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Hi,
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Today my AD741 thickness height adjustment stopped working, seemingly out of the blue. Following are the details:
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My AD741 has power feed, but the issue is not related to the digital drive. As a matter of fact, the numbers on the display continue to go up and down, but the table does not move. Upon opening and inspecting, I noticed that the shaft attached to the drive motor does spin (circled in red). However, the gear on the opposite side of the piston does not (circled in blue). I can manually rotate the larger gear (circled in green) which in turn will rotate the small (blue) gear as well as rise or lower the table. However, when turning either of these gears, the shaft? on the opposite side of the piston (red) does not rotate. This means something connecting the shaft to the gear is broken. I had a look at the exploded parts view (attached) and it seems there is only a simple bolt (34) connecting the shaft to the gear. I have no idea if the gear is keyed at all or if the bolt only holds the gear in place by pressure.
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Has anybody had this happen? Is it indeed a snapped bolt or could it be a striped thread on the shaft (I won't know which would be worse)? And why would this happen during a simple rise/lower operation? Lastly, and most importantly, how do you go about repairing it? I don't want to take apart more than I absolutely must, but the bolt doesn't seem to be accessible without removing a lot of other components first ....
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Many thanks in advance for your help!
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Regards,?
Cornelius Schultze-Kraft
Cyprus?
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Pull the electric motor assembly #29, don't loose the key #35, and see if the shaft #30 feel like it is in two pieces. It looks like it is necked down for quite a distance, I'm guessing it is snapped off where it goes from the smaller diameter thru the bearings to the larger diameter on the outboard end. Don't pull the shaft completely out in case it might drop the sleeve #38 down the center of that tube. It's possible that the gear on the end is rotating on the shaft as well, can't tell and don't see a key on that side, so suspect it had a D or double D shaped hole in it and that's what keys it to the shaft.
Regardless if you can turn one end of the shaft and the other doesn't turn the gear, then the shaft is the issue somewere along it.
Brian Lamb blamb11@... lambtoolworks.com
On Saturday, February 8, 2025 at 06:56:32 AM MST, Cornelius <cornelius@...> wrote:
Hi,
?
Today my AD741 thickness height adjustment stopped working, seemingly out of the blue. Following are the details:
?
My AD741 has power feed, but the issue is not related to the digital drive. As a matter of fact, the numbers on the display continue to go up and down, but the table does not move. Upon opening and inspecting, I noticed that the shaft attached to the drive motor does spin (circled in red). However, the gear on the opposite side of the piston does not (circled in blue). I can manually rotate the larger gear (circled in green) which in turn will rotate the small (blue) gear as well as rise or lower the table. However, when turning either of these gears, the shaft? on the opposite side of the piston (red) does not rotate. This means something connecting the shaft to the gear is broken. I had a look at the exploded parts view (attached) and it seems there is only a simple bolt (34) connecting the shaft to the gear. I have no idea if the gear is keyed at all or if the bolt only holds the gear in place by pressure.
?
Has anybody had this happen? Is it indeed a snapped bolt or could it be a striped thread on the shaft (I won't know which would be worse)? And why would this happen during a simple rise/lower operation? Lastly, and most importantly, how do you go about repairing it? I don't want to take apart more than I absolutely must, but the bolt doesn't seem to be accessible without removing a lot of other components first ....
?
Many thanks in advance for your help!
?
Regards,?
Cornelius Schultze-Kraft
Cyprus?
|
Hi Brian,
Thanks for your feedback. I didn't even need to pull the motor assembly - it became apparent that the shaft was snapped right at the entry point of the center piston as soon as I started the process of removing the motor (see attached video). I guess I will need to order a replacement. The thought of dropping that sleeve #38 down the center of the tube is scary! Still not sure how I will replace the shaft without taking everything apart since I need to get to bolt #34 somehow in order to pull that gear and attach the new shaft. The drive rod #40 is completely blocking access to #34.?
Regards,
Cornelius Schultze-Kraft Cyprus
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Sorry for the slow reply, was out yesterday. Well, you found the issue... as for getting it apart, you may have some issues getting the bevel gear off the broken shaft, If... and that might be a big if, you can get at the screw that holds the bevel gear on the shaft while the bevel gear is still engaged in the vertical bevel geear, that might hold the shaft from rotating enough to get the bolt out. When you get the shaft loose, you might be able to pull it out from the motor side and push a wire in from the bevel gear side to keep the spacer from dropping. If the center tube is hollow all the way to the bottom, dropping out might not be a problem.?
You will most likely need to remove the screw holding that bearing in and get the bearing out to re-assemble everything.
Hope that helps... I doubt it will be easy or quick, but it is doable.
Brian Lamb blamb11@... lambtoolworks.com
On Saturday, February 8, 2025 at 08:53:02 AM MST, Cornelius <cornelius@...> wrote:
Hi Brian,
Thanks for your feedback. I didn't even need to pull the motor assembly - it became apparent that the shaft was snapped right at the entry point of the center piston as soon as I started the process of removing the motor (see attached video). I guess I will need to order a replacement. The thought of dropping that sleeve #38 down the center of the tube is scary! Still not sure how I will replace the shaft without taking everything apart since I need to get to bolt #34 somehow in order to pull that gear and attach the new shaft. The drive rod #40 is completely blocking access to #34.?
Regards,
Cornelius Schultze-Kraft Cyprus
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Hi Brian,
I have successfully removed the broken shaft. It was actually easier than expected.? Once the motor is removed, the entire shaft/spacer/bearing/gear section is simply pulled out in the direction of the motor. This means that bolt #34 does not need to be accessed or removed until the shaft and gear are?completely pulled. The gear is actually slightly smaller in diameter than the bearing.? In order to pull it through,? the only thing necessary is the removal of two bolts on the motor side of the large piston.? Those bolts hold the bearing in place laterally.?
