG" attached to my post #71.



The 2''x18'' is the area that's left where I must place the motor and where the rack & pinion mechanism will be placed and attach to the long tube.My tubular lifter is in the that space already.
My post in 53 is showing you indicated by the arrows that the 2''x18'' is the space where the motor and the rack & pinion mechanism will be placed in. The lifter is in that space too but what's left is an area of 2''x18''

Right! There should be NO pink area from the tubular lifter to the wall this is where the motor,rack&pinion mechanism and the lifter. In post 71 you have the lifter tube hindden in the pink area. which it shouldn't be.

If you can Picture two leaf style cellar doors that open from hortizonal to vertical there should be nothing blocking that area to enter.
 
  • #81
tyroman

I edit post 71 to show you what the top view would look like if you were looking down at the two door.

As you can see you have the tubular lifter than the mechanism then the left-over space which would now be 1-1/4'' from the mechanism to the wall.

As stated in post 53 and 80.

The pink area ENDS where the tube lifter begins.As indicated in edit image.
 

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  • #82
nvn,

I think it is less important to cybertron that the doors move "exactly" in unison than it is that the motion of the mechanism begins with both doors at 0 degrees and ends with them in a 90 to 100 degree position... can you find a way to position the A and D connections and adjust the length of links A-B, B-C and C-D to make this work? Perhaps have the A and/or D connection(s) made at a "crank" attached to the short tubes (see attached "nvn's links.PNG" sketch).

Also, since cybertron's earlier clarification that the mechanism does not have to be "inside" the long tube and that the long tube will be installed "with a 1-1/2'' spacer under the tube", there is more vertical room to position your mechanism if you attach it to the side of the long tube rather than inside.

Mounting the motor as you have described (off the end of the long tube) may be unacceptable to cybertron (based on the 2"x18" work space)... but I think this can be solved with your design if the motor is connected to a right-angle drive
see:
http://www.torquetrans.com/right-angle-gear-boxes/miniature-right-angle-drive.htm
http://www.torquetrans.com/right-angle-gear-boxes/images/ra202_figure_1.jpg
or bevel gear:
http://www.qtcgears.com/KHK/newgears/KHK230.html [Broken]

which is then connected to a pinion mounted on the side of the long tube. The pinion would mesh with teeth on the edge of your link B-C (which would be made from a rack of appropriate length). See sketch "door-mechanism-05 (with motor).png" attached. This would also be the way to motorize the double rack and pinion design if that is the way cybertron decides to go.

Again, I believe your design will be stronger and simpler than the double rack and pinion design... if we can make yours work.
 

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  • #83
tyroman: I tried about ten different ways, so far, and could not get both doors to end in the range 90 to 100 deg. But I will continue trying all of your new suggestions (or any others you may think of) over the next several days, to see if I finally get lucky and find a combination that works. I'll let you know as soon as (if) I find something that works.
 
  • #84
tyroman

I just want to know if the two doors don't open in unison how would both doors open exactly at 90 and 100dgs. And close at the same time at 0dgs.

If one door starts to open,then the other door follows 20dgs behind how would both doors
reach 90 0r 100dgs exactly. I would think one would be at 90 the other door would stop at 70dgs or less. That would be unacceptable.

Now if both doors start opening from 0dgs in unison both doors will stop exactly at 90 0r 100dgs went motor stops at that angle.This is how they must open. If they don't one door could block the entrance at a predetermine angle and that's not good.

They must open in unison to close in unison so either door does not block the entrance do to the small foot print of the opening.
 
  • #85
tyroman


In post you also showed nvn in the first image how the door are attached to the short tubes,They are not attached there.

