101

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Lawsy; I'm in the process of printing parts and gathering all the materials needed to do both this; and your Mk5 Jigsaw at the same time; but I'm having a hard time trying to figure out what extra fastening hardware I might need; and I'd hate to tear my machine apart only to realize I'm missing a screw or two; in particular M3's.  M4 and larger I can find just about everywhere local; but M3's typically have to be ordered special (in which case I usually just order it online myself and direct ship).

Long story short; on-hand I have M3-8; M3-12 (and as of tomorrow afternoon M3-25); however in the thingiverse comments you talk about an M3-50.  I can't see any place on my machine where I might already have some that'll be free'd up; so should I just go ahead and order some of those?  Any other sizes that might not be needed for now but are really useful to have on hand that I should order at the same time?

And yes; I'm sure I could find the closest size in SAE and use a matching nut there; but since the (majority of the)  machine started as metric; I'd like to keep it that way.

|                                                           SD3                                                |
| Mk5 Jigsaw |:| Overkill Y-Axis Bracket |:| Lawsy's X/Y Carriage Replacement |
|  M5 Z-Axis  |:|         Glass Bed            |:|               Plexiglass Enclosure       |

102

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

shan.destromp wrote:

Lawsy; I'm in the process of printing parts and gathering all the materials needed to do both this; and your Mk5 Jigsaw at the same time; but I'm having a hard time trying to figure out what extra fastening hardware I might need; and I'd hate to tear my machine apart only to realize I'm missing a screw or two; in particular M3's.  M4 and larger I can find just about everywhere local; but M3's typically have to be ordered special (in which case I usually just order it online myself and direct ship).

Long story short; on-hand I have M3-8; M3-12 (and as of tomorrow afternoon M3-25); however in the thingiverse comments you talk about an M3-50.  I can't see any place on my machine where I might already have some that'll be free'd up; so should I just go ahead and order some of those?  Any other sizes that might not be needed for now but are really useful to have on hand that I should order at the same time?

And yes; I'm sure I could find the closest size in SAE and use a matching nut there; but since the (majority of the)  machine started as metric; I'd like to keep it that way.

Heh, I'm thinking of doing the same tomorrow as well (my bearings came in today). I got some handfuls of random M3 screws but don't think I have any that are M3-50... so I'd be curious to know too.

103

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

I have just measured the model and M3-50 is definitely required. These are for the two bolts which hold the extruder to the centre carriage top piece. The original ones that do the same job should be quite long as thy also go from the front of the extruder to the back of the original extruder carriage.

104

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Just ordered 3 rods. Hopefully I can get to this soon!

http://www.mcmaster.com/#88625k67/=ol90nj

105

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

I have uploaded slightly updated versions today. Found in the original Thingiverse link and marked with '_2', they feature:

- Slight thickening and ribbing to increase strength
- Nut traps moved inwards slightly to increase strength
- End stop holes enlarged to 2mm diameter
- Holes in the centre pieces moved outwards slightly in anticipation of under carriage 30mm fan duct

106

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

I figured out why my nut traps under the X carriage broke.  Both of the bolts holding the belt ends were a little too long, and met in the middle before the belt was tensioned all the way.  Since the bolt I was screwing in couldn't move forward any more, it instead pulled the nut backward until it snapped the plastic.

107

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Where is the right carridge 2? is that not needed?

108

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

My oversight, uploading now.

109

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

I hope my stuff comes in today. I will need to wrap my bearings in tape. I tried upping my flow to the point it was making my prints look like crap. Even then the bearings were not tight.

110

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

My stuff should be arriving tonight. I tried 2 layers of blue painters tape and my bearing can still move slightly. I may have to go three layers. Will everything be OK like this?

111

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Oh, boy. I'll report back, 6 hours in tonight. 5mm rod conv complete. Working on carriages, Not going so well. I'll report back tomorrow eve.

112

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Think it'll be okay if I had a little lifting on the corners of some parts?

http://img811.imageshack.us/img811/2686/icu8.jpg

113

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

muddtt wrote:

Think it'll be okay if I had a little lifting on the corners of some parts?

http://img811.imageshack.us/img811/2686/icu8.jpg

I know I had some warping at the corners of my pieces but they still seem to work fine.

114

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Should you lube the LM8UU bearings before putting them on? or is just lubing the rods after good enough? or no lube whatsoever?

115

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

muddtt wrote:

Should you lube the LM8UU bearings before putting them on? or is just lubing the rods after good enough? or no lube whatsoever?

