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make a micro controller driving a honing machine do what i want it to do....

watahyahknow

hello im ronald from the netherlands in europe and new to the website and a real noob to programming and micro controllers in general

 

i'm in the process of building a cilinder honing machine based of this idea

 

https://www.youtube.com/watch?v=7fctqivBqlk

my version has the cariage moving up and down part made slightly different as in i will use a crank to move the carriage up and down so the steppermotor driving that motion only has to rotate in one direction to hopefully make it a more fluid motion

adjustments in debt and stroke size will be done mecanicly on the crank and the length of the frive axle driving the hone

same as the machine on the youtube video i want to use an encoder on the hone motor to controll the steppermotor that makes the hone go up and down in the cilinder while the hone is spinning at a certan rpm (say one stroke to every 2.05 rotations or sumting like that)

this i can do with an arduino eazy enough i seen the step by step how to and the programmingcode for controlling a steppermotor with an encoder on youtube its one of the first standard experiments for cnc use using the arduino

 

heres the snag :

with the rpm of the hone staying the same you need to adjust the speed / distance per x for the up and down motion depending on the cilinder bore size and rotational speed of the hone to get the propper crosshatch from the hone

when a cilinder gets (a few mm ) bigger in diameter the hone travels a larger distance along the cilinderwall keeping all the speeds the same would mean a shallower angle crosshatch on a bigger bore or steeper on a smaller bore the best crosshatch pattern is about 45 degrees to shallow will wear out the piston rings faster to to steep might cause oil consumption in the engine from the start

 

wat i like to find is a way to put the formula below in the micro controller and make it user friendly for a non computer / calculus wizzard grease monkey/backyard mecanic (like me)

if the micro controller calculates the speed of the stroke all the mecanic has to do is enter the data he knows from the engine hes honing like L F and R intoo the system with up down keys

and have the micro computer calculate and set the calculation of S in the ratio for the up down motion between the encoder signal and the stepper steps

 

the formulla

Tangent (A/2) = {(L-F)xS} / (DxR)

A=included crosshatch angle in the middle of the bore

L=length of bore

F=stone length

S=strokes/minute

R=rpm

 

about stone length : some engineblocks dont alow for the stones on the hone to come out the bottom of the bore as they will crash intoo the webbing for the crank

so the total stroke needs the length of the stones subtracted at the bottom of the stroke , i like to be able to compensate for different length stones as i might use different hones

 

i like to have the formulla embedded in the program , if that isnt possible i would like to know how to use this formula in an excell file to get the needed data i dont have

 

i like to know wat micro controller is best to use in this aplication and hopefully the programming for it that alows me to put the formulla intoo it

and does wat i want it to do

i have found a lot of the loose items to make the hone machine do the moves one of them is a design for a digital leadsrew that alows paople to make treads on a lathe

 

but dont know yet how to get them to work together

any help would be apreciated

 

Parents
  • 0

    Hi Ronald,

     

    Sorry I won't be able to be of much help but I will post to your thread to bring it back to the top of the list. I am interested to know how this works out for you. It is possible you may not get replies of use until you provide more information. Sometimes you can look at other machines like CDC and 3D printers to find one that is doing a similar job and copy their mechanical structure. This appears to be a fairly precise and complicated application which may make the build more challenging. I hope you are able to build it.

     

    John

Reply
  • 0

    Hi Ronald,

     

    Sorry I won't be able to be of much help but I will post to your thread to bring it back to the top of the list. I am interested to know how this works out for you. It is possible you may not get replies of use until you provide more information. Sometimes you can look at other machines like CDC and 3D printers to find one that is doing a similar job and copy their mechanical structure. This appears to be a fairly precise and complicated application which may make the build more challenging. I hope you are able to build it.

     

    John

Children
  • 0 in reply to jw0752

    thank you verry mush for youre help with this

     

    i had shown the idea and explaned the changes to the basic setup of the honing machine

    on the controller side i found sumting that should work , the electronic leadscrew that clough42 is working on

    https://www.youtube.com/results?search_query=clough42+electronic+leadscrew

    he posted everything needed for the setup for free allready including the software for his use and it seems to be exactly wat i need in terms of controlling the the travelspeed based on the rpm of the honemotor picked up with the encoder,

    he uses it to cut single point tread on a lathe so the programming and travelspeed settings are a bit off for my need and he doesnt have the option for calculating the speed needed

    his design is based of

    a TI launchxl f28849c

    a 8 bit LED digital 8 key display stm138 modile for the arduino ARM

    and a small circuitboard of his own design

     

    in terms of hardware it should be perfect , as he explained in the first video of the series its a faster processor thats better in calculating on the fly compared to other micro controllers

    i'm just not knowlege able enough to write the code for the formula so that it automaticly sets everything up based of the data inserted in the parmeters

    when i listened at his explanation on the programming to see if i could change it for my use my eyes glazed over , and about 5 minutes after that i was in a corner with my aems around my knees rocking back and forth mumbling to make it stop , its just to mush info to learn in the time i have set myself to complete it

