I know a common fault of the T610 and other Bauer Studio Line machines is often, after many years of standing idle, an issue regarding the threading mechanism.
I have had to do some work myself in the past regarding these issues and because of this, I would like to post something of a technical write up surrounding these issues.

The freedom of the linkages on the Bauer series of projectors and many others it has to be said,is of uppermost importance to enable a good,healthy and reliable threading mechanism.
Here i hope to highlight and show via a set of photographs the work that is needed to be able to correctly "free up" any mechanism that is proving to be troublesome after many years of lack of use.

I will begin by showing the correct position of the top roller and curved feed guide when all is as it should be. The curved plastic feed guide into the gate should move consistently down into position in order to make the film enter the steel rear gate guide without causing any hesitation or bunching.


This first photograph here shows the position the curved plastic feed guide should be in for the film to be able to load on autothread position which is the first position of the main control knob in the forward direction.

This next photograph shows the position the top roller and curved feed guide should be in when the film has correctly threaded onto the take up reel and the main control knob is moved into position 2 or 3 (half or full lamp power, forward projection mode)


note how the curved guide should now, reliably and consistently, move completely away from the running film leaving the film itself to stay within the original shaped loop created by the curved guides initial threading position.

Now we move onto the lower "assist" guide and roller.
Again in the initial threading position, as selected by the main control knob, this is how it should appear if all is healthy and working A1.



note on close up inspection on this photograph how the roller sits right up against the assist lower plastic guide to enable the film to forced into the tiny slot for the magnetic head section, both accurately and completely reliably.

Now we move onto how the lower roller and assist guide appear in the run position (position 2 or 3 in the forward direction on the main control knob, main projection lamp lit on half or full power).


note now how the "assist" guide and roller again move completely out of contact with the film. Once again, once the film has entered the magnetic head section, it will have formed a lower loop of it's own from where the roller and guide forced the film to enter into the magnetic head section.

For all this mechanism to work correctly and reliably as seen in the photographs above, it relies entirely on a series of linkages and springs to all be present and all be free to move exactly as they were designed to do so.
The majority of this linkage arrangement can be seen here in this drawing taken from the 502/525/610 service manual.
please study the drawing to gain a general understanding of how the linkages are arranged and assembled in the factory.



In particular, please take note of item 1160. It is a pivot point within the mechanism that if you will pardon the pun, is absolutely pivotal to the rest of mechanism working reliably and accurately each and every time. It is this part in particular that can often be very stiff in it's movements and can therefore cause many issues surrounding the threading action at both the top and lower loops.

Yes- I am having the same issue! Continue! :)

coming up Alan.

The following procedure now allows you to gain suitable access to part number 1160 in order to lubricate and "free up" this part of the linkage mechanism if this part has either seized or semi seized as can very often be the case here.

Begin by removing the lens completely. (I will assume all owners are familiar with doing this task for routine cleaning.)


Now remove the lamp and place the projector into "service" position by rotating the main control knob as far as is possible in the reverse direction with the lamphouse cover removed,



Next, release the Pilot lamp away from its holder. Be careful not to pull excessively on the two cables as these can be in some cases a very tight fit to the lamp holder.


From here on the following tools will come in very handy to avoid dropping any small screws, washers or other components inside the projector slider vents. Believe me, unless you completely cover everything or use the following tools, there is every chance you may lose a tiny screw from the magnetic heads at the very least!


What you see here is a magnetic tray,a magnetic attachment to place on the end of the instrumentation screwdrivers, an inspection mirror and a set of instrumentation screwdrivers that are perfect for undoing most of the small fasteners used in these machines. Not illustrated but will also be needed are a pair of snipe nosed "Surgeons" pliers, a decent inspection lamp and a larger flat bladed screwdriver for some of the next stages.
Note avoid placing anything magnetic in close proximity to the projectors electronics,it can do a lot of harm to many different components.

Now you will have to remove the main lampholder.


