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Cutting foam sheets... with a needle!

Anyone know of where one could get the needle guide kit? I do not have access to a 3d printer and want to see if I could possible get this done. Just want to cut foam planes and eventually do balsa/foam kits with the kids as they get older lol. And you are so right jhitesma
.... outright sexy!

Also.... any more pictures on clean set ups for enclosed electronics and with the wire chains?
 

jhitesma

Some guy in the desert
Mentor
Can't really help you with enclosed electronics...mine are still just sitting on the table with wires almost everywhere because I'm having too much fun cutting stuff to take the time to clean it up :) I did use some cheap shower curtain hangers to keep the wires that run out to the Z axis from getting tangled in things.

20170716_165104.jpg

It's not fancy...but one pack of shower curtain hooks is enough to equip 3 or 4 MPCNC's...add in a few zip ties and it works surprisingly effectively. I printed some drag chains but wasn't happy with how they came out and as often as I change things on my machine was pretty sure they'd wind up just getting in the way. This also weighs less than drag chains and less weight on the gantry is always nice.

Not sure just what you mean by "Needle guide kit" - are you referring to the entire needle cutter? Or just the pre-guide? Or the final guide?

If you want a printed cutter I could print one for you - we could work out the details in a private message. But they don't have to be 3D printed. David (djk4linux) posted one a year or so back in this thread made out of a mousetrap. See this post: http://forum.flitetest.com/showthre...with-a-needle!&p=290432&viewfull=1#post290432

20160505_111754 (1).jpg

It would be better to make it taller we now know...and a few more bits of mousetrap could be attached to act as pre-guides. But since it's all wood the final guide can just be screwed right in with no need for a separate insulator. (I'd also suggest doing a flywheel even if you have to cut it out of wood - the cranks are just too finicky IMHO.)
 
I could go back through the thread, but I'm lazy today. What are the sizes of the wire / guide tips you guys use?
Hi Balu,
I am using a 0.03" (0.762 mm) wire and 0.035"(0.889 mm) tip. David started this thread with a 0.25" wire. I chose my size because I have a spool of it that I bought in 2001 during my welding hobby phase.

Mark
 

jhitesma

Some guy in the desert
Mentor
balu, I'm using 0.62mm wire in a 0.030" welding tip as a guide. (yeah, confusing that the wire is in mm and the tip is in inches)

Which I guess is also 0.024" wire in a 0.030" tip

or

0.62mm wire in a 0.762mm tip but I've never seen welding tips specified in metric.

My old cutter I was using 0.032" wire (0.8mm) in an inflation needle (unknown size) and sometimes with a 0.035" welding tip.

I switched to the thinner wire because I wanted to see if I could get an even finer kerf and figured it would flex easier so possibly last longer. I also figured it would run cooler since it has .006" of room in the guide vs. 0.003" the thicker wire in the .035" tip had which ran very hot for me. I don't think the extra .003" of slop in the guide has affected accuracy noticeably and as I suspected it does run MUCH cooler.

In fact, one thing I kind of miss with the new cutter is the smell. The old one I could smell the lubricating oil when it was running, the new one stays cooler and I can't smell the oil which I kind of enjoyed ;)
 
...
In fact, one thing I kind of miss with the new cutter is the smell. The old one I could smell the lubricating oil when it was running, the new one stays cooler and I can't smell the oil which I kind of enjoyed ;)
[chuckle]... Weird! ;)

Regarding welding tips: I think the welding tip markings are NOT the actual size of the bore... but identify the diameter of the wire it is supposed to handle. As best I can tell, a 0.035" tip is about 0.043" actual bore... designed to handle 0.035" wire? I can't find any other size tip to try but one of my inflation needles appears to be about 0.050".

Does anybody in the know have the straight skinny? -- David
 
Mark,
Did you make a Needle Keeper for the 8mm bearing or did you only make one for a 10mm bearing?

https://www.thingiverse.com/thing:2429886
Mark may have done both, Michael... but if he didn't, I did. I've printed both but they've not been tested extensively in actual use...

If you're into Onshape, you can find both 8mm and 10mm keepers in this document... as well as the designs for most/all of the parts to my latest foam cutter machine. I've been trying to pull together and organize my machine designs (most are a bit messy but they're working for me) a bit so I could share the link with you guys...

https://cad.onshape.com/documents/c...754352147776bee8cd/e/3c4b06da0b263e2c0650606a

I've just added the STLs to my Foam Cutter thing and you can download them from there...

https://www.thingiverse.com/thing:2528032

-- David
 
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Mark may have done both, Michael... but if he didn't, I did. I've printed both but they've not been tested extensively in actual use...