The two doors sit at the 1-1/2'' spacer level sits. I did not indicate at all that the doors would sit on top of the shorter tubes nothing can go on top of the shorther tubes,But There will be a bend piece of metal that will be attached to the top of the shorter tubes bend at a 90dg angle then 3'' down then bend at another 90dg angle then attached to both doors. I stated this in my post in 67. The two doors sit at the wooden base level,not on top of the shorter tubes.I showed you in post 82 how the tube would look from a top view. Because the two doors sit at the woodenbase level or floor level. I did state in post 67 that a piece of bend metal will accommodate for the 3'' heigth difference do to where the two doors sit. They do not sit on top of the shorter tubes.
 

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  • #86
I have not been able to get both doors to end anywhere near the range 90 to 100 deg using the asymmetric post 14 concept. Therefore, as mentioned in post 80, I am starting to think you may be required to use a symmetric design.
 
  • #87
nvn said:
I have not been able to get both doors to end anywhere near the range 90 to 100 deg using the asymmetric post 14 concept. Therefore, as mentioned in post 80, I am starting to think you may be required to use a symmetric design.

Ok, So the concept for that propose mechanism in post 14 will not work at all, what was the reasons for not getting the doors to 90dgs,was it the limited space or other factors of the design. And using an optional motor.



As for a symmetic design will this concept work, and will it work in such a small area with the optional motor as mentioned.
 
  • #88
The main reason the post 14 concept does not work is due to the asymmetric mechanism geometry.

I have not worked on a symmetric design much, myself (except for posts 7 and 10).
 
  • #89
Tyroman

Is your mechanism design concept a asymmetric as nvn concept in post 14 or is your concept symmetric as nvn proposes that a symmetric design will be needed.

Will your concept as proposed work also.
 
  • #90
nvn said:
What about something like this? Not to scale.

nvn

In this design concept as proposed in post 10 is there a way for this to work in the small limited space that i have and using my motor that's been mentioned in this thread with the concepts that already been stated and suggested by you as well as tyroman suggested with right angle gears and rack parts.Is there any other combinations that you could come up with in this concept that can work in my project do to the limited space and geometryand getting the doors to open and close at 0-90dgs.
In post 67 i increased the height with a 1-1/2'' spacer to compensate for the rack and pinion that tyroman advised,So I have now about 3'' from the wooden base to the top of the shorter tube to give some more height to the area.

I hope you have not given up on me just yet! But i do Apperciate all the time you have given to me on the mechanism design and to this thread.
 
  • #91
Something might be workable. I might investigate a symmetric version of something somewhat similar to posts 68 and 10.
 
  • #92
nvn

OK.That seems knid of interesting meshing post 10 and 68 into in someway.

I looked at the space much closer, if the motor that i will using is placed length wise as indicated in post 82 that will limit the lenghts space from 18'' to 14'' deducting 3'' for the motor that's including the shafts length on the motor, (plus 1/2'') on each side for any variances for adjustment that's tight,So if you keep or place the motor like in post 82 that would be OK ''but, there will only be 14'' left for any placement of a symmetric mechanism concept in that area but you will have the 3'' in height do to the added spacer as indicated in post 67.

Maybe the parts that tyroman suggested could help with the symmetric design where it could fit and will work.
 
  • #93
I now found a solution using my asymmetric post 14 design concept. The attached video file, below, shows how the mechanism works. Study this file to see how linkage bars AB, BC, and CD move. In this video, I rotate the left-hand door 100 deg, which causes the right-hand door to rotate 101.4 deg. You can make the image repeat in your viewer by selecting Play > Repeat, or View > Loop. The support blocks for linkage bar BC are shown at points E and F in my post 14 diagram.

For the design shown in the attached video, the (x, y) coordinates, in mm, of points A, B, C, and D when the doors are at 0 deg (closed) are A(17.00, 25.40), B(164.83, 0.00), C(414.83, 0.00), D(477.00, 0.00). The coordinate system origin is located on the left-hand end of the long square tube, at the tube longitudinal centerline. The linkage bar lengths (from pin centerpoint to pin centerpoint) can therefore be computed from the above coordinates, and are |AB| = 150.00, |BC| = 250.00, and |CD| = 62.17 mm. The long square tube is 460.00 mm in length.

