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Posted · UM2 Fan Shroud Replacement

Funnel design, airflow, etc... Slightly, ever slightly off- topic, but do you know, that in the case of super sonic flight, ie the Concorde, the air hitting the compressor blades in the front of the engine must never EVER reach Mach 1.

The machine actually travels Mach 2.02, so does the air in front of the intakes.

While I am at it; In the case of technical Musei, where hardware from begone times is shown off, having been replaced by "better", "faster", etc designs, the exception the Concord, which has not been replaced wrgt super sonic, as the main design feature.

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Posted · UM2 Fan Shroud Replacement

Funnel design, airflow, etc... Slightly, ever slightly off- topic, but do you know, that in the case of super sonic flight, ie the Concorde, the air hitting the compressor blades in the front of the engine must never EVER reach Mach 1.

The machine actually travels Mach 2.02, so does the air in front of the intakes.

While I am at it; In the case of technical Musei, where hardware from begone times is shown off, having been replaced by "better", "faster", etc designs, the exception the Concord, which has not been replaced wrgt super sonic, as the main design feature.

 

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Posted · UM2 Fan Shroud Replacement

This may seem like a silly question, but why do designers of fan ducts for the UM2 connect the left- and right-side ducts across the middle in front of and below the hot-end?

Wouldn't it be easier to have two pieces - a left- and a right-side duct? Seems like this would alleviate issues as to heat from the hot-end.

If airflow needs to be directed away from the hot-end, connect the two pieces across the bottom with a thin piece of metal, like the piece of beer-can Venkel used as a heat-shield on his version.

 

Yes I have done this while testing but Is not the point of my design. This Is just to test main design function so I can then make a full metal Shroud. Its faster and easier to design and test the whole thing in plastic. Also Venkels Little metal bit only protects against the sides, you need to protect the sides and bottom. While this is easy for some, not all people have the ability to cut and shape bits of metal. For me I just cut a finger off a kevlar glove I had lying around and shoved that in there and it works perfectly.

This is one reason why I did just load it straight away on youmagine as I haven't worked on a way for everyone to easily protect it against the heat. But quite a few people wanted to test it so I just uploaded it.

You may want to try mnis design or follow what pm_dude is working on as he is doing what you mention.

 

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Posted · UM2 Fan Shroud Replacement

Labern

will download your design for when i have new block fitted I only print in PLA at moment but would out source to a print bureaux to have it printed in Nylon.

will let you know how I get on. I can shape in metal and would try this first

 

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Posted · UM2 Fan Shroud Replacement

Sorry but I loaded the wrong model on youmagine. Have just updated it. the one there wasn't for the Olsson Block.

 

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Posted · UM2 Fan Shroud Replacement

Thanks for that will re download the file I looked had has a print time if 5+ hrs at 0.15 layerht how long did your take.

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Posted · UM2 Fan Shroud Replacement

I Wanted a nice finish inside and out. Printed at 30mm/s with 0% infill and took about 6.2Hours

 

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Posted · UM2 Fan Shroud Replacement

0% infill ? Thanks will let you know how I get on when I fit the block which will be soon now have all the parts in place

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Posted · UM2 Fan Shroud Replacement

Yeah, the gaps are small and when printing slow they are easy to bridge.

 

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Posted · UM2 Fan Shroud Replacement

While playing around with the printer the other day. I had the fans set on 100% and slowly covered one side of the exit holes. you could really hear the fan motor drop in speed. just covering it a small amount really seemed to make quite a difference. So this convinces me more that making the orifices smaller isn't a good Idea.

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Posted · UM2 Fan Shroud Replacement

Labern- You are absolutely right. The fans on the um2 are not designed to be restricted. If you look at the fan curves for this kind of fan you'll see than when restricted the air flow plummets.

You need compressor/blower fans if you plan on restricting the flow.

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Posted · UM2 Fan Shroud Replacement

Crazy idea alert!!

Just wondering, has anyone tried running a compressed air line to the head? It could be run next to the bowden and into almost any shaped duct without having to worry about flow.

It could be controlled using a regulator and valve. The air would be much cooler than the hot air above the heated bed that the fans currently circulates.

I would think you'd also have a significant weight reduction on the head.

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Posted · UM2 Fan Shroud Replacement

it can work using compressed air. But the cost of running a compressor and the noise wont out weigh the benefits. A crazy idea would be to use a vortex tube on the compressed air. but again, they are super noisy. or why not a dry ice cooling system?

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Posted · UM2 Fan Shroud Replacement

We use large quantities of liquid nitrogen at work :p now that would be a crazy idea!

Access to compressed air is easy for me at work. If the regulator was outside and set to 0.5 bar it should be reasonably quiet.

Question is, is it worth the effort?

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Posted · UM2 Fan Shroud Replacement

It wouldnt be hard to implement. compressors are expensive to run, but if work paying :p

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Posted · UM2 Fan Shroud Replacement

You don't need to regulate the air, just use a restrictor.

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Posted (edited) · UM2 Fan Shroud Replacement

I did this (added a manifold for compressed air) a while back.  The pictures were in my old forum gallery. It worked pretty well, and reduced my print head mass substantially.  My pancake compressor (mini) is burning out, and I haven't yet plumbed the large garage compressor to the house so I went back to the fan.  Printing ABS mostly of late, so it hasn't been a priority.  I have to run right now.  If interested, I'll repost the pictures later.

Matt

Edited by Guest

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Posted · UM2 Fan Shroud Replacement

Laburn

Do you use Kapton tape on your design which I now have printed before I fit it to Olson block

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Posted · UM2 Fan Shroud Replacement

I use Kevlar cloth but i think a few layers of Kapton tape would be best. Maybe one on the shroud and one around the block? I'm yet to buy some to try.

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Posted · UM2 Fan Shroud Replacement
I use Kevlar cloth but i think a few layers of Kapton tape would be best. Maybe one on the shroud and one around the block? I'm yet to buy some to try.

Where did you get Kevlar cloth from and how did you stick the clothe to the Unit ie epoxy?

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Posted · UM2 Fan Shroud Replacement

We use Kevlar gloves at work, I just cut a finger off an old one (not easily :) )

And poked a hole in it for the nozzle to stick out. It just sits there and the nozzle sticking through the hole is enough to keep it in place.

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Posted (edited) · UM2 Fan Shroud Replacement

Hello to all

I have a maybe newbie question.

Do I need an heat isolation for this Dual Fan if I print with XT ?

My Printer is already printing it with the transparent XT .

thx

Edited by Guest

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Posted · UM2 Fan Shroud Replacement

Hello to all

I have a maybe newbie question.

Do I need an heat isolation for this Dual Fan if I print with XT ?

My Printer is already printing it with the transparent XT .

thx

 

yes :)

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