Fadal 4020 Drawbar question

I have a 4020 purchased needing a new spindle. Replaced the spindle, all seemed to go well. Has thru spindle coolant. When doing a tool change, the spindle pushes the tool down dislodging it from the clips in the ATC. It is, however well aligned when the ATC comes in. I’m a newbie, so difficult to explain what is happening, but long story short, on tool change, the ATC comes in aligned with the tool just fine, but as the drawbar releases the tool, it pushes it down forcing it out of the clips. Air blast pressure seems fine and don’t think that is the problem. Was thinking about getting a drawbar force gauge to measure the drawbar force and removing the drawbar to check the balls etc, but figured someone here might have a better idea. Thanks in advance.

Sorry to hear of the troubles.

They have a different number of bellville washers depending on the drawbar configuration. Not only do the number of washers determine the drawbar force, but it also determines the amount of travel. Are you sure the drawbar and washers are the same as the ones you removed?

Who did the spindle come from? I see 10K grease pack spindles for sell on ebay every so often. Rebuilt (by whom) or Old New Stock but they never seem to know anything about them. So in other words, they might "fit" in the machine but there are other configuration items you need to know.

I hope you and the vendor get it figured out because they aren't cheap. I'm in the same boat and will be looking for a new or rebuilt spindle for my 4020 soon. Hopefully I can find a reputable vendor.

Richard

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Originally Posted by rwskinner

Sorry to hear of the troubles.

They have a different number of bellville washers depending on the drawbar configuration. Not only do the number of washers determine the drawbar force, but it also determines the amount of travel. Are you sure the drawbar and washers are the same as the ones you removed?

Who did the spindle come from? I see 10K grease pack spindles for sell on ebay every so often. Rebuilt (by whom) or Old New Stock but they never seem to know anything about them. So in other words, they might "fit" in the machine but there are other configuration items you need to know.

I hope you and the vendor get it figured out because they aren't cheap. I'm in the same boat and will be looking for a new or rebuilt spindle for my 4020 soon. Hopefully I can find a reputable vendor.

Richard

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Bought the spindle from ItsCNC a while back. I’m thinking I had to use my old drawbar due to the thru spindle coolant, but don’t quite remember. I will reach out to them Monday and pull the drawbar to count the washers. Was a 7500 rpm spindle locking drawbar, so maybe that is the issue. Appreciate the quick response. I debated with rebuilding the old spindle myself (bearing replacement) but after researching it a bit, to do it correctly would require some specialized tooling and not worth the effort. I should have sent back the core for credit, but have kept it. I might pull it apart just to get a feel how difficult a DIY bearing replacement would be.

ItsCNC called me today after I sent an email on Sunday. Actually, they sent me an email back Sunday saying they would call me Monday and did. After a description of the problem, the spindle guy there called me 5 minutes later and walked me thru some troubleshooting ideas. I will pull the drawbar and check, and when I diagnose the problem, I will post it here. I also ordered a drawbar gauge from ebay (which I needed anyway). Posting this just to give credit to the guys at ItsCNC as they went above and beyond in a remanufactured spindle that I bought in 2016 and am just now getting around to troubleshooting. Top notch company that impressed me. If your looking for a spindle, my experience with them has been great.

Great, please do tell us what the issue and solution was in order to help others later down the road.