Issue type: Equipment Problem
Area: Woodshop
Equipment: Drum Sander - Supermax 25/50
Summary: A piece broke when I turned it on.
Additional Info: I left the broken piece on the machine.
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Any eta on the drum sander being back online?
Hate to be the bearer of bad news. ETA is probably more than ten days. I asked Robert to order the part. Not sure if he has or not. It takes about a week to come in (luckilyit is in stock, normally is not). Once the part comes in, someone has to install it. Is about a 30 minute job to a couple of hours job depending if the person doing it has done it before or not. Since I looked at it, it has been in my mind because that part is not supposed to break first. Under normal use the spacer (red plastic) supposed to give first, is the sacrificial part. Then the coupler on the drum shaft. And last the coupling on the motor shaft which is the one currently broken. The only thing I can come up with is that the drum was fully engaged on stock and then it was turned on or the bearings of the drum seized. I did not trouble shoot the drum since I quickly found the broken part. So if you check the drum see if it turns freely, no more parts are going to be needed. However if it does not turn obviously the bearings need to be ordered and compounds the time of repair as the taking apart, checking other parts involved for damage, and putting back together takes much longer, not exactly an easy task. If you needed for smaller parts suggest making a sled or backing board so you can use on the wide belt sander. Double sided tape is usually involved in this process. I am not currently in TX so I can not look further into it until I get back (around Dec 5th). Just thought to give you a realistic answer.
Thank you, I appreciate that. I’ll adjust my plans to use a different tool
I have been 3d printing some excellent shaft couplers that performed better than what I could find for sale.
Got a pic or link to this part? I might be able to just make one.
You could also take off the on on the drum shaft, they are the same. Be advised there should be two set screws. I think they’re off set 90°. Once loose the coupling comes out very easy. In the Stewart’s closet there is a kit of various sizes of set screws and spline keys.
Just FYI, that looks like a pretty standard part you could get from any industrial supply.
Probably so but it would require someone to verify that the steel/cast iron is the same along the measurements. My investigative days have been done a while ago as my use of micrometers. Also, I do not have the qualifications to make that call nor do i want to have in my mind that someone got hurt because the alternate part that was used did not work the same as the OEM part. Once the call is made it also requires someone to go around Austin and find it. I do know that this part(s) are designed to break during overload to save the drum and or motor which are more expensive and harder to acquire. So ordering the $10 part makes a lot of sense. If they would listen to experience and order let’s say four of these and keep the spares on hand along with other often breakable parts it would be less time waiting for some machines to get repaired. Instead when machines break right now often is reactionary to order parts and play the waiting game. Slowly Robert is starting to build this inventory. I know there are some spare parts for the SawStop and jointer. At the end of the day, taking in consideration time spent, gas, and cost of part would be more than the $10. I did that to get the last parts needed to get the wide belt sander operational. I spent most of one day going to Grainger and other places around Austin to get five pneumatic parts. When I got home I did 20 minute research, the very same parts would have cost 1/4 of the money I spent and would have been there in two days. So I learned my lesson and when I know a machine is broke, I quickly provide the part numbers and the source so they can get them ordered.
Have we broken the coupler a lot? It is a wear item for sure, but I think it should last a really long time. If the coupler is breaking often, I wonder if there is some misalignment causing it.
My 2 cents. I assume people are pushing it. @JOSEGAYTAN probably has great insight into the durability of the item.