If you're into Onshape, you can find both 8mm and 10mm keepers in this document... as well as the designs for most/all of the parts to my latest foam cutter machine. I've been trying to pull together and organize my machine designs (most are a bit messy but they're working for me) a bit so I could share the link with you guys...

https://cad.onshape.com/documents/c...754352147776bee8cd/e/3c4b06da0b263e2c0650606a

If you'd rather, I can give you the STL's.

-- David
David, Thank you for the quick response. I created an account to view the keeper. I could not figure out how to get it to an stl file. If you could share the stl with me I would be very appreciative. Thank you!

One more app to learn. LOL I was trying to copy the keeper to my new account and I copied your whole folder. Sorry! Obviously I need to watch some of the tutorials. SMH
 
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jhitesma

Some guy in the desert
Mentor
[chuckle]... Weird! ;)

Regarding welding tips: I think the welding tip markings are NOT the actual size of the bore... but identify the diameter of the wire it is supposed to handle. As best I can tell, a 0.035" tip is about 0.043" actual bore... designed to handle 0.035" wire? I can't find any other size tip to try but one of my inflation needles appears to be about 0.050".

Does anybody in the know have the straight skinny? -- David
You know...that makes a lot of sense. I haven't actually measured them to try and tell. I basically just tried my various wires and went with what "felt right" anyway - so there's probably more clearance than I posted...which would make sense because they don't feel THAT snug.
 

jhitesma

Some guy in the desert
Mentor
David, Thank you for the quick response. I created an account to view the keeper. I could not figure out how to get it to an stl file. If you could share the stl with me I would be very appreciative. Thank you!

One more app to learn. LOL I was trying to copy the keeper to my new account and I copied your whole folder. Sorry! Obviously I need to watch some of the tutorials. SMH
Getting the STL is pretty easy. In the Parts list on the lower left just right click on the part and select "Export..."

Screen Shot 2017-09-12 at 12.44.18 PM.png

That will bring up a dialog box...STL should be the default and all of the default settings for it should be fine. That will then download the generated STL when you click Ok:

Screen Shot 2017-09-12 at 12.48.05 PM.png
 
You know...that makes a lot of sense. I haven't actually measured them to try and tell. I basically just tried my various wires and went with what "felt right" anyway - so there's probably more clearance than I posted...which would make sense because they don't feel THAT snug.
Jason,

I found the following chart online that indicates the tip ID may be "ballpark" 0.008" +/- 0.003 over the wire diameters we are all using for our needles.

Screenshot_2017-09-12_20-14-46.png

I measured 0.043" for the 0.035" tip I had so the chart values seem reasonable.

Really doesn't change anything I suppose... but there it is. -- David
 

jhitesma

Some guy in the desert
Mentor
I'm having an issue with Inkscape. I import a page from a FT PDF to a new 20 x 30 document, do all the usual ungrouping and cleanup and then open a 2nd Inkscape, rinse and repeat. All's good if I save them as SVG files for Estlcam. This particular plan is for the Mini Mustang. There's a fair sized piece of empty real estate on page 3 that's for poster board. I figured if I grouped all the parts as individual components, I could then do some rearranging and fit the wing from page 4 and make a single board plane.

I got everything placed and saved to a SVG. But when I open in it, it's not as it looks in Inkscape. Components are missing or moved. A mess. I've tried grouping all, ungrouping all and exporting as a DXF and nothing works. I've also got results of where the scale is tiny.

Hopefully, like my last question about Inkscape, there's a simple solution to this as well. I like the idea of a single sheet plane. Also it'd be nice to be able to rearrange components for spares and such.
 

jhitesma

Some guy in the desert
Mentor
ironkane - I've run into that as well...but always had success just by saving as a different format. I've yet to run into one as bad as you're describing where it won't work as DXF or SVG and I haven't tried the mini mustang yet either.

I'd offer to give it a try and see if I can replicate the issues...but I won't be able to get to my computer with estlcam on it until this weekend. If you're still struggling with it by then I can give it a go.

I'm still not sure if it's an issue with the PDF's, or Inkscape or Estlcam that causes that when it happens - but am curious to try and figure it out.