Results 21 to 36 of 36
07-20-2007, 02:04 AM #21
Rubber baby buggy what?
Alan, the normal operation of the axis halts the travel before before physical contact with any hard surface.
To block an NC, you have to make the block tall enough to stop the Z while it is stil within it's operating range.
I generally do this by lowering it onto a 4X4 block until the emergency clutch just starts to "clack"...which if I remember correctly, will e-stop the machine and it will sometimes have to be manually raised to clear the error (as the servos can't adjust on startup and you'll get a position error).
Honestly, I think this helps but would be more useful if the block were really hard....cast or better. I've always felt that the weight of the Z....especially with table mounted....would compress the wood (and certainly rubber) to the point that the balls in the screws were still doing exactly what Ross described.
This thought comes from someone who cares about ballscrews, but also sometimes drives a big truck. In other words, I'm going down the bumpy road many times thinking "that wood ain't doing cr*p at this point and I know it".
Again, the wood blocking probably helps but I feel that the cast iron is going to win the "push" over several hundred miles. Keep in mind, you don't really need "travel" here to do damage, just pressure.
The other school of thought here would be to run the Z down all the way until it stops, then shut down the machine and dial it down a few more turns manually (must remove side panel on some machines to do this). The idea is that if any dimples can be made, they are made in a non-operable part of the screw.
Of course, that's hoping that the screw is softer than the balls and oval balls aren't what we want (in a machine tool anyway [img]smile.gif[/img] )
If Deckel were to design anything in this regard, I would think it would be an exactly sized hard block that stopped the Z travel at the lowest final turn of the screw, and required manual lowering to secure the block.
I think that would be the best of both worlds.
Even better would be a long "jack" screw that you could gently install between the saddle and the Y axis ram to eliminate "bounce" once you were there.
Don't forget to lock the heck out of the axis as well, and also remove the table if going any significant distance.
Humble opinions expressed.
07-20-2007, 01:52 PM #22
Point taken... I think that we are talking about the same design changes though, just different material. [img]smile.gif[/img]
07-20-2007, 03:16 PM #23
Maybe Alan, but I don't see it as a design change, but rather a rigging accesory.
I doubt any of us (maybe Arno or DD) have actually unpacked a factory new NC, but wouldn't it be neat to see how they dealt with this?
Ross makes a good point about "dimpling", but I've actually seen a machine with the lower bearing housing collapsed...so blocking is important for more than one reason.
I know exactly which section of road Ross is speaking of. I'm ready to start mowing down "road workers" about 10 minutes into it.
Never came across such a section on the autobahn, so maybe it wasn't a needed design consideration at the time
07-20-2007, 03:50 PM #24
As some of you know, I used to work for SAP (thank God I'm free) which is a huge German company. There were a lot of German folks, of course, here in Palo Alto. I used to hear them moan and groan about our freeways versus the Autobahn (with reference to bumps).
I've never quite understood why their freeways are smoother. I have kind of come to the conclusion that it must have to do with earth movement not construction. The two pricipal causes would be earthquakes (yes, they *do* cause a good amount of permanent movement) and settling. The latter could be from earthquakes, aquifer depletion or high water table.
I would be surprised if the Germans spend more money on their freeway system, but I could be wrong... I don't think it is a function of budget, equipment or technology.
Anyhow, the point about design change is still valid, I think. With the thought Deckel put into their machines, I would have guessed that they would have incorporated an integral "shipping block" onto which you would lower the table... But, it is a moot point. Obviously the machines aren't produced anymore.
07-20-2007, 06:06 PM #25
Hmm...so *THat's* what that thing is for....I thought it was a Deckel doorstop!
07-24-2007, 04:50 AM #26(Maybe a 10 kHz sound can't get through a cell phone connection?)
07-24-2007, 11:59 AM #27
Went for $8,600 this time. What do you think, $4,600 next time?!?!?? Funny, when I click on the bid history I don't get that, I get some industrial video equipment that Reliable has for sale. Anyone else experience this?
