URSA MINI SEMI-PRO 4.6K???

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robert Hart

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URSA MINI SEMI-PRO 4.6K???

PostWed Dec 23, 2020 7:17 pm

Here is the conundrum. I have been mustering broken URSA MINIs with a view to eventually combining enough bits to make up a complete camera. One is an URSA MINI 4.6K which presented with a substantially damaged upper case with the top broken out.

The described history was that it had functioned after its accident but had since succumbed. In the course of its journey, something must have jolted into place. It was fully working when I decided to power it up to see what was left of it that worked. I was mainly after the SSD recorder it was wearing.

I was minded then to move its inner workings across to a Mini Pro core frame which is identical. The Mini Pro itself was dead. On taking apart the URSA MINI I find that the front piece which supports the sensor PCB and the lens mount is also substantially damaged with small pieces falling away.

The lens mount itself was loose but it may have been left that way following exploratory visitations. With this part having to support the weight of lenses, sticking together the many pieces of broken magnesium alloy castwork with JB weld won't cut the mustard.

It must have had a very substantial accident, like left on a car roof and fallen off type of accident or crashcam maybe.

I had hoped to transfer this entire front piece because the seal of the sensor and IR filter would not be disrupted by the move. It would also match the left side cover and monitor. However it is also fractured. So the sensor board itself has to migrate to the good URSA MINI PRO front. This is where it gets complicated.

The URSA MINI PRO front also contains a ND filter wheel assembly. The URSA MINI PRO left side cover and swing-out monitor is completely different with more electronic bits and pieces attached. The URSA MINI left case and its screen will bolt up to the URSA MINI PRO core frame but the added filter wheel assembly takes up more space and fouls the side cover.

The display screen connection appears to be the same however the touch controller may be routed differently. The ND wheel would be nice to have operating but the rest of the functions will be just ornaments in the side cover.

There is a lot of dust inside the URSA MINI 4.6K. It looks like it has faithfully earned its keep. The URSA MINI PRO case was clean inside but caved in at the right side cover with the main PCB having been sprung in at least 5mm inwards and then rebounded back. It seems unharmed to the eye but that smack in the gizzard was near the main processor with all its many little solder joints begging to fail.

I shall have to have a good think about this or pack all the loose pieces in a box and wait for some more busted URSA MINI 4.6K cams to come along in the fullness of time.
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Ellory Yu

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Re: URSA MINI SEMI-PRO 4.6K???

PostWed Dec 23, 2020 7:55 pm

Unless this is a hobbyist playing around or to learn, why not just buy a working UMP?
MSI Raider X99 MB / Intel i7 5280 6 core CPU / 2 x AMD R9 390X 8Gb GPU / 32Gb 3200 RAM / Decklink 4K Mini Monitor / 240Gb SSD OS Drive / 4Tb RAID 0 SSD Cache/Scratch Drive / 24Tb 7200rpm Data Drive / Win 10 Pro 64bit / Resolve 17
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robert Hart

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Re: URSA MINI SEMI-PRO 4.6K???

PostWed Dec 23, 2020 8:11 pm

Ellory.


There is a bit of both going on. Being a bit low on the funds is also a factor. I have been lucky enough to patch cameras up in the past, Sony, JVC, and Sony TCD audio recorder. When they have been physically damaged there is most times a line of cause to follow. Mysteriously dead electronics are another matter. I also hit lucky with the "big" URSA when it went down after a sensor was replaced. It also had an intermittent power thing going on. That turned out to be fixable with a bit of solder on the Molex plug pins. There is a lot of waste when things get the chuckout. Mostly they are gone for good but some can be recovered. Now if only I could jump into BM's dumpster for half an hour. If anyone has an Ursa Mini Pro well out of warranty support with the magenta screen of death, the sensor assembly on this one may be good although the mainboard is toast.
Last edited by robert Hart on Wed Dec 23, 2020 8:15 pm, edited 1 time in total.
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rick.lang

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Re: URSA MINI SEMI-PRO 4.6K???

PostWed Dec 23, 2020 8:12 pm

Why climb a mountain? Because it’s there. I’m enjoying hearing about Robert’s adventure.
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Ellory Yu

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Re: URSA MINI SEMI-PRO 4.6K???

PostThu Dec 24, 2020 4:30 am

robert Hart wrote:Ellory.


There is a bit of both going on. Being a bit low on the funds is also a factor. I have been lucky enough to patch cameras up in the past, Sony, JVC, and Sony TCD audio recorder. When they have been physically damaged there is most times a line of cause to follow. Mysteriously dead electronics are another matter. I also hit lucky with the "big" URSA when it went down after a sensor was replaced. It also had an intermittent power thing going on. That turned out to be fixable with a bit of solder on the Molex plug pins. There is a lot of waste when things get the chuckout. Mostly they are gone for good but some can be recovered. Now if only I could jump into BM's dumpster for half an hour. If anyone has an Ursa Mini Pro well out of warranty support with the magenta screen of death, the sensor assembly on this one may be good although the mainboard is toast.


