Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - Callistemon

Pages: [1] 2
1
Project Progress / Re: K'nex 3D printer
« on: September 21, 2020, 05:44:03 am »
Do you have an approximate piece count? I was wanting to try some design concepts on this, but it is extremely advanced. Would it be possible to combine a 2D printer into the same unit?

The injection molded K'nex pieces would need to be heated to 360 degrees to melt it into a base plate. It would be much easier to place the base plate's mold under the extruder, but then the base plate would have the same melting point as the filament. Polypropylene also has a high melting point (can also be boiled), but would be more than 100 degrees less.

Yellow 5-way connectors sliding along each other would not be very smooth, as the tops of connectors are usually not flat. It would be smoother to slide along a long rod through a connector. For the design in image 5, if the yellow rod the wheels spin around can be anchored with a 1-way connector that allows free rotation and clips to a rod at the center of the yellow connector, that would reduce the resistance. The motor can be 12 or 24 volts, just depends on the power supply.

2
Site Feedback and Questions / Re: Bug: Cannot post in forum
« on: September 21, 2020, 04:52:24 am »
Same thing happened when I tried publishing a completed build. It had an error, even though the size of the images was below 65536 kilobytes, and it is stuck as unfinished (orange in the list), and cannot even be deleted. Another time when uploading images to a poll, there were no images afterwards, even though they were uploaded and were less than 64 megabytes.

3
Project Progress / Re: Back with my FEL trash truck
« on: September 03, 2020, 05:48:27 am »
That's almost complete! Where the yellow gear turns the axle gear, it should also turn another gear on the opposite side of the input gear, and the two halves of that axle should be decoupled. That would incorporate a differential system.

4
Misc / Interior Trusswork
« on: September 02, 2020, 05:37:17 am »
Interior Trusswork
--> View Model



This is a new and different method of reinforcing cubic towers with trusses. Instead of the four sides being filled with trusses, the truss beams cross through the center, and the two perpendicular beams intersect in the very center to form a plus shape (when viewing from above). Unless you have a large supply of orange peg clips, this can only be assembled using blue 3D connectors in the center. If there were white rods running horizontally between the yellow connectors, equilateral triangles would be formed, but that requires many peg clips.

At the top of the truss section, the white rods should be angled outward in all directions, and an X can be added. This requires 6 peg clips if you are alternating in a checkerboard pattern between gray 3D connectors and red connectors along the vertical running corners of the tower. As long as all four connectors on the top and bottom edges are gray 3D connectors, the tower cannot lengthen and shorten from rods sliding through the red connectors.

With exterior truss, even if there are available blue rods between X units, adding a solid connector railing requires a blue rod to clip onto at every green unit, and connectors cannot clip onto a green rod beside a white connector. Interior trusses retain robust structural strength while allowing there to be blue rods on every single horizon. The trusses do connect to the edges by looping yellow connectors through the blue rods, but that does not interfere with adding railing unless there will be less than 1 connector-width (6mm) between the rails.

Instructions will be coming soon (hopefully).

5
Project Ideas and Help / Orange gear rotation inverter problem
« on: September 01, 2020, 08:30:02 am »
I recently received 4 orange half-crown gears for building mechanical rotation inverters (spin continuously in one direction and outputs reciprocating rotation). Supposedly, half of the time with Design 1 (left), the output gears (blue) are turned by either the orange gear on the left or the right side, and all else being equal, turning a gear on the opposite side reverses the output rotation. The direction adjusts based on the rotation, not by the second (slower rotation induces slower alternation). With Design 2, which functions essentially the same, instead of alternating which side both output gears are spun, it alternates which yellow gear turns the output axle (gold). These mechanical inverters would be the opposite of my upcoming mechanical bridge rectifier, which would use ratchets to sort the movement to one channel or the other based on direction of input rotation, and then reverse the reverse.

There is one huge issue, enough that I demolished these and will not attempt further unless someone prints a custom gear. Whenever switching directions, instead of momentarily disengaging the first and then engaging the second, there is a bitter instant where both are engaged, and it is a tough grind to switch directions. Someone (which should be lazy me) needs to print a custom orange gear with 2 fewer crowned teeth, and with the interlocking slots exactly perpendicular to the crown half. When 2 of the existing orange gears are inserted with opposing crowns on a single rod, and are clipped with tan clips, there is 1 tooth of transition space on one side and 3 teeth of 'neither' space on the other, even though it should be 2-2 or 3-3.

