Re: [Sailcut-users] Assymetrical SPI and Sailcut 6.10

[Simon B. <sim...@gm...>]

Thanks for the kind suggestions. I thought about my different options
during the design process and decided not to go ahead with a few options.

My main objective was to make significant time savings when plotting
triradials. Making a cloth cutter would have been very nice, but it mostly
requires a vacuum table and increases the cost and complexity of the CNC.
Since I'm only making sails for my own use, the plotter won't be used so
often and cutting the sails manually with a roller blade is already quite
fast.

Plotting on a non-vacuum table works very well with dacron but I expect
some challenges with lightweight nylon. I'll be able to tell in about a
month or so.

Thanks Robert for the idea of the kitchen flooring, that is indeed a very
nice option that I will consider for smoothing the tables! About the X axis
backlash, it seems to come mostly from the Z axis mechanism and there is
not much I can do about it. I may eventually compensate it in the
controller code, but it is so negligible that I guess I would be better off
going sailing instead! :-)

I'll keep you posted,

Simon



On Wed, Mar 30, 2016 at 5:03 AM, Robert Lainé <rob...@sa...>
wrote:

> Simon,
> nice kit you have made!
> For the X axis backlash, if you increase the tension in the teethed belt,
> backlash will reduce.
> For the joint between board, there is the option to cover the plywood with
> linoleum or thick plastic flooring which come in a roll. That will provide
> a smooth surface even over a gap of 1mm. Alternatively glue the plywood
> edges together on a backing plate to keep them flush.
>
> A suggestion for holding the cloth in place: make a vacuum table connected
> to any household vacuum cleaner.
> Table made of 2 layers of plywood or chip-boards separated by 32x32mm
> strips of wood such that it forms a box with sealed edges but make sure
> that the internal 32x32 spacers are leaving at least 32mm gap at each end
> for sucking the air.
> Drill on the under face a hole into which you insert the vacuum hose
> (hence the need to ensure communication across the whole board)
> On the top face drill 1mm holes every 5 cm such that inside vacuum can
> sucks the cloth. If there are large area of the table not covered by the
> cloth put kitchen foil or flower bunch foil on it to maximise the vacuum
> power under the cloth.
>
>  Regards / Amitiés
>    Robert LAINEhttp://www.sailcut.com   Free sails design open software
> ------
>
> On 29/03/2016 16:49, Simon Béliveau wrote:
>
> I will prepare a web page in a month or so about my home sailmaking setup,
> including the CNC. There is almost nothing covering this on the internet as
> far as I know.
>
> My CNC is based on this:
>
> *An arduino GRBL controller that I installed in a plastic food box, you
> can find the whole package for about 10USD on ebay, look for CNC Shield +
> UNO R3 Board + 4 X A4988 Driver Kit.
> *The controller itself uses v-slots bought from an easily accessible web
> site.  I am using their belt and pinion idea for the x-axis and the linear
> actuator for the Y axis.
> *The Z axis has been the most complex to me, see the picture in the link.
> I can easily use any kind of pen/pencil or marker. There is a pen spring
> inside the top mechanism to ajust for the table deflexion. The top
> mechanism has been 3D printed, thanks to a friend that has one, but I would
> otherwise have managed to thinker something myself. The up and down motion
> is made with an MG90S micro servro (metal gear version) from ebay.
> *The control is made with Grbl controller, I had to modify it to control
> the Z azis. I wish it had a backlash compensation because my system, albeit
> very accurate for my needs, has a 1mm play in the x axis. Not bad for a
> 4.5m long axis driven by a belt. I feel like programming the backlash
> compensation but I admit it would be a loss of time because I don't need
> that precision.
> *I bought the belt on ebay (10m GT2 belt and pulleys) because it was the
> cheapest option and it works very well.
> *There are a few challenges I have to address like when the pen crosses
> the boundary between two plywoods, it tends to stick to the slot. I wish
> also the Y axis was longer, it now is about 1.35m, which covers sailcloth
> 52in wide, but I just bought my spinnaker cloth and it's 60in wide, so I'll
> either waste more cloth or I'll otherwise fiddle to make more print jobs
> and save some cloth.
> *Total cost: around 600USD.  Not bad for a printer very similar to one
> that sells for 9500$!
>
> Here are some photos (change your vewer to HTML or remove the [img]
> markings on the lines:
>
> [img]http://i.imgur.com/NxJvvm8.jpg[/img]
> [img]http://i.imgur.com/9wEvn7g.jpg[/img]
> [img]http://i.imgur.com/FME2MC5.jpg[/img]
> [img]http://i.imgur.com/bQ2LHpp.jpg?1[/img]
> [img]http://i.imgur.com/LANXAhm.jpg[/img]
>
> Simon
> Montreal
>
>
>
>
>
>
>
> ------------------------------------------------------------------------------
> Transform Data into Opportunity.
> Accelerate data analysis in your applications with
> Intel Data Analytics Acceleration Library.
> Click to learn more.http://pubads.g.doubleclick.net/gampad/clk?id=278785471&iu=/4140
>
>
>
> _______________________________________________
> Sailcut-users mailing lis...@li...://lists.sourceforge.net/lists/listinfo/sailcut-users
>
>
>
>
> ------------------------------------------------------------------------------
> Transform Data into Opportunity.
> Accelerate data analysis in your applications with
> Intel Data Analytics Acceleration Library.
> Click to learn more.
> http://pubads.g.doubleclick.net/gampad/clk?id=278785471&iu=/4140
> _______________________________________________
> Sailcut-users mailing list
> Sai...@li...
> https://lists.sourceforge.net/lists/listinfo/sailcut-users
>
>