07-24-2007, 12:00 PM #28
Well , looks as though Reliable lost money on this deal. Final selling price (2and time around) was less than the price they paid at the auction. Not to mention the transportation costs along with the cost to a man to be at the auction (plane fare, car etc...) Not sure about their business model but in this case don't think it worked out. Hope the new owner will appear here and say hello. Not a bad machine, and not a crazy price.
07-24-2007, 06:29 PM #29
Hard to say if they lost on the aggregate though, Ross. I seem to recall that Reliable shows up with a semi and does their own rigging. If that is correct, then the shipping might not be as severe a loss as we are projecting. And, as we've pointed out before, they buy a lot of other stuff at these auctions; stuff that has a higher profit margin. The Deckel may have been a nice fill-in load for them. Even so, clearly losing money isn't a good thing. [img]smile.gif[/img]
I sure miss the days when we could see who won this stuff... Now that ebay just puts "bidder xx" on there, it is much less fun to watch (of course, the scams were getting pretty bad and the "new" approach makes sense).
07-24-2007, 09:35 PM #30I seem to recall that Reliable shows up with a semi and does their own rigging. If that is correct, then the shipping might not be as severe a loss as we are projecting.
But yeah, they probably do well on most of the smaller stuff. I just wonder why they bother to pay top auction prices for machines like this Deckel when they should know by now it's difficult to get decent return in their situation. Oh wait now I remember, it's because they are saying "Hi" to Sean ! :rolleyes:
07-25-2007, 12:08 AM #31
Hence the comment about the Deckel being the fill-in load. You are right that if they went up there and just bought the Deckel then they'd be losing their shirt. But Reliable buys up a huge portion of the auctions they attend (or the ones I have also attended). The Deckel was probably just a fraction of their spend that day.
07-25-2007, 12:23 AM #32
Wrench, you are right of course but Ross and I were never discussing "the aggregate" as their potential profits from the total auction take aspect was obvious from the get go. We are discussing that one machine and I have been in similar discussions where they have lost money on other CNC machines.
So, the mystery remains, why do they pay top dollar for CNC machines when they must know by now they stand a good chance of loosing money on them ? One theory is they simply feel the need to "take control" of the whole auction and create the impression they are going to pay whatever it takes for everything, such that the other bidders just "give up" and let them have the tooling and smaller stuff cheap. Personally I think that is a flawed theory, but it could be what they are thinking.
Another theory is they want "variety" at whatever cost, to create the impression amogst their followers that they "have everything", thus creating more "excitement" and a more dedicated following that helps to run up bids on the smaller stuff.
07-25-2007, 04:15 AM #33it's because they are saying "Hi" to Sean !
When I was at Reliable, they had a 24' stakebed. They changed that out for a 14' Isuzu stakebed. Not sure what they have now.
Basically it just comes down to how far out of town they are.
Once they "buy" a line truck, they are kind of compelled to fill it...I know how this feels. Sometimes you overspend because of it.
When I was there, they had about 3 owner/operators they generally used, with a few more that had dedicated runs (ie LA to SF).
07-26-2007, 08:22 PM #34
Kind of like my garage... I am "compelled" to "fill it." Now I cannot move and I am compelled to clean it out. I think they have professional help for this type of thing. [img]smile.gif[/img]
P.S. When you were at Swiss Machine, they must have had a big guy... I could have sworn Reliable was using a flatbed then. Interesting comments about how they carry their stuff though. I'd have thought 14' would be a bit small for an operation their size.
07-26-2007, 09:46 PM #35Now I cannot move and I am compelled to clean it out. I think they have professional help for this type of thing
07-26-2007, 10:11 PM #36
Alan, the flatbed is for inspection equip'.
In other words, the non-forklift items, fragile items, and short local hauls.
Out of town, they would decide whether to take the 14', hire a tractor/trailer, or both.