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Author Topic: Replacement drive shaft for DP70 Markus Ito Film Handler Posts: 27 From: San Diego, CA, USA Registered: Apr 2011 posted 02-17-2014 11:43 AM                     During the credits of our last movie (incidentally the last movie we will ever show on 35mm), the main drive shaft on one of our DP70s failed. It appears that the shaft sheared at the point where it slides into the helical drive gear. Fortunately for us future movies will be on our digital projector, but since we run a changeover booth, we need to get this projector working again if we are to ever show 35mm again. Are replacement parts for this projector available? I would also be interested to hear any theories on how this happened.  |  IP: Logged Pete Naples Phenomenal Film Handler Posts: 1565 From: Dunfermline, Scotland Registered: Feb 2001 posted 02-17-2014 12:09 PM                     Wow! You don't often see a DP70 that broken. Some parts are available, get your local Kinoton dealer to check stock with the factory. Be warned that a; there's not much left and b; parts are EXPENSIVE. I'd also be looking at why the mech is putting enough load on that shaft to shear it. Ruling out issues of metallurgy of the shaft itself, or the bearing binding, overheating. Doesn't look like it from the pictures but it's hard to diagnose without the evidence in hand. The photo doesn't shoe classic shear failure of the shaft, ie it doesn't look like it failed with a twisting motion. Typically the broken ends look 'swirled'. My dad used to have a pet metallurgist on his staff, he was immensely informative with things like this as he'd look at it, tell you how it failed and why it failed. I often wish those guys were still around  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 02-17-2014 12:17 PM                     Kinoton still has new parts available for mucho $$$$. I've worked on gobs of DP-70 but have never seen that happen. It is hard to tell from the picture if it has ever been replaced before. Even more odd are the fact that those shafts are not hardened and so won't generally have a tendency to just snap off. They are soft steel just like the parts in a Brenkert are. Be aware when you replace it that the whole drive shaft assembly has to be removed from the projector to do the job properly. You will have to press the gear back on the new shaft, drill the correct # size hole for the (new, don't re-use the old one) split pin and then press the pin into place. Where most techs make a big mistake is doing all this with the drive casting in place. With the shaft being soft steel tapping on the split pin to get it back in will likely very slightly bend the end of the shaft where the gear sits. There are a lot of DP-70 sitting in Wyoming that Film-Tech member Randy Pryde owns. You might consider contacting him and grabbng an entire machine from him so you have spare parts for all eternity. Many of those are DP-70 that I have rebuilt. There are other dealers that may still have used parts but be weary and get a money back guarantee on any used item you buy!! I have seen drive shafts in DP-70 with as many as four holes drilled through them for various gears refits. Mark  |  IP: Logged Dick Vaughan Phenomenal Film Handler Posts: 1032 From: Bradford, West Yorkshire, UK Registered: Jul 2000 posted 02-18-2014 06:04 AM                        Pete as a metallurgist in a former life , haven't actively done any fracture analysis on a regular basis for 30 years, I have to say that does look wierd! You're right a straight forward torsional falure would have a twisting , swirl type surface. This almost looks like a fatigue failure with progressive " tide marks" . It's a bit difficult to tell from this picture. The confusing bits is that it seems to be bi-directional with an origin point at the centre. The fact that the two series of curves meet opposite the grub screw holding the collar/gear is interesting as well. If I'm talking complete rubbish please excuse me it's been a while !  |  IP: Logged Pete Naples Phenomenal Film Handler Posts: 1565 From: Dunfermline, Scotland Registered: Feb 2001 posted 02-18-2014 06:28 AM                     You know more about the subject than I do Dick. I just go on what I learned from my dad and his cohorts when I were a lad. It just doesn't look like a classic shear failure, does it? Which lends weight to Mark's point about servicing that shaft in place.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 02-18-2014 04:47 PM                     You also need a V block behind the gear when the new split pin is pressed or tapped into place. The V Block should be made of oak or equivelent hard wood. Needs to be softer than the metal you;re backint it with.  |  IP: Logged Markus Ito Film Handler Posts: 27 From: San Diego, CA, USA Registered: Apr 2011 posted 02-18-2014 08:21 PM                     Thanks for all the great advice. I think I will try and contact Randy and see if he would be willing to sell us a projector. Having a few spare parts would definitely be handy. We priced out a new shaft from the company that services our projectors and they quoted us $1700 for the shaft only, not including the helical end gear or installation cost. We might be able to salvage the gear from the old shaft but since it is pressed on, it looks like getting it off will be tough with nothing to grip on to.  |  IP: Logged Pete Naples Phenomenal Film Handler Posts: 1565 From: Dunfermline, Scotland Registered: Feb 2001 posted 02-19-2014 10:04 AM                     Markus, knowing the cost of DP70 parts from the factory as I do, that price doesn't sound unreasonable to me. A couple of years ago we supplied a pair of factory fresh intermittent units to customer, co-incidentally the last ones Kinoton had. I've bought a nearly new car for less than the bill for 2xDP70 intermittents!  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 02-19-2014 10:39 AM                       I have 2 new in the box DP70 intermittents found in various UA/Regal cinemas I pillaged a few years ago. No shafts though. Randy will help you out I'm sure, but it's a long way to Wyoming.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 02-19-2014 01:01 PM                     You can absolutely salvage and re-use the old drive gear and you should. Just take it to a competent machine shop. They'll press out the pin and then press the broken shaft piece out of the gear. BTW: Those drive gears are ONLY sold in matched sets. They are also well over a grand for the set. All of this is really a job for a qualified machinist rather then the every day projector service guy. Few service people ever come into contact with these projectors. If I lived closer I'd do it for free... just because! Mark  |  IP: Logged Markus Ito Film Handler Posts: 27 From: San Diego, CA, USA Registered: Apr 2011 posted 02-22-2014 01:58 PM                     I contacted Randy and he offered to sell us a projector head. The cost including shipping ended up being less than the cost of the shaft so this ends up being a great deal and assures us of replacements parts for a while. Mark, you recommend reusing the old gear over the one that comes with the replacement? Is this because the gear and the fiber gear it meshes with are matched and won't work with a new one?  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 02-22-2014 07:26 PM                        I have 2 vertical shafts (23 inches?) new for AAII. Louis  |  IP: Logged Steve Matz Jedi Master Film Handler Posts: 672 From: Billings, Montana, USA Registered: Sep 2003 posted 02-22-2014 07:30 PM                     That's pretty pathetic that a company would have to charge $1700.00 for a piece like that. If you can find a competent machine shop that has say a HURCO 5 AXIS CNC MACHINE. They could reproduce that piece and easily be inside 1/10,000s tolerance or 1/100,000 if need be for a few hundred dollars. their speed and tolerance control is something you have to see in person to believe..Amazing  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 02-23-2014 11:32 AM                     And by the time you pay someone do do an autocad drawing, purchase and set up any special tooling needed, set up the machine and then operate it... for one part? Steve it would cost way more for that first part. If you were going to produce multiple parts like Wolk or LaVezzi did then it's a good idea. This is a part that virtually never ever wears out. Yes, re-use the old gear. You may find a completely different gear pair in the projector you are buying. There were fine pitch gears which was discontinued and the coarse pitch that you have. The gears have been running together and also have established a wear pattern between them where they make contact. So re-use the old one. Mark  |  IP: Logged Steve Matz Jedi Master Film Handler Posts: 672 From: Billings, Montana, USA Registered: Sep 2003 posted 02-23-2014 06:18 PM                     [quote]And by the time you pay someone do do an autocad drawing, purchase and set up any special tooling needed, set up the machine and then operate it... for one part? Steve it would cost way more for that first part. If you were going to produce multiple parts like Wolk or LaVezzi did then it's a good idea. This is a part that virtually never.[quote] Mark; you must be talking older CNC Machines; These Machines today have 3D Scanning Properties in them and could program a setup for that shaft in less than 5 minutes. All that's needed is what piece of billet Stock your using. Whether its say a piece of 4340 Carbon Steel,or what ever Kinoton originally used. That shaft would be a piece of Cake;in fact even at 200 dollars an hour That piece would probably take maybe 20 minutes tops to produce. Even an older Bridgeport Vertical could handle that pretty easily. I think German pride is coming here. There is no way a piece like that should be costing 1700 dollars. Reminds me of what the Automotive Paint Mfgers started doing in the later 80's. Jacking up Catalized Acrylic Enamel that sold on an Average of 30 dollars a gallon to the Paint/Body shops to over 300+ dollars. It gets even worse every year. CALLED GREED!  |  IP: Logged

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