Saturday, February 13, 2010

Pricing the Mini Mendel




I will be going ahead with both my Mini (M3) Mendel, and my M4 Mendel in parallel. So I figured I would do some US costing for a Mini Mendel vs it's M4 big brother. Just a reminder the M3 Mendel is not in development, and I am doing this more out of curiosity than trying to get a fuctioning printer out of it.

Threaded Rod:

Cheapest place I have found for M6 threaded rod is a local fastener company that sells it for $3 for a 1 meter stick (zinc coated). That would mean I need 6 sticks of rod if I cut them in this pattern. $18 plus sells tax

1 4x244
1 270,230,257,230
1 270,230,320,84,82
1 244,244,183,183,102
1 320,102,102,102,84,84,84,82
1 82,82,82

Smooth Rod:

Considering we are using bearings the rod doesn't have to be quite as good as bushing rod. I will be going with wttool.com. They sell a 36 inch (914cm) long 6mm smooth rod for $2.70. That's 1/10 the cost of the vxb linear motion rod which runs $25 for 30 inches. at 36 inches I will need 2 bars. About $6 dollars plus shipping

1 224,224,272,
1 275,275,272

Fasteners:

Local supplier usually beats bolddepot.com, but without the shipping costs associated with them. Luckily I have a good bit of M3 nuts, washers, and socket caps left over from my Makerbot, but I plan on costing out all the M3 so I can have a good idea of the real cost of this project. I don't use nylocks, I use lock tight instead because I am very forgetfull, and always end up stripping them. Costs without Nylocs would be $54 dollars.

m3x12 100 $5.41
m3x20 100 $5.93
m3x30 100 $8.42
m3nut 200 $4.32
m3washer 400 $7.44
m5mudwasher 17 $2.55
m6nut 200 $9.38
m6washer 200 $6.94

Steppers:

NEMA 14 motors are hard to find. The only NEMA 14 motor that I could find online was at phidgets.com for $15 dollars each. They are only 1250 g/cm, which is a little lower than the suggested 1400 g/cq torque suggested for the Mendel m4. Has anyone seen a high torque NEMA 14 stepper in the US? If I can't get a good prospect that doesn't break the bank, I might have to go with the lower torque ones. Also I plan on going with a Makerbot gear motor for the extruder, just because that's what I know.

Bearings: I usually use vxb.com because I usually can't beat their price. I came up with 4 sets of vxb 623 for $60 and 1 set of 20 vxb 626 for $25 for a total of $85 dollars worth of bearings (ouch)


RP parts

I am averaging 20-30 hours a week of print time at this point, and should have my m4 Mendel printed by next Friday. Good thing is I will be able to print ALL the parts for the m3 Mendel in 1 week! That will be a fun change of pace.

Total cost of m3 Mendel for me will be Stud $18, Rod $6, Fasteners $54, Lasercut (Don't know where I am getting my lasercut parts yet, but assuming $30 for all the LC parts), Electroncis $175 (makerbot), belts form mcmasters for $20, bearings $85 and motors $100

$500 for a fully functioning slightly larger than Makerbot scaled, belt driven RepRap is not that bad. Considering it will only take $300 out of pocket for me I think this is doable.

Any suggestions on cutting the cost?

7 comments:

  1. it took me way to long to figure out why it was on a doughnut..lol good idea on where to store the material used for printing.

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  2. Lasercut parts can be made at ponoko. Why using lasercut if it is cheaper to reprap them?

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  3. Yea, found out that was an underestmate. looks like $70 for the cutting with me providing the acrylic. EEKK!

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  4. http://reprap.svn.sourceforge.net/viewvc/reprap/trunk/mendel/mechanics/mini-mendel/Documentation/mendel-m3-assembly-data-sheet.xls?revision=3493&view=markup

    The parts sheet

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  5. I built mine with a build platform the size of the original mendel, and only needed 5 1-meter threaded rods. I didn't build the spool part, though. I also needed a third smooth rod because of the size increase.

    You listed 40 623 bearings. I barely managed to put mine together with 42, should have used about 5 more. Found a better deal from http://stores.ebay.com/Ultimate-Industrial-Solutions

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  6. Oh, I also saved on the thick sheet by not laser-cutting. I bought a sheet of acrylic and used my dremel and a stencil to cut a close-enough version of the froglet. With the flex shaft and a plastic-cutting disk, it was shockingly easy.

    For a build stage, I bought an 8"x8"x1/4" sheet of aluminum that just needed mounting holes drilled and polyimide applied (turns out, I really should mill the surface flat, too), but I'll probably swap it out for MDF or some other insulating material (any suggestions?) to carry a pcb heated platform similar http://www.thingiverse.com/thing:2172

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