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.
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
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
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
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)
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?