Modeling 3/8-16 ACME thread

Discussions about CAD use and designing

Modeling 3/8-16 ACME thread

Postby Defy » 2014-Jul-Wed-20-Jul

Anyone know a good way to model 3/8-16 ACME thread? I currently only use OpenSCAD but I hear it's not good for threads and such. What do you guys think?

Looking to build this flange to test out before I spend 30 bucks a piece on brass ones.

Or if anyone wants to make an stl of a 25mm long threaded rod so I can difference it from my drawing of this that would be great!!!
  • 0

You do not have the required permissions to view the files attached to this post.
User avatar
Defy
Printing skirt...
 
Posts: 155
Joined: 2014-May-Sat-14-May
Location: Omaha
Reputation: 6

Modeling 3/8-16 ACME thread

Sponsor

Sponsor
 

Re: Modeling 3/8-16 ACME thread

Postby marmil » 2014-Jul-Wed-21-Jul

If you have Sketchup installed you might check to see what's available in the vast community library. Export as stl to bring into OpenSCAD.
  • 0

CG & 3D enthusiast • Printrbot+ Kickstarter backer • Mods: GT2 belts, custom aluminum y-carriage and print bed
User avatar
marmil
Honeycomb infill 25%...
 
Posts: 284
Joined: 2011-Dec-Sat-14-Dec
Location: Glendale, California
Reputation: 6

Re: Modeling 3/8-16 ACME thread

Postby Defy » 2014-Jul-Wed-22-Jul

Thanks, never messed with sketchup I'll have to look. I have been holding out till I can get a good deal on solidworks so I really only have played with OpenSCAD and it's been fine so far this is the first project I haven't been able to do in OpenSCAD.
  • 0

User avatar
Defy
Printing skirt...
 
Posts: 155
Joined: 2014-May-Sat-14-May
Location: Omaha
Reputation: 6

Re: Modeling 3/8-16 ACME thread

Postby thawkins » 2014-Jul-Wed-23-Jul

Defy wrote:Thanks, never messed with sketchup I'll have to look. I have been holding out till I can get a good deal on solidworks so I really only have played with OpenSCAD and it's been fine so far this is the first project I haven't been able to do in OpenSCAD.


http://dkprojects.net/openscad-threads/
  • 0

Jonbot+
225mm x 200mm - Heated Bed
RAMPS 1.4 running Marlin 1.1.0
Full Graphic display.
-------------------------------
Zen Toolworks CNC/3d printer
230mmx360mm bed
Dual j-head hotends.
Dual heated beds.
RAMPS 1.4 running Marlin 0.98
-------------------------------
Flashforge 3d Creator Pro
Dual Extruder
220x143x150mm
Mightyboard rev e, runnimg Sailfish 7.7r1234
-------------------------------
Photon, self designed printed printer.
User avatar
thawkins
Print winner 2nd
Print winner 2nd
 
Posts: 1636
Joined: 2013-Aug-Sun-10-Aug
Location: Manila, Philippines
Reputation: 172

Re: Modeling 3/8-16 ACME thread

Postby Defy » 2014-Jul-Wed-23-Jul

I saw that but the Acme threads are different.
  • 0

User avatar
Defy
Printing skirt...
 
Posts: 155
Joined: 2014-May-Sat-14-May
Location: Omaha
Reputation: 6

Re: Modeling 3/8-16 ACME thread

Postby evanalmighty » 2014-Jul-Thu-01-Jul

Have you checked to see if McMaster Carr has that flange in solidworks format? They have 3D cad files for most of their products. If you can't find it let me know and I'll see if I can draw one up with Solidworks this weekend.
  • 0

User avatar
evanalmighty
Layer 650 of 1234
 
Posts: 689
Joined: 2014-Feb-Mon-15-Feb
Location: Irvine, CA
Reputation: 45

Re: Modeling 3/8-16 ACME thread

Postby Mooselake » 2014-Jul-Thu-08-Jul

There's several openSCAD thread libraries. Google is your friend.

At least one talks about multi-start so ACME and/or trapezoidal should be included.

Kirk
  • 0

Modified KickStarter Classic Plus 7/2012
KS Thingybot Delta Pro 10/31/16
Creality Ender 3 Pro 12/2019
User avatar
Mooselake
My next printer is...
 
Posts: 3623
Joined: 2011-Dec-Tue-23-Dec
Location: Moose Swamp, Upper Michigan, USA
Reputation: 177

Re: Modeling 3/8-16 ACME thread

Postby Mooselake » 2014-Jul-Thu-11-Jul

I stumbled across a thread library that includes acmes.

