Suggestions for printing big model

[rross]

Yes it was veroboard with the heated bed. I haven't tried it without heating the bed yet.
Oh and one more thing, I have found it much easier to remove parts when the bed has cooled down for about 15 minutes - they come out quite easily compared to very difficult when it is still hot

[ssozonoff]

Along the same lines of providing a non smooth surface for the ABS to adhere too, what about laying down some 80grit sandpaper on the platform? Anyone tried sand paper?

Serge

[William]

I tried with 600 grit. It did not work as well as the painters tape. Acrylic conformal coating has worked the best for me.

[-soapy-]

Now that is an inspired idea! It's even copper clad which will spread the heat better than the regular aluminium. How are you attaching the veroboard to the platform? With tape?

changfrancis, you cannot print with the heated bed off, as far as I know - it is automatically turned on when printing.

[trebuchet03]

Now that is an inspired idea! It's even copper clad which will spread the heat better than the regular aluminium.

Not to make you unhappy (rather, temper your thermal expectations)... I tried a copper spreader underneath, I had it around, figured to give it a shot. It was about 130x130mm.

Results: Physics and Heat Transfer Win - it conducts faster, but also conducts heat away faster. I measured the same thermal delta.

I did measure a nearly immeasurable increase in power consumption (we're talking a few kWhrs difference over the control measurement) - if I had accurate enough equipment, I'd say that verifies the conduction increase observation - more heat is escaping to the environment and therefore more heat is needed to maintain T.

The protoboard is sweet, I've ordered a big one to use when I start getting warping issues I think the advantage there is more mechanical rather than thermal.

[Gilius]

So does it actually help with big print warping?

[hardness]

Results: Physics and Heat Transfer Win - it conducts faster, but also conducts heat away faster. I measured the same thermal delta.

I did measure a nearly immeasurable increase in power consumption (we're talking a few kWhrs difference over the control measurement) - if I had accurate enough equipment, I'd say that verifies the conduction increase observation - more heat is escaping to the environment and therefore more heat is needed to maintain T.

A few...KWhrs?!
How few is a few?
What was your control measurement?

[trebuchet03]

Results: Physics and Heat Transfer Win - it conducts faster, but also conducts heat away faster. I measured the same thermal delta.

I did measure a nearly immeasurable increase in power consumption (we're talking a few kWhrs difference over the control measurement) - if I had accurate enough equipment, I'd say that verifies the conduction increase observation - more heat is escaping to the environment and therefore more heat is needed to maintain T.

A few...KWhrs?!
How few is a few?
What was your control measurement?

eeek! A few watt hours! Sorry for that and thanks for calling me out

Control is the Up! as stock. Idling for about 48 hours with green paint at about 20C ambient (not super sophisticated measurements, some swings up/down during the day/night are unaccounted/controlled) - preheating. 1.9KWhr

Same conditions with copper shim - 2.1 KWhr for the same time period.

There's enough room for measurement error and environment factors to account for that difference (which is why I'm calling it nearly immeasurable).


Material was an off cut from McMaster part # 2545T42 - it was a little over 1mm thick.

[-soapy-]

I'll not bother then! The veroboard, on the other hand, I will be buying.

[TeamTeamUSA]

The perfboard trick is baller! Big UP!s rross!

I haven't had any warping since I started printing on it and I'm going deep and wide and tall. Of course I've done the platform leveling and nozzle height adjustments, but until I printed on perfboard, I'd get some warping on wide, long or thick prints. If you can't find copper plated perfboard, no worries; it's the holes, not the copper, that does the trick.

A few tips if you decide to do this:

1. READJUST NOZZLE HEIGHT!!! Since you're adding ~1.5mm to the top of the platform, your current height will cause the nozzle to meet the perfboard in an unsightly way.
2. REMOVE! Remove the platform from the printer before attempting to dislodge the print from the perfboard. The print sticks well and you don't want to subject your printer to the forces necessary to to unstick it.
3. BIAS! Cut the board on an angle so that the perfs are not parallel to the printer's X and Y axes. I belatedly noticed that rross cut his on a bias; my utility knife scoring wasn't spot on, so it's all good. Yours will be better if you plan for this.
4. TAPE WELL! Ensure that the tape - blue painter's tape works great - sufficiently wraps around the top and bottom of the platform. On my first print, I wrapped the tape miserly on the perfboard and while printing, one of the strips detached. No prints suffered during this episode.
5. COOL! Definitely allow the platform to cool a few minutes before removing the print. The plastic in the holes contracts and makes removal easier.
6. DON'T PREHEAT! One of the bonuses of printing on perfboard is that the platform doesn't need preheating. This saves time, effort and watts.
7. OVERLAP! When printing multiple models, I overlap the rafts a bit so that all rafts are connected. This ensures that raft areas that fall outside the perfs are still secured by those that do (maybe less of any issue if you cut the board on a bias).
8. LED! Most of the plastic comes out of the holes, but to remove the bits that remain, LED leads work great (we all have the odd LED laying about, yes?)!

