Re: [multimachine] quality of threaded rod
- Hi DaveThanks! I discovered the differences earlier. Lucky did not buy it to swap Metric for Imperial nut for the leadscrew. Nick's idea getting a G-clamp and cutting it. Usually leadscrews are far more longer unless a shorter one.Steve WanOn Sat, Jun 22, 2013 at 11:30 AM, Nick Andrews <nickjandrews@...> wrote:Speaking of cheap sources of ACME-ish threaded rod, how about Harbor Fright (or better) C-clamps? They are usually on sale for half price and the 5" clamp has at least a 6" long threaded piece, plus I bet you could cut the clamp and have a ready-made 'nut' for it to weld onto a project or bracket.On Fri, Jun 21, 2013 at 9:10 PM, David G. LeVine <dlevine@...> wrote:On 06/18/2013 11:17 PM, Steve Wan wrote:
Speaking of square threads or acme threads, any idea where's the supplier? Having problems find it on the net. Note: Acme threads come in either inches or metric. Steve Wan
Sorry, Steve, but Acme is a specific thread for Imperial dimensions, the Metric equivalent, trapezoidal, has a slightly different profile. See http://www.roton.com/trapezoidal-lead-screws.aspx?line=Trapezoidal and http://www.roton.com/acme-lead-nav.aspx?line=Acme for a discussion.
Since there are different classes and accuracies, as well as different surface hardnesses, I can't give you all the vendors, there are thousands. Try going to Use-Enco.Com and looking for COMPONENTS THREADED ROD & STUDS ACME THREADED ROD, there are some 338 different sizes there.
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- Anti backlash nuts can be used to eliminate backlash even on low precision acme thread if that is all that is required.
A precision class acme thread will have a tighter tolerance between the thread pitches.
For example 10tpi thread
2G class has a tolerance of .0095
3G class has a tolerance of .0044
2G class has a tolerance of .0032
On 6/23/2013 1:05 AM, Pierre Coueffin wrote:
If you have a disk indicator with a long stroke, it might be interesting to measure how consistent the travel is per revolution of the screw. Also, measuring the play along the axis could be useful.
On Mon, Jun 24, 2013 7:20 AM PDT Bruce Bellows wrote:
>A precision class acme thread will have a tighter tolerance between the thread pitches.
>For example 10tpi thread
>2G class has a tolerance of .0095
>3G class has a tolerance of .0044
>2G class has a tolerance of .0032
Wow, aren't those tolerances huge!? Would definitely need a lot more accuracy to produce a diffraction grating. 100,000 or more threads per inch.
- On 06/24/2013 11:36 AM, Chris Tofu wrote:
>> A precision class acme thread will have a tighter tolerance between the thread pitches.No, they are not. Differential accuracy is MUCH better with a preloaded
>> >For example 10tpi thread
>> >2G class has a tolerance of .0095
>> >3G class has a tolerance of .0044
>> >2G class has a tolerance of .0032
> Wow, aren't those tolerances huge!? Would definitely need a lot more accuracy to produce a diffraction grating. 100,000 or more threads per inch.
nut. If you move a foot, you could see 0.01" error, while moving a few
thousandths would more likely be in the tenths or hundredths of a
thousandth range or smaller.
"A word to the wise ain't necessary - it's the stupid ones that need the