|
Forum: Pentax SLR Lens Discussion
12-25-2023, 03:36 PM
|
| |
The same contact assembly (Part 48120-0-M291 POWER CONTACT ASSY) is interchangeable on a lot of lenses: DFA's 24-70, 70-200, 15-30. I've replaced a few. I've had really good success with preventing breaking the tabs off by adding a drop of superglue to the edges of the exposed part of the contact tab. The glue usually ends up all over the contact and I remove that by wiping and scraping.
My theory is that the superglue wicks in under the tab and sticks it down or at least provides a miniature 'ramp' on the edges of the tab preventing it from being so easily moved during lens changes. I've never had an issue with broken tabs since doing this to all 3 DFA's.
|
|
Forum: Pentax K-1 & K-1 II
01-16-2023, 04:46 PM
|
| |
Mark the copper earthing plate is very thin, I think 0.25mm from memory, it is basically a square and does not cover the whole underside of the area underneath the hotshoe. So, just replacing that 'plate' would be better than original, but I don't think it would be as robust as what I did. You would also need to attach the earth wire to the plate somehow.
Some of my thinking behind my solution:
Aluminium is light and easily machined, is not magnetic and has some flexibility.
Having a plate that closely matches the underside flat area under the hotshoe would allow the transference of forces / movement to the vertical and sloping surfaces of the top cover which would be more rigid (I think I also added superglue under the aluminium plate to take up any space and increase rigidity).
There is enough room for a plate of this thickness (1.5mm) under this area - including near the cut out in the PCB forward of the hotshoe pins / soldered connection (this is where the space is smallest).
Having done it twice, I can now see that it can be a relatively straight forward procedure, especially if wires were soldered to the hotshoe terminal block pins and looped around to the PCB. If someone had a machine shop produce a number of aluminium reinforcing plates using CNC machines / laser cutting and a supply of screws and wires, a number of top covers could be done in a day ready for swapping.
|
|
Forum: Pentax K-1 & K-1 II
01-13-2023, 11:26 PM
|
| |
Part 2 Making Reinforcing plate / Modification Of Top Cover
(See Part 1 here:
Pentax K1 Top Cover Reinforcement Procedeure - Part 1 - PentaxForums.com)
Using the old top cover as a template:
Remove/ cut off / scrape off the PCB locating pin (shown with screwdriver).
Cut out a piece of aluminium 17 x 23mm and then cut it finish it with a file in a trapezium shape (21mm opposite the 23mm side) and notch out 1 corner. I used a piece of paper pressed into the top cover with a sharp lead pencil pressing into the corners to make a template that I transferred to the aluminium.
Hold the plate under the top cover while drilling down through the top cover with the 1.6mm drill for each of the 4 screw holes (I used an appropriately sized piece of timber in a vice under the plate and top cover).
Coat the top side of the plate with a marker and scribe around the bigger hole of the top cover to obtain an outline of the hole required for the hotshoe terminal block
(This plate is a first attempt and wasn’t quite right).
Drill and file the hole and make sure all of the holes line up with screws etc. Do a dummy fit up with the hotshoe and terminal block. When everything fits properly dismantle.
(I used “Blu Tack” during a trial run to make sure there was enough clearance with the plate fitted).
Terminal Block Pins
These need to be made longer due to the thickness of the aluminium reinforcing plate. I used 2 methods – each is a little tricky.
1- Solder solid copper wires to the pins
2– Add solder ‘strings’ to the pins
Assembly Of Hotshoe
Have the Loctite applied to the 4 hotshoe screws and silicon sealer ready plus appropriate screwdrivers.
Using a very small screwdriver or similar, apply a small bead of silicon to the mating face of the terminal block and fit it to the top cover (this replaces the white sealant removed when dismantling).
Apply some superglue to the top cover especially in the corners to the left and right of the hotshoe recess. This is not so much to bond the metal hotshoe, but more to take up the tiny spaces underneath it.
(Edit: I think I also applied a little superglue under aluminium reinforcing plate for the same reason)
Fit the hotshoe, the aluminium reinforcing plate, the copper earth plate and the 4,5mm screws before the superglue dries, checking everything is where it should be and any excess glue wiped off.
