Up Mini perf board heater mod

Post improvements made for UP, and share ideas.
roller
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Location: Brisbane, Australia

Re: Up Mini perf board heater mod

Post by roller » Wed Jun 26, 2013 8:52 am

marto wrote:You could always just replace the thermal controller underneath the board. It is a 50C unit they sell 70C and 100C ones I think which are exactly the same just different part numbers. Just take out the bed. Unsolder it and add on new one. Much easier than adding all the other gear. You might find though that you need to replace the printed support under the bed as it gets melty.

Are you having any issues with that?

I posted the part number somewhere on the forum. They were about $5.

*Edit* The control of the mini's temp board is done via a all in one D2PAK sized unit which takes power and then regulates the power to the heater, I believe it has a thermistor and control circuitry inside it but it has been a while since I read the data sheet. This means that there is no way this modification can be done in software.
Yes, as Steve says it is hardware controlled external to the Up mainboard unlike the Plus which is software settable. If it is as easy as Steve suggests then why oh why don't they make this change in the factory! 100C might be too high if you want to print PLA though I found PLA a real problem with the way the Mini cabinet retains heat. The Mini is an excellent machine if not for this one flaw.

marto
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Joined: Wed Nov 14, 2012 2:01 pm

Re: Up Mini perf board heater mod

Post by marto » Wed Jun 26, 2013 9:09 am

Another side thought.

As there is no feedback from the bed. Why not just add a switch for PLA and turn the bed right off? That would solve a lot of the heat issues.

Steve

roller
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Location: Brisbane, Australia

Re: Up Mini perf board heater mod

Post by roller » Wed Jun 26, 2013 12:05 pm

marto wrote:Another side thought.

As there is no feedback from the bed. Why not just add a switch for PLA and turn the bed right off? That would solve a lot of the heat issues.

Steve
Worth trying although the system may detect the lack of continuity or current draw as a fault. Hopefully it's not that smart but of course you could possibly fit the original and 100C device and switch between the too. A little heat is nice for PLA especially if you want to use a medium like glass.

marto
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Re: Up Mini perf board heater mod

Post by marto » Thu Jun 27, 2013 3:23 am

Measuring that current is being drawn is way too much of a hassle I doubt they would bother. I also remember someone here saying they fried the mini's bed and they were printing without it heating up.

Steve

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Up Mini perf board heater mod

Post by jeeplvr » Thu Jun 27, 2013 5:54 am

Im using Octave black or white fillament. I have zero warpage or lifting throughout my models as far as I can tell. In fact removing the models from the perf board is very hard to do.
I like the controller because it is adjustable. My perf board heats to 80c in about 10 seconds. It is so much faster to get printing using the new heater. It never shuts off if you don't want it to so the perfboard is always hot and so is the Mini heater. All I have to wait for is loading the layers an heating the print head. I use clips on the front and rear of the perf board to keep it from sliding around during a print job. The stainless sheets I put above and below the new heater are slippery but they even out the heat better than not using them. I haven't had any problems yet.

twocycler
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Joined: Tue Aug 21, 2012 5:09 am

Re: Up Mini perf board heater mod

Post by twocycler » Thu Jun 27, 2013 9:09 am

Have you checked to see how much change there is to the ambient heat inside the mini enclosure from raising the bed heat by 30C? I would think this would help with the abs contraction of the entire model.

How much was the total parts cost? Are you ready to share a parts list? Thanks!

roller
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Location: Brisbane, Australia

Re: Up Mini perf board heater mod

Post by roller » Thu Jun 27, 2013 10:30 am

marto wrote:Measuring that current is being drawn is way too much of a hassle I doubt they would bother. I also remember someone here saying they fried the mini's bed and they were printing without it heating up. Steve
Yeah I certainly doubt they would have bothered but was just wondering. The extra heater will certainly help with heat in the Mini enclosure too.

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Up Mini perf board heater mod

Post by jeeplvr » Fri Jun 28, 2013 3:27 am

All parts from Mcmaster Carr
1 3254K177 Multipurpose 304 Stainless Steel Foil, Bright Finish, .001" Thick, 6" X 10' Roll 32.78
1 4314K2 Easy-to-use Programmable Temp Controller, Type J, 32 To 392 Deg F, 1/8 Din 186.20
1 3648K32 Easy-to-attach Thermocouple Probe, Adhesive Back, Type J, 30-ga Wire, 32 To 400 Deg F 41.07
1 35475K752 Ultra-thin Heat Sheet, 115 Vac, Rectangle, 4" X 6", 120w @ 5w/sq Inch 59.58
1 35475K362 Ultra-thin Heat Sheet, 115 Vac, Rectangle, 1" X 5", 25w @ 5w/sq Inch 42.79
Grand total 362.42 :o
This was not a cheap way to do it but it solved the problem quickly.