I always lube my linear bearings lightly. If your bearings have a wiper like mine i would suggest adding it before you put them on or youre not doing much

116 (edited by muddtt 2013-11-02 00:15:45)

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Finally installed my carriages. Those LM8UU's are a pain to work with. Kept losing balls as I was trying to carefully insert the shafts tongue I did this on an SD2. Did any of you guys lose some table width after doing this? I was surprised that I couldn't make it to x=0 anymore cause the center carriage would run into the motor bracket.

Think I'll have to take this all off for now. That interference cracked my X motor bracket.

117

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Interesting to hear that. I tried to design it to keep the travel. I think mine can still reach X0, can anyone else verify?

118 (edited by pretenda 2013-11-02 07:10:38)

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Do you have a screw in the x carriage for the end stop switch?

Edit - lawsy, mines great. The only thing I've installed that limits movement is the cable chain, doesn't quite go all the way to the y extent. Especially if I have the belt guard in place.

119

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Yea i put the screw in to home the X-max.  I was kinda surprised that the two things were interfering cause so many people had good results. Maybe i just installed mine wrong somehow. Wish i took more pictures when i had it all together. I'll reprint some parts and give it another go.
I had my x rods with a very tight fit into the holes. Maybe thats what messed it up. Otherwise it was working great.

120

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Firstly, thank you to everyone who has contributed to this thread (esp. Lawsy).

I need some help with a couple things.  I just finished putting the x-axis rods and printed center pieces on and I noticed that they don't slide very smoothly.  The original bronze bearings had much lower friction.  I've tried using different bearings, but no improvement.  I replaced all of the rods (X and Y) because the original rods were even worse.

I am using these components:
http://www.ebay.com/itm/12pcs-LM8UU-8mm … OC:US:3160
http://www.mcmaster.com/#6112k136/=pov9rq

Should I lubricate the linear bearings?  If so, what type of lubricant?  Is white lithium grease ok?

Also, the holes in "center_top carriage" line up with the outer holes in "center_front carriage" and "center_rear carriage".  So what are the inner holes for (the ones with the nut trap)?  I think I must have done something wrong because the center carriage bumps into the M3 mounting screws that hold up the X motor.  Thanks!

121

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

I had the same problem with the bumping...so I had to remove it. It eventually broke the motor mount for me.

from what i read you don't need to lubricate the bearings. But you can if you want. People lube with white lithium, 3 in one oil, superlube oil, pick your poison. Lighter the better. The bearings do take a little to break in and get smoother though.

122

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

muddtt wrote:

I had the same problem with the bumping...so I had to remove it. It eventually broke the motor mount for me.

It seems like the holes with the nut traps would work great if there were matching holes in "center_top carriage".  I could just drill them out and then grind off the bottom left sides of the front and rear pieces to gain back the range of motion.  Would be better to fix it in the original file though.

123 (edited by downeym 2013-12-06 17:00:00)

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

when you say that the bearings arent "smooth" does that mean you feel some notching or just that it takes more force than you think it should?

If you disconnect the belts, do they feel free and smooth? Are both axes acting this way?

I did notice that you need to play with the Y belt tension to get both axes lined up properly and smooth. If the belts are too tight, you will get binding and it will be difficult to move. Make sure that you dont have one side of the Y axis pulling the carriage out of alignment. Remember that these are toothed belts and you can have one side out of position, pulling the Y axis off center so the carriage is not parallel and that will cause the linear bearings to bind and cause more friction. Usually you can feel it as a notchy feeling as you slide the carriage manually with the motors off.

124

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

Actually, I didn't even put the belts back on yet.  I was just comparing the smoothness of the LM8UU bearings vs the stock bronze carriage.  I have the old carriage and rods still intact and when I compare them side by side, it seams like the LM8UU bearings are worse.  For now I put some white lithium grease in them and I am going to put everything back together, let it run a few days and see what happens.  Maybe I just have cheap bearings or maybe they need to break in.

125

Re: Printable x and y carriage replacements (Level 2 - Techie Consumer)

I have noticed that there is a night and day difference between cheap and quality linear bearings. The last set I bought from McMaster and although they are significantly more expensive, they are a lot smoother and precise.

Run it for a while and see if it helps. If not, consider upgrading to nicer bearings.

It should be more precise than the bushings now... even if it has a little more friction. there is a lot of slop in the stock bushings.