Robert, Don't get me wrong, I'm all for recycling, salvaging, restoring in the name of learning and the fun of bring dead things back to life. So more power to you! I stand beside Rick and read about your BMD adventure as they come along. :D
MSI Raider X99 MB / Intel i7 5280 6 core CPU / 2 x AMD R9 390X 8Gb GPU / 32Gb 3200 RAM / Decklink 4K Mini Monitor / 240Gb SSD OS Drive / 4Tb RAID 0 SSD Cache/Scratch Drive / 24Tb 7200rpm Data Drive / Win 10 Pro 64bit / Resolve 17
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robert Hart

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Re: URSA MINI SEMI-PRO 4.6K???

PostThu Dec 24, 2020 2:56 pm

One postscript to the odyssey is that with the URSA MINI 4.6K front lens mount support was fractured along with the microphone supports. That leaves only the the URSA MINI PRO front lens mount support with its ND filter wheel available to use.

That will not fit inside of the left side cover of the URSA MINI 4.6K. In the course of investigating, I also discovered the sidescreen must have taken some of the hit. It is fully functional but the hinge is not quite what it once was, with a few cracks and a ruptured look about it.

After all that apparent violence, it is a minor miracle that it continued to operate.

The front sensor board of the URSA MINI PRO and the front lens mount support are cleverly donkeytrapped with an extra locator pin. The older sensor board cannot be mistakenly mounted to the newer front lens mount support.

For now, the bits and pieces have to remain asleep until another donor cam comes along with an intact frame.

The URSA MINI PRO seems to have a lot in common in its core with the older camera but it is much more feature loaded with the left side cover being much more complex. Goodness knows what the innards of the 12K look like. It is probably very cosy and tight in there.
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robert Hart

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Re: URSA MINI SEMI-PRO 4.6K???

PostThu Dec 24, 2020 7:27 pm

The further postscript is that impatience has won out. I had some JB Weld I bought in a while back.

The front lens mount support is attached by four screws which pass through tabs cast outward at the corners. The upper two tabs had cracked off along with the nearby in-camera microphone attachment points.

The front of the camera had been firm when I tested it. While the tabs had cracked off, the cracks were irregular in shape and surface texture. The assembly had remained gripped together until I took out the fasteners then the tabs fell off.

For the time being I have reattached the front lens support to the core frame by the lower two screws, attached the two tabs with the two upper screws after I laid a bead of JB Weld in the breaks.

To firm the assembly, I added a small web of JB Weld across to the frame on each side in positions where it can be conveniently cut later for the entire piece to be replaced.

URSAS BUSTED 2.jpg
URSAS BUSTED 2.jpg (99.72 KiB) Viewed 941 times


The takeaway lesson is that the structure of the assembled casework is well fit for purpose It has been artfully designed so that there is no unnecessary bulk, unlike the big URSA which will make a weightlifter of you.

In a fall, the big URSA which would probably just chip some paint, crack a screen or crunch a hole through whatever it hits or fracture your ankle and foot bones. The Mini casework will be unlikely to suffer falls with a heavy lens attached, a top handle attached directly to the upper case, a side handle attached to the right side cover without experiencing structural damage.

The trend for folk to add cheeseplate cages around their cameras as a turtleshell may have merit. The camera body can be supported top and bottom. Concentrated stress points by top and side handles are taken by the cage and distributed to multiple points on the camera body.

All the very best for your Christmas and New Year folks and hopefully you are not forced to dance with Rona before you can receive your shots.
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robert Hart

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Re: URSA MINI SEMI-PRO 4.6K???

PostFri Dec 25, 2020 5:28 pm

The final chapter. Very early this morning before the glow in the East started, I copped a dose of allergy and a spider bite. There was not going to be much useful sleeping so I got up and put the camera back together using the best pieces of the two wrecks.

The JB weld glue patches on the front lens support frame are surprisingly strong. Until another front end comes along, it will suffice but obviously no heavy 500mm lenses are going on the front.

The impact must have seriously loosened some connections. The original damaged frame rocks on the bench on the opposing corners so it is quite out of shape. This may have pulled some plugs out of proper connection. It was reported as having no sound from external mics. So far as I can see everything works as it should, with and without phantom power.

The side screen is delicate with a crack in the case below the buttons. The plastic trims at the hinge were fractured but the hinge and pivot remain intact.

