Converting to metric fastenings

[drskullster]

Hi there,

I'm looking to build your version of the prusa I3. I looked at your files and it seems that you use imperial mesures. Do you know any fork of your version that uses metric mesures ? If not, can you advise me on how to change your files easily ? I plan to use Illustrator but it's gonna be a lot of work. If you have a better idea I'm all for it !

Thanks,
Jonathan

[alexborro]

Hi Jonathan, you can use this adapter for M3 nuts:
http://www.thingiverse.com/thing:167206

Best Regards

[HegerTechnik]

For Graber i3?

I use m4 and m4 nuts. Perfect Fitting.

Am 18.10.2013 um 13:25 schrieb alexborro notifications@github.com:

Hi Jonathan, you can use this adapter for M3 nuts:
http://www.thingiverse.com/thing:167206

Best Regards

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[alexborro]

In my case, M4 bolts didn't fit in the original holes. Instead of re-drill all the holes, I chose to use this plastic adapter.. but both are valid solutions, it is up to you choose one.

[misan]

I re-drilled holes to M4 in the Mini i3, much better than M3 for the frame brackets.

[drskullster]

Thanks for your answers.

Alexborro, the adapter is a good idea if you already have the lasercut parts. In my case I think I'll just adapt Graber design.

HegerTechnik, I'll try but having had the same problem on the printrbot jr design I'm not sure it will work.

misan, drilling is fine but didn't you have a problem for the nuts ? As I see in the design the slot for the nut is 8mm. I measured a M4 nut and it's 7mm :

I'm afraid the nut will not be blocked in the T hole.

[misan]

It works for me. here you have a picture: http://imgur.com/bWgwyZP

Of course if you are modifying the design it may well be interesting to shorted the slot width.

[HegerTechnik]

I Send a picture.. When i at home..

Apfelmail

Am 18.10.2013 um 16:20 schrieb drskullster notifications@github.com:

Thanks for your answers.

Alexborro, the adapter is a good idea if you already have the lasercut parts. In my case I think I'll just adapt Graber design.

HegerTechnik, I'll try but having had the same problem on the printrbot jr design I'm not sure it will work.

misan, drilling is fine but didn't you have a problem for the nuts ? As I see in the design the slot for the nut is 8mm. I measured a M4 nut and it's 7mm :

I'm afraid the nut will not be blocked in the T hole.

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[7harry]

to continue this discussion - I understand that the whole frame is assembled using M4 nuts&bolts. But what about the big ones in the X carriage? The ones in parts U and Z? I am trying to pick between M5 and M6, as the cap size in the drawings is right between the two, 9 mm, while the hole is actually M6 - and the M6 cap does not fit.. And it seems that the original Prusa i3 uses an M4 bolt for the idler.

[alexborro]

Check out this table:
http://bit.ly/187Bo94

All bolts, nuts and rods for Graber I3

2013/11/1 7harry notifications@github.com

to continue this discussion - I understand that the whole frame is
assembled using M4 nuts&bolts. But what about the big ones in the X
carriage? The ones in parts U and Z? I am trying to pick between M5 and M6,
as the cap size in the drawings is right between the two, 9 mm? while the
hole is even larger than M5 - .. And it seems that the original Prusa i3
uses an M4 bolt for the idler.

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Reply to this email directly or view it on GitHubhttps://github.com//issues/6#issuecomment-27607992
.

Mit freundlichen Grüßen - Best Regards - Saudações.

Alex Borro

[7harry]

Ah, pity I did not see your BOM earlier - it's a great list! By the way, can you tell me - do these bolts need to be that long? The major part of each seems to be left behind the nut.
Unfortunately I already went ahead and redone the whole drawing to use M4-sized fasteners (I am of the bigger-is-better conviction and anyway, the originals looked like M4 rather than M3). The round holes had to be reduced in size as well as the nut spaces. Am having this laser cut today - will check the result myself, but in the meantime if anyone is interested check out the Sketchup
https://dl.dropboxusercontent.com/u/50408087/graber-atx-metric.skp.zip
and DXF (converted into 2010 DXF version as Sketchup saves in 2013 DXF which is somehow different - my local shop could not open it in their old Autocad app)
https://dl.dropboxusercontent.com/u/50408087/graber-atx-metric.2010.dxf.zip
Let me know if I have missed something screwy..