Kirk
  • 0

Last edited by Mooselake on 2014-Jul-Thu-11-Jul, edited 1 time in total.
Reason: Moose can't type very well
Modified KickStarter Classic Plus 7/2012
KS Thingybot Delta Pro 10/31/16
Creality Ender 3 Pro 12/2019
User avatar
Mooselake
My next printer is...
 
Posts: 3623
Joined: 2011-Dec-Tue-23-Dec
Location: Moose Swamp, Upper Michigan, USA
Reputation: 177

Re: Modeling 3/8-16 ACME thread

Postby spitfirehauser » 2014-Jul-Thu-13-Jul

what you are trying to model looks like this thingiverse object http://www.thingiverse.com/thing:278089/#files i use the 50mm and it works great at giving me extra Z height without backlash
  • 0

Steve Hauser
Modified Simple 2014 kit
User avatar
spitfirehauser
Waiting for extruder temp...
 
Posts: 95
Joined: 2014-Feb-Mon-10-Feb
Reputation: 4

Re: Modeling 3/8-16 ACME thread

Postby Defy » 2014-Jul-Thu-19-Jul

Mooselake wrote:I stumbled across a thread library that includes acmes.

Kirk



Cool I'll play with that.
  • 0

User avatar
Defy
Printing skirt...
 
Posts: 155
Joined: 2014-May-Sat-14-May
Location: Omaha
Reputation: 6

Re: Modeling 3/8-16 ACME thread

Postby Defy » 2014-Jul-Thu-20-Jul

evanalmighty wrote:Have you checked to see if McMaster Carr has that flange in solidworks format? They have 3D cad files for most of their products. If you can't find it let me know and I'll see if I can draw one up with Solidworks this weekend.


Did not see one where are they located? http://www.mcmaster.com/#acme-precision ... ts/=svshra

spitfirehauser wrote:what you are trying to model looks like this thingiverse object http://www.thingiverse.com/thing:278089/#files i use the 50mm and it works great at giving me extra Z height without backlash


I have seen that but I need 3/8-16 acme threads I got a great deal on some rod and bought it then looked for the nuts afterwards and they are 20-50 bucks a pop! I found one 10 dollar one but before I buy 4 of them for my projects I would like to 3d print one and see how that works.
  • 0

User avatar
Defy
Printing skirt...
 
Posts: 155
Joined: 2014-May-Sat-14-May
Location: Omaha
Reputation: 6

Re: Modeling 3/8-16 ACME thread

Postby EddB » 2014-Jul-Fri-13-Jul

Defy wrote:

I have seen that but I need 3/8-16 acme threads I got a great deal on some rod and bought it then looked for the nuts afterwards and they are 20-50 bucks a pop! I found one 10 dollar one but before I buy 4 of them for my projects I would like to 3d print one and see how that works.


I am using the 3/8-16 acme rod and nuts from printrbot (a few weeks back you could buy 2 rods, 2 nuts and 2 z couplers for $20. Now everything is individual)
I tried printing a T-nut/flange to fit exactly on the 1405 pb simple. First, there is no room to fit a 3/8th flange and rod on the simple. The 3/8th rod is almost eaxactly the size of the delrin flange z mount. Only way you could mount the flange would be upside down unless you drilled out the original mounting hole.
Second, the PLA acme t-nut I did try wore out after a few threadings by hand. Didn't even mount it to the Simple. It was initially too tight and I was just playing with turning it. Got too loose and had slop after threading back and fourth a few times by hand. Would have had a lot of wobble.
So I decided to print the mount without the z flange. The mount z flange itself with a 3/8-16 acme t-nut embedded into it. While printing, I waited for the acme-nut hole to be deep enough to contain the acme nut, paused the print and pressed the acme nut into place, then restarted and continued the print. Perfectly encased and doesn't have any slop or move at all.
This was only a test as I had planned to print a anti-backlash/wobble version with 2 nuts and a spring encased. But so far it doesn't need it. It's a very tight fit and has no play/backlash at all. Hopefully it remains like this, but if it loosens up after a few weeks of printing, I'll print the anti-backlash/wobble mount!
Something you might want to consider (at least for testing). You can pick up 3-4x 3/8-16 acme nuts from printrbot for the same lowest price as a single one you are looking at. Try an spring mounted anti backlash version if you like. Acme nuts are $4 from printrbot: http://printrbot.com/shop/38-acme-nut/
Ed
1405704539809.jpg
  • 0

