I want to try to use squair steel tubing with the paper templates use the punch to make marks then pre drill then drill holes the same as contraptor parts.

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joshua w.

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Dec 22, 2009, 1:18:12 PM12/22/09
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I want to try to use squair steel tubing with the paper templates use
the punch to make marks then pre drill then drill holes the same as
contraptor parts. Then cut larger access holes on the other two sides.

I have seen discussions about steel angle but I have not herd anything
about squair steel tubing.

Vitaly Mankevich

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Dec 22, 2009, 1:54:13 PM12/22/09
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I've been long looking at this tube, thinking that it might work with
Contraptor: http://www.mcmaster.com/#6535k21
Doesn't say what is the hole distance but I'm pretty sure it's 1/2" or 1"

Riley Porter

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Dec 22, 2009, 2:06:51 PM12/22/09
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Joshua:
I would like to eventually transition to using a steel tube framework for the linear slides in the future.  They provide less "special stuff" needed.  Readily available and pretty easy to work with.  (hack saw).  The thing in question right now is how do we make the "mounts" DIY and contraptor friendly.  Meaning I used laser cut masonite (cheap) to make the mounts.  
Then added the correct spacing needed.  This is DIY'able with a 3/4" wood chisel and a square tube to use as a template... hit it with a hammer into the wood and now you have the needed outline use a wood chisel to remove the inside and its done.

So I don't see this method being that hard to implement since it complies with contraptors fundamentals.  DIY'able and aligns.

So we will see.  However if you want the skp file of my experimental stuff I can get it to you.


Vitaly, not sure how that would be used to be a linear base for bearing to run on.

Ril3y

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Riley Porter
Sr. Network Security Engineer

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joshua wojnas

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Dec 22, 2009, 2:22:56 PM12/22/09
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this also works well with squair steel tubing or aluminum squair
perforated or not I emailed mc master about the hole center spacing
and hole diameter. I also would like it if you would see this... if it
was tapped down the center your steel tubes could slide down the
channel.

http://www.mcmaster.com/#8672k31/=51n9o5

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thanks for your time,
Joshua Wojnas
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My webpages on electronics
... comming soon

Vitaly Mankevich

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Dec 22, 2009, 2:23:28 PM12/22/09
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Riley used 3/4" steel tube for linear rails which I think is a great
concept. For structure, you want 1" tube, however it can also be used
in the linear rail arrangement as well.

By the way I got the package with masonite templates and mounts
yesterday and after holding the mounts in my hands I have to say they
look and fit very nice. I think just a few adjustments to make them a
bit more universal is all that's needed. Also I'd like to find DIY
equivalents in aluminum.

joshua wojnas

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Dec 22, 2009, 2:24:22 PM12/22/09
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I like delrin myself I think drilling streight holes and getting the
bearings in right and adjusting everything else would be a problem
also if it is supported by that wood stuff that could be a problem.

Vitaly Mankevich

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Dec 22, 2009, 2:25:55 PM12/22/09
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UHMW channel walls actually curl inward, and it is pretty tight, so I
don't know if this would work well.. But with steel tubes you could
use all kinds of bearing arrangements

joshua wojnas

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Dec 22, 2009, 2:27:48 PM12/22/09
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I think aligning a squair on its side is hard. Now it could be
adjusted with screws in the end if it was a pipe then use delrin with
a hole in it as your slide.
why not keep everything level and modular?
Also level and modular might work with the delrin u channel. it is not
uncommon. granger has it online stores have it. wallmart cutting
boards have it...

--

Vitaly Mankevich

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Dec 22, 2009, 2:28:41 PM12/22/09
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Yeah that's one issue I have with masonite, it's only strong in its
plane. It would work great however to support the ends of the rails,
whether they are square tubes or round rods of arbitrary sizes

joshua wojnas

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Dec 22, 2009, 2:28:59 PM12/22/09
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Oh your right they do curl in. Would that be a problem I thought tight
bearings to a point were good with screw drives.

Riley Porter

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Dec 22, 2009, 2:29:31 PM12/22/09
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I misunder stood about the structure stuff.. yah you are right.  About the Masonite (end mounts we can call them to clear up confusion)  They are very nice and fit great.  But the best part is since we are using 10-24 screws you can still be a bit off if any of the other parts are not spot on and still get away with it.

