- July 12, 2017 at 8:14 pm #38151
I am mostly finished with my Lowrider build. It is up and running on a temporary table, and I have run some tests with a pen. First cuts on foam will probably be tomorrow. While it is still fresh on my mind I thought I would share some lessons learned for the benefit of future builders. Most of these come from mistakes that I made or things that were not obvious to me at first. If you have other tips feel free to add them here.July 12, 2017 at 8:19 pm #38152
Leave the bolt for the center bearing on the rollers loose until the roller gets mounted on its plate. Tightening will cause the holes on the roller to not line up with the matching holes on the plate. If you wait until after the assembly is mounted on the rails to tighten the center bolts it will be easier to get the rollers on the rails. Though, it might not be easy to reach the bolts to tighten them depending on your assembly order. If tightened before mounting it isn’t too hard to get the rollers on the rails.July 12, 2017 at 8:26 pm #38153
Bolt direction matters. Pay attention to the assembly diagrams and follow them. In particular, if you put the nut side out on the roller bearings that go through the cut outs on the Y Plate the nut will collide with the spacer. In addition the bolts for the Y Rollers on the 611 plate should have nut side facing the center of the plate. This will give more clearance for the aluminum angle hose support.July 12, 2017 at 8:31 pm #38154
It is possible to assemble and mount the XZ Assembly upside down. I had one right side up and the other upside down. I got it completely assembled and did some pen testing before I realized my mistake. The only problem that I noticed was one side of the gantry was 1/4 inch higher than the other when it was fully lowered. This was probably my most boneheaded mistake :/. The chamfers on the XZ Plate should face up.July 12, 2017 at 8:36 pm #38155
When I measure the distance from the top of table to the bottom of the rail on my Lowrider there is a difference of about 1/16 inch between the two ends. This is probably due to some minor variance in the XZ or Y plates. Before I turn my Lowrider on I manually raise the gantry a bit and place some equal height blocks under the rails on both ends. When I turn it on and raise the Z the rails are parallel with the table.July 12, 2017 at 8:48 pm #38156
It is hard-coded in the Marlin firmware to disable all steppers after a program completes when running from the SD card. This is not desirable for the Lowrider because the gantry (and spinning router) crashes down on the table. To prevent this flash the firmware after making the following change in Configuration_adv.h:
#define SD_FINISHED_RELEASECOMMAND “M84 X Y Z E”
#define SD_FINISHED_RELEASECOMMAND “M84 X Y E”
An alternative solution would be to keep all steppers enabled so you could disable them in your ‘program end’ gcode. This would also be useful if you do the multi-program method for tool changes. I have not tested this but I assume it works. In Configuration_adv.h:
#define SD_FINISHED_STEPPERRELEASE true
#define SD_FINISHED_STEPPERRELEASE falseJuly 12, 2017 at 8:56 pm #38157
I followed the instructions on the firmware page to flash the firmware to my mini-Rambo. The instructions were good but I had to add one additional step which was to install the USB driver for the mini-Rambo (Windows). Without the driver the mini-Rambo was not showing up in the Ports menu of the Arduino application. There is a link to the driver on the Rambo RepRapWiki page.July 13, 2017 at 3:31 pm #38239
Nice thanks for that. I will really have to finish the instructions soon and stop building new machines. Sorry for the troubles.July 13, 2017 at 6:20 pm #38245
No worries. The instructions as they are get you far enough that the rest is pretty obvious. Most of my troubles were due to a lack of attention to detail on my part.
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