  • 0 in reply to watahyahknow

    Hello Ronald,

     

    I know very well the kind of machine you show in your first video. Unfortunately, the second link (with a playlist?) seems not working. Anyway, I know very well this kind of mechanical job, it is done when you have to repair the cylinders of a fuel motor and you should remove come 1/1000th of mm to the Aluminium head. I think that for a better understanding of the feasibility of the projects a handwritten draft scheme may be useful, explaining to us better what is the difference in your engine design. The friend   (John) suggest a 3D printer engine or similar. ost of the aspects in choosing the right mechanical approach (math sounds good to me) depends on two main factors: the material you need to manage and the kind of precision you want to reach.

    As far as what I know, this project is more impacting the mechanical aspects then the effective microcontroller you will use. A small microcontroller (one of the Arduino family for example) can be sufficient if you need a not too complex logic but what is more important is the motor and the moving design of the parts.

     

    Enrico

  • 0 in reply to balearicdynamics

    i fixed the link

     

    i can basicly make the mecanical part work without the microcontroller , it would take some experimenting on the speed of the steppermotor and a speed controller that drives the carriage up and down to get the right crosshatch pattern

     

    i could do that with building sumting like this :

    https://www.youtube.com/watch?v=jshb1Emadvs

    using an old drillpress i have allready

     

    the thing with using an encoder is that the machine starts to move as soon as the hone start rotating and slowing the hone down like from friction off the hone or the ramp up to full rpm will cause the up and down motion to adapt it movements

    it puts the stones in the right place of the rotation every time as the encoder tells its location in the turn and not so mush the rpm

    if i was to do this without the encoder it would basicly asssume that the the hone is rotating at 100 rpm all the time even at the ramp up to speed at start up or gets bogged down , its less precise doing it that way

     

    a 3d printer has cnc option and could move steppers youre correct but it cannot calculate the puls (encoder) to step (steppermotor )ratio on the fly  say it needs to move one step every 201 pulses and the total amount of pulses per revolution is 4000 youre going to end up offset so you need to keep going intoo percentages of a revolution or calculate when the rotations do come to a full number

    like i said my eyes started to glaze over from the explanation of clough42 but i do understand that only texas instruments 32 bit processor can take a long string of ratio calculations real time without interuptions , he tried arduino , and quite a few other microcontrollers but they couldnt do it in decimals for different reasons

     

    the first step is the calculation to set the ratio needed based on the inputs of the user

    once thats set that doesnt need to happen again on that engine as that ratio will be used throughout that job

    someone who knows how to set up excell could make a small program to get the last setting / stroke to rotation ratio needed

    the second step is to aply that ratio between the signal of the encoder and the stepper

    the stroke length influences the hatch pattern too but thats included in the calculation and hopefully automaticly entered intoo the system

    the stroke itself is set manually on the machine by moving the tap on the crack to or from the center of the crank the ratio changes when the stroke changes and when the bore size changes the speed at wish the steppermotor turns is set by the ratio of the encoder signal

     

    as for how the crank should look , think of this video but with the slot rotated horizontally and just using a direcly driven disk as a crank  , the slot will be machined in the base of the carriage that moves the hone up and down

    https://www.youtube.com/watch?v=E6micQrJKiI

    im planning to put multiple holes on different distances from the center of the disk that is the crank so i can set the stroke larger or smaller as needed for a job

    to set the maximum dept i might just shorten or lengthen the shaft driving the hone by chucking it in deeper or less deep in the drilhead holding it

    the hone will be moved using the cariage , its not yet sure if i will mount the motor and drillhead to the carriage or mount the motor above the carriage to the steel beam holding it and use a colapsable shaft

    https://www.youtube.com/watch?v=bqJwqjDHGHM like a drillpress spindle

    to drive the hone (the motor might be too heavy for the stepper motor to move up and down at speed)