The best way to ensure the screws successfully end up in your magnetic tray and not the machine, is to undo slightly using a larger screw driver to begin with just to loosen the screws, then use the largest flat bladed instrumentation screwdriver along with the magnetic tip tool to ensure the screws, once removed cannot fall if you support the lampholder with your free hand.

You now have suitable access to the magnetic head section. All 3 magnetic and erase heads must be removed as also must the the cast holder for the heads. Here is how to successfully carry this work out:

Begin by completely removing all 4 tiny M2 screws that secure the main recording and playback magnetic heads, use the appropriate sized flat bladed screwdriver and magnetic tipped tool to assist the successful removal of all 4 screws and then place them all in the magnetic tray or somewhere secure.



Now remove the two metal spring straps that straddle the magnetic heads and keep them secured in their housing and under the correct pressure. Place these also in the magnetic tray or with the tiny screws in a secure box.

now unclip the plastic plug on connectors and place the two main magnetic heads somewhere secure but NOT in the magnetic tray.



Note the centre black protection strips in position on the magnetic heads. Sometimes these can be missing but when new they are fitted and should be kept in position on the heads and not removed. Put back immediately if they fall off during the removal stages of the heads.

Now it is time to remove the erasing head. Follow the same procedure as with the main heads but be extremely careful as you attempt to remove the actual head. it has a metal jacket surrounding it which makes it a particularly snug fit within the housing. The cables to the erasing head are also very thin and delicate and cannot be removed on this head as they are permanently soldered to the head, therefore use tweezers or small surgical pliers to very gently free the erase head away from its housing still with the outer metal jacket and all cables in tact.



Note: it is both natural and normal for the erase head jacket to unpeel slightly once removed. Simply pinch it to the head with your fingers when the time comes to refit it all back into its housing position within the upper cast shell.

Now it time to completely remove the casting. Please observe the following photograph before attempting to remove it. You will gain a better understanding of how it can easily be released from the main casting within the body of the projector.


Note the open lug close by the Duoplay Track selection button. This is attached as a CLAMP fit by it's set screw. On the other end of the casting, the screw which is far more visible, this end has to have it's set screw completely removed. DO NOT remove the clamp fit end set screw. It is completely unnecessary as well as quite difficult to access and therefore even to do so.

Now continue to remove the first screw on the casting at the LHS of it, then loosen the RHS screw. Now the casting may be slid to the left slightly, then completely removed.


You will now be at the stage where you have exposed the lower nylon pressers for the magnetic heads. As this routine is not one you may do too often, it;s always a good idea to clean and inspect this area completely.



This photograph now clearly shows the set screw from the magnetic head upper casting that remains in the body of the machine where the open lug fits into upon refit.

You are now finally at the stage where you can gain suitable access to the pivoting linkage (part number 1160 in the service manual) to allow yourself to test all of the mechanisms movement via the main control knob while observing if everything moves freely and to its full extent.
It is also a good idea at this stage to tuck away first, all of the magnetic head leads, pilot lamp and the erase head (gently) out of harms way close to the shutter blade, inside the machine.

See the photograph below and in particular, the Red and Black arrows pointing to part number 1160 at both of its extremities.


Now make sure the power lead is off the machine and in any case the machine is switched in the "OFF" position before moving the main control knob to test the movement of the linkages.

As you rock these extremities backwards and forwards with your finger tips, and as you operate the main switch in all positions,you should be able to see if the movement is reliable, free and consistent with no binding each time you move it. Lubricate the pivot point using a very light machine oil or mineral oil and apply using a q tip or syringe. Do not allow any excess oil into the electronics below. Only a tiny drop of lubricant will be necessary to begin bringing the rocking motion back to original if applied precisely.

I will send you a video Alan now showing a healthy mechanism and its movement range.

There are another few linkages that travel up to the top feed mechanism that can only be accessed by removing the rear cover, If this proves necessary beyond what you have seen here, I will post more on that tomorrow.

Good Luck!

That is an incredible tear down of this wonderful machine. Excellent work! I will start the work on my machine tomorrow and will let you know the outcome. This is a great resource for any Super 8 do it yourselfers (which is almost all of us these days!) and your work is very much appreciated. I know it took a lot of time and man-hours so a very big Thank You from me!!

