B axis stuck error

[Simon Allen @simonallen]

If you do not know there is another axis other than x, y and z. The B axis, Pete told me, is the axis in the print head when the nozzles do their little dance. Half way through a print this error popped up. It would not go away what ever I did and Pete suggested it was lack of grease on the cam post inside the head. I opened it up but it looked to me if there was plenty of grease. I had some lithium grease but I did not add any more. Anyway the print head was returned to Pete and he wrote back to say it was as he suspected a lack of grease on the post. He ran a test print through it and then returned it the print head to me. I installed back into the machine and ran a purge. The bed temperature came up and I waited for the nozzle to heat. After about 5 minutes even though it was showing a target temperature of 235ºC it remained at ‘Cold’ and then I had the now familiar ‘B Axis Stuck error’. Clearing the error does not work as it returns a few seconds later. I have removed the head. Checked the power cable connections at each end and both are firm. I have looked at the pogo pins all move freely. There is no sign of burning on the pins or on the pads in the head. I note also that the axis movements x, y and z do not respond but that is something I have seen before and the central light in the Robox reel does not light. So I still do not having a working printer. Anyone had this error or can suggest anything I can try.

 

[stevnkrn @stevnkrn]

I am wrestling with the B axis stuck error as well. I just got a replacement head after waiting for a month and the head exhibited this error as soon as I tried it for the first time. My orginal head had a valve seal leak. I’ve tried everything I can think of with this head. Apparently I have a little more functionality than you, Simon. I too have firm cable connection and correctly operating pogo pins. I am able to get the Robox to recognize the head with the M105 G code. I can manually turn on the light and fan using AM. Also using Automaker I can manually control nozzel temp and move the head in X, Y and Z axes. What I can’t do without the B axis stuck error is use the home button in AM or manually open/close either nozzle valve. I have read other forum entries about the silicon grease fix for the B axis error but that seems a little unlikely to me. It was not clear from that thread what post they wanted to grease. If you know that, please let me know.

I’ve not opened my head yet. I am waiting for CEL to tell me to do that. I don’t want to risk any warranty issues. Frankly I kind of have an issue with CEL even asking me, or anyone to do that. This is a brand new machine that is under warranty. I don’t feel like any new Robox user should be required to be unpaid service technicians for CEL. However, if it gets me up and running again without having to wait another month, I’m willing to try. Like you I am on head #2 and not Roboxing. Since getting my Robox in September I’ve run it for a total of three days with “full” functionality. Most of the rest of the time has been waiting for CEL’s glacial responce to service ticket E-mails or waiting for this head to ship in both directions. I ask myself every day if it is worth the trouble. I was in the Kickstarter pre-order group, not the beta group, but is sure feels like I am part of a big experiment.

[Simon Allen @simonallen]

I would not open the head. I have opened it myself, when Pete suggested it, and I could to check the post to see if it was dry. I was dubious that this was the fault but Pete after all lives an breathes with this printer and I have only just come into the 3D printer world. However, I do have a good amount of mechanical expertise. I used to repair old clocks and mechanisms so the mechanics are familiar to me. I can send you a photo that Pete sent showing where the post is but since you and others are seeing the same error and since my head has gone back precisely to fix this error, it does suggest that it is somewhere else. So the reason I say do not open the head is I am doubtful it will fix it for you. I have raised another support ticket and Pete usually responds within a day or so. I do share your frustrations. I just want to get back to printing. Whilst waiting for the Robox to be available, I was in one of the groups that had onsite training at Portishead for a day, I have amassed a quite a number of objects to print. Some I have designed in OpenScad and there are several from Thingiverse. However, like you my Robox has mostly been inactive. I did have a few days when it was printing for many hours.

If you are curious to know what the head looks like inside that this article shows it quite well. https://robox.freshdesk.com/support/solutions/articles/1000077303-head-assembly

It does not show the post that where lack of grease was thought to be a problem. As I said I can send you Pete’s photo of that.

I cannot suggest what else to try. In another post, I think it was in ‘chatter’ ‘gid’ suggested trying the power lead and pogo pins. A useful suggestion but I cannot find a fault there.

[stevnkrn @stevnkrn]

Since Pete no longer works for CEL I doubt whether he will be contacting you. Chris White contacted me last Thursday about my B axis error and suggested the issue was post lubrication and asked if I would be OK opening the head. I am a mechanical engineer so taking products apart and puting them back together is not an issue for me. So far I’ve not been asked to do anything, but based your post above plus others I think he is going to suggest lubrication. I have to assume Chris knows what he is talking about, so I am willing to give him the benefit of the doubt and try whatever he suggests. However, if it does not work I expect prompt action.

Simon, since you spent a day at CEL I take it you live somewhere close to Portishead? I would imagine it only takes a few days to get replacement parts, assuming CEL has them on hand. Those of us who live overseas have much longer waits (and shipment expenses). As I said above, the reasons repairs are required, and how CEL is dealing with it is where I take issue. It is like buying a new automobile and having the dealer ask you to take the engine out and repair it yourself if you want it to work. Keep in mind there is also a cost of tools and lubricant involved in doing this repair. Maybe others have tiny metric hex head wrenchs and silicone lubricant just laying around. I for one do not. I have already spent over $50 sending in my first head. If I have to buy tools and lubricant to try and repair it myself and that does not work I’ll be stuck with those expenses plus the cost to return this second head. CEL should be offering some sort of compensation if we are expected to make repairs like this. Who knows how long it will be before we get working Robox’s again.

Can you post the photo on the forum? I know others have written about the B axis error. I would imagine they would like to know which post to lubricate as much as me.

