V-Slot (Linear Acuator) Bundle (belt drvien)... can it be sourced for cheaper?

[J.Dugan]

Hey Gang-

I believe I had asked about this in a the past a little bit...   and still a bit out of my league here..

but I found this:

http://openbuildspartstore.com/v-slot-nema-17-linear-actuator-bundle-belt-driven/
* 1000mm length
* with stepper
* cost: $110.00 USD

Which looks like it has everything one would need to get up and running, right out of the box..(outside of power management)

Travel for the 1000mm version is 845mm = 33.2677 in. = 2.772308333 ft.

Which I'm hoping enough travel...  (I'll know more once I get closer to sourcing the rest of the components)

The 1000mm of rail/stock (V-Slot® 20x40 Linear Rail) seems to only cost about (roughly) $15 bucks or so..

And a nema stepper can usually be found laying around.. or salvaged from some printer/scanner..etc..  (although I'm not sure if the stepper needed, needs to fit certain specs or dimensions?)

can all those pulleys, belts, brackets..etc..etc  be sourced elsewhere?  for cheaper?  (even better if another site had a whole bundle.. but cheaper)


That being said.. I have some questions for those who are familiar with this mechanical hardware.. (this will be my first stepper projects.. and first time messing with anything rail/slider/mechanical related)

How does this 'bar' mount?

* I see one side has an open bracket.. that would/could attach to your intended 'base'... but how does the side with the stepper mount/attach/secure itself to your 'base'?

* Mounting position/direction? Does the 'gantry plate' need to be flat? (facing up?).. like in the pics:
http://openbuildspartstore.com/v-slot-nema-17-linear-actuator-bundle-belt-driven/

or can it be turned.. and be on its 'side'.. with the front/top of the gantry plate facing towards you (if you were standing in front of it?)  Does that put odd stress/pressure on the v-wheels?

After the initial project/prototype... I'd like to make some more for friends... so am looking for the best route to keep costs down.. as well have everything I need, so I dont miss anything.


*Please keep comments on-topic to linear rail systems!  :) 

thanks!

[the_digital_dentist]

What are you building?

If you're trying to minimize costs it isn't difficult or expensive to find pieces for that stuff, and fabricate a motor and pulley mount.  We have a machine shop...

[J.Dugan]

Hi Mark-

I'm building one of those 'bar-bots'..  so currently focusing on the mechanical/engineering portion of the 'gantry' (if it can even be called that)..

Basically a simple "X"-axis linear rail system.


I'm trying to minimize costs a little...  but not sure if the trade off in time making things from scratch make sense.

The main 'v' slot material/bar cost is fine...

Being new to this.. I guess I was taken aback  how much the other things cost.. if the motor is $17 & the rail is only $15.. thats roughly $80 for the belt, pulleys and brackets.

Maybe this is just the normal costs of this stuff?

It would be nice if the whole bundle kit was around $50.00  LOL..

Hence I was wondering of other places to source...etc.   (just not my scene yet, to know much about this hardware)..

I dont need any custom profiles or anything... so the v-rail stuff works for me.

I think if I had more exposure to this sort of stuff (like had built several 3D printers or CNC machines)... I'd be more comfortable knowing what I can improvise on and what I can make on my own..etc.

So if we take the motor out of the equations.. we're (roughly) $92 bucks!

How can we get it down $40 more?  :)

Is any of this stuff I am looking at 'proprietary'?  As in only one place will sell this part?  (customer profile bar.. with custom wheels that need to be used with it..etc)

I'd like to be able to freely choose from any vendor that has the part for the right price.  (So I hope I havent been wasting my time on this specific bundle)

[the_digital_dentist]

Belts cost about $1/meter, or I may have some spare stuff you can have, depending on how long it needs to be.

Pulleys are just flanged ball bearings that cost about $2.

Motor mount can be printed plastic or made from scrap aluminum.

Pulley mount is scrap aluminum.

The V wheels are available from different sources, but it's probably easiest and not too expensive to just buy one of the kits for the carriage that moves along the rail.

Belt clamps are 3D printable, if needed.

[Kevin Bruce]

Perhaps the links in the description of this vid will help.
https://youtu.be/WKmzlMvxC7I

[J.Dugan]

Thanks for the link!

The links in the description are great!

So if I attempt to piece things out and build it myself...

I understand that one of the pulleys is connected to the stepper shaft via set screw....

but I'm not clear how to other end/pulley mounts?

In that video.. it looks as if the pulley (the one -not- connected to stepper motor) is mounted... upside down?  (is it on a bearing or something to allow it to freely spin?)

Posting/thinking out loud here..

Required BOM:

* Linear Bearing Slider Blocks: (4) - https://www.amazon.com/s/ref=as_li_ss_tl?url=search-alias=aps&field-keywords=SCS8UU+&linkCode=sl2&tag=nc07d-20&linkId=37324e043fafd794da379c8234d7a9ab
* Linear rail/rods: (2)  8mm x 1000mm - https://www.ebay.com/itm/8mm-x-1-meter-Precision-Chromed-Rod-for-RepRap-Chrome-Prusa-3D-printer-CNC-O1/331047793540?epid=1531524429&hash=item4d13fc7384:g:nXIAAOSwsQVZe26c
* Linear rail support/mounting blocks: (2) 8mm - https://www.ebay.com/p/Hot-2pcs-Sk8-8mm-Bearing-CNC-Aluminum-Linear-Rail-Shaft-Guide-Support/1492943918?iid=232727843661&_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D44040%26meid%3D16c667e668bd460e8a3ff8f27332abc7%26pid%3D100005%26rk%3D6%26rkt%3D12%26sd%3D182405980017%26itm%3D232727843661&_trksid=p2047675.c100005.m1851
* Timing Belt Pulley: (2) GT2 16 Tooth - https://www.ebay.com/itm/GT2-16-Tooth-Pulley-5mm-bore-3D-printer-REPRAP-ROSTOCK-Mendel-Prusa-i2-i3-/331463063315
* Timing belt: (reel) - https://www.ebay.com/itm/330987181822?rmvSB=true