The drive mechanism for this design is shown in the attached .png file, below. The .png file shows a side view of the mechanism, and a partial bottom view.

See all my previous posts for a detailed description of this design. All of my parts are inside the square tubes, except for a portion of linkage bar AB, which passes through slots in the long and short square tubes, as stated in post 39. The motor is also outside.

Notice in the video, the brown plate at point D interferes with the bottom face of the long square tube. Therefore, you might need to cut a slot in the long square tube if the brown plate interferes, unless a refinement in the exact dimensions (such as adding the hinge thickness, etc.) resolves the problem. The above coordinates currently assume coincident tube faces, as shown in the video. I.e., no allowance is currently given in the above coordinates for hinge thickness, because an exact hinge thickness in mm has not yet been given.
 

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  • #94
nvn.

Will this design solution work and function as stated, is this the finished design. Can I start asembling the mechanism.

Also I'M not do sure about where these two number indicator at.Please explain!
When the two doors are in the 0deg closed position, on the x y corrdinates for point A these two numbers 17. 00 and 25.40 are placed where on the shorter tube.

As for the flate bar material what do you think i would need in size and thickness because you didn't not state this for in side the tube.

I did find on-line Alumimum flate stock and steel, sizes 1'',1/2,3/4'' 5/8'' wide and for the thickness 0.05'' 3/16'' or 1/8''. what material would be the way to go steel or alumimum.

In post 68 and 94 in the drawing this part in the low bottom right.Please explain.

What is the brown plates dimensions was not mentioned.

I'm assumming the thinkness for the hinges is appox .2'' 0r 1/16'' have not purchased any hinges yet.
 
  • #95
cybertron: No, the design concept is not finished yet. Let's first try waiting for three or four days to see if tyroman has comments.
 
  • #96
nvn said:
cybertron: No, the design concept is not finished yet. Let's first try waiting for three or four days to see if tyroman has comments.

OK. I will wait
 
  • #97
nvn & cybertron,

My comments will be brief.

Nvn, have you done any calculations to establish the forces which components of the mechanism must withstand? Do you believe that cybertron's motor will be powerful enough? (see my post about the free body diagram).

cybertron, as I understand nvn's design, manual operation and motorized operation of the doors are not independant. In other words, if the doors have been opened by the motor, they can not be closed by hand (distinct from use of a hand crank which you rejected when I suggested the worm-drive design). The motor (or a crank) will have to be used to close them. Are you OK with that?

In general, nvn's design appealed to me when I learned that the doors weigh 10 pounds each. This is because his simpler design had an advantage over the rack and pinion design since it would allow larger (stronger) components within the limited space available (about 3" from bottom to top). However, if his current design is installed inside the 1" square tube, that advantage is lost.

Lastly, for cybertron, I'm confused that you seem OK with the parts of nvn's design which occupy space in the "off-limits" area which you have defined. Neither the motor nor the link attachment point at "D" are within your 2" x 18" work area.
 
  • #98
tyroman: I have not investigated nor considered motor power in any way. Yes, I did a very preliminary calculation of linkage bar axial force for the post 94 mechanism. Neglecting hinge thickness, neglecting short square tube self weight, neglecting hinge friction and friction at support blocks E and F, and assuming a door weight of 44.48 N, I got a very preliminary maximum linkage bar axial force of 409 N tension, and 332 N compression. These are the maximum axial forces in linkage bars AB, BC, and CD. The maximum axial force in linkage bar HB would be close to 409 + 332 = 741 N tension, neglecting the aforementioned items. In the future, if I have time, I will assume and implement a hinge leaf thickness of 2.10 mm (total hinge thickness, 4.20 mm), which may slightly alter these force values.
 