 

[Simon Allen @simonallen]

Here it is.

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[Simon Allen @simonallen]

I am confused about Pete. There was a post that pyropetepete had left. Oddly it was posted by Pete. However, I do not think Peter Wright has left. I think he may be on annual leave. I do not live near Portishead. It was about a 4 hour journey for me and I stayed overnight. So popping into Robox’s premises is not an option for me. Chris White has just responded to my support ticket on this issue and I have carried out a few tests and reported back to him. If you do take the head apart since you are a mechanical engineer you will not have any trouble. The link I posted described the process well with instructions and photos. You need to look out for the LED that illuminates the print as it sits in a shoe on each side of the casing and I had to wriggle it very gently to let me close the case again before screwing the case together.

[stevnkrn @stevnkrn]

This is a quote from Chris White last Thursday explaining why it had taken so long for anyone to respond to my ticket.

“We’re really sorry it’s taken this long to get back to you - I’ll be taking over your tickets for a while. Unfortunately Pete Wright is no longer working with us, hence your ticket getting somewhat ‘lost’.

Thanks for the tips and the suggestions. I had already read all about taking the head apart from the information in the support forum. It looks pretty straight forward to me. There was also a post from uhuglue a couple weeks ago with some information on greasing the cam with a reference to the same freshdesk link you suggested. If Chris asks I’ll try whatever he wants me to try as long it doesn’t take long to resolve and the commications are regular until it is resolved. As much as I bitch about my Robox I really do want it to work. I just need CEL to instill some hope in me soon.

Did you make any progress with your head from the latest suggestions from Chris?

 

[gid @gid]

@simonallen : “Pete” (a.k.a @Pete) and “Pete Wright” (a.k.a @pyropetepete, no longer at CEL) are different people, confusingly both answering support tickets. Similarly, Chris White (a.k.a @chrisyt … geddit?) and Chris Elsworthy (a.k.a @chris, ie. Mr. CEL) are different people, both design engineers, and distinguishable mainly by altitude. CEL are still waiting on delivery of a batch of new first names.

Tom Gidden -- Bristol, UK -- New Roboxer? Check out the wiki, and add yourself to the map! http://roboxing.com/user_locations

[Simon Whiting @simonwhiting]

I’m also getting the “B axis stuck” error. In my case, it has gone along with intermittent operation of the head light and the head fan (when controlled from AM). Gently squeezing the head front-to-back allows AM to turn them on and off intermittently. In the case of the light, it quite clearly flickers on and off relating to how much I’m squeezing. So it looks very much like a problem with the head contacts, and I suspect that the “B axis stuck” error is probably also due to problem with the contacts. The contacts all LOOKED alright, and I can’t see anything wrong with the head mounting as such. But it looked to me - just from roughly eyeing up the dimensions - as if the contact plate on the head must only push on the contact pins very slightly, even when fully home. And I noticed that the pair of pins fourth from the right were quite a lot lower than the rest - I have seen the advice that some pins are lower than others, but I do wonder if being so low, this pair aren’t contacting well. As squeezing gently does enable both the fan and the light, I wonder if this pair provides the common power? (or return).

I appreciate that all this wouldn’t fully fit with @stevnkm’s situation, if AM is able to control the head light & fan. So possibly more than one cause of this error message.

• This reply was modified 2 months ago by  Simon Whiting.
• This reply was modified 2 months ago by  Simon Whiting.

[stevnkrn @stevnkrn]

It seems we are collecting quite a number of people with the B axis stuck errors. It also seems we are collecting first names by the pair, but that is a topic for another day. Simon Whitings comments make a lot of sense to me based on my symptoms. The second head I received is very difficult to install. I’m mentioned this to CEL a couple of times in my daily messages to tech support but they have yet to comment on it. The original head that came with my machine was very easy to install and remove. It only took a couple of light turns of the wheel to get the head to register in AM. With this second head I have to really push to get it in position to even start the screw and then I need to tighten the screw very hard or it won’t register in AM. There is a intermitent state too where the head will just register but the nozzle temp will skyrocket uncontrollably when I turn the machine on. I can only get control by quickly turning off the machine and adding another hard turn or two of the wheel. I am really afraid I am going to strip the screw because I need to tighten it so much. That nozzle temperature spike is actually a little scary. If that happened and someone was not paying attention it seems like it could cause a fire. I agree with Simon W that there does not seem to be much room for those pogo pins to mate with the contacts on the head circuit board. The circuit board is buried so deep in the head’s housing, and pins are so short it seems like they would barely reach. I also noticed that the contact circuit board sets noticeably slanted in the head, presumably making it that much more unlikely to get solid contact with the pins resting on the right contacts. I have suspected that pin contact could be at least part of my issue, but I have nothing solid with which to base it.

Hopefully at least on of us will get some helpful news from CEL soon regarding this error. I’ve not heard from anyone in tech support since last Thursday.

[Anonymous]

If you are getting the skyrocketing temperature issue then you have not replaced the head properly. That’s an old well-known and reported issue that has yet to be addressed by CEL. Pete did say they’d had some discussion about the head design. Basically, AM should warn the user if the head has not been replaced properly. As it is, it is actually dangerous and would result in something failing pretty spectacularly if it wasn’t spotted. Fortunately most users do spot it, turn the machine off and refit the head.

[Simon Whiting @simonwhiting]

P.S. - Obviously a problem with contacts could explain a head going back to CEL - seeming OK to them (possibly after some servicing), if their test machine had slightly more prominent contact posts - but then not working on return, if the user machine had inadequate contacts.

Just a thought …

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