It should also be pointed out that part numbers 1130 and 1134 should have adequate grease lubrication surrounding these parts, in particular, where the main control knob gear meshes the main slider toothed rack.
Also around the elongated slots on the main sliding linkage. (1134)

Typically, I've found, the original manufacturer grease is both adequate and still perfectly serviceable, but this part of the mechanism is crucial to a totally free moving mechanism so ensure adequate, serviceable amounts of grease still exists and if not, replace with new.

Andrew, this is just the sort of thing to forward to phil at CHC for the mag

Yes Tom, feel free to print it off if you like and post it to him.
Maybe even get Phil to join us all here and then he could print his own and add whatever he liked, with the authors and moderators permission of course.

Phew !!!! Thanks for that information Andrew I am sure it will be of great value to some users.

yes, not much use to many, but Alan did tell me he had been having issues and as I had already experienced similar issues myself, I just wanted to give him a head start David.

The principles within the write up applies to many machines that have plenty of linkages for their autothread systems.

Ironically, the projector with the fewest linkages that I've ever come across for an auto threading projector, is the Beaulieu. It only uses links from the main control knob just to move the mag head assy.

The GS is another model that I don't think has many, given the piano keys and electronic drive system. Micro switches and solenoids seem to be the issue on them, where threading the machine is concerned.

How are getting along with this one Alan?

I am now waiting for my Magnifying light and lens! And then I tackle this beast in a few days!

The Projector is 100%! And I got the piece from Van Eck to fix the framing. Lovely machine and the replacement part is PERFECT! Thanks Andrew and Van Eck.
But of course once it was all fixed, I went and watched "Rocky" on the Beaulieu. I couldn't help it! 1200ft reels! :)
One last question..what are the specs of the Pilot light on the machine? Mine went out. Thanks!

They're an unusually high voltage lamp, for a pilot lamp Alan. Around 36v from memory.
They are also quite difficult to get hold of though FFR and Van Eck do stock these. I've got a few if you're struggling in any way to find one, just pm me and I will post you one alongside a Christmas Card!

Great to hear its running sweeter now Alan. All the very best to you my friend.

Ps Edwins framer replacement kit really is a God send on these. Before he released them, my first machine snapped its tiny pin and I had to fit an m2 countersunk screw c/w loctite to repair it.

It has stayed strong and at least it is now made of steel, but it would have made everything a whole load easier had Edwins kit been available then than trying to drill and tap 2mm diameter with a countersink into 3mm plastic!
Yikes!!!

I am revisiting this thread because my Bauer developed the bunching up of the film after the gate and when it hits the first lower roller! I assume I will have to tear this baby down to the bare bones. Sigh....anything else I need to know Mr. Woodcock? I know you have worked on this exact same problem! Thanks!

Sorry Alan, I never even saw this last post when it came in! (busy year at times, sad to say!)

I do hope you got it sorted buddy, but if not, we can always re-visit it again if you like?

Andrew, your instructions are bang on, the machine was relatively easy to tear down, but I'm at a slight loss as to where to lubricate?

See the red and black arrows in the photographs Stuart.
Aim for the pivot point around these arrows (roughly in the middle of these two arrows in the photo)

A light machine oil only btw and only a tiny drop necessary!!

It's all about the "freeing up" the rocker mechanism, back and forth.

https://m.youtube.com/watch?v=A2eU2CG3WN8

The swinging cod piece only to beaten in the 80's by "Single Life" or "Word Up!" Or best of all "Candy! "

https://m.youtube.com/watch?v=sn8KYD1Vco0

https://m.youtube.com/watch?v=oRsmpQRbeuM

Well that seems to have done the trick! Been shuttling back and forth and the loop is holding, plus its lacing up better. Also gave me the opportunity to give the heads a really good clean.

Nice one Stuart, I feel like Reginald VanJohnson of Die Hard acclaim now! 😊😊