My gadgets3d mendelmax 1.5 kit build

I'm looking for some suggestions.

I purchased the gadgets3d complete kit, then had someone print up the parts for it so I could build my first printer. My goal was to have something up and running that was a proven design, nice build manual, etc.

The kit was shipped really fast considering it came from China, and everything was packaged well, each of the different size nut, washers, bolts, etc in little zip lock baggies with the part discription written on them. Pretty impressive.

As I started putting it together I found it was missing some screws, washers, but was able to source those either locally or from open build parts store.

When I went to put the z-axis together I found that the ball screw nuts were missing. I had the threaded rod, but no nuts. They are a nut with a flange and three holes. These were to be screwed with M3 screws to the x-ends. I emailed asking about them and it turns out that they actually have two different kits that get shipped. One has the ball screw nuts with the lead screw already afixed to the motor. The other kit comes with a coupler, threaded rod and M8 nuts. The bad thing is that the printed parts they have you download and have printed only support the ball screw nut. You can't use a M8 nut.

So they sent me two new files to have printed. So I got those printed and shipped to me, started putting it together to find out that these two parts are expecting M10 threaded rod with M10 nuts. Best I can tell it is this part: [www.thingiverse.com]

The kit uses 10mm smooth rod for z-axis, 8mm smooth rod for x-axis and M8 threaded rod. Any ideas on how to use a printed part for M10 nuts when you only have M8 nuts? I really don't want to have to order two more x-ends.

I looked at getting these: [store.makerstoolworks.com] but they have the ball screw nuts with the flange so they won't work with my parts either. Can I use M10 nuts with these lead screws? I can buy M10 nuts locally.

Any other suggestions welcome,
dave

You really have two choices here:

Work with the dealer to get them to make things right. Since you bought a partial kit (no printed parts) there still will be some hassle. They should be able to point you to the stl's for the parts you have. The world has moved from 8mm thread rod to 10mm thread rod. The parts you are looking for are the "old" parts.

second choice:

Give up on these guys. Approach this as "I have a few parts and am starting from scratch". Look at the current designs and pick one. Compare the parts you need to what you have. Buy what you need. 10mm thread rod is cheap, motors and smooth rod - not so cheap.

It's tempting to try to do a little of both approaches. That's likely to drive you nuts in the end. The sooner you make the decision the better. Based on what you have said, I'd probably pick option number two....

Suggestions where I can find M10 threaded rod, turned down at the end to support an M8 coupler? Do I want 1.5 or 1.25 pitch threads, I see both available.

thanks
dave

Here is an idea, but I do not know how well it would work. Couldn't you have someone make you bushings for your M8 nuts. They would be abs and your m8 nut would slip inside it, the outside of the bushing would be the size of the m10 nut. I hope this makes sense.

The link below has a drawing of idea - red is m8 blue is bushing sized to m10
[drive.google.com]

A buddy suggested I take an M10 nut, superglue an M8 nut to it, and use that stacked nut, like a bushing. I could then get it printing well enough to print up a proper set of x-ends.

I was hoping to hear back from the vendor, but nothing yet.

dave

Edited 1 time(s). Last edit at 12/19/2013 02:39PM by dpeart.

I superglued the M8 nuts to M10 nuts centering them the best I could. I put them all together with backlash springs and they appear to work pretty well. I do see a small amount of twisting by the M10 nut just due to the tolerance of the printed part. I may be able to slip some aluminum foil in there. Any problem with glueing the bottom nut to the printed par?

One of the reasons I bought this kit is that it included ball screws and nuts that I could bolt to the part, so no slippage. Was a dissappointment to not get those.

After getting the threaded rods on, I notice that the x-ends they had me print do not allow the x-axis idler, carriage, and drive to be aligned parallel to the x-axis rods. I had purchased some idler pulleys from here: [openbuildspartstore.com] so I used them instead of the bearings in the hope that the edge of the pulley would help keep the belt on the idler. I was able to use three M3 washers as shims and turned the gear on the motor around backwards to try and get them into closer aligment. How close in alignment do they need to be? Wherever these parts came from the alignment is off terribly.

I'm now ready to square and true everything up, then put on the electronics.

Here are some pictures. If you spot something I've done wrong please point it out.












dave

Edited 1 time(s). Last edit at 12/20/2013 09:32AM by dpeart.

A question about VREF. In tuning the motors, I find that my x, y run a VREF around .33v, while the z requires .9v. I expected z to be larger because there are two motors, so I would need at least twice the current. Do these numbers seem OK?