I have a lot of stainless left over and I used all 20 gauge insulated wire for the connections with exception of the power cable which I robbed from an old lamp. The heaters are wired in parallel so the heat up evenly. The thermocouple is attached to the large heater for quick response of controller. All wires are zip tied and routed where it cannot be affected by the movement of the internals of the printer. The instructions that come with the controller are good but to get the controller to control a heater directly I had to add a jumper to the controller. I can make a wiring diagram if anyone wants one.

jeeplvr
Posts: 212
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Re: Up Mini perf board heater mod

Post by jeeplvr » Fri Jun 28, 2013 3:30 am

I think I forgot to mention the heaters have a sticky back to adhere to whatever. I stuck them on a square of stainless foil so the heaters would not stick to the Mini heater. It makes the heaters removable.
Also you can get controllers cheaper but I got jipped on a cheap controller from china that used a thermistor instead of a thermocouple and the delay in the thermistor was too long. I nearly burned up the works by the time I got the controller unplugged. Mcmaster Carr's stuff is easy to match up so for those of us that arent master I&C guys it lessens the chance of screwing up. Mcmaster Carr's website is unbelievably awesome to navigate and all their parts have clear pictures or drawings and descriptions so you know what you are gettiung. I have been buying from them for 20+ years.

swort
Posts: 16
Joined: Wed May 29, 2013 9:50 pm

Re: Up Mini perf board heater mod

Post by swort » Wed Jul 03, 2013 1:01 am

I wonder what this https://www.sparkfun.com/products/10080 would do if we could get it on the platform size.
It's a Peltier element, getting hot on one side and cold on the other. (can be switched around)

Let's say we can heat one side, to get the other cool. or cool (fan) one side to get the other side very hot.
I think this would help of easy removal (very cold) and better stickyness (while being hot).

If these only would be around the platform size then i would have bought one to test it..;)

jeeplvr
Posts: 212
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Re: Up Mini perf board heater mod

Post by jeeplvr » Wed Jul 03, 2013 1:34 am

I have tried a few models at different temperatures and settled in om 80c for the heaters. I get the best results and I found that if I leave the door open on the Mini the models don't stick too bad to the perf board. I'm happy.

GrantWatson
Posts: 29
Joined: Wed Mar 20, 2013 9:53 am
Location: Western Sydney, Australia

Re: Up Mini perf board heater mod

Post by GrantWatson » Mon Aug 19, 2013 4:26 pm

So I've gone ahead and replaced the thermal breaker on the bottom of my Mini's heatbed with an 80C part. Cost me $10 including freight.

The first test print is running on it now, and its something that I know I've had some problems printing before. I will leave it to run its course and report back results, but I can confirm the following:

1. The PCB is reaching and holding 80C without issues.
2. The cabinet temperature seems to have climbed from sitting around 41C to 54C.
3. So far, there is zero raft lift on the print, and I would usually see something askew on this model by now.

I'm going to let it run overnight and will report tomorrow. Also, I will be testing this higher temperature with a Gekko board. I've tried Gekko at the stock temperature, and it was met with limited success. I believe it was borderline on being hot enough. So hopefully, this will now prove to be in the right temperature range for good adhesion to the Gekko.

And if not, I can always get a 90C or 100C part from the same vendor. For those of you in Australia who are interested in this, checkout RS Electronics. This is the part that I am using -> http://australia.rs-online.com/web/p/th ... s/2532745/

Stay tuned!

twocycler
Posts: 59
Joined: Tue Aug 21, 2012 5:09 am

Re: Up Mini perf board heater mod

Post by twocycler » Mon Aug 19, 2013 9:01 pm

Hi Grant,

I looked into doing this a while back but chickened out. The stock part is a thermostat chip that is normally a closed circuit, but in the case of the Up Mini becomes open at 60C. I worried that to attain a higher temperature that the heating element may draw more current than the system board was designed to supply and could burn out a component. I always have to wonder if it was as easy as changing one component for another, then why didn't they do it in the first place. Don't get me wrong, I think additional platform heat will help deter warping, and please let us know your results.

Thanks!

roller
Posts: 1622
Joined: Sat Oct 06, 2012 9:09 pm
Location: Brisbane, Australia

Re: Up Mini perf board heater mod

Post by roller » Tue Aug 20, 2013 1:44 am

I wouldn't think it should draw more current just turn off later after running longer but I think your concerns may be valid about whether everything in the Mini can handle this longer duty cycle. I only think there must be some issue otherwise they would have upgraded it to a run to a higher temp since the 50C target has proved to be problematic to say the least. My Mini went back for primarily that reason - As an experienced reprapper I was never happy with the printing ability of my Mini but my Up Plus was brilliant from the get-go.

