Search found 254 matches

by northbear
Thu Jul 26, 2012 4:26 pm
Forum: Design Ideas
Topic: Are idler pulleys really needed or can we just use bearings?
Replies: 11
Views: 3829

Re: Are idler pulleys really needed or can we just use beari

Imho, can't see the advantage of avoiding the smooth idler, made for a given belt cross shape. Neither a price advantage. Assuming you have a 1/4" (or 6mm) wide belt I agree with you. From Inventables the price for the bearing is $1.50 each plus $0.20 for the precision washer, it is only cost $1.55...
by northbear
Thu Jul 26, 2012 1:52 pm
Forum: Design Ideas
Topic: Rated torque on pulleys?? Why is there not a problem here?
Replies: 12
Views: 11175

Re: Rated torque on pulleys?? Why is there not a problem he

Comparing MXL and GT2 obtainable linear resolution value needs to take in account accuracy and backslash properties of MXL vs GT2. If your "extra fine" MXL resolution value go below its accuracy/backslash characteristics, positioning is not following your equation. MXL has a 0.02" positioning error...
by northbear
Thu Jul 26, 2012 3:52 am
Forum: Discussion
Topic: For nema23 motor
Replies: 14
Views: 3576

Re: For nema23 motor

It does make me wonder however, if there was a specific design reason that Bart chose to go with MXL belts for usage with Makerslide.. Curious if anyone else has any input on this topic. Curious about the same thing... see my post here regarding the torque rating on these mxl pulleys http://www.sha...
by northbear
Thu Jul 26, 2012 3:33 am
Forum: Design Ideas
Topic: Rated torque on pulleys?? Why is there not a problem here?
Replies: 12
Views: 11175

Re: Rated torque on pulleys?? Why is there not a problem he

The values shown in the SDP/SI table for MXL are surprisingly low. But after studying this, I really prefer GT2 pulley/belt instead: better accuracy, better teeth design against backslash. If you read the Table 34 on the PDF you linked, you find: GT2 pulley for 3mm pitch / 6mm belt width / 18 groov...
by northbear
Thu Jul 26, 2012 3:07 am
Forum: Design Ideas
Topic: Are idler pulleys really needed or can we just use bearings?
Replies: 11
Views: 3829

Re: Are idler pulleys really needed or can we just use beari

Wow Improbable Construct, you go above and beyond! Bummer that it doesn't work (at least for your belt arrangement) I was considering going with a wider belt but was having a hard time sourcing inexpensive wider idler pulleys and thought "well... do I need them?" I guess I have my answer! Thanks!
by northbear
Wed Jul 25, 2012 9:54 pm
Forum: Design Ideas
Topic: Are idler pulleys really needed or can we just use bearings?
Replies: 11
Views: 3829

Are idler pulleys really needed or can we just use bearings?

I am digging into the drive system lately (http://www.shapeoko.com/forum/viewtopic.php?f=11&t=543) and was thinking the idler pulleys may not be necessary. The flange is already on the drive to keep it in location and the bearing is 5 mm wide x 2 = 10 mm (.394"). If the washer is used between the be...
by northbear
Wed Jul 25, 2012 7:43 pm
Forum: Design Ideas
Topic: Rated torque on pulleys?? Why is there not a problem here?
Replies: 12
Views: 11175

Re: Rated torque on pulleys?? Why is there not a problem he

I just double checked and the belts do indeed skip on the teeth of the pulley if I run the gantry into the side plates....... I am running my alternate belt configuration. ....... Looking at that belt configuration I estimate that you have the belt wrapped about 40 deg around the drive pulley, whic...
by northbear
Wed Jul 25, 2012 7:12 pm
Forum: Discussion
Topic: For nema23 motor
Replies: 14
Views: 3576

Re: For nema23 motor

It does make me wonder however, if there was a specific design reason that Bart chose to go with MXL belts for usage with Makerslide.. Curious if anyone else has any input on this topic. Curious about the same thing... see my post here regarding the torque rating on these mxl pulleys http://www.sha...
by northbear
Wed Jul 25, 2012 5:54 pm
Forum: Design Ideas
Topic: Rated torque on pulleys?? Why is there not a problem here?
Replies: 12
Views: 11175

Rated torque on pulleys?? Why is there not a problem here?

Looking at using larger motors then the standard design and after reading comment by Improbable Construct (http://www.shapeoko.com/forum/viewtopic.php?f=4&t=539#p4441) regarding his motor and driver and that the belt skips before the motor stalls got me to thinking.... What is the rated torque for t...
by northbear
Wed Jul 25, 2012 3:14 am
Forum: LinuxCNC
Topic: Stepper driver options for LinuxCNC
Replies: 15
Views: 12988

Re: Stepper driver options for LinuxCNC

Rhynier wrote:Once I have my system up and running I can provide feedback ... should be a couple of months as I don't even have the mechanical kit I ordered from Inventsbles yet.
Please do provide feedback as I am having the same dilemma you did!