Really struggling....

Oh dear. The Stepcraft self-assembly process claims another unsuspecting victim.

I presume by your references to "Stoney Croft" and "Stoney Craft" you mean StoneyCNC? This doesn't sound like Rory you're dealing with though.

Pete, I'm sorry to say that you're going to have to do some research on this forum to find the source of your problems. There are some recent threads which will help.

I'm too far away in Scotland to help.

Doug

Thats the one - been a long day. Rory was helpful replacing incorrectly supplied part but suggesting we go back to scratch as a solution is quite frank lame - the mounting bracket for the Kress is really to shallow for the collar and the problem with the Y axis is really frustrating. My assistant who put this together is an extremely talented and methodical guy ( he is a German as well but I am sure that is no qualification) who I don't think I can ask to take apart and reassemble the machine a third time. I really could do with a successful user to come and look at the machine and assess it for us.

We build ukulele and were hoping this would be the solution to hand cut inlay work. As it stands, we cannot even level our sacrificial work table!

Hmm. I am trying to build entire electric guitars with mine so I am on your wavelength here!

It does not matter how skilled or methodical the assembler is because there are flaws in the design and excessive powder coating on the end plates prevents correct alignment.

I suggested a few key tips for axis alignment on another thread:

1. Some free play in the bearing seat(s), especially at the non driven end is actually helpful. The track roller and extrusion provide the alignment, the lead screw & ball nut assembly provide the linear drive. The two functions are not fully mutually inclusive 😉 A number of users have facilitated this by removing some powder coat from the bearing seat as you acknowledge.

2. Once there is sufficient free play in the lead screw(s), align it/them by loosening the end plate or gantry, drive the track rollers/gantry to one end, align each (in the case of Y axis) then tighten up the end plate screws. This process acts to self-align the assembly.

3. The spindle holder needs to be aligned (trammed) relative to the bed. There are no instructions on how to do this. Check out post #42414 on this thread for my method:

https://www.stepcraft-systems.com/en/forum/assembly-and-maintenance/3367-spindle-bed-tramming-840-supports

I hope this helps.

Doug

Hi Pete,

Having to hammer home the T slot aluminium baseplate does suggest that something severely amiss in the whole Y-axis assembly. It sounds as though the Y-axis extrusions are too close, and that the fixing screws at both ends need slackening to allow the baseplate to slide in. Before doing this, slacken off the moving rollers, they need to be adjusted almost the last thing in "tuning the Y-axis

For what it is worth here is some advice, based on my own build experiences, that I passed on to another Forum member.

"When I tuned mine, I made sure that the moving rollers were all slackened off when I adjusted the end plates. That way I could be sure they were not the cause of any tightness. It's important to make sure the two gantry sides are equidistant from the end plates too (i.e. the X-axis is at 90 degrees to the Y-axis).

I know Stepcraft suggest a 1/4 turn - IMHO that is a nonsense, it leads to grossly excessive forces and is likely to cause surface damage to the aluminium extrusions and the rollers themselves.".

I'm happy to offer what advice I can, but the forum is a slow laborious way to communicate - contact me by private email and perhaps we can set up a better method.

Regards,

Peter.

Hi Pete.

We had slight issues with our 840 here with the aluminum t-bed.

After much head scratching we took the end plates off and re adjusted the screw rods on the "y" axis.
once this was done the end plate was re-attached but not tightened down. the gantry was moved to that end to home. the aluminum bed was slid into the channels all the way back and then the front end plate was attached but not tightened down.

the rear plate was slightly tightened and the gantry moved all the way to the other end, once there the end plate was tightened and we then moved the gantry all the way to the other end and repeated.

We moved the gantry by grabbing the belt and moving that by hand, this in turn meant we could check that it moved freely and did not jam.

once this had been done several times just to check and re check it was all tightened up.

the only thing we may need to do is change the y axis brass screw guides as it seems there may be a little play in them, why they were made out of brass is beyond me.

Hi Pete.
The only thing we may need to do is change the y axis brass screw guides as it seems there may be a little play in them, why they were made out of brass is beyond me.

I also found that my aluminium T-slot bed inserted just fine when the end plates were loosened off. Before the penny dropped, I had the rubber mallets out. :blush:

I suspect the engineering judgement behind the lead nut being made out of brass is so that is the replaceable wear item in the linear drive system. If this is the case, this seems a reasonable judgement to made if ball nuts cannot be used on cost grounds but it is a pain that the machine will need to be nearly fully dismantled to replace them. :angry: Hopefully with the intended light hobby duty they are intended for, this will not be for several hundred hours of use.

I am still hoping that a regular on here or Stepcraft themselves comes up with a ball nut upgrade which uses the very nicely machined existing ball/lead screws.

Doug

No ball nut upgrade! Was an official SC statement a while ago ... maybe in a german thread, don't remember that detail.

Despite taking apart the machine yet again and following the helpful advice of everyone we still cannot get the Y axis to return. When we fitted the aluminium bed, unlike the useless particle board that was supplied with the machine and which slid in easily, we had to drive the bed into place with a soft mallet and block. Could it be that the bed is tapered?

We are rapidly losing interest in this project. So here it is, offer of the week! £250 to anyone who can visit the workshop and get our 600 working. If not, look out for a second machine on eBay. We will buy one from Marchant Dice who offer a full installation and training package 🙂

I don't understand the collective whimpering about ball nuts! The way things are everyone here can claim having Big Brass Nuts :woohoo:

Hi Pete forgot to mention, before sliding the t-bed in i applied 3 in 1 light machine oil in the channels using a cloth with a good amount of oil on it then i ran the cloth with some more oil along the edge of the t-bed top edge, bottom and sides it then slid in easier, try that. failing that I am based in south wales so wouldn't take too long to get to you, where about are you?

Nr CAERNARFON...

... 3 in 1 light machine oil ...

What??? 3 in 1 light machine oil??? Don't be ridiculous, this is the only lubricant that will do the job!

FWIW.

http://www.thingiverse.com/thing:1626585

Any luck with this Pete? Did you get any help?

I joined the Facebook Stepcraft Crafters page (via my wife's account) to post up some cutting videos at Rory's request.

There was a recent post by someone using their Stepcraft 2/840 for 6-7 hours a day, 5 days a week to make guitars! They looked great too.

I saw another picture from someone who made a banjo and the fretboard had impressive scallops so there's definitely hope for us.

Doug