Meaning, if your linear slides (the alum tubes with bearings hanging off of... the ones i made) were not exactly right you can adjust the tubes a bit to help them square up.  So as long as you are not WAY off its pretty easy to square stuff up.  And its really easy to get things close using the laser cut templates.  Infact its almost easy to get it 100% perfect. 

Riley

Vitaly Mankevich

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Dec 22, 2009, 2:29:53 PM12/22/09
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Oh yeah they can be too tight easily

joshua wojnas

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Dec 22, 2009, 2:36:00 PM12/22/09
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Ok how about make a squair of contraptor parts then 4 machine screws
to adjust the location of a squair rail that is horisontal not at a 45
degree angle? that way it uses modular contraptor parts.

Vitaly Mankevich

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Dec 22, 2009, 3:00:55 PM12/22/09
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45 degree square rail results in fairly compact arrangement of the
carriage with bearings. BTW, round tube could also be used in place of
the square rail, but you would still need to adjust it relative to the
second rail.

Vitaly Mankevich

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Dec 22, 2009, 3:12:12 PM12/22/09
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It's a valid concern - I agree that it might be hard to align square
tube at 45 deg angle using end mounts made with a chisel - if you get
the mount a bit off (and you probably will) then you need to rotate it
a bit with no point of reference (which you have in case of lasercut
mount)

Riley Porter

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Dec 22, 2009, 3:56:18 PM12/22/09
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well for me its easy :)  I just used the contraptor templates.  But you can do it by print templates and "dotting" the corners.  Line up the square corners on the dots hit with hammer done.

Thats just how i see it.

Ril3y

On Tue, Dec 22, 2009 at 3:12 PM, Vitaly Mankevich <albanetc.sr@gmail.com> wrote:
It's a valid concern - I agree that it might be hard to align square
tube at 45 deg angle using end mounts made with a chisel - if you get
the mount a bit off (and you probably will) then you need to rotate it
a bit with no point of reference (which you have in case of lasercut
mount)

On Tue, Dec 22, 2009 at 11:27 AM, joshua wojnas <jos...@gmail.com> wrote:
> I think aligning a squair on its side is hard. Now it could be
> adjusted with screws in the end if it was a pipe then use delrin with
> a hole in it as your slide.
> why not keep everything level and modular?
> Also level and modular might work with the delrin u channel. it is not
> uncommon. granger has it online stores have it. wallmart cutting
> boards have it...
>

joshua wojnas

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Dec 22, 2009, 4:13:41 PM12/22/09
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I found some information from mc master carr

The holes on our part number 6535k21 are on 1 inch centers.
&

Hole Diameter 11/32 "
Wall Thickness .083 "
Wall Thickness Tolerance ±.008 "
Height x Width 1 x 1" "
Length 6'
Length Tolerance ±1/8 "
Straightness Tolerance Not Rated
Tolerance Standard

so it seems to be contraptor compatible is the hole size much
different than the contraptor and the bolts and nuts that go with it?

On Tue, Dec 22, 2009 at 3:56 PM, Riley Porter <riley...@gmail.com> wrote:
> well for me its easy :)  I just used the contraptor templates.  But you can
> do it by print templates and "dotting" the corners.  Line up the square
> corners on the dots hit with hammer done.
> Thats just how i see it.
> Ril3y
>

> On Tue, Dec 22, 2009 at 3:12 PM, Vitaly Mankevich <alban...@gmail.com>

Vitaly Mankevich

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Dec 22, 2009, 4:16:24 PM12/22/09
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Contraptor bolts are 10-24, the head is 3/8" dia, so washers is
probably be a good idea

joshua wojnas

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Dec 22, 2009, 4:32:59 PM12/22/09
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Now your method of using a hammer to cut the holes to support your
rails but is this system scalable like the contraptor is it modular?
It proably would not be able to be made long or heavy...

Now if you used flat pieces of delrin and squair tube with the delrin
tapped it could be tightened down on all sides of a squair steel tube
and use all standard contraptor parts.

http://www.mcmaster.com/#plastics/=51oylo

Riley Porter

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Dec 22, 2009, 4:51:10 PM12/22/09
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There is no such thing as one way to do it.  Meaning if you need a small tube under 3' then do it this way.  If you need a longer stronger one.. do it another.  I just cant see how doing it one way is going to be possible.  Not to mention UHMW is not equal to linear bearings.