  • #99
tyroman

I assumed that nvn design could be opened by handcrank, hand manually and motor stated in his design as well as with a the motor. If his post 14 revised design cannot be open or closed by hand but only with a motor, if that's the case, is it because the mechanism is on the inside of the long tube or will it work if the mechanism was on the outside of the longer tube or is it the limited space available.The 18''

Also by looking closer at nvn revised 14 design I don't think there would be any room for the motor if the mechanism is located inside the 18'' long tube and that would be the entire length of the tubes space. How would a motor fit and work if the motor was to be inline with the 18'' long tube this would extend that length to 21'' plus, which dose infringe on the off-limited space as you stated tyroman. I do see this.

tyroman Yes i did reject the hand crank. Reason for this was stated in one of the post i posted. Security, Time it takes to open the doors with a handcrank and anoption to use a motor. Now looking closer at the space that's available
18'' in length there's only 2'' in he width for a Handcrank to turn if it sits an the bottom of the woodbase and inline at the end of the long tube.

If nvn can made the mechanism that he revised that's inside the longer tube and includes the motor, But dose not extend the mechanism length into the off-limit space and can made the doors open and close by hand as well with the motor but off-sets the position of the motor to the side of the 18'' long tube, would this work.

If the doors cannot be opend or closed by hand or with a motor independantly then a motor would be used to open and closed the doors.

Tyroman Is there a way to use nvn design on the outside of the long tube and have it open independantly by hand but without a so call handcrank mechanism. I did like what you suggested by using bevel gears to move the bar in nvn design is there a way to still make that work in nvn revised #14 design.

Also. i need a design that dose not use any custom forged parts. All parts must be off the shelf readly available.


The motor that i have can lift 75 in lbs meaning it can lift 75lbs to 80lbs maximum and hold it one inch up from the front of the Box do to the high gear ratio this was stated by the vendor where i purchased the motor from.

Is your rack and pinion design still being work on. I still need a mechanism to construct.
 
  • #100
cybertron,

I have attached a sketch made from a snapshot of nvn's first animation and one of his motor drive sketches. Two areas are highlighted with GREEN to indicate the parts of his design which would be in the "off-limits" area, outside of the 2"x18" area you have established.

As I understand your last post, you did not realize that the motor would be in the off-limits area and you now want to know how nvn's mechanism could be motorized differently. What about the other location (at link CD) where the mechanism is "off-limits"? If this is NOT acceptable, then nvn's entire concept may have to be re-thought and the exercise of re-designing its motorization could be wasted effort.

Please consider the above and decide what is acceptable to you.

If you decide that link CD being off-limits is acceptable and still want to know if the motor could be made to work within the 2"x18" area in some way; my answer to that question is a qualified NO. This is because, with the linkage BC INSIDE of the long 1" tube there would be very little room for a gear to be driven by your motor. If nvn can re-design his mechanism to be mounted OUTSIDE of the long 1" tube, then YES the motor might be easily connected. This is up to you and nvn.

Note; CAPs above are for emphasis... not a shout.

PS; in future, I suggest you print out the sketches posted by nvn or me and take the drawing to your nearest auto mechanic or hardware-man so they can help you understand what the sketch is showing.
 

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  • #101
tyroman

Yes the green circles indicating the off limits: Went nvn posted the video I didn't think at frist if that would be a problem until I looked closer at the limited area available for the long tube and by watching the video many more times.

I think the reason why nvn had not gotten the doors to open and close in uinson,and at 90degs is that he needed more mounting space to extend the mounting points for the required angles with that extended plate so that the doors would open at the 100 and 101degs in the revised video.This is my understanding in the video.

This is why i didn't realize that the motor would be in line with the longer tube and extending the 18'' to 21'' plus.
The other location at (CD) would be acceptable if the extended brown plate is not more then 1'' in width I could adjust for this.
I cannot adjust for the other side where the motor is place inline with the longer tube there would be no room to fit the motor there that would make it well over 21''. That would be unacceptable.