Fit the PCB over the hotshoe pins and apply pressure to it with a screwdriver etc. whilst soldering the PCB(I fitted an older flash to the hotshoe to make sure there wasn’t any pressure forcing the pins out whilst soldering).
This can actually be the hardest part of the whole process to get right and may take several go’s at each pin without getting each one too hot and melting and distorting the terminal block, but getting the solder hot enough to melt onto the pin which is now just below the surface of the PCB. And / or it may mean putting a piece of wire down through the holes in the PCB to get a good solder joint. Take your time.
Use a multi meter on the PCB and the terminal pin on top to check each solder joint is OK.
IN HINDSIGHT,I would solder 4 insulated wires to the terminal block pins, feeding them forward between the PCB and the copper earth plate, looping them back over the PCB (as there’s plenty of room) and soldering them to the PCB similar to the audio wires attaching to the main camera PCB. This should be a lot easier to make good soldered electrical connections.
After soldering, I applied a tiny amount of superglue around the edges of each of the 4 terminals on the top side of the hotshoe to make sure they were sealed.
The flexible PCB needs to be slightly bent so it will line up with the locating pins near the GPS switch and it functions properly – if you don’t, the switch will be slightly skewed and won’t function properly. Some new or more double sided sticky tape may be needed to hold the PCB in place on the GPS switch plate.
Refit the 3 screws for the GPS switch plate.
Refitting The Top Cover
Solder all of the top cover wires to the body assembly
Refit the wiring harness to the terminal plug on the body.
Remove the temporary ‘bridge’ at the end of the new on / off switch brush and be careful not to bend the brush during reassembly.
Remove the clear protective plastic from under the LCD cover and make sure there is no dust or loose debris under the cover or on the main camera body etc.
Fold forward slightly the portion of the top cover PCB that you removed the adhesive from when removing the hotshoe, otherwise it will foul on reassembly.
Check all adhesive tape is in place and all wires are attached and not caught up and fit the top cover making sure it fits down as it should. This may take a few go’s and require a little pressure as things have been disturbed and there is now slightly less room above the viewfinder mechanism, but all should fit snuggly.
Replace all screws as per removal of the top cover taking note of the “O” ring behind the viewfinder adjustment dial, and test everything works.
Don’t panic if it doesn’t, just remove the top cover and retrace your steps.
It all looks complicated and scary under there, but each item and step is just that – one at a time.
|
|
Forum: Pentax K-1 & K-1 II
01-13-2023, 10:00 PM
|
| |
I have replaced the top covers TWICE on both of my K1's (a Mark i and a Mark ii). I do a lot of events etc. with flashes on top most of the time and the top covers develop cracks under the hot shoes as there is very little strength in the plastic. It is definitely a weak point as there is no metal in the vicinity, just 5 holes through the plastic of the topcover that eventually crack.
But, the last time I added a small aluminium reinforcing plate under the top cover and the whole hotshoe area is now much more solid. I didn’t check the before and after effects on the GPS but from my observations, the GPS unit is forward of the hotshoe(above the pentaprism) and perhaps slightly above it, hopefully if there is any effect it would be minimal.
Just replacing the top cover is a straightforward repair for a technician and not too complicated for someone with some skills with hand tools and a steady hand with a soldering iron.
The replacement top covers came with printed calibration tables, I assume these would be needed by Pentax technicians to recalibrate the GPS (it appears to be part of the top cover assembly) and compass. I intend on passing these on to my repairer the next time I send each body in for a service.
I performed these operations in August 2021 (5 months ago, so am relying on memory to a degree). The images aren't great, I took them purely for reference at the time.
Tools Needed:
JIS #00 screwdriver (similar to a #0 Phillips but a better fit)
A set of flat bladed jewellers’ screwdrivers
Tweezers
Soldering iron
Tray for small parts
+1.5or better reading glasses or similar
Good lighting
A clean floor (in case of dropping small screws
Hacksaw
Marker
Scriber(sewing needle)
1.6mmdrill bit
Cordless drill
Small files
Multimeter to check electrical continuity of the soldering to the hotshoe pins.