It is still perplexing to me how the shaft can snap since there is no way for any tilt or twist, considering the fact that motor, shaft and piston are all tightly locked to the table bed and cannot tilt independently to cause the shaft to crack. And I doubt the motor is strong enough to crack a 12mm shaft in rotation.?
In any case, I shall now wait for replacement parts. The only remaining question is how to reset the digital readout to match the actual height of the table since the numbers no longer match true height at this point ...
Many thanks!
Cornelius Schultze-Kraft? Cyprus?
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Cornelius,
The method to reset your planer DRO should be in the manual.
I have shared this and so far no one has mentioned that it does not work, i.e., Felder uses same method across it machines. Not sure if the new machines are any different.
If you use inches, first power up the machine while pushing the reset button on control panel to switch to mm.
Then very slowly plane a board to 20.00 mm thickness exactly. Measure with digital calipers as you approach the target thickness. Ignore the machine display reading during this. You do not want to go thinner than 20.00 mm as you will start over again (there is a workaround but likely best to start over). Once at 20.00 mm thickness (without changing table height) press reset button the display will changes to 20 mm.
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On Feb 11, 2025, at 8:34?AM, Cornelius via groups.io <Cornelius@...> wrote: ? Hi Brian,
I have successfully removed the broken shaft. It was actually easier than expected.? Once the motor is removed, the entire shaft/spacer/bearing/gear section is simply pulled out in the direction of the motor. This means that bolt #34 does not need to be accessed or removed until the shaft and gear are?completely pulled. The gear is actually slightly smaller in diameter than the bearing.? In order to pull it through,? the only thing necessary is the removal of two bolts on the motor side of the large piston.? Those bolts hold the bearing in place laterally.?
It is still perplexing to me how the shaft can snap since there is no way for any tilt or twist, considering the fact that motor, shaft and piston are all tightly locked to the table bed and cannot tilt independently to cause the shaft to crack. And I doubt the motor is strong enough to crack a 12mm shaft in rotation.?
In any case, I shall now wait for replacement parts. The only remaining question is how to reset the digital readout to match the actual height of the table since the numbers no longer match true height at this point ...
Many thanks!
Cornelius Schultze-Kraft? Cyprus? <20250211_151019.jpg> <IMG-20250211-WA0000.jpg> <20250211_151042.jpg>
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Imran,
Great! Thank you. I just gave it a try and it worked - obviously without actually making any real adjustments yet since I am still waiting for the parts. But the actual reset to 20mm works. I did search my manual for "reset" but nothing popped up. It turns out my pdf manual is not searchable ... odd.
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The shaft broke from stress risers in the sharp corner between the smaller section and the larger section. Pretty common thing to have happen... so you just got lucky! :-) It's nice that they designed it to be able to be installed or removed right thru the center hole, could have been a lot worse.
Brian Lamb blamb11@... lambtoolworks.com
On Tuesday, February 11, 2025 at 07:49:26 AM MST, Cornelius <cornelius@...> wrote:
Imran,
Great! Thank you. I just gave it a try and it worked - obviously without actually making any real adjustments yet since I am still waiting for the parts. But the actual reset to 20mm works. I did search my manual for "reset" but nothing popped up. It turns out my pdf manual is not searchable ... odd.
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Hi Brian,
Is there something I should or shouldn't be doing when I use the machine in order to avoid this from happening in the future?? Understand the stress that caused the failure,? but not sure what I did to have caused this stress.?
As far as design is concerned, yes, I was happy that is was that simple to take apart,? but why does the shaft have to go through the center of that large piston in the first place, narrowing down at the point of entry? Why isn't the vertical, spiral drive shaft and gear simply on the same side as the motor??
I hope I will be able to reassemble to the same tight tolerances. After all, it is supposed to be repeatable to 0.1mm up/down.
Many thanks!
Cornelius Schultze-Kraft? Cyprus?
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I doubt there is anything you did that caused the problem. Most likely a defect in the material or like I said, to sharp of a radius in the corner. The shaft most likely was designed to go thru the tube as it supports the shaft. If it was all to one side, another bracket would have had to be designed and bolted to another portion of the machine (maybe the bottom of the table?) to support the shaft. It's a logical design, especially given the gear is small enough to go right thru the tube.
There are no tight tolerances to worry about upon installation. The assembly just goes in far enough to engage the two bevel gears. The up/down tolerance won't be effected as the resolver portion of the drive system that feeds back to the DRO is attached to the electric motor. As long as you always approach finished dimensions from lower to higher (thicker to thinner), all backlash will have no effect and you will be as accurate as it ever was.
Brian Lamb blamb11@... lambtoolworks.com
On Tuesday, February 11, 2025 at 08:45:04 AM MST, Cornelius <cornelius@...> wrote:
Hi Brian,
Is there something I should or shouldn't be doing when I use the machine in order to avoid this from happening in the future?? Understand the stress that caused the failure,? but not sure what I did to have caused this stress.?
As far as design is concerned, yes, I was happy that is was that simple to take apart,? but why does the shaft have to go through the center of that large piston in the first place, narrowing down at the point of entry? Why isn't the vertical, spiral drive shaft and gear simply on the same side as the motor??
I hope I will be able to reassemble to the same tight tolerances. After all, it is supposed to be repeatable to 0.1mm up/down.
Many thanks!
Cornelius Schultze-Kraft? Cyprus?
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imran