ScrapStrap (A RepStrap from Scrap)

Hi all,

I've been collecting bits to build a Mendel for a while now and as my electronics have arrived (the last major item except for plastics), I realised I better get a move on with my Repstrap. First thoughts were to go with an OverlapStrap, but after being reminded by Sebastien that the WolfStrap might be a better solution I decided to go with that.

As I am building my RepStrap out of scrap that my wife keeps encouraging me to throw away, I decided the name should be ScrapStrap.

If you're interested then please go see my blog!!

PS: If I posted this in the wrong place, please let me know where it should be.

Craig

Edited 1 time(s). Last edit at 06/22/2010 04:32PM by CraigRK.

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[blogger.kritzinger.net]

As I am building my RepStrap out of scrap that my wife keeps encouraging me to throw away, I decided the name should be ScrapStrap.
Neat! I've read on cnczone that there is variation in quality of drawer slides; I hope yours work for you.

PS: If I posted this in the wrong place, please let me know where it should be.
No worries; this forum seems to be one of the places people do build-logs.

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

SebastienBailard Wrote:
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> Neat! I've read on cnczone that there is
> variation in quality of drawer slides; I hope
> yours work for you.

Ditto. I don't think these are the best quality, but they are pretty solid over the level of travel that I need.

They don't have much side-to-side movement (as mounted in the ScrapStrap - ie what would be up down in a drawer), but the bed might end up with a tendency to drop down at the back as it slides backwards. I will be measuring the run out and will possibly accommodate by adding a small wheel (aka bearing) to the bed to stop it dropping away.

Last night I spent a fair amount of time trying to figure out the x-axis drive. I have decent size stepper out of the plan printer and a perfect length of belt. Making brackets and finding suitable pulleys took ages. No pictures yet, waiting till I have finalised it.

For the Y & Z axes I will be trying to use the drive mechanisms that I salvaged out of ink jet printers (I have a few of the older stepper driven ones - most new ones are servo driven).

I don't expect this machine to be greatly accurate or a real long term survivor, but if it can print Mendel plastics then that get's me on my way. As I am making it from scrap (I will be using proper electronics) I should be able to do it cheap as well which is a bonus as my brother down in South Africa also wants one, but money is tight.

C

I've made a small amount of progress tonight with adding a salvaged belt drive to the X-axis (I noticed that some refer to the lower axis as Y, but I have it in my head as X, sorry).

I have also identified some parts for the Y & Z as previously noted, pictures on my blog...

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[blogger.kritzinger.net]

All the axes now have their drive mechanisms. The next step is fixing the Gantry in place.

I have also updated my blog to fix the reference of which axis is which.

Craig

Edited 1 time(s). Last edit at 07/03/2010 03:18PM by CraigRK.

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[blogger.kritzinger.net]

The ScrapStrap cartesian bot is complete. I have tested the motion using some stepper drivers I had from a previous CNC project and Mach3. I may need to change the tensioning spring on the Z-axis drive to a bolt, but other than that all is well.

I have moved on to the electronics now. I bought a Tech Zone Remix set (sans PSU due to shipping costs). Today I started blogging about setting these up while following the various forum topics and wiki pages that exist. There are still holes in the knowledge for the non-savvy. I'll try to highlight these as I stumble into them.

This topic is likely to continue for a few episodes......

Happy reading (see my signature).

Craig

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[blogger.kritzinger.net]

Me again...

Making slow but sure progress on the ScrapStrap. I have been connecting up my TechZone electronics. I detailed the process step by step in case I need to repeat it in the future. I hope to update the wiki HowTo later as well.

On the side I tried to make a barrel/nozzle on my lathee and failed miserably (not blogged yet), so ordered different materials and will be trying again soon.

Electronics details are on my blog...

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[blogger.kritzinger.net]

As blogged, the ScrapScrap is Scrapped.

I just wasn't getting the time to work out the kinks and I really want to move on with the project, so I invested in some RP parts (already having everything else) and have started assembly of a Mendel. (All detailed on my Blog)

Craig

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[blogger.kritzinger.net]

The Mendel assembly is coming on apace.

I've not been sticking religiously to the script, so tend to find myself running out of parts. e.g. I have been assembling the Z & Y-axes today, but don't have the thick or thin plates yet so can't finish.

So tomorrow morning I'll be tackling the thick plates...

Enjoy!

Craig

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[blogger.kritzinger.net]

Hi Craig
For the thick parts, I'd like to recommend the squashed froglet by nophead : http://www.thingiverse.com/thing:2107 I made mine from some acrylic I had lying around and it looks great, but is a bit on the wobbly side, so I'd take nopheads advice and make it in dibond.

And the standard thin sheets do not fit the tech zone electronics, so you have to make your own. For the y axis I just mounted a quite large, square piece of alu from a beer can, and it works great. For the other axis beer cans work, but I'll want to change to something more rigid (or a microswitch) later.

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-Nudel
Blog with RepRap Comic

Nudel,

Thanks for the suggestion. I was thinking of using the Dibond as I still have a number of sheets left over.

Craig

Edited 1 time(s). Last edit at 09/19/2010 03:13AM by CraigRK.

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[blogger.kritzinger.net]

Hi,

I've spent most of the day on the Mendel (as blogged) and now have frame sans Y-axis, but all Y-axis bits ready for installation having made Nophead's froglet out of Dibond.

Craig

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[blogger.kritzinger.net]

Another quick update. I got bored inside and came out to tinker. Got all the axes fitted and belted. Then hooked up the Techzone electronics set I'd made up on a thick sheet before and got the X-axis working!!!!!!!

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[blogger.kritzinger.net]

Connected up the remaining axis steppers on my Mendel today and reprogrammed the firmware back to standard Mendel spec (from my hacked ScrapStrap) spec.

The axes are moving great, but when it came to mounting to optos I managed to damage one as they don't fit properly being the TechZone ones. I'll continue on another day and see if i can fix the Opto and make some mountings and alternative thin sheet parts as these are different as well.

Craig

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[blogger.kritzinger.net]