Yes. Points CD is acceptable.Only if the extension with brown plate is no more then 1''
No. Motor placement in off-limits area, its indirect line with the long tube unacceptable. It would extend beyond the 18''. not enough room.

Enclosed image: Arrows show what's Acceptable and Unacceptable.
 

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  • #102
nvn


There seems to be a problem in placing the motor inline with the longer sq tube.Did you know that there are off-limt structural areas in the space i have available to place the mechanism to the lifter. The area is 18'' x 2'' so the mechanism can not be beyond the longer tube which is 18''.


I thought that the motor would be within the 18'' length of the longer sq tube in your design #14 #98 But it extends beyond that which would make it over 21'' which would be unacceptable beacuse there's not enough room to place the motor inline with the long tube.

I realize this by looking closer at the available space i have and by watching your original 14 post and the new revised design on the video in post 98

Also tyroman pointed this out to me as well! He include a edited snapshot of your revised video in post 101 to show me that the revised design would extend beyond the 18'' and into the off-limited areas.

So please read tyroman post 101
And my post 102 as what I will accept and can not accept in your revised design.

There might be a solution to the motor placement to the revised design by placing the mechanism on the outside of the long tube instead of inside. As tyroman suggested.

The Enclosed image could be an option for motor placement but the longer linkage bar in your design may need to change to a rack as indicated in image.

nvn
Please look at my post 67 and post 82 for off-limits areas and available space I have to work with in this project.

Tyroman is that any other option that you can think of where nvn revised design can still work with new placement of the motor I'm using.
 

Attachments

  • door mechannism with bevel gears .png
    door mechannism with bevel gears .png
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  • #103
My linkage system is essentially independent of the drive mechanism. You could drive it in any way you choose. And, my linkage system is perhaps somewhat independent of whether you choose to mount it inside or outside the square tubes. Therefore, I will cover only the independent linkage design herein.

I now implemented a hinge plate thickness of 2.10 mm (total hinge thickness, 4.20 mm). Therefore, the attached video file, below, now contains very accurate, exact geometry, whereas the previous videos did not. I also attached, below, a .png file, which includes the support blocks.

For the design shown in the attached video, the (x, y) coordinates, in mm, of points A, B, C, and D when the doors are at 0 deg (closed) are A(10.00, 29.60), B(157.05, 0.00), C(417.05, 0.00), D(480.00, 0.00). The coordinate system origin is again located on the left-hand end of the long square tube, at the tube longitudinal centerline. The linkage bar lengths (from pin centerpoint to pin centerpoint) can therefore be computed from the above coordinates, and are |AB| = 150.00, |BC| = 260.00, and |CD| = 62.95 mm. The long square tube is 460.00 mm in length. The coordinates of the hinge rotation centerpoints, called points J and K, are J(-5.00, 14.80), K(465.00, 14.80). The centerpoint coordinates of support blocks E and F are currently E(180, 0), F(365, 0); and the support block length is currently 14 mm. The gap between the long and short square tubes when the doors are at 0 deg (closed) is 4.20 mm.

Assuming a door weight of 44.48 N, I got a maximum linkage bar axial force of 429 N tension, and 336 N compression. These are the maximum axial forces in linkage bars AB, BC, and CD. The maximum axial force in linkage bar BH would be 750 N tension. The required door opening force applied by a human at the inner edge of the left-hand door is 57.2 N when the doors are at 0 deg. The above force results include hinge friction and support block friction.

Therefore, due to the above force results, the cross-sectional height of each linkage bar is currently 5.0 mm. The cross-sectional width of each linkage bar layer is currently 2.7 mm. In other words, the cross-sectional size of linkage bars AB and CD is 5.0 mm high by 2.7 mm wide. The cross-sectional size of linkage bar BC is 5.0 mm high by 5*2.7 = 13.5 mm wide. The linkage bar (and square tube) material is mild steel. The governing stress is currently linkage bar AB buckling stress. I used an ultimate factor of safety of 2.0.

