discussion A new little friend.

[stillp]

Why are the supports so difficult to remove Dave? Is the process very different from removing moulded parts from a sprue?
Pete

 

[Jim R]

Why are the supports so difficult to remove Dave? Is the process very different from removing moulded parts from a sprue?

I was also wondering why it was so difficult

 

[Dave Ward]

Why are the supports so difficult to remove

was also wondering why it was so difficult

The supports actually touch the model in more than one place, from the build plate up to the piece they are supporting ( the printer can't print on thin air ) and along the side of the model, which you can't actually see. Theoretically they should just snap/twist off, but they rarely do! You can alter the distances between the support & model, but to provide support they do have to touch! If you make the distance too big, then the part you are trying to support will droop down & fuse to the supports, making it even worse. Another factor is the PLA - it's not like polystyrene - it's tough and resilient, and can tear lumps off the surface it you're not careful. The model is constructed of printed layers, which can split ( delaminate ) if you are unlucky, or use too much force.
There's no real formula for this, the model has to be assessed, and orientated to the best position, which gives the least supports, or the supports running on a flat surface, where they are easier to remove. I have read that putting the model in the freezer can make supports easier to snap off, but I haven't tried that yet!
It can be very frustrating at times!!
Dave

 

[Guest]

Both the printer and your ability are impressive to us mere plastic stickers !
Nice one Dave, you must be thrilled that it paid off .

 

[stillp]

Couldn't you saw the supports off with a razor saw Dave?
Pete

 

[Dave Ward]

Couldn't you saw the supports off with a razor saw Dave?

On larger flat pieces, yes, but on curved & indented areas that's not feasible - screwdrivers, side cutters, pliers, scalpel & Stanley knife are the tools of choice
These are the supports running up the side of a cruiser

and the underside of the supports

Theoretically, the 'join' between support & model should be light enough to just peel away, but that's not always the case.
It's not too bad on big parts, but the small parts need careful consideration
This is the same part - 1/350 deck gun from the USS St Louis printed in 3 orientations, to see which is best..................

The one on the right is a non-starte, the printer can't cope with the vertical barrel
The centre is with the barrel on the build plate ( inverted ) - it looks better, but there's a nasty scar on the top ( visible ) barrel. The left is with the gun in it's fitted position. The top of the barrel is clear - the problem being the supports will need very careful removal. The gun has a separate cradle & turntable. Luckily the St Louis has only 2 of these guns!
On a better note, this in John Cobb's Railton Special Land speed record holder from 1948

This model takes a long time to print, as it is hollow - it has outer walls & inner walls, with infill between. If it were 'solid' it would only have outer walls and infill, which takes less time to print. The original model, in 1/24, would have taken 14 hours to print - this is in 1/48, and took just over 6 hours to print.
Dave

 

[Dave Ward]

Sad to say the Monoprice died - I'd been printing some small parts for the gun carrier - I heard a slight fizzing sound & I looked up to see it puffing blue smoke. I hurriedly unplugged it. After a cooling down period, I plugged it in again, but nothing. I opened the case - the mainboard had a burnt-out chip - it had actually burnt a hole in the circuit board! So, the board is a write-off, I looked for replacements, but they run out at about £50. You can upgrade the board, but that's even more expensive & in my opinion that would be like fitting a modern engine to a Morris 1000! The machine was a cheap 'for repair' purchase from ebay. I'm going to keep an eye out for a non - working one on ebay, but not many around ( It's over 5 year old - an age in FDM printers! ).
It's very useful to have a smaller printer - the SunLu prints big parts very well, but with print times of 10 hours+, a smaller compact printer could be turning out several smaller parts in the same time. I'll be keeping an eye out for a suitable replacement!
Dave