Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Gunsmithing
HELP: Out of Windage - Scope Base Screw Hole Alignment Check?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Trickymissfit" data-source="post: 743324" data-attributes="member: 25383"><p>Another reason why I hate the Bridgeport variable speed heads! I got it aligned to within .0003" only to learn that the firicking splindle column and pullets need a complete rebuild with new bushings and drive keys (oversized.). Bridgeport and the clones used a plastic bushing inside them, and these allow the keys to eat up the splines. Male spline shows a little wear, but is salvagable. I'll have to figure out what exact key size to go with. I told him the saddle will probably go one more year tops. Now he's faced with the choice of dumping $2000 in the machine plus new ball screws, or pitching it for something better. But for about $4K I can give him a better machine than Bridgeport ever did.</p><p> </p><p> Now he has a line on a gently used (what he said) K&T MM 600 with the CAT tooling. This machine probably had the "D" series Gemini controll, but might have an Allen Bradley 8200 or 8300 control. Told him a full tilt mechanical rebuild will probably set him back $50K at the most (assuming the spindle is in great shape). I think this one has the flat table top instead of the CNC rotary table that comes built into the X axis slide from the way he described it. In good shape it's a rock solid .0003" machine in two feet of travel. These machines are fairly easy to rebuild, and the worst case thing would be a bad spindle. I can get that all plated and reground up in Muncie. Bearing packs alone will cost close to $2.5K for Barden bearing sets (absolute best made), but think this machine would do fine with MRC or Fafnirs. I've rebuilt two or three MM800's and several MM2200 and MM2300's. They are similar in concept, but much larger. Also a lot more labor intensive. Also told him that he'd better have a long talk with the power company because what he has isn't good enough. I guess he has a line of a steady flow of work out of another company that is good enough to pay for his investment in 18 months. I've heard that one more than a couple times in the past. I told him to plan on a 40 month pay back, unless all his labor and tooling was super cheap. Lastly he's found a nice vintage 3' x 5' cast iron surface plate that he says needs to be touched up. I told him fat chance in hell! I could do it, but it really takes another plate to master off of that's also much larger and has the correct profile for mastering (probably something like a 6' x 9') . Even that way is the incorrect way, but also is the way most folks would do it. The correct way is to have two masters that are well beyond lab grade. I could do it with the six by mine by alternating the areas I master off of (kinda trickey, but do-able). When you start out your rubbing and cutting about five times a day, but as the pattern increases you spend more time cutting. Towards the end you rubbing at best twice a day. And one false pattern may make you start all over (don't ask me how I know!) Be way ahead buying a lab grade 3' x 6' granite table.</p><p> </p><p>gary</p></blockquote><p></p>
[QUOTE="Trickymissfit, post: 743324, member: 25383"] Another reason why I hate the Bridgeport variable speed heads! I got it aligned to within .0003" only to learn that the firicking splindle column and pullets need a complete rebuild with new bushings and drive keys (oversized.). Bridgeport and the clones used a plastic bushing inside them, and these allow the keys to eat up the splines. Male spline shows a little wear, but is salvagable. I'll have to figure out what exact key size to go with. I told him the saddle will probably go one more year tops. Now he's faced with the choice of dumping $2000 in the machine plus new ball screws, or pitching it for something better. But for about $4K I can give him a better machine than Bridgeport ever did. Now he has a line on a gently used (what he said) K&T MM 600 with the CAT tooling. This machine probably had the "D" series Gemini controll, but might have an Allen Bradley 8200 or 8300 control. Told him a full tilt mechanical rebuild will probably set him back $50K at the most (assuming the spindle is in great shape). I think this one has the flat table top instead of the CNC rotary table that comes built into the X axis slide from the way he described it. In good shape it's a rock solid .0003" machine in two feet of travel. These machines are fairly easy to rebuild, and the worst case thing would be a bad spindle. I can get that all plated and reground up in Muncie. Bearing packs alone will cost close to $2.5K for Barden bearing sets (absolute best made), but think this machine would do fine with MRC or Fafnirs. I've rebuilt two or three MM800's and several MM2200 and MM2300's. They are similar in concept, but much larger. Also a lot more labor intensive. Also told him that he'd better have a long talk with the power company because what he has isn't good enough. I guess he has a line of a steady flow of work out of another company that is good enough to pay for his investment in 18 months. I've heard that one more than a couple times in the past. I told him to plan on a 40 month pay back, unless all his labor and tooling was super cheap. Lastly he's found a nice vintage 3' x 5' cast iron surface plate that he says needs to be touched up. I told him fat chance in hell! I could do it, but it really takes another plate to master off of that's also much larger and has the correct profile for mastering (probably something like a 6' x 9') . Even that way is the incorrect way, but also is the way most folks would do it. The correct way is to have two masters that are well beyond lab grade. I could do it with the six by mine by alternating the areas I master off of (kinda trickey, but do-able). When you start out your rubbing and cutting about five times a day, but as the pattern increases you spend more time cutting. Towards the end you rubbing at best twice a day. And one false pattern may make you start all over (don't ask me how I know!) Be way ahead buying a lab grade 3' x 6' granite table. gary [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Gunsmithing
HELP: Out of Windage - Scope Base Screw Hole Alignment Check?
Top