I have assumed the door system is operated in a slow, normal manner. I currently have not assumed adverse conditions, such as gale winds, nor human misuse of the system, such as opening the doors far too fast. Therefore, the listed linkage bar cross section sizes constitute a minimum.
 

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  • door-mechanism-05-04-80-msv1-75.avi.zip
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  • door-mechanism-05c.png
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Last edited:
  • #104
cybertron (paraphrasing) said:
The drive mechanism cannot be in-line beyond the long square tube.

Here is a new drive mechanism concept. To open the doors, rotate the 6.35 mm square drive socket head counterclockwise. Remember, this diagram is not to scale. Use the coordinates listed in post 104 instead. The coordinates of points A, B, etc., in post 104 are exactly to scale. You can mount the linkage mechanism inside or outside of the square tubes, whichever you prefer. Let's see if tyroman has comments.
 

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  • door-mechanism-06.png
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  • #105
nvn

The change for the drive mechanism could work, But only if the motor is placed and some way connected in parallel to the drive gear mechanism do the width in the available space. If you look at post 67 the width is 2'' wide from the tube to the wall and the motor is 3'' long so the motor cannot be connected directly inline to the revised drive mechanism.
Is there a way to connect a right angle drive gear between the drive mechanism and the motor to drive the revised drive mechanism. Maybe tyroman has a way to drive the motor opposite (parallel) to the revised drive gear mechanism.
 
<h2>1. What is a mechanical double lid lifter?</h2><p>A mechanical double lid lifter is a device used to lift and open two lids simultaneously. It is typically used in industrial settings to increase efficiency and productivity.</p><h2>2. How does a mechanical double lid lifter work?</h2><p>A mechanical double lid lifter works by using a system of levers, gears, and pulleys to transfer force from a motor to the two lids. When the motor is activated, it rotates a shaft which moves the levers and gears, causing the lids to open.</p><h2>3. What are the benefits of using a mechanical double lid lifter?</h2><p>The main benefit of using a mechanical double lid lifter is increased efficiency and productivity. It allows for the simultaneous opening of two lids, saving time and effort. It also reduces the risk of injury from manually lifting heavy lids.</p><h2>4. What types of lids can a mechanical double lid lifter open?</h2><p>A mechanical double lid lifter can open a wide range of lids, including metal, plastic, and glass lids. It can also handle lids of various sizes and shapes, making it a versatile tool for many industries.</p><h2>5. Is a mechanical double lid lifter easy to maintain?</h2><p>Yes, a mechanical double lid lifter is relatively easy to maintain. It requires regular cleaning and lubrication of its moving parts to ensure smooth operation. It is also important to regularly check for any wear and tear and replace any damaged components to prevent malfunctions.</p>

1. What is a mechanical double lid lifter?

A mechanical double lid lifter is a device used to lift and open two lids simultaneously. It is typically used in industrial settings to increase efficiency and productivity.

2. How does a mechanical double lid lifter work?

A mechanical double lid lifter works by using a system of levers, gears, and pulleys to transfer force from a motor to the two lids. When the motor is activated, it rotates a shaft which moves the levers and gears, causing the lids to open.

3. What are the benefits of using a mechanical double lid lifter?

The main benefit of using a mechanical double lid lifter is increased efficiency and productivity. It allows for the simultaneous opening of two lids, saving time and effort. It also reduces the risk of injury from manually lifting heavy lids.

4. What types of lids can a mechanical double lid lifter open?

A mechanical double lid lifter can open a wide range of lids, including metal, plastic, and glass lids. It can also handle lids of various sizes and shapes, making it a versatile tool for many industries.

5. Is a mechanical double lid lifter easy to maintain?

Yes, a mechanical double lid lifter is relatively easy to maintain. It requires regular cleaning and lubrication of its moving parts to ensure smooth operation. It is also important to regularly check for any wear and tear and replace any damaged components to prevent malfunctions.

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