Gina

Unfortunately, the Z drive motor pinion became loose on the shaft so I'm having to print a replacement on my Titan printer. Goodness me what a racket after the almost silent new Mini printer!! And I wonder if the Titan will not only be quiet but also more precise when I convert it to Duet control.

Spent this afternoon titivating. Tidied up the gears for the Z drive and a bit of tidying up of the Z carriage, making sure the wheels all made contact with the V-slot rails then re-levelling. The gears are not well printed so I think I'll either reprint them or replace with timing belt and pulleys. This printer is already printing better that any other I've had so I'll use it to print new gears for itself

I can reduce the cost of new V-Slot aluminium extrusion by using the front and back frame members on the sides and getting new front and back pieces. I have 4 pieces I could cut myself but I think I would rather pay the price for accurately cut pieces for the main frame to be sure top and bottom measurements are identical as the X axis relies on that. The Z carriage (alias XY frame) is less critical as I can adjust that to make the wheels fit the main frame uprights. Since everything is made from the same type extrusion, everything expands and contracts at the same rate if the temperature changes, so two of the pieces of extrusion I already have can be used on the Z carriage, leaving the front and back members of the main frame (4).

In checking things I found this comment about the 400mm square heater pad :- They are saying this heater pad is suitable for a heatbed 500mm square which is what I have (haven't attempted to cut it down). So it seems to me that I could go for a larger printer by just increasing the frame sizes a bit. I already have 500mm available height.

Th WiFi has gone again

I think I've found the cause of the regular rings round the column in the Z direction - there's a slight problem with a tooth on the Z drive gear and the drive is not perfectly smooth.

Calibration results :- X=100mm, Y=100mm, Z=102mm. Orthogonality :- XY fine, XZ slightly out, YZ fine. Print Quality :- slight curling on corners, tiny imperfections on column, poor printing at top of column. Why it should print well all the way up to around 95mm and then become poor, I don't know. Of course, it's a good test with a tall narrow column. This is with cheap ABS filament. No part cooling. Extrusion temperature :- 260°C, bed 100°C. Printing time :- 2hr 4m. Photos :- On print bed, closer in, sideways lighting showing up more surface detail.

Photos of the calibration test print run.

I'm now running the calibration test print and it's going well

I did restart the Duet - several times but not the router - didn't really think of that as the other WiFi devices were working. I did try closing Firefox and restarting but no joy. Then I thought I would see if the connection via USB still works - it does. Sent M552 and it said WiFi idle. Sent M552 S1 and it turned WiFi ON and now WiFi works But how/why did it get turned off? The config.g tells it to turn on automatically. Is this going to happen every now and again? Surely it shouldn't be necessary to have a USB connection available and suitable computer just to re-set the WiFi? Maybe it will settle down

I had the Mini printer working quite well yesterday but today it refuses to connect to WiFi So I'm back to the Giant while I wait for inspiration or get help. From my experience with the Mini printer I have changed my mind about the mountings for the XY motors. Access for threading up is paramount and vertically mounted motors would make access difficult so I'm going back to having the motors mounted horizontally just in front of the front rail. This leaves the drums out in the clear and readily accessible. A couple of photos - top view and underside view. The drum is just representative of one possibility and was taken from the Pilot printer with the motor. I shall probably be using a smaller drum in the final version.

The mains voltage bed heater pad has arrived, would you believe - sooner than expected. Sometimes a slow boat fro China is not so slow Pity I don't have a working printer to put it on!!!!!

I dunno!!! I get the new printer working nicely do a minor mod to the hardware and now it won't work! I haven't touched either the firmware or any setup files. In fact I've been nowhere the Duet board since I had it working yesterday. Guess I'll put it to one side and go back to my Giant printer until someone can suggest something or I can think of something myself. I dare not try the second Duet on my Titan printer until I'm sure the Mini is working reliably. Looks like I need your help again Dave @tekkydave, please

Well, it's no good if it's not going to be reliable It can't be signal strength, I brought it to less than 6ft from the router and it's been working a lot further away than that.

Now the dratted WiFi won't work and I haven't done anything that could affect it. The router is alright as it's connected to my laptop by WiFi. I want to check the calibration further.

Extrusion cut to length. So now the printer should be as accurate as it can be hardware-wise. Next is the check Z calibration I think. After that it probably orthogonality which the Duet is able to correct in the event of error. This printer has been designed with a view to getting orthogonality correct straight off. Actually, I can combine the Z and orthogonality calibration prints as a single print.

I'm afraid that the problem with Crayford focusers, I've gone for rack and pinion.

Regarding extrusion, I have two pieces I can salvage from my Pilot printer that are a little longer than I need, so just a matter of cutting them shorter.

Sorted out the drive drum on the RH motor and it now runs true I've had another look at the print bed frame and by far the simplest solution will be to use aluminium rails. Changing to two wheels at the back of each rail would mean considerable changes to the way the cords are attached and the vertical adjustment. Also, this would mean the frame would not be as rigid at the front as it would with wheels at the front. It could skew slightly using the rear rails as pivots - or put a lot of stress on the wheels by leverage. I have spare aluminium extrusion.

Been looking at where there could be problems in the printer that could contribute to errors in printing. As I posted above, I found a drum that was running askew very slightly. I thought it was both but it turns out to be only the RH side motor the other is easily within 0.1mm. I shall see why the errant drum is out of alignment. The other problem is the Z carriage (print bed frame) wheels. ATM I have some 6mm plywood attached to the underside of a pair of rails with wheels on the ends running on the corner upright V-slot rails. When I built the printer the wheels were right up against the rails but now I find there's some clearance. I think the problem is that this is relying on the stability of plywood and that is just not sufficient. Humidity changes cause changes in length and when damp the rails are pushed effectively inwards on the screws, then when it gets drier the wood contracts and leaves a gap. What seemed a good idea at the time has proved not to be, so I'm going to change the design. I think the answer is to have wheels either side of the corner rails at the back. These 4 wheels when mounted on metal plates will be quite adequate to hold the bed in position laterally. An alternative would be to replace the plywood with two aluminium rails. Not really sure so I shall sleep on it and decide later. The suspension cords take care of the Z axis. Here's a photo of the current arrangement with one wheel on each corner. The brown envelope was to stop the reflection from the flash in the glass.

Latest print is fine except for lifting off the bed at the corners - but I wasn't using a brim so no wonder.

I see. Or do I. My Titan printer uses Marlin and I set the Duet to the same for compatibility. Anyway, Slic3r seems to work fine though I haven't tried support yet, which Cura is reckoned to do better.

My M555 has been P2 all along.

I don't have a front or a back bar on my Mini but then I'm using 4 cords to support the bed in the Z direction. And you're using a different wheel arrangement for your Z carriage, Dave. Might be better than mine.

Checked the size of the 100x100x10mm block and 99.93x99.97x10.49mm. Latest print is flying Trying a different infill - 3D Honeycomb. Could have sparser infill though.