I'm still pondering a better way to attach the perfboard to the platform. Tape works for now, but...

1. Clips on the side to mechanically affix perfboard and platform?
2. Remove platform and print directly on perfboard?

Hmmm...

Go!

=ml=

[Gilius]

No preaheating??? I'm confused. Have you measured your models? Are they coming out OK?

[TeamTeamUSA]

No preaheating??? I'm confused. Have you measured your models? Are they coming out OK?

Yes, the prints are the correct dimensions. Why wouldn't they be? The platform is heated, it's just not pre-heated.
Warping is eliminated via mechanical means - plastic nubs in the perfboard - rather than thermal means - trying to control the gradient across the platform.
It's a K.I.S.S. solution, that works great!

If you decide to try this, please follow at least the first 2 tips.

Go!

=ml=

[Gilius]

I have high temperature kapton tape around. I suppose that works just as well if not better than painter tape for attaching the perfboard.

[-soapy-]

A lot of people have tried the Kapton tape, but, I think, most have stopped due to cost and the rapidly wearing out nature of it.

[TeamTeamUSA]

I have high temperature kapton tape around. I suppose that works just as well if not better than painter tape for attaching the perfboard.

Kapton tape will work to attach the perfboard to the platform as long as you wrap it around the platform edges. I have 1/4" MBI Kapton tape but haven't tried it because the 1 3/4" blue tape is less expensive and more readily available. If Kapton is all you've got, give it a try; the goal is to prevent the perfboard from moving in X or Y, because it will not warp (move in Z).

Go!

=ml=

[TeamTeamUSA]

I posted some shaky iPod videos of a print I did that reaches the maximum XY envelope of 130mm (140mm less 5mm on each side). This required printing on perfboard; no other technique worked.

* Edges: http://vimeo.com/17783942
* Flatness: http://vimeo.com/17784142

Go!

=ml=

[-soapy-]

Wow, that's amazing! Great results.

I'm just ordering some perfboard now, along with a few others bits, so hopefully I'll have something to add in a few days.

I might get my mini CNC mill set up and take a small cutter to my existing baseplate and add a few thousand little holes to it. But I'll wait until I've tried the perfboard first.

[trebuchet03]

I might get my mini CNC mill set up and take a small cutter to my existing baseplate and add a few thousand little holes to it. But I'll wait until I've tried the perfboard first.

That's actually a pretty awesome idea.... A few weeks ago, we had steel tooling sent out to add texture. My understanding is that it's a chemical etch process - which is the reason for the consistency we've come accustomed to. I wonder if they can do small aluminium parts...

[TeamTeamUSA]

Wow, that's amazing! Great results.

I'm just ordering some perfboard now, along with a few others bits, so hopefully I'll have something to add in a few days.

I might get my mini CNC mill set up and take a small cutter to my existing baseplate and add a few thousand little holes to it. But I'll wait until I've tried the perfboard first.

It's all thanks to rross that I tried it out, and yes it's nice to finally grind the lip [sk8geezer am I].

As for perforating the build platform, the holes will increase the surface area and therefore increase the heat dissipation; maybe not what you want.
Or perhaps by creating more surface area, more evenly distributed increased-heat zones will be available - a win. Hmmmm... [I'm not a mechanical engineer; I just play one on the Interwebs]
The print flatness is achieved via mechanical means, so the change in platform temperature might not matter at all - unless of course the electronics can't handle it.

Go!

=ml=

[Chris.e]

What vero-board are you using? I have two types here to choose from, the epoxy/glass fibre and fenolpaper board..I guess the glass fibre board will hold up better. Any objections to that?