Time and Patience!
Parts Needed:
Top Cover Assembly (or reuse the original one).
1.5 X 17mm or wider flat aluminium
4(or more) M1.7 x 4 mm (or longer and shorten to fit) machine type screws – ie.threaded, not self tapping types (I got mine from a computer parts supplier).
Loctite222 “Screwlock” (you don’t want the hotshoe screws coming loose after all this work)
Superglue
Silicon sealant
Solder
Copper wire for hotshoe pin extensions
Part 1 Top Cover Removal
Refer to the following video from Digi Service for top cover removal and replacement:
You Tube
|
src="https://www.youtube.com/embed/lg304Qv_4Zo?controls=1" allowfullscreen>
|
As it doesn’t cover unsoldering and resoldering I’ve included images of wires and positions. From memory there are 2additional wires closer to the pentaprism (Black & Orange?) plus a Black wire with a lug that only needs the loosening of the screw at the top of the last image in this section. It seems allof these wires have to do with the audio inputs and outputs and the flash synch socket and none of the main camera operations.
The screws are all JIS standard (handy to have at least a #00 to tighten all manner of body and lens screws).
(Note also the second image (cut away view) on the post linked below showing the room directly under the hotshoe (about the only place there is some free space!):
Help! K1 hot shoe came off (warning: k1 gore) - Page 2 - PentaxForums.com)
Removing Hotshoe Etc.
New top cover:
Remove the 3 screws that retain the GPS switch plate.
Gentlypry away the printed circuit board (PCB) that is stuck to the top cover just above where the viewfinder would be and peel off the adhesive (it’s no longer needed and gets in the way).
Little by little, alternating each hotshoe pin, soften the solder whilst gently prying under the hotshoe PCB. Do not apply too much heat as the hotshoe pin mounting block is easily melted.
Scrape away all of the white sealant from around the 4 hotshoe screws and remove the screws and the thin copper earth plate.
The hotshoe, hotshoe terminal and pin assembly will come free.
With a flash mounted on the camera and it wobbling around as you move around, this section flexes - as you can see there's not much material between the screw holes and the terminal block hole. Also, the ground plate is very thin and the heads of the hotshoe screws have very little surface area underneath them. The result over time is cracking from the screw holes and also in the rear internal corner.
Part 2 will deal with making and installing the reinforcing plate and refitting the top cover:
https://www.pentaxforums.com/forums/190-pentax-k-1-k-1-ii/451285-pentax-k1-t...ml#post5684831 |
|
Forum: Digital Processing, Software, and Printing
04-16-2022, 04:13 PM
|
| |
Thanks for your thoughts and experiences guys. Especially you Class A, I appreciate the time and effort you've gone to in such a comprehensive reply, that's very helpful and what I was after.
Wheatfield, where I am the internet connection is very average and sometimes disrupted after storms etc.
I initially looked at Capture 1 some years ago after reading a blog etc. by Jay Goodrich and initial impressions then were good. When I can free up some time I'll make some more serious appraisals of Capture and the other suggestions hear.
Thanks again guys.
|
|
Forum: Pentax DSLR Discussion
09-01-2021, 02:42 AM
|
| |
| |
|
Forum: Maintenance and Repair Articles
10-17-2015, 10:20 PM
|
| |
I don’t post much as I’m time poor and slow on a keyboard, but I have numerous times been much helped by the posts and information given by others, so an opportunity to give back…
A few months ago while on a job covering school age gymnastics, while I was using my 2nd body, a K-5 with a wide lens, my main body (a K-5IIs) with Sigma 70-200mm 2.8 attached, rolled off a trampoline and landed on concrete. I didn’t see it but heard the crash. The lens parted company with the body pulling the mount off the body. I cried, literally.
(see photo 1)
The lens was ok, but it had pulled the metal body mount ring off the body. The 5 mounting points on the body had screw threads pulled out and some had pieces broken off or out of them, meaning that it wasn’t just a case of screwing it back on. Also the metal mount ring and contact spring were also bent. (+ a spring locating pin/spigot was broken off).