GrantWatson
Posts: 29
Joined: Wed Mar 20, 2013 9:53 am
Location: Western Sydney, Australia

Re: Up Mini perf board heater mod

Post by GrantWatson » Tue Aug 20, 2013 2:22 am

Hi all,

I ran the idea by a few electrical engineer friends of mine and they basically said the same thing. The current draw isn't likely to increase a marked amount, but the duty cycle will be longer.

As it stands, at factory temperature the machine is near useless for anything other than tiny parts that arent flat, so if it kills the heater circuit then so be it, ill do something with a kapton heater for the platform. Thinking about it, it should also be easy enough to use an external power pack to drive the heater if the on board circuit cant handle it.

However, the good news!

The trial print came out absolutely perfectly. No warp that I could detect. No raft lift, good adhesion across the perfboard. And the usual third party filament issues with support removal, but thats beyond the scope of this problem.

In short, this mod worked a treat. I went ahead and printed some of these bag clips next up. These have had horrible issues with curling and separation from the raft at the stock temperature and third party filament. With the 80C bed mod, it works perfectly.

Further, the bed now gets hot enough for the Gekko sheets to reach a high enough tac level to be useful.

Very happy with my $10 mod. I'll post again with long term results, but at this stage I'd say go for it.

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Up Mini perf board heater mod

Post by jeeplvr » Tue Aug 20, 2013 11:52 pm

Excellent work!
It is still amazing to me that the manufacturer put such a low thermostat in the Mini. I cannot see a reason other than the enclosure keeps some of the heat in and it would help issue of warping. Still, it make no sense to set up the machine with a heated platform that is below the proper heat range.
Thanks Grant for the simple mod.

GrantWatson
Posts: 29
Joined: Wed Mar 20, 2013 9:53 am
Location: Western Sydney, Australia

Re: Up Mini perf board heater mod

Post by GrantWatson » Wed Aug 21, 2013 5:52 am

Yeah, it blows my mind that they wouldn't have rectified something like this in a minor revision of the machine. It's clearly a source of complaints with the machine, and not just for people using third party filament either. The number of prints that I've had warp or curl off the perfboard with the OEM filament I couldn't count.

The only problem I've had since doing the mod is that I killed a Gekko board because I didn't re-calibrate the deck heights first. But thats my own fault!

Still going strong, popped out another couple of flat models which terrified me before, and they printed flawlessly this time. Come on Delta Micro, work out a revised heat bed part for your customers! They'd sell like hotcakes! (pun intended!)

Protonite
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Location: Bern, Switzerland

Re: Up Mini perf board heater mod

Post by Protonite » Wed Aug 21, 2013 4:31 pm

I could see two, maybe three reasons why they are still running a 50°C thermostat inthe mini.
First one, is product safety. Maybe they are scared that more people would burn theyr fingers when handling the hot plate. I know, they give you a pair of gloves and tools, but maybe they would have some regulatory problems because there are product safety laws in certain parts of the world and they could get the product banned from the market if the printer is not according to these regulations. Not shure about that, but i work in a heavy regulated part of the electronics industry (Security Systems), and its really time consuming and expensive to get a product ready for international sales even without melting plastics at 260°C...

The second one could be related to product longevity/durability. By making the build platform hotter in the mini, everything around it gets hotter too, so we see metal expanding, motors and pulleys getting stressed more and even the electronics on the main-board get heated up more. Maybe that is the idea behind a relatively cold bed (althou, it is more common these days to actually make products that break/fail on purpose, so we have to buy spare parts and/or replace machines :roll: )?

The third one is that they maybe ordered a big load of heater platforms or themistors already and still have a big stockpile around that they want to transform back into $$ before making something new. We all know, electronics only get cheap if you order a big load in one single order... :mrgreen:

Anyway, thanks for the feedback on your mod. Seems like i have to find some similar drop in replacement at Mouser, Digikey or Farnell. I did have a quick look once, but was not successful at the time.

roller
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Location: Brisbane, Australia

Re: Up Mini perf board heater mod

Post by roller » Thu Aug 22, 2013 11:16 pm

It's unlikely to be the first one since the Up Plus which does not have an enclosure runs its bed at over 100C. Hopefully its just the result of an economic decision and not one relating to failure during heavy duty cycles.

GrantWatson
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Joined: Wed Mar 20, 2013 9:53 am
Location: Western Sydney, Australia

Re: Up Mini perf board heater mod

Post by GrantWatson » Fri Aug 23, 2013 6:27 am

Personally I think it has to do with the bulk ordering of components like suggested by Protonite, but also that it gives another very good reason to upsell to the Plus.

If the heatbed in the Mini allowed it to produce good results at factory settings with larger and flatter parts, then the only significant difference between the two would be the build volume and the 0.15mm resolution option. Surely it would cost them some sales of the Plus if they made the Mini work right.

So far, still working great. Other than a software glitch that cost me a print with some strange geometry appearing in it at random, I've had no wasted prints since.

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