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» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Prevost P-70 ( Zeiss Favorit 70 ) restoration project. Updated. (Page 2)

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Author Topic: Prevost P-70 ( Zeiss Favorit 70 ) restoration project. Updated. Giorgio Volpi Film Handler Posts: 51 From: Caracas - Venezuela Registered: Mar 2002 posted 11-26-2003 01:32 PM                     If you need to contact Prevost factory directly send an email to: attilio.prevost@prevostsrl.it (Ing. Attilio Prevost) paolo.prevost@prevostsrl.it (Ing. Paolo Prevost) Regards, Giorgio Volpi Prevost Italia  |  IP: Logged Steven H. Krams Film Handler Posts: 14 From: Miami, FL, USA Registered: Oct 2002 posted 11-30-2003 03:50 PM                     The bases are still in the warehouse. If you want them now would be a good time to collect them as I will likely sell the building in the coming year and would hate to put them in the dumpster if they are of any use to you or someone else. Good luck on the restoration. PS we have a good relationship with Paulo Prevost at the factory in Milan Italy . If you require something let me know.  |  IP: Logged Erick Akers Arse Kicker Posts: 201 From: Dallas, TX, USA Registered: May 2001 posted 12-04-2003 11:12 PM                     Hi Guys and Gals, Moving steadily along, Kicking Much Arse and Taking Many Pictures Along The Way! Just ran into my first mechanical problem. Posted below is a picture of the outer portion of the sound drum on machine #2. As you can see, it is slightly dimpled on the Eastern & Western edges. Please note, item was previously removed and packed separately in a box containing all of the goodies. The tarnish indicated to me that a previous owner; not Steven, had some difficulty removing it, guess they never heard of DMSO. Anyway; If it is soft enough to dimple like this, I am hoping that the dimples could be rolled or expanded from the inside, where it could once again have full contact with the film edge. Would any of our wonderful Film Tech machinist or mechanics, like Mr. Mueller, or Mr. Gulbrandsen care to take a stab at it? Is there some type of flat roller bearing expander type of hand tool for large pipe possibly? Thanks, Erick Redited for a clearer description, and a better disposition. Must be the Winter Blues!!! [ 12-05-2003, 10:56 PM: Message edited by: Erick Akers ]  |  IP: Logged Greg Mueller Phenomenal Film Handler Posts: 1687 From: Port Gamble, WA Registered: Jun 99 posted 12-05-2003 09:00 AM                        The problem on that particular part is that it was hardened and ground (usually). When you harden things they get brittle. So expanding the dents outwards and then regrinding for smoothness might result in cracks. Grinding alone would be espensive. I'd say it would be cheaper to get another one rather than try to repair that one, even if you could. Sorry PS If you try to repair it and get to the point where you want to have it ground, you need to do with it's shaft attached so it will all run true in it's bearings  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-05-2003 07:19 PM                     The proper way to repair it would be to have both end bells hard chromed to a thickness that would be enough to allow a re-grind between centers on the original shaft. This would get rid of the dimples. If you can live with a little deeper groove than a clean up grinding would also take care of that, but its a matter of how far things protrude from behind it so nonthing ends up running the film. When we rebuild any sound reproducer we always have a clean up grind between centers done on the sound drums film supporting surface. Superior Grinding in Salt Lake City has always done a really good job for us and although not cheap to do its also not super expensive. We also have them do a plunge grind on the DP-70 sound drums as the BACP reader LED mount requires a slightly wider groove..... BTW: The DP-70 has one very hard sound drum.... about RC 60 and a plunge grind is the only way to widen a groove in metal that hard. We only believe that the the highest quality work will result in a happy customer. Also, you definately do not want a highly polished supporting surface for the film as the film may simply slip past the drum. If this happens you'd end up with excessive flutter. The Christie sound drum is a prime example of how not to make a sound drum. Overly polished and then they attempted to correct the problem by adding those stupid "O" rings to increase the stiction and cause the drum to rotate at the proper speed...... Totally stupid! Another consideration with the older Prevost and Shakeamecannicca machines is the width of the area for the film to lay down in. You will find on older machines that its a bit wider than 35mm and you have quite a bit of side weave of the track. This is bad for good stereo decoding. Shakeamecannicca offered new "stereo" drums for their machines to minimize the side weave. If the P-70 is still in production Prevost may offer the same thing. If you're serious about really making everything on these machines correct then new drums are in order. If the new drums are not available then thats also something that might be done during an overplating and re-grind operation. Also one point in mind. Many European machines sound drums are made from brass and then plated with hard chrome. This may be why the dimples are so bad in this particuluar one. The Brass was to alow it to be as non-magnetic as was possible while still giving good wearing surface for the film to run on. If these were really hardened steel then there would not be dimples in the drums that large unless someone hit it with a hammer. Mark @ CLACO  |  IP: Logged Richard Fowler Film God Posts: 2392 From: Ft. Lauderdale, FL, USA Registered: Jun 2001 posted 12-05-2003 11:50 PM                     Most of the problems I had with P-70 involved the sound drum and intermittent sprocket. Flutter due to dimpled drum and sprocket short life with mylar film. Newer designed replacement parts should solve this.  |  IP: Logged Erick Akers Arse Kicker Posts: 201 From: Dallas, TX, USA Registered: May 2001 posted 02-26-2004 11:31 PM                     Yeah, I know it's been a while since I have updated this post, but I thought that it was time that I fill everyone in on my continued progress. As some of you know, A WANTED POSTER: Seeking some OEM reel arms & magazines to help me complete my project, And Thanks again to Brad & F-T, not only did I find exactly what I was looking for, but I also found enough spair parts to keep me running for many years to come. Brad, I will be sending the single side copies of the Tech manuals for a new addition to library. ( sorry it took so long to get them done, but they will be on the way this weekend ) Bruce, I may have even found what you're seeking, If you are still interested, please get back with me by e mail and I'll let you know more when I receive an update on the inventory of spair parts. And yes, I have taken more pictures and will be sending them to Brad for the Picture Album. At this time I would also like to thank every one who has taken their time to help me locate everything I was looking for. If it wasn't for Film-Tech, this project may very well have taken me years to complete. As is, It looks like I will be able to come well within my origional projected time frame!!! Thanks Film-Tech!!! "The ARSE KICKER!!!"  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 02-27-2004 06:37 PM                     When, oh when, will we get to see some pix ?  |  IP: Logged

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