I assume McMaster Carr is our friend for this part
I have used drum sanders since pretty much they came in the market (the current ones anyway). You are right those parts are supposed to last a long time. There is no miss-alignment prior to this instance as if there was the drum would be very hard to match to the shaft of the motor. I happen to be the one that installed it. Also you would not be able to adjust the drum to sand flat from left to right. The adjustment tolerance is about 1/8" if I remember correctly. The problem is the lack of education or experience in the users. If they forget to turn on the drum and engage the stationary drum to a piece of wood, if they flip the switch on, take a wild guess what happens when the motor starts torquing? There is a plastic part that goes in between the couplings that is supposed to cushion the torque and for the most part it does if it doesn’t encounter enough resistance. This part does wear out even under normal use as it looses elasticity over time. But if the drum remains stationary either the motor overheats and pops a breaker/capacitor or the couplings break. The motor of the 25-50 is too strong so normally it breaks the couplings. If something gets jammed between the drum and the housing during operation, same thing except that on this instance, while the motor is trying to recover, it over heats the plug behind the step motor (sometimes it burns it quick) and the circuit board of the intellisander step motor. Way back there were some sanders direct driven and did not last long as a bent shaft would become a costly repair or pretty much ruin the equipment. I belive Performax and Delta came up with the current couplings. Performax, Jet, Laguna, and a couple of other brands in between are pretty much the same machines. Different outer bodies same inner parts.
I believe this is the second, possibly third, time that this has happened in the last 2-3 years.
The Stationary Sanders class teaches how to set the drum height dynamically. We make it very clear the part shouldn’t even slide on the feed belt, which is way short of stalling the drum. So either people are ignoring their training or using it without the proper training.
Shaft couplers are very standard items. Getting a non-OEM one shouldn’t be a problem as long as the specs are right. I think that’s the main value of getting OEM parts, certainty about the specs and quality. I agree with Jose that having a spare on hand is worthwhile.
(Someone mentioned maybe 3D printing a replacement. Using plastic instead of metal here would be a great example of “way out of spec”. Don’t do that.)
Parts have been ordered for this.
The piece from Laguna came in.
Piece has arrived! I am putting it in the machine in an envelope with an extra bolt. I noticed a stripped head from a bolt that might need to be removed to do this. I at least have the replacement
I came in to use the drum sander after seeing the part had come in a couple days ago but it still had a Red tag on it. I looked and the coupler that was broken seemed to have been replaced and all looked good. I turned it on and it spun freely with no issues so I figured maybe someone just forgot to remove the tag? I used it and it seemed to be in perfect working order. Hope that is OK and I didn’t make a mistake.
Using a machine that still has a red tag on it is never appropriate. You cannot know whether not removing the tag was an oversight or not; there may have been something else still wrong.
I find it interesting that people expect someone else to fix equipment expeditiously after parts arrive. Anyway, I’m the one that installed the coupling along a few other “bad” parts, fixed the blast gate, and tried to get the drum sander fully operational Wednesday night. At 10 pm, my cut off time (I live an hour away), I still could not get the conveyor belt to track right. I made one final adjustment and left. If the belt is not stopped on time, it can tear and become unusable. That’s why I left the red tag on even though it could have been more of a yellow tag. So either the final adjustment i made Wednesday night fixed the tracking of the belt, or someone else fixed it since it worked right for you. Today, I also used it for about an hour with no problems other than the rubber stick to clean the belt is missing.
Bluntly the power abrasive machines in Asmbly are being broken for failure to follow very basic techniques or user lack of knowledge. I’m not saying this in malice nor am I pointing fingers at anyone. I can do a lengthy post of why I say that but instead I will offer to give a few free classes of basic techniques and how to properly use the machines. Abrasive machines are: orbital sanders, belt/disc sanders, spindle sander, drum sander, and wide belt sander. The class is very simple, should not take more than an hour and a half. I’m not sure how this is set up. You can post your interest in here and see what happens. So, I’m offering two classes in January (after the 7th), free of charge, with the caveat that if you take the class, you will help educate other members when you see them operating the equipment incorrectly. Outright I can tell you i am not an expert but I can take any of the above machines appart and put them back together. Often just by looking at them running, I can tell you if there is anything wrong or going bad with them. Any takers?
If folks have an opportunity to learn something from Jose, please take it. He’ll show you more things in an hour than you’ll learn from YouTube in a week.
I’m in, Jose. Thanks!