You do not have the required permissions to view the files attached to this post.
Complete printable 1405 Simple https://www.youmagine.com/designs/compl ... s-edition/ or thing:425164

True Wireless Slicing and Printer Cloud+Web Server w/ AstroPrint PcDuino v2

Printrbot Simple 1405 with XL bed and
Printrbot Simple 1311 Printing ABS andPLA on kapton/borosilicate glass
Printrbot XL volume / tower upgrade GT2 X Timing Belts (thing:194686) GT2 Y Timing Belt Mod (thing:194586)
Custom 320 x 230mm aluminum bed frame w/ 3 x 8mm rods
430 watt ATX power upgrade for 8.5" heat bed via SSR
EddB
ACME leadscrew
 
Posts: 376
Joined: 2013-Dec-Thu-00-Dec
Location: Burbank, Calif.
Reputation: 28

Re: Modeling 3/8-16 ACME thread

Postby Defy » 2014-Jul-Fri-17-Jul

I bought that set for 20 but the set I got is 3/8 -12. I bought the 3/8-16 because I figure more threads per inch more precision, but as i read more and more it's not nessary. Either way I got 3 3' sections of 3/8-16 so I am using it!
  • 0

User avatar
Defy
Printing skirt...
 
Posts: 155
Joined: 2014-May-Sat-14-May
Location: Omaha
Reputation: 6

Re: Modeling 3/8-16 ACME thread

Postby Mooselake » 2014-Jul-Fri-18-Jul

At 16x microstepping the precision is way, way more than you could ever use. For example, 16 (microsteps/step) x 200 (steps/rev) * 12 (rev/inch) is 38,400 steps per inch (1512/mm). That works out to 26 millionths of an inch per step (or 660 millionths of a mm). Way beyond practicality or possible printing, when you're lucky to get .05mm layers. Besides you'd grow older than me waiting for a .001mm layer print to finish. For a Z axis it makes more sense to go the other way, and decrease the microstepping ratio.

Plus it's not really that precise. The tolerances on the screw are way less than that.

Kirk
  • 0

Modified KickStarter Classic Plus 7/2012
KS Thingybot Delta Pro 10/31/16
Creality Ender 3 Pro 12/2019
User avatar
Mooselake
My next printer is...
 
Posts: 3623
Joined: 2011-Dec-Tue-23-Dec
Location: Moose Swamp, Upper Michigan, USA
Reputation: 177

Re: Modeling 3/8-16 ACME thread

Postby Defy » 2014-Jul-Fri-19-Jul

Yeah i found that out after i bought them. I will have to figure out what numbers to put into the firmware too.
  • 0

User avatar
Defy
Printing skirt...
 
Posts: 155
Joined: 2014-May-Sat-14-May
Location: Omaha
Reputation: 6

Re: Modeling 3/8-16 ACME thread

Postby Mooselake » 2014-Jul-Sat-12-Jul

it's 16 threads per inch, 16x microstepping, and 200 steps/revolution motors. So one inch is 16 revolutions, one revolution is 16x200, or 3200 steps. That gives you 51,200 steps per inch of Z travel. Since the 3D printer world has adopted the french system of measurement, and there's 25.4 of those guys per inch, it gives you 2015.75 steps per mm, to more decimal places than you need. Assuming my hoof hit the right calculator keys, of course, so double check it.

While it's popular to print and measure for calibration, the calculated values are much more accurate.

Good Luck! I'd like to see how this works out for you, and what difference it makes.

Kirk
  • 0

Modified KickStarter Classic Plus 7/2012
KS Thingybot Delta Pro 10/31/16
Creality Ender 3 Pro 12/2019
User avatar
Mooselake
My next printer is...
 
Posts: 3623
Joined: 2011-Dec-Tue-23-Dec
Location: Moose Swamp, Upper Michigan, USA
Reputation: 177

Re: Modeling 3/8-16 ACME thread

Postby Defy » 2014-Jul-Sat-13-Jul

Sweet thanks i am not there yet. Still trying to get some alu cut for my x axis, and expanding one of my printers to be able to print 9 inches. I have the bed for it but it only prints 8 because of the bearings.
  • 0

User avatar
Defy
Printing skirt...
 
Posts: 155
Joined: 2014-May-Sat-14-May
Location: Omaha
Reputation: 6


Return to CAD & design

Who is online

Users browsing this forum: No registered users and 1 guest

cron