Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread Gregg Eshelman via Emc-users
-- From: "andy pugh" <bodge...@gmail.com> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Sent: 7/31/2017 5:53:04 AM Subject: Re: [Emc-users] Rack and pinion - tension or not On 31 July 2017 at 12:13, Tomaz T. <tomaz_...@hotmai

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread Les Newell
If they are pre-loading to full contact, I fail to see the diff between a spring load and a pre-load. With a spring, it might have enough give to ride over a wood chip falling on the pinion. The problem is that racks produce a significant force pushing the pinion out of mesh. If I remember

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread andy pugh
On 31 July 2017 at 18:12, Gene Heskett wrote: >> http://nexengroup.com/nxn/products/prod-nav/lp/Roller+Pinion+System > > That I like. It reminds me uncomfortably of:

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread Gene Heskett
On Monday 31 July 2017 08:02:54 Reggie Crane wrote: > Have you considered Nexen linear positioning systems? > > http://nexengroup.com/nxn/products/prod-nav/lp/Roller+Pinion+System That I like. And I'd not be surprised to find that the racks can be butted together to get the effective lengths

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread Gene Heskett
On Monday 31 July 2017 07:13:05 Tomaz T. wrote: > For my future project (cnc router) I will have to use helical rack and > pinion system on two longer axis (2 and 3.5m). There are some designs > where pinion is forced against rack with spring tensioner, on the > other side, if I follow Atlanta's

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread Bari 00000
http://www.machinedesign.com/linear-motion/go-long-pros-and-cons-rack-and-pinion-systems Another option are master and slave pinion drives: https://servotak.eu/products/custom-products/zero-backlash-rack-pinion-gearbox-systems On Mon, Jul 31, 2017 at 6:13 AM, Tomaz T.

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread Les Newell
Tensioning the gear against the rack works reasonably well for plasma cutters as they are lightly loaded. One problem is that gears generate a force that is trying to push them apart. If I remember correctly the generated force is about a third of the linear thrust. You end up having to use a

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread andy pugh
On 31 July 2017 at 13:42, Tomaz T. wrote: > Something like this would reduce backlash to "zero" (without gearbox): > https://www.damencnc.com/products/mechanical-components/rack-pinion/r-p-drive-antibacklash-diy-includes-gears15t/_404_w_74_554_GB_1 Or

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread Tomaz T .
Something like this would reduce backlash to "zero" (without gearbox): https://www.damencnc.com/products/mechanical-components/rack-pinion/r-p-drive-antibacklash-diy-includes-gears15t/_404_w_74_554_GB_1 >It ocurred to me a while ago that if using a double-helical rack and >pinion then you

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread andy pugh
On 31 July 2017 at 13:02, Reggie Crane wrote: > Have you considered Nexen linear positioning systems? > > http://nexengroup.com/nxn/products/prod-nav/lp/Roller+Pinion+System I rather like the Servobelt idea. It should be much stiffer than a conventional belt, for

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread Reggie Crane
Have you considered Nexen linear positioning systems? http://nexengroup.com/nxn/products/prod-nav/lp/Roller+Pinion+System On Mon, Jul 31, 2017 at 6:53 AM, andy pugh wrote: > On 31 July 2017 at 12:13, Tomaz T. wrote: > > For my future project (cnc

Re: [Emc-users] Rack and pinion - tension or not

2017-07-31 Thread andy pugh
On 31 July 2017 at 12:13, Tomaz T. wrote: > For my future project (cnc router) I will have to use helical rack and pinion > system on two longer axis (2 and 3.5m). There are some designs where pinion > is forced against rack with spring tensioner It ocurred to me a while

[Emc-users] Rack and pinion - tension or not

2017-07-31 Thread Tomaz T .
For my future project (cnc router) I will have to use helical rack and pinion system on two longer axis (2 and 3.5m). There are some designs where pinion is forced against rack with spring tensioner, on the other side, if I follow Atlanta's installation manual for their system, they forbid