Problem Solved! .......... And a new problem arises

I added the stick-on rubber feet to the Mendel and they raised it just high enough for the Z-screws to clear the bench. I also found that using lock washers on each side of the Z-axis bearings solved my problem with the washers contacting the mounting screws. This means that I am good to go for the rest of the build.



Or it would if I hadn't encouontered another problem as soon as I moved on. The Z-axis belt proved to be too short, even with the tensioner in the loosest position (as these pictures show. I obviously messed up my parts order somehow so I will take a look at the bill of sale to see where I went wrong.

This doesn't mean that I am stalled again. I should be able to proceed with everything else while waiting for the new belt to arrive. I now have all the motors installed and I have the x-axis moving smoothly (by hand). I think that the next step is to install the electronics and the build table.

X-Carriage Rebuild

A correction of my last post. The part that I broke was not part of the extruder. It was actually the lower X-carriage. See Below:


When the upper and lower parts of the carriage were assembled the 2 sets of 180 bearings did not close on the steel rod. When I tightened the bolts on that side the two parts of the carriage were drawn together and the lower one snapped. You can see the stress marks where it broke.

When I took it apart tonight I found that it had also broken at the belt clamp mount.


I carefully measured everything that I could think of to compare the original parts that I got from Nophead against the new ones but they seem to be identical. I can only assume that I did something incorrectly during the assembly that threw off the fit but I had completely disassembled it by the time I realized this so I will probably never know. At least I can confirm that Nophead's parts were not the cause of the problem. That comes as no surprise since they have been excellent in fit and quality throughout the build while my own skills have proved to be .............. slightly less than excellent, shall we say?

It only took a half hour to take it all apart and reassemble it. It now fits fine, moves smoothly and I can proceed to fixing my problems with the Z-axis.


I picked up some rubber feet for the bottom of the machine today. They should lift it up enough to resolve my problem with the Z screws contacting the bench and also will help with vibrations. I still have to figure out how to assemble it so that the screws move smoothly. currently the bearings are being contacted by something and won't rotate.

I'm not Dead!

I'm back!

I never expected when I paused for my vacation back in July that I would still be paused at the end of December. Some health problems combined with an extremely busy fall/winter have kept me away from the workshop for far too long. I notice that I am not the only one as the frequency of posts from all the blogs that I follow has fallen off considerably over the last 6 months.

I went downstairs yesterday and tidied up the workbench so I can start working on the Mendel again. Just to recap - I have finished the basic mechanical structure and I am working on the z axis mechanism. I had to get a new set of extruder parts since I clumsily broke the ones that Nophead made for me by overtightening the bolts. The new parts arrived long ago and need to be assembled. This will be the third time since I had to toss the first set of cast parts that I bought due to their poor quality.

My current problem is that the washers that sandwich the bearings for the Z-axis rods are not the right size. They are too large and interfere with the operation of the bearings. I haven't been able to find the correct washers anywhere here so I have used my bench grinder to modify the ones that I have. Hopefully that will take care of things and I can get moving again.

Also, the z-axis rods extend too far below the chassis. I think this is due to the 1/4" nuts being too large. I will have to put some rubber feet on the Mendel to prevent the rods from contacting the bench.

Hopefully, I will have more progress to report later this week.

I'm Back!

Just back from 3 weeks vacation in Canada's northern forests. This has got to be the greatest place in the world to live, a six hour drive gets me to the limit of civilization. Nothing but bush and lakes over most of the northern part of our province. Lots of bears this year but they didn't bother us, wish I could say the same for the bugs.

Unfortunately I won't be leaping right back into the work on the Mendel. I have an old Jaguar that has been up on axle stands for the better part of a year for some engine work. The work isn't that complicated but I have been very lazy. The other guys in my car club are starting to wonder why I always show up to our get-togethers in a Toyota! I am going to focus on getting the car back on the road for the next week or so and hopefully I can then get back to the Reprap.