Ril3y

>> On Tue, Dec 22, 2009 at 3:12 PM, Vitaly Mankevich <albanetc.sr@gmail.com>

joshua wojnas

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Dec 22, 2009, 5:01:40 PM12/22/09
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true but the 3 foot tube could be cut down with more pieces to spare
afterwards it would be easy to source.
Now you mention UHMW is not equal to linear bearings you mean skate
bearings? or do you mean the linear bearings that sell for a lot more?
Their are sinthered bearings meaning their a soft metal and other
things that slide smooth and do not have ball bearings in them. You
can see how ajustable delrin or UHMW poly... bars or strips could be
adjusted by screws and tightening them down or adding spacing. Now
trying to adjust the system for skate bearings would be much harder
would it not? also the tollerances you loose by drilling holes for the
skate bearings isn;t that not a good way?

I jus tthought ther might be a way to make it work for pc board making
to table size it is not a universal fit but within that range it might
work.

>> >> <alban...@gmail.com>

Riley Porter

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Dec 22, 2009, 5:51:30 PM12/22/09
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I mean skate bearings.  The design I used needed 2 cuts for the whole rail.  No plastic cuts nothing.  2 more cuts for the "trucks" tube.  and its solid it does not move a bit.  It provides fine adjustment for table levelness as well as moving the rail tubes in and out if needed.  This is not a theoretical argument. This is something I have sitting on my work bench.  The difference is huge.  Friction decreases, speed increases with skate bearings and steel.  

From a business standpoint any "custom" parts that we  (as in contraptor owners) have to do is done by 1 of 2 things.

Find someone who will extrude plastic in small affordable amounts.  Which is next to 0 chance of that.

Or build these parts by hand for every kit sold.  We do not make much money on the kits already.  And if we increase the "build time" then we make little / nothing.  

Steel tube skate bearings are def the way to go.  They are indeed where the next version of the mini-cnc is going.

Understand that I am talking from an production / co-owner point of view.  The idea of DIY'ers is our previous build plans can always be used and adapted any way they want.  From an "offical build" perspective the contraption (mini-cnc) and more importantly the framework will continue to move forward but improving on cost to time ratio and cost to quality ratio.  Let me  be clear about the above statement.  
We intend on keeping contraptor DIY'able but might choose an official version of xyz part over another version due to not only performace but ease of build / cost of build.

So when you think of an idea that will work thats cool post it up.  But something to keep in mind is we are trying to keep costs down for people who want to buy the framework too.  So by keeping designs easy and minimizing "special fab" parts to a minimum there is a cost saving that is passed directly to the consumers.

Ril3y

joshua wojnas

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Dec 22, 2009, 4:23:26 PM12/22/09
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washers would throw the tolerance off wouldn't they allow the entire
thing to slide around? Could a ratchet extention fit inside to tighten
down a nut or bolt? Maby larger bolts and nuts could be used with this
for a modular off the shelf contraptor.

joshua wojnas

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Dec 22, 2009, 9:59:00 PM12/22/09
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Humm I do not have one so you definitely are right since you have both
to compare.
I appreciate you taking time to discuss and write back. My kit is
coming in and maby sometime in the future I will try the skate
bearings if they become standard contraptor practice.

>> >> >> <alban...@gmail.com>

Riley Porter

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Dec 22, 2009, 10:17:22 PM12/22/09
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NP josh and the reason you do not have a kit yet is we are still waiting for out angle to come in :)

We will always have time to talk to ppl excited about contraptor.  I hope I didnt come off talking like.. I have one so shut up.  Cause that was not my intention.  I too used to think in a "I can make that.. its not that hard" style.  But I have had to adjust my thinking to a "can we make that cheap enough so that people will buy it?" or "if we can make this part cheaper is the quality still high enough to be good" kind of thing.  So its tricky for sure.  Infact Vitaly and I have got into disputes about that exact stuff :) so all is normal!  We are learning and adjusting at we go.  So bear with us!

Ril3y

joshua wojnas

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Dec 22, 2009, 11:00:30 PM12/22/09
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Thank you & yes he told me the angle is what your waiting for the wiz
not bang not boom electronics is proably where you guys can make some
$ off your kits especaly if you master the lazor & hotplate & maby a
stencil for placement... or get a contraptor & vacume+ porus UHMW
poly... to pick n place.
I know me and my dad get into engineering "discussions" a bit.

>> >> >> >> <alban...@gmail.com>

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