I have had my Sindoh 3D printer for quite a while and it is a lovely machine to use in conjunction with Fusion 360. I have printed all manner of items for the workshop, for projects and for friends and family.
For some time it has been a problem to print objects central on the bed. While they would print OK, they are reluctant to come away from the bed surface and then having removed them from the bed, the raft would be very reluctant to leave the printed object. I have got round this by offsetting the print position in X and Y on the table. If I have a large object to print that overlaps the problem area I sprinkle talcum powder on the bed surface to ease freeing the object from the bed but this does not help the raft removal.
The print bed is an aluminium sheet that slides in and out of the machine. This has a PTFE style laminated coating sheet held in place by adhesive. If I inspect the centre of the plate I can see the clear outline of bubbles under the lamination sheet. These have got worse as time has gone by. I imagine the bubbles create a finite air gap that upsets the temperature stability of the plate in the damaged area.
The situation had reached a frustrating peak today and lead to me totally removed the laminating sheet to leave bare aluminium. The printer could not cope with bare ally and the PLA would not stick. Some other laminating medium was going to be needed.
I had seen discussion regarding the use of what we in the UK call Masking Tape as a laminating medium. I use 3M Blue Multipurpose Builders Masking Tape for Super Glue mounting of stock on the milling machine. Having this to hand, I thought it worth a try. The tape is 48mm wide so I had to fix a number of strips across the plate to cover it completely and then trim the edges. As you can see below, I didn’t quite get them parallel and butted to each other I was keen to run a test print.
Maybe I was lucky but the job came off the tape easily and the raft pulled off straightaway with no damage to the print. The tape hasn’t bubbled or coming off in any way so it looks good.
I am not sure how long the tape is going to last but I have got a full reel to keep swapping it out.
My close friend in France also has a Sindoh 3DWOX DP200 3D printer. We bought them at a similar time. He has probably been a busier user of the machine. He has designed and making a very complex camera mount for tracking celestial objects. He is using an Arduino as the controller and has never written code before. He is having fun and keeping his brain stimulated.
A few weeks ago he reported that the raft that the machine was laying down before printing objects was not uniform and had ‘holes’ in it. The result was that the PLA being extruded for the object being printed, would droop down into the void in the raft and spoil the finish of the object while also making it hard to separate from the raft afterwards.
We swapped ideas remotely about what might be the cause and tried various tests and experiments but to no avail.
As it happened a few days ago we were travelling down into France and calling in to see him for lunch so I had a chance to see the problem first hand. More head scratching until …. I had the printer bed in my hand near the window and the sunlight caught the surface of the plastic laminated to the metal bed. My eye caught a slight bubble in the plastic surface where the adhesive bonding the plastic to the metal had presumably parted company. This was the problem ! The air bubble, small though it was, was causing a discontinuity in the bed temperature profile leading to the PLA not flowing from the nozzle correctly.
We ran a print and put the object on a different area of the bed where there was no bubbling or scratches and the raft and the print were good.
Had a bad day on Saturday. I was milling a small tooling plate on the PCNC440 and got distracted. Result was a coolant puddle migrating into the bottom of the Tormach keyboard followed by a broken Haimer tip. Doom and and major gloom. The keyboard was a write off as the fluid had got into the capacitive keyboard laminated sheets.
As it turned out a new keyboard was much cheaper to buy from Amazon than import another one from Tormach being only GBP6 and the Haimer tip while a bit more expensive was imported from Germany via Amazon.
I was in the process of trying to work out why the Z settings appeared to be changing while drilling the matrix of holes on the tooling plate. The drill bit length was still the same figure as entered in the offset tooling table but the hole depth had reduced. I think it might be the Tormach Tooling Collet not being fully seated into the spindle and it had jumped home. Having just installed a new air compressor for the Fog Buster and the tool changer, it could be the air pressure was a bit low and not fully opening the R8 collet. As soon as the new Haimer tip arrives I will get back to it.
While ‘off-air’ so to speak I have been doing some 3D modelling on Fusion 360 to create some home grown Christmas gifts for the kids. First one off is a customised napkin ring with a brass ring at each end. The exercise taught me how to form text around a circular body (thanks to John at NYC CNC for the demo video). Not very sexy but functional.
I struggled with cutting the brass rings and was about to design them out and go to all PLA when I had the idea to use the Kennedy Power Hacksaw like a bacon slicer to cut off thin circular shims of brass from a 2″ tube. It worked well, was more efficient on waste than parting off in the lathe and gave a consistently wide slice.
Next request is for customised wine bottle stoppers. Not sure wine bottles stay unfinished long enough in our house to justify this but let’s see what Fusion can deliver for the kids.