Another Arduino project

[Scott_M]

As I had mentioned in TorontoBuilders thread I needed to make a small machine to automate a repetitive job I do. I was fairly apprehensive about tackling a new programming language and have put this off for too long. Well reading all the other threads got me motivated so I bought a Genuine "Uno" a SainSmart L293D Motor Drive Shield and a couple of CanaKit nema 17 steppers, I also used a RC servo I had in my box of RC stuff. I think these will work fine for my application.

the process is

1st Step motor turns rubber feed wheel an exact amount feeding stock a specific distance.
servo motor brings down a hot wire past the end of the plastic rod and retracts, this polishes the end
2nd stepper motor brings down a razor blade and cuts the plastic rod to length and retracts.
repeat a specified number of times.

It took a couple of evenings of head scratching but I think I have proof of concept at this point. At least enough proof that I will feel comfortable making the rest of the mechanical parts.

Here is a short video of my progress.

www.sdmfabricating.com/upload_page/StepperTest.wmv

Scott

 

[chucketn]

Looks good from here, Scott.
You may have heard that Radio Shack is in financial trouble. I visited the local store a few days ago to see what they might have in Arduino stuff. The store was almost empty, and was having a 50% off closing sale. I managed to pick up a breadboard component assortment, a Seeed Studio motor shield, and a blank copper circuit board. The total was $40! The motor shield was the last Arduino accessory left, $4.00!
There's another store a few miles in the other direction, I hope to check that one soon.

Chuck

 

[canadianhorsepower]

It took a couple of evenings of head scratching but I think I have proof of concept at this point. At least enough proof that I will feel comfortable making the rest of the mechanical parts.

Here is a short video of my progress.

www.sdmfabricating.com/upload_page/StepperTest.wmv

Scott

I can't watch the video

 

[Scott_M]

Hi Chuck
Yeah I heard about Radio Shack, I'll be in town tonight and thought I would stop as well.

Luc
Not sure why you can't see it. I just put it on my website ( don't want it on youtube), in IE the link should open your media player and just start playing. In Chrome it downloads and you have to click on the download to make it play. I am in Win 7. I don't know anything about Macs if that is what you are using.

Scott

 

[Swifty]

Can't view it on my iPad either, another page opens, but there's nothing there.

Paul.

 

[TorontoBuilder]

Can't view it on my iPad either, another page opens, but there's nothing there.

Paul.

I think the video issues stem from it being a windows media file...

 

[TorontoBuilder]

As I had mentioned in TorontoBuilders thread I needed to make a small machine to automate a repetitive job I do. I was fairly apprehensive about tackling a new programming language and have put this off for too long. Well reading all the other threads got me motivated so I bought a Genuine "Uno" a SainSmart L293D Motor Drive Shield and a couple of CanaKit nema 17 steppers, I also used a RC servo I had in my box of RC stuff. I think these will work fine for my application.

the process is

1st Step motor turns rubber feed wheel an exact amount feeding stock a specific distance.
servo motor brings down a hot wire past the end of the plastic rod and retracts, this polishes the end
2nd stepper motor brings down a razor blade and cuts the plastic rod to length and retracts.
repeat a specified number of times.

It took a couple of evenings of head scratching but I think I have proof of concept at this point. At least enough proof that I will feel comfortable making the rest of the mechanical parts.

Here is a short video of my progress.



Scott

Good work... you have it beat if you got that all working. I took the liberty of trying to fix the video issues for everyone

http://youtu.be/ULf2l8mX2v0

 

[Nerdz]

Do you have sensors for the job? You cant rely on counting steps all the time, you should have some sort of proximity switch to detect when the wire is at the desired length.

 

[Scott_M]

Thanks TB

Chris
Thanks for your input.
On the first motor ( Feed ) I am going to see how it works without a sensor. The stepper will have a rubber wheel with an adjustable "pinch" against a bearing to drive the material, this should offer little resistance to the motor, I do not think it will lose steps. I will find out.
On the second motor I am going to have a micro switch for it to "home " to in the start sequence.
The material I am cutting is in 1 meter lengths, this means I will only be doing about 45 cuts before I have to stop it, reload, reset and start over.
I am thinking it can't get too far out of whack in that short of a run .
But.....you never know !


Thanks

Scott

 

[TorontoBuilder]

Do you have sensors for the job? You cant rely on counting steps all the time, you should have some sort of proximity switch to detect when the wire is at the desired length.

Agreed... I'd feed my stock to be cut until it broke a beam from a photo sensor, or laser.

That way you could use a normal less expensive motor if you wished and get to learn something else.

 

[Scott_M]

Is anybody else receiving "email notifications" really late ? I just got this one. Almost 24 hours.

I did a little figurin' and with the diameter of my drive wheel and my stepper using "interleaved" steps I should be getting about .003" of linear movement of my stock per step. That is plenty close for this application. If I can hold .010" I will be happy.
I think it may be rather difficult to sense the end of a 1.5mm piece of plastic with out being anywhere near it. The hot wire has to "finish" this end , so it has to be free and clear of anything else.
I am going to try it just counting steps and hope it does not bite my butt.
I will set up a few tests before final design and hopefully get it figured out before I make the final assembly.

I do appreciate the feedback and suggestions !! Keep'm coming.

Scott