(see photos 2,3 & 4)
I sent it to the distributors in Australia (CR Kennedy) for a repair quote and was informed it was not economical to repair, needing a replacement mirror box assembly (the ‘core’ of the camera). This means a full day for a technician replacing and then adjusting and calibrating numerous components to obtain correct alignment. I obtained a Pentax service manual and had some idea of the magnitude of the work involved.
Funds for a K-3II were donated by my generous (& gorgeous) partner and said body obtained. It seemed a shame and a waste of a good body though so I made enquiries about repairing the K-5IIs.
Some of the info I discovered:
· The mirror box seems to be basically the same for all models from K10 through to K3.
· The material is a carbon fibre re-inforced plastic that doesn’t like super glues.
· Alignment is critical to achieve proper focus side to side and top to bottom.
· I didn’t like the idea of just gluing the screws back in so I checked the depth of the screw holes and sought longer screws
· The flash head of a Pentax AF-360FGZ Flash has 2 screws the same diameter (2mm) as the mount ring, but longer – 20mm vs 4.5mm. But the heads are larger and thicker.
(see photos 5,6,7,8 & 9)
------------------
Continued in Part 2
|
|
Forum: Pentax K-1 & K-1 II
03-30-2019, 06:20 AM
|
| |
I've made a prototype “L” bracket for the K-1, that can be used with or without the battery grip to suit Manfrotto RC2 tripod heads.
I use Manfrotto heads and the Spider Pro holster system on a Think Tank Pro Speed belt, hence the ball pin.
My intention was to keep it simple for my own use, with this in mind, it is not possible to access the output ports on the left of the body or change the battery while the bracket is attached. When I shoot professionally I have never needed to change batteries mid shoot (I use 2 batteries).
If there is enough interest expressed here and elsewhere I will look at putting it into production.
I have set it up, so the lens axis maintains the same lateral centre when switching from horizontal to vertical, with or without the grip. Same goes for body to subject distance (fore and aft) if you decided to remove or add the grip.
To prevent the grip twisting there is a “u” shaped bracket that is screwed to the “L” bracket upright. Without the grip, 2 button head screws are removed from the bracket upright and screwed into the base to locate in the same holes in the body that the grip uses to locate itself.
Other than the 2 capscrews that hold the bottom RC2 plate more or less permanently, all the other screws use the 1/8” allen key that is stored securely in the front side of the bracket upright.
When the grip is not used, the ¼” screw that holds the "L" bracket to the grip is removed and screwed into the hole in the middle of the bottom RC2 plate. The “u” bracket is removed by removing the countersunk screw in the upright, the 2 button head screws are removed from the upright and screwed up through the base. The RC2 plate on the upright can be put onto the lower position to keep the same lateral axis position and reduce the overall height of the bracket. Pins in the upright prevent this plate from twisting.
More images: DaveR's Album: K-1 L Bracket Prototype - PentaxForums.com |
|
Forum: Maintenance and Repair Articles
10-17-2015, 10:22 PM
|
| |
Assembly
· Bare the end of the black wire that comes out near the #3 hole and solder it to the new Mount Spring (Pentax 27230-A105). As it is steel, be sure to use acid core solder NOT resin cored as you will not be able to solder.
· Screw the focus mode selection switch back on using the shortened screw.
· Using a cotton bud, apply a film of thin oil (household or sewing machine oil) to the body mount ring where it may come into contact with epoxy. The same goes for the threads of any screws (unless you want them stuck in permanently!).
· Position the Mount Spring and then the Mount Ring on the mirror box. For the holes that were damaged significantly and were not very deep (ie. there wasn’t much thread engagement even after drilling and tapping) – in this case hole numbers 2 & 5, I used a small amount of epoxy as a ‘filler’. I used a very fine flat blade screwdriver to place the epoxy into the holes. Then screw the appropriate length screws into their holes.
