Whells

Adapt wheel with servo

Description : Instructions of basic assembly of an easily purchasable wheel in any commerce of R/C model, this he has a diameter of some 7 cm for 2,8 cm of wide, and this composed one for two parts; a rim manufactured in plastic PVC hardened and a covered with flexible rubber with camera of air.

For the traction of the wheel, in this case we will use an I serve standard futaba S-3003 al that previously there we will be tricked so that rotate 360º, this I serve has a sufficient pair and an adequate, slow velocity for robots explorers or of most greatest.

As to do it ? : Keeping in mind that the axis at the outset of an I serve not this manufactured for to be adapted to a wheel what we will cause is to adapt it ourselves depending on the type of chosen wheel.

The wheel that I and chosen is of an upper diameter al so great of the I serve so that this remain high of the floor some centimeters, thus same also has a wide rim and by this, the interior bucket of the rim is large with what the head of the I serve will arrive in no case by if alone to the external part of the rim to be able to screw it. 

To solve this I throw one must manufacture a supplement for cover the distance and thus in this way be able to screw the head of the I serve to this and on the other side the rim. Just as it can be appreciated in the photo , I have used a large dish of the head of the I serve (of the various that brings each I serve in its package) and it and screwed with screws pasantes al block that will do of supplement to arrive until touch the interior part of the rim of the wheel. The block this built with 3 bars of plastic "evergreen" of 6,3 x 6,3 mm. but a laminates of 2 mm. to complete the total of thickness required of >= 8 mm. all the assembly this filed in its tips to be adjusted perfectly al interior bucket of the rim and to avoid in this way that displace itself or vibrate. (The construction of the block of supplement can be of any material that we have by hand that cover the necessary distance)

Now alone it remains us to put the assembly in the interior of the bucket of the rim and to perforate the It splits frontal of this to pass the screws pasantes that set both parts, lending special attention so that the dish of the I serve remain well centered in the wheel, since otherwise would be able to remain disoriented and al to cause to rotate the wheel to go giving leaps as a tappet.

The screw of obsession of the dish of the head of the I serve we will introduce it for the central hole of the wheel al that previously will have widened by means of a reel of the adequate so that even measure the head of the screw. Thus therefore the wheel we will put it and we will remove by means of this only screw that maintains it united al axis of the I serve.

If all to gone well we will have the wheel adapted al I serve just as is shown in the following photo.

As it finalizes thing to comment that some exist kits of improvement of the servos that bring the upper part of the I serve with a very adequate metallic bearing to use it in this assembly, for thus avoid wear of the axis and outskirts.

Adapt 360º for servo Futaba S3003

Adapt 360º

Description: In the following lines will be shown like to modify or "trucar" an I serve standard Futaba S3003 to do that this rotate 360º free and itself behavior as a motor with cruise control and direction through PWM (" I Press Widht Modulation ", modulation by width of impulse).

Steps to Continue : The first step to modify the I serve will be to open the subsequent cover of the I serve desenroscando the 4 screws with a screwdriver of star of the adequate measure, after which we will dismantle completely the I serve.
	The second step will be to remove the upper cover that encloses the box reductora composed by gears, we will take special attention to the disposition of all the gears before dismantling them and if he were necessary we will aim him in a role for to forget us not.
Availing oneself of a well sharp cleaver we will have to cut the mechanical stop of the gear at the outset of the I serve just as he is shown in the photo, for in this manner leave to rotate freely and without limitations al axis in the 360º. Being careful of leave no remainder or marks of the cleaver in the axis or gear since otherwise will produce friction and noises al to be moved.
	Once it finished the mechanical modification we pass to the electronic part. The modifications to do in the circuit of control of the I serve are the following: Substituting the potentiometer of original 5K for one of 5K multiturn vertical as the one that is shown in the photo in blue color with screw of adjustment.
To the variable resistance multiturn we will weld 3 cables just as is seen in the following photo, in this manner the screw of adjustment remained situated to a side of the I serve and practicing a hole with a reel of 3 mm. we will be able to do the adjustment of stop since the outside of the I serve without having that to open it again. (there is a type of resistance multivuelta with horizontal adjustment although is but difficult of finding in square so better format to weld the wires hehe)
Schematic & circuit intern + modifications

Operation And adjustment: we Will Connect the circuit of control of I serve and we will send the sign PWM equivalent to the position of stop of the motor (central position), normally this sign will be the half of the wide total of the pulse (0,5-2,5=2mS/2=1mS+0,5 =1,5mS). With this continuous sign in the entrance of the I serve we will adjust the potentiometer multiturn until the motor stop completely with which we will have adjusted the point of stop or medium. A sign but wide or but narrow that the sign of stop, will do that the motor rotate in one or another sense and as much as but be greater or smaller that the central sign , but quickly rotated with what already we have cruise control and total direction.

They arrived at this step the I serve he will behave mechanically as a current and normal motor.

If we use two servos for the traction of a robot we will have to do a fine adjustment of the velocity so that the robot straight advance and himself he deviate not due to different adjustments in each I serve. To do this we will send the same sign to the two servos and by means of the screw of adjustment we will do that the two servos rotate exactly to the same velocity.

I dissuade to convert again the I serve as was before once modified, by the electronic part there is not problem and can be mounted again all just as was but the mechanical part no longer has stop and if what we will cause is to force the potenciometer of the axis at the outset of the I serve that will do the times of stop, with the consequent wear or badly operation.

Production of CrazyWhell

Crazy Whell

Description :Production of a crazy wheel or rolls of queue, for robot with easily purchasable components of the mark Meccano, the total height of the assembly once mounted is of 4 cm. and the weight is scarce, with what do it adequate for small robots "sniffers"

The components used can be seen in the following image:

Necessary materials and codes of pieces of Meccano:

Instructions of assembly : For this assembly due to the simplicity and rapidity of assembly I am not going to put photos neither steps, and what you will be able to see will be a video of assembly with what I almenos believe that is the best system and the but easy to see as is mounted. The axis of it has a length of 3 cm. and we will have to cut it with a saw of iron or pliers of large cut.

I expect that you like this assembly and you do not limit to the typical wheels of table or chair of sale in hardware, since this wheel remains but harmonious with the type of assembly of a robot besides having some measures but adequate.

Articulation for Servos

Articulation Universal for Servos

Description :as many times we have wanted to do a leg with servos and we have seen the same problem... ? the axis of the I serve suffers a lot of al to charge the alone weight in a side, aside from the mechanical deficiencies that involves. Therefore well and here a solution practices to said problem, of quickly assembly although not so fast construction, besides we will be able to adapt as many servos as we want.

Production : The articulation this composed one for 2 parts just as can be seen in the photo, these two parts are you throw from 2 sections of 2 cm. of pipe of aluminum of 60 x 40 mm. To an of them himself him to cut the face but long (60 mm.) and to the other himself him to cut but leaving in both sides a separation of 1 cm. with what remains a hole of 4 cm . to put the I serve and with the flippers of centimeter that have remained can be screwed the I serve. The disk of the I serve he is screwed to the piece in the shape of OR by an extreme and by the other goes a screw M4 to do of second axis, for covering the distance among the part of the I serve and the OR mobile itself pondran some washers of nylon that at the same time avoided the total blockade of the axis al to press the nut that certainly to of being autoblocante so that press not of the all and not itself desenrosque.

Plans of construction and mechanized

Uses: It owed al original design, this articulation can be mounted of diverse forms to do for example extremities for robots, for do a small robotic arm and putting many in line to would be able to do a worm that move with the waves created by the movement of the servos for imitate the behavior of a worm or snake.