URSAS BUSTED 3.jpg
URSAS BUSTED 3.jpg (86.59 KiB) Viewed 889 times


It would have been cool to have used the left side panel from the wrecked Mini Pro but there is too much hardware which is different and too much extra wiring with nowhere to go.

One thing I do not know about and that is how hot the body should become. This one gets quite warm on the right upper side and upper right vent. That is logical because that is where the Xilinx processor is and they get really hot. The heat pipes run up inside the right to the heat exchanger which runs across the top under the mesh vent. It may be normal behaviour. Any advice will be appreciated.

So in a sense it was my Christmas present to myself by 7-30am in the morning.
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Overlander

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Re: URSA MINI SEMI-PRO 4.6K???

PostFri Dec 25, 2020 5:35 pm

Fascinating fix! Particularly Xmas morning. Good old JB Weld. I once fixed a round baler drive wheel with JB just to get use through the next field. Years later is was still chugging along.
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robert Hart

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Re: URSA MINI SEMI-PRO 4.6K???

PostFri Dec 25, 2020 5:46 pm

Two-part resins seem to have come a long way. At first I thought the material had gone stale in the shop because it did not do much after being pasted into and across the joints. It had hardened overnight.

As for the cameras, there is an order in which things should be dismantled and some things which do not have to be unfastened.

I am not confident the mainboards are a candidate for solder reflowing if they have gone dead after some violence. Whilst roasting joints on one face of the 4 layer PCB, there are parts on the opposite face which are going to fall off.

From a business POV it is certainly not worth the labour cost for a maybe-maybe not outcome and possible failure in the near future.
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robert Hart

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Re: URSA MINI SEMI-PRO 4.6K???

PostSat Dec 26, 2020 1:11 pm

I took the combined camera to the local sportsground for a quick test. Definitely ND filtering is a must. I was forced to a fast shutter and f16/f22 aperture which introduces diffraction. There are bound to be some dandruff flakes or dust motes on the sensor somewhere.

I just haven't found them yet in the image. I filtered the air as best I could with an evaporative airconditioner running, reasoning that as it filters out stuff which provokes my allergy, it might take out some environmental dust as well.

The camera is a different beast to the "big" URSA but a lot easier to handhold. With a proper grip handle it would be easier. Handcradling was a bit of a mission with my arthritic wrist.
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robert Hart

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Re: URSA MINI SEMI-PRO 4.6K???

PostSun Dec 27, 2020 4:08 pm

For sake of curiosity, I had another look at the mainboard of the donor dead Mini Pro which I drew from to repair the URSA Mini 4.6K. Things look intact but when I gently warp the board slightly, it creaks, very faintly.

This hints that maybe some of the Xilinx processor solder joints onto the main board have disbonded or the entire board has begun to delaminate. The kick in the guts it got from a fall on the sidehandle would have certainly shaken it up. The conundrum is how does one resolder the processor onto the mainboard without all the parts on the reverse face of the board falling off?

The short answer probably is "you don't". The longer answer might be "very carefully". Apparently surface-mounted electronic parts which are attached by the solder reflow process are good for one shot at original assembly. I have some reading to do.

I had been very tempted to test the Mini Pro sensor board by connecting with the mainboard off the URSA Mini 4.6K I do know to be good. However I thought better of it, there being no point in taking the risk of bricking the good mainboard. There are times when one should not be too greedy. This has been one of them.
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robert Hart

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Re: URSA MINI SEMI-PRO 4.6K???

PostSun May 09, 2021 5:22 pm

Well, it seems that the broken and fixed URSA Mini 4.6K may yet live on. It has about 12 hours up after yesterday after being second camera, filming an event.

What do you do when some housebreaking thieving sod has thugged your 200mm Nikon f2.8? Put a doubler on the back of a vintage Sigmatel-for-Nikon 135mm f1.8. It did the job. Why the lens prop? I was fretful about too much stress on the JB Weld-ed internal magnesium framework.
URSA PATCHED.jpg
URSA PATCHED.jpg (27.02 KiB) Viewed 361 times


Now that I have discovered that I can change settings on the main screen without having to race around injuring my claws inside menus, things have improved. It is not a bad camera, still down a bit on gain compared to the Sonys I have played with but not bad at all.

I am still eyes-open for a physically distressed URSA Mini Pro as I have most of the casework and attachments. However the only specimens which appear seem to be the "died-with-blackscreen" examples at extortionate asking prices offered as "for parts-only.

Some folk are buying them at the asking prices. I suspect there is a bit of buyer's remorse going on.
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rick.lang

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Re: URSA MINI SEMI-PRO 4.6K???

PostSun May 09, 2021 7:26 pm

Congratulations Roger on the success of your adventure to resurrect the URSA Mini 4.6K. Good to see you were rewarded.
Rick Lang

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