· After an appropriate time to allow the epoxy to set, remove the screws and gently rmove the Mount Ring to check the repair
(see photo. This shot shows #5 hole repaired with the new Mount Spring pin/locator above it.)
On reassembly and with some test shots, the repaired K-5IIs focusses and performs fine.
|
|
Forum: Maintenance and Repair Articles
10-17-2015, 10:21 PM
|
| |
Repair Procedure (continued from part 2)
(see photos 1-2)
· Remove the screw holding the focus selection switch to the mirror box and shorten it approx. 1 mm (.040”). I used a pair of long nose ‘vise grips’ or locking pliers and a grinder.
(see photos 3-4) [Photo 4 shows the screw (out of focus) temporarily reinstalled without the switch]
· Use epoxy glue (Loctite brand in my case – NOT super glue) and glue the broken piece of mount ‘pad’, using the original screw to clamp it in place ensuring it is not twisted. Before the epoxy has fully hardened, remove the screw (so it can still be removed easily). Make sure both parts of the epoxy are well mixed.
· Using a pin vise or similar hand held drill chuck with a 1.6mm 1/16” drill bit, drill all the way through each of the 5 mount holes taking care to remove filings/chips etc. often so as to lessen the chance of debri inside the body when the drill breaks through the bottom of each hole. You should be able to feel when the drill bit breaks through, don’t get carried away and drill into other components hidden behind the mirror box flange (especially hole #1 – the bottom one).
(see photos 5)
· Use the same drill bit to drill a hole at the location of the broken mount spring locating pin to around 3mm (1/8”)
· Make a new pin from a 1.6mm (1/16”) nail around 4mm long and insert it in the hole making sure it does not protrude too far and thus foul on the mount ring when it is installed.
· Using a very small triangular file (or similar), file two lengthwise grooves on the end of a flash head screw (one each side) so the screw becomes a makeshift thread tap.
· Screw your tap into each of the 5 holes, tacking it out often to remove shavings etc. until you have cut a thread all the way through.
· Cut a piece of ¼” or 5/16” timber dowell say 3-4” long (75-100mm) and drill a 1.6mm (1/16”) hole lengthwise in one end.
· Screw a flash screw into the end and use the dowel as a handle to grind the head down to 0.6mm thickness [I used a 100mm (4”) angle grinder with a thin/fine cutting disc clamped to a bench]. Check your proceedings with a digital caliper. There should still be enough of a ‘+’ for a #0001 phillips head screw to work OK.
· Reduce the screw head diameter by turning the dowel as you gently touch the edge of the head to the grinder. Aiming for 3mm diameter or slightly less.
(see photo 6)
· Your screw should now fit into the recessed mount ring screw hole without the head protruding or sticking as the screw is turned. Four screws to go!
(see photo 7)
· Using side cutters/pliers, cut each screw 1mm or so longer than the lenghts I have given (in red pen on my notes) and using small ‘vise grips’ hold the head and grind the screw to length. Clean up the burrs with a fine file. NB: length measurements refer to the threaded portion and do not include the head thickness.
(see photo 8)
· Without screws, make sure your new Mount Ring (Pentax 77240-A104) fits properly onto the mirror box mount ‘pads’ and doesn’t ‘rock’ on any protrusions. I had to file the #1 (bottom) pad down as it was higher than the other 4 after gluing. I had to do this very carefully with a fine, very flat file using steel toolmakers parallels sitting on the other ‘pads’ so as to gauge how much to take off, but not too much.
(see photo 9)
----------------
Continued in Part 4
|
|
Forum: Maintenance and Repair Articles
10-17-2015, 10:20 PM
|
| |
Repair Procedure (including some changes due to hindsight):
· Keep debri out of mirror box and other internals
(see photos 1- 6)
· Remove body base plate by removing the 10 screws from underneath
· Remove the front cover by removing the 7 (?) screws, including the one hidden behind the rubber under the ‘K-5IIs’ logo
· The cover won’t come all the way off until the screw holding the flash synch. socket is removed from behind the front cover and the middle of the socket is pushed through
(see photos 7-9)
--------------------------
Continued in Part 3
|