Photo looks bad even after editing due to dingy 80 CRI light. Always choose 95+ CRI.

6
Misc / Small-size Mass Damper
« on: September 01, 2020, 07:36:32 am »
Small-size Mass Damper
--> View Instruction



First off, I apologize for publishing the second consecutive instruction. Please, someone besides me, publish something. Anyways, this is a small-sized mass damper weight that swings around at the top of a tower. Mass dampers respond to vibration and reduce the movement and swaying of tall structures. It is ideal for towers that are the size of a blue square.

The weight is partially surrounded by a slick 37mm tire. The upper 2 white connectors have 2 Y-clips on each side that hold the tips of 2 white rods, one on each side. The length of the suspending rods can be varied to adjust the frequency, but a single white rod is the shortest length. The mass unit can swing in all directions, similar to a universal joint.

This design can be extremely beneficial, useless, or somewhat harmful depending on the frequency and amplitude of vibration. It is most effective for high frequency vibrations with small amplitudes. Lower frequency and/or larger vibrations may cause the mass unit to collide with the tower frame (because my designs are always poor designs).

When paired with base isolation (which I will be more motivated to publish if someone else publishes something), mass dampers can be used to simulate higher masses (more inertia and resistance to movement) on the base isolation springs without substantially increasing the weight load (less gravitational force to overload the springs).

Pieces Count
Slick 37mm Tires: 1
White Connectors: 5
Red Connectors: 2
Orange Connectors: 2
Purple Connectors: 2
Green Rods: 2
White Rods: 4
Blue Rods: 2
Y-Clips: 4
Metallic Blue Clips: 1
Tan Clips: 1
Black Caps: 2
Silver Spacers: 2
Blue Spacers: 10

7
Misc / Re: Rod-Gear Interlocking System without Tan Clips
« on: August 07, 2020, 12:16:21 am »
This is a stronger version with blue rods instead of white rods. The splice clips cannot fall out unless the assembly is allowed to widen. Three orange connectors clipped on the axle break off before any interlocking assembly failure with blue rods.

8
Misc / Rod-Gear Interlocking System without Tan Clips
« on: August 06, 2020, 11:46:29 pm »
Rod-Gear Interlocking System without Tan Clips
--> View Instruction



This is a rod to gear interlocking assembly that does not use any tan clips. I was experimenting with using splice clips and an orange connector to try to make an improved gear coupler that does not clamp to the rod and spaced the gears further apart, but I ended up developing this that does clamp the rod. The splice clips protrude into the orange connector, and the orange connector is clipped to white rods that hold purple connectors clipping into the metallic gold yellow rod. The tips of the white rods would not fit until the splice clips were angled to the side.

When twisting the purple connectors directly, it is extremely tough and unbreakable. However, when twisting the gold rod with orange connectors clipped to it, the assembly breaks apart under slightly more force than a tan clip can tolerate before detaching. This can be solved by using blue rods in place of the white rods and clipping more purple clips to the gold rod, but even with the white rods this assembly would require a wide chamber compared to a tan clip, like a blue unit wide instead of a green unit. Also, the crown gear must be facing towards the assembly, and if a crown gear needs to be facing away then another gear must be coupled adding unacceptable complexity and width (unless you 3D print a gear with the center area extended on both sides). The interlocking assembly has much more slack than a tan clip.

9
I did not forget to add images, but they never went through. I tried to add them again, and it stalled for long before the entry fields turned blank, and the images were not uploaded. 65536 KB is supposed to be the file size limit.

10
This is part of the structure surrounding a compact camera holder in a travel set. For years, there were 3 vertical blue rods, as shown in the first photo, and that was one of the aspects I admired since I like rods shooting straight through connectors and the build is overdone with shorter rods and 3D connectors. However, I was recently making upgrades, and while most of them were obvious and I will never look back, this was one where both styles were good. Now there is one, long horizontal red rod shooting through 3 connectors, which is refreshing for a structure overdone with short rods. Both styles are nice, and as the king of paralysis, I don't know which configuration to choose.

