Project I've been working on

[Charley Davidson]

Started this a while back but had to put it on the back burner because of space restraints, moved into a bigger unit and been crack-a-lackin on it.

I'm ready to start making the internal table parts & motor mounts Hope to have it up & running very soon.

http://www.facebook.com/photo.php?v=3539111524517

http://www.facebook.com/photo.php?v=3541189616468

 

[Neverdone]

Do I spy the makings of something CNC?? Plasma? Hydro? mill?

 

[Charley Davidson]

Do I spy the makings of something CNC?? Plasma? Hydro? mill?

Plasma/Router

 

[jfg455]

I still need to build a water table for my plasma. Sooo handy to have! Looking good.

 

[Neverdone]

Plasma/Router

Soooooo........ couple questions.............

What are you using for software?

You using stepper or servo drives?

Your own design or some one elses?

I need more info on this please..................

 

[Charley Davidson]

Soooooo........ couple questions.............

What are you using for software?

You using stepper or servo drives?

Your own design or some one elses?

I need more info on this please..................

Mach 3 but I think it's a limited version that came with my stepper motors & drives

Stepper motors

My own design which changes as it goes[S

Trying to make it as sturdy as possible so I can do some light milling in aluminum as well a routing in wood.

 

[Neverdone]

Your own eh, well then we definitely need more info on this monsterpiece! What kind of stepper drives?
Type of interface to the drives?

 

[Charley Davidson]

As far as electronics go I have 4 640oz stepper motors and the appropriate drivers/Bob's for them but I did drop one motor so may only have 3
I'm using an old windows based computer not sure what OS it has yet.

Need to figure out the gearing I'm gonna use and parts so I can make my motor mounting plates and get it under power.

 

[echnidna]

The optimum gearing is found when you set the accuracy of the machine to the motors. eg if you want the machine to be accurate to .001" then 1 step of the motor should move the machine by .001"

If you half step the motors then one half step needs to move the machine .001"

This means the machine can operate at your finest tolerance at maximum speed

Be wary of micro-stepping much finer than a half step as many motors do not have accurate linear movement much below half step.

 

[Charley Davidson]

The optimum gearing is found when you set the accuracy of the machine to the motors. eg if you want the machine to be accurate to .001" then 1 step of the motor should move the machine by .001"

If you half step the motors then one half step needs to move the machine .001"

This means the machine can operate at your finest tolerance at maximum speed

Be wary of micro-stepping much finer than a half step as many motors do not have accurate linear movement much below half step.

Is this something I have to figure out before buying my gearing?

 

[echnidna]

Is this something I have to figure out before buying my gearing?

yes, it determines the ideal ratios you need for best performance

 

[Charley Davidson]

Guess I need to do some studying [S

 

[Charley Davidson]

I'm planning my motor mounts and gearing so I'll need some expert help as I only want to do this once.

What info do you need to calculate what gear ratio I'll need?

My steppers are 640 oz, 4 phase, step angle deg/step 1.8

The thread on my Z axis is 9-10 per inch

My gantry Y axis is a hauser linear drive hle100 you can google and get a pdf with all the specs

all the info I have at this time.

 

[echnidna]

1.8 degree motors have 200 steps per revolution in full step mode

Using as an example only,
if you have .001" movement/step then 1 motor revolution gives .2" movement.

With 10 threads per inch on the Z axis, 1 turn of the lead-screw will give you a .1" movement. So a 2:1 gearing is required.

I'm not familiar with hauser linear drive hle100 rack and pinion

Also you have not mentioned your x axis and whether both the X and Y axis will use lead-screws or rack and pinions or even chain drives.

 

[26Troadster]

all that stuff is french to me, i'll stick to the old ways, manual. good to watch thought.

 

[Charley Davidson]

1.8 degree motors have 200 steps per revolution in full step mode

Using as an example only,
if you have .001" movement/step then 1 motor revolution gives .2" movement.

With 10 threads per inch on the Z axis, 1 turn of the lead-screw will give you a .1" movement. So a 2:1 gearing is required.

I'm not familiar with hauser linear drive hle100 rack and pinion

Also you have not mentioned your x axis and whether both the X and Y axis will use lead-screws or rack and pinions or even chain drives.

My X axis will be a fixed chain drive (chain pulled tight and fastened to each end then the sprocket will travel)

I'll try to attach a PDF of the houser, it is my Y axis, it is all internal

I'll also post some files of the driver info

 

[Charley Davidson]

Here are some specs I got with the steppers/drivers

 

[Neverdone]

This is some great info guys!!! Keep it coming!

 

[echnidna]

Unfortunately most cnc forums / websites don't go into the resolution (movement per step) or how to determine the gear ratios you need to use.

I am decidedly rusty on cnc stuff and as you have found it can get a bit heady at times.

I'll have a look at your data over the next day or so and get back to you.

Do you know how accurate you want your machine to move, ie do you want it to move accurately to .001" or finer or coarser. Finer means the machine will work slower and coarser means it will run faster. That said speed is not usually so very critical as the machine will keep doing its job while you sit there and watch it work.

as a guide a .001" step on a turned steel shaft can just be felt with the tips of your fingers, you won't feel much finer

 

[Charley Davidson]

I think .001 should be fine as it will primarily be used as a plasma cutter. Routing in wood that will be extremely good and should be pretty good for some milling in aluminum or as a boring table


I just discovered I can use E-Machineshop http://www.emachineshop.com/ to design/draw my parts so I'll be busy with that for a couple days. Not sure what the limitations/restrictions are on that program though.