Folgertech Prusa i3 first print report and first post

Hi,

I recently bought the folgertech i3 and was a frustrated at first with prints not sticking and the scale being wrong. Prints came out half scale. I made many blobs of ABS! To get it working well - I did the following things.

1. mounted printer on 3/4 MDF with 1/8" thick aluminum angle brackets attached to the threaded rods running below the Y axis rods.
2. used longer screws to attach the bed to the Y carriage assembly. I set the tension (still using their springs) on the screw for the home position then carefully adjusted the Z stop so I had nice tension on a sheet of paper at the home position. The longer screws allowed me to put a washer as necessary under springs on the other corners so the height could be adjusted without putting a lot of tension on the spring and acrylic Y carriage. The Y carriage would easily warp out of shape with too much spring tension on any corner.
3. I leveled the bed at room temperature and then releveled it with both the print head and bed hot.
4. folgertech says in their build manual to run the bed at 70C. I increased the temp and am running the first layer at 95C and then reducing to 85C. I don't know if this is optimum, still having some lifting at corners of test cube. 85C setting in Repetier gives an actual 70C measured by IR thermometer on the bed surface.
5. I uploaded firmware from folgertech and found that a 40omm cube would print at 20mm. Settings in the header file had to be doubled to get the prints to come out close to correct scale.
6. I calibrated the extruder and made changes in firmware header file.

Not trivial to get this thing going, but happy now. Any suggestions for further improvements appreciated.

Valerie

Can I ask you about how you built the first part? I have the aluminum 2020 i3 and thought i was missing the halves that cover the two bearings but support told me they do not use them on the newer model. So wtf I can't find a clear diagram or pdf that shows the 2020 aluminum build? In step 3 it shows using the bearing covers. Sorry for imposing on your post but hoping I can get started on this.

Okay NM I think I finally stumbled across it!

Half scale could be because your RAMPS board has the stepper drivers set one way and your firmware set another. Make sure they are both the same.

Edited 1 time(s). Last edit at 06/13/2015 09:32AM by madmike8.

You may have already figured out that they changed the design, but not the build manual. The bearings just sort of sit in slots in the acrylic (aluminum in your case) and are tie wrapped in place.

The jumpers are set as shown in folgertech build manual. Is there anything wrong with changing the mm per step settings in the firmware vs changing the jumpers? I'm making pretty good prints right now.

Hi

First for abs printing your bed must be at 110 deg c. Or it will not stick and may move during long print.
Your fan for cooling the extruder blow directly on the x carriage, be sure that no air flow bounce back on your print, this increase the part cooling, then the abs start shrinking faster and your print will be deformed and messy
Try rotate the fan 90 deg left or right.

Your print looks good,

Play with speed, and jerks, with holes in the cube and 40mm, to find the speed limit of your printer.
After that you must do fine adjustment to be able to print mechanical parts with precise measures.
Like single wall cube to adjust filament and wall thickness.
Bridges to print holes without supports.

After you will be ready to print everything

Do you have the problem of 40mm cub and sort out 20mm? If yes, then check your motor drivers, you may have the dRV8825, which are 1/32 drivers, it mean that you have to double the value in configuration.h

Quote
Laopa
you may have the dRV8825, which are 1/32 drivers

Unless they've changed it in the last couple months, this has A4988 drivers. That's what mine came with.