At .9V I have to use a fan to cool the driver, but not much of a fan. Otherwise it gets pretty hot to the touch. The others don't seem to need any additional cooling.

thanks,
dave

depart,

I got the same Mendal Max kit from Gadgets 3D and have the same issues. Had to run to the hardware store 4 times already just to get the missing screws / nuts discovered during each of the build phases. I too am missing the critical ball screw and a GT2 belt. Gadgets 3D should really have posted the missing pieces on their site. In hind site, it's better to pay a higher price for a complete kit, plastics and screws, versus trying to go for pricing.

In any case, looks like the replacement X-ends you have don't use the bushings on the X-axis. The original design had the X-axis bushings to eliminate binding on the Z-axis.

Why not use the maker tool leadscrew and ball screw with the original X-ends?

The maker tool leadscrew is a 10mm leadscrew and the original X-ends expect a 8mm lead screw. I tried that. Also the nut is not the same size.

I need to make x-ends that will support the maker leadscrew. Their parts use bushings and not lm10uu bearings so I couldn't use them.

I did find a part from a guy on another forum, that has the x-ends that will work with 8mm x smooth rods, lm10uu bearins and M8 threaded rods. If you are interested I'll ask if they can be shared. I "think" they will work without having to do the M10 nut superglue trick I did.

For the record, I contested my payment with Paypal and had gadgets3d refund me $42 so I could buy the maker tools leadscrews.

dave

Thanks. I'm likely to put in a dispute with Gadgets3D via Paypal also. I bought some M8 T nuts ( $0.80 ) and will be modifying them to work with the original X-Ends. What I really would like is the anti-backlash lead nuts though.

The lead screw and nut was a primary reason I chose this kit. Was sorely disappointed when that wasn't there.

dave

A small update. I was able to finally get a print to come off nicely. I printed a replacement large extruder gear. I couldn't get the natural colored PLA filament I got with the kit to print anything without warping. I swapped it out for some black that I had purchased elsewhere and it printed beatifully. I wish I had just started with that first off.

Now on to designing replacement x-ends to use the threaded rod I bought as replacement for the M8 threaded rod.

Things I learned:

If the hot end gets too hot, it will melt too much of the filament and jam the extruder.
If the bed gets too hot, the part will collapse a bit
Printed parts are hard to get off Ultem sheeting, and it helps to let the bed cool down.
Not all filament is created equal.
Use lock washers on the M4 bolts that hold the extruder to the hot end. If you don't they will rattle loose halfway through your print.
Level your bed after it is heated

dave

I got my x-ends designed/modified and printed to support the lead screws I bought Maker's Tool Works. They work very nicely.

I'm printing on Ultem sheeting and it holds the parts very well, need to cool it down before trying to remove the part, but it is well worth it.

Now looking to add auto bed leveling, and thinking about moving the extruder from the x-carriage to the top of the frame, and running a bowden tube from the extruder to the hot-end. I'm surprised that I can't find anyone that has already done this on a mendelmax. I hope this will let me print faster without the extra load from the extruder on the x-carriage. I don't know, maybe someone already tried and found out it was a waste of time, but who know.

dave

I got my bowden extruder setup and working well. Still have a little ooze, but I'm hopeful I can get rid of it all by increasing the retraction setting a bit more.

I was also able to print faster. Now to push it till it breaks . . . right?

I made a bowden plate, it holds the tubing anchor that I got from HD and bolts onto the hot end instead of the extruder. Pretty simple actually.

I also printed my first tall object 62mm, tall for me anyway. The new lead screws with the printed couplers pretty much removed my z-wobble. With the m8 rod I had a very discernable z-wobble about every 8 layers. Now I cannot see any wobble with my eye, but do see a little bit if I use a jewlers loupe. Happy with the results.

dave

Awesome! I was thinking about a bowden extruder setup also. You have pictures? Also, how fast can you print? I can do 120mm/s with the stocked Gadgets3D hardware.

I was never able to get the print quality to where I wanted it. I applied the bowden options in slic3r and that made a big difference, but the print still wasn't as good as I can get with Wade's extruder so switched back. The speed was faster, and there was less movement in the printer when printing with the bowden, but it wasn't enough to make up for the loss of quality.

dave

Hello Guys, Im fixing a Gadgets3D mendelmax 1.5 its a very early version because it works with the normal threaded rods inthe Z axis

its missing some parts and being a custom machine from G3d the parts from thingiverse do not match

does anyone has the original STL files and could share them?