11
Since I am looking to sell 9 K'nex Bridge Track Section Connectors and need to know how many stamps to use, I looked up the mass per piece on K'nex User Group like I always do when I want to know weights. However, their page claims each piece is 38 grams, so 9 of them would supposedly be 12 ounces. That was obviously incorrect, so I emailed them but they said it could not be verified since the part was discontinued.

I don't have a scale, and weight scales are not always very accurate at low weights. So, I decided to assemble a small K'nex balance, even though I thought I did not have enough parts. It's not complete, and will eventually be upgraded with more metallic rods and two X supports that will require 4 orange clips, but it still functions. I placed the envelope on one side and placed orange connectors on the other side, hoping their mass rating of the orange connectors was more accurate than of the one-off piece. It took 42 to 43 orange connectors to equal the envelope, which equals a much more reasonable 2.14 ounces. It's important to ensure the center of mass on one side of the balance equals the other, or else it will be as biased as completely different weights.

Balances use gravity, but are not affected by the strength of gravity. Balances measure mass, and weight scales measure weight. Devices that put gravity and centrifugal force to competition at a set speed measure the strength of gravity. If you want, you can assemble a spindle with several diagonal rods where balls can slide up & out or down & in, but I cannot because I think I have an abundance of purple clips compared to other parts when it is just about a pint.

12
Project Progress / Crank fan neon connector upgrade
« on: August 05, 2020, 03:49:05 am »
I recently unboxed and washed 100 used neon connectors, gears, and random pieces, packaged in paper as requested and sold at an expensive price. 311 pieces isn't enough to get very far, especially since there were 0 white connectors, but one thing I did accomplish was upgrading the red and green connectors in the crank fan to neon connectors. It gives a large boost and makes for a change, and makes it easier to find.

The shaft spinner part was assembled several years ago based on the drill model, and a propeller was added later. There are orange flexible rods for visibility and appearance. The handle axle, which has not crumbled since being upgraded to a stiff tan rod, spins a yellow gear that meshes with a blue gear to change the axis of rotation. If there is only one tan clip, the clip widens, slips, and chafes the axle. Two tan clips cannot line up oriented upright unless they are of the old style, and if they are placed opposite than the second clip pries open the first. If the two clips are offset by 90 degrees then it is usually reliable but a clip is occasionally ejected at high speed.

Any propeller or impeller inserted has it's own set of the red connectors. The red axle of the shaft spinner just pushes through the blade set's white connector and clips to the blue 3D connectors. It detaches quickly when desired. The curved panels are floppy and fall off, which creates sudden imbalances at 600 RPM that cause serious failures. I would like to build more blades with regular panels and add rod locks to this curved panel blade. Instructions will be made for this crank fan eventually, but I do not have enough parts to rebuild it and it has too many issues.

13
Site Feedback and Questions / Optional Part Index in Profile
« on: August 05, 2020, 02:51:58 am »
There is currently a short Personal Text entry and a Signature in the profile, but there is no entry for text only displayed on the profile page. I would like if there was an optional entry for Part Index, where users can specify some of the types of parts they have (users can choose which part types to even list) and show a status of Insufficient, Sufficient, and Excessive. That way I can easily see if I want to buy or sell parts to another member. I have a medium desire for this, it's not very important but it's not useless.

14
Other Discussions / K'nex Bridge Track Connectors (9) for sale or trade
« on: August 03, 2020, 03:32:39 am »
I don't ever use these 9 bridge track section connectors, because the 30 centimeter bridge tracks are just a one-off piece that can easily be made with solid orange connectors instead. They cost $1.31 each new and are rightfully discontinued. These parts are washed for visual cleanliness only (not that they were visibly grungy before), and have trace amounts of maroon and blue crayon that cannot be removed easily (haven't tried a brush). All 9 pieces are packed in a paper envelope, free shipping (message for location, lax negligent United States). One piece was discovered after the photos were taken, but it is completely identical to the other 8 in condition.

Payment: $11.79 of used K'nex (using new prices) or $9.43 cash
Angled Orange Clips ($0.15 each)
Curved Panels ($2.75 each)
Light Green Flexible Rods ($0.48 each)
Rod Locks ($0.62 each)

Most used discontinued parts are more expensive than they were new.

15
General Knex Discussion / [deleted]
« on: July 14, 2020, 12:16:28 am »
[deleted - please allow full deletion]

Pages: [1] 2