Isaac Mendel build

Hi everybody
I've been reading the forums and searching for parts online and I finally decided to go ahead and order an Isaac kit from Fleming CNC. I got 4 NEMA 17 motors, a Wade's extruder kit, a bearing and rod kit, an extruder nozzle kit, nichrome wire, a thermocouple sensor, and thereaded pulleys from various vendors on ebay. Also, I ordered a complete electronics kit excluding power supply from Botmill and I got the power supply from Hobby King. Now I'm waiting for the parts to arrive and I'll try and locate the threaded rod and other nuts and bolts locally or from Mcmaster Carr. I'll post pics of my kits as they arrive and document everything about the build here on the forum. I've spent roughly $1,000 on parts so far.
I use Autodesk Inventor to produce models and I'm very excited to find out about this technology. The forum has been very helpful so far in figuring it all out.

Hi, I went a similiar route. I have my Isaac working right now, but not printing yet. Once I get back from vacation I am going to put some documentation up and try and make it easier to get the Isaac up and going. The Issac is a great design, it is just not readily available and poorly documented. I am hoping I can change the documentation part.

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-Steve

I'm prepared to wait a few more weeks for this design. I've been in contact with Brett Fleming through email and he was able to guide me to the best parts deals on ebay and elsewhere. He suggested that I go with the bearing kit from VXB on ebay for $79 and get the threaded rods in 5/16 and nuts from a local hardware store to save money. I was thinking of buying an expensive hardware kit at first but realized that I can cut a few rods with a hacksaw if I can save $100. So far there has been some confusion with my order at Botmill, after I paid for the order it still appeared in my cart. The $236 electronics kit was charged to my paypal credit account and, although it was refunded, I'm having trouble accessing the funds for that account because the $236 still shows as part of my credit account balance . After finding out I didn't want the hardware kit I sent an email to Gil Mayron asking if I could cancel the order because it wasn't letting me add the hardware kit together with the electronics kit, only one or the other. The site is very glitchy. He canceled the entire order and I went back online to reorder the electronics kit only and it was available for sale now without the included power supply option for $206 total. So somewhere in between me asking to restructure my order and going back online to try it again they changed the options for the kit. Now I'm waiting up to 45 days for a power supply from hobby king. From what I can tell, Botmill is the only place selling everything I need for the electronics for this so I'm hoping everything goes smoothly with the transaction.

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jkelso
Now I'm waiting up to 45 days for a power supply from hobby king

WHY are you waiting 45 days when you can buy 12V 6A power supplies for $10 on EBay?

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

I looked on ebay but I was searching 5A supplies going off the information provided on the botmill site for their kit. I'm hoping the 45 days number is the most I'll have to wait. If it starts holding me up I will no doubt find another power supply somewhere. My first kit arrived today from ebay, a Wade's extruder with hardware. Finally something to get my hands on. I am getting ready to check out the assembly instructions from the reprap page and I realize I forgot to order the hobbed M8 bolt so I picked that up for $16 from ebay just now. I've got one NEMA 17 motor coming from Polulu and a 3 pack of them coming from ebay. These printed parts are strangely smooth, very interesting because you expect them to feel rough to the touch because of the texture of the extruded plastic on the surface. The accuracy is amazing and I've never examined parts made this way before.

YES, 12V @ 5A should be enough to run a Mendel but an extra ampere in reserve isn't a bad idea.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Thanks for the advice. In preparation for building this, I realized that I have no useful indoor work area for mounting a vise and drilling holes, etc. So last night I found this metal workbench on casters on craigslist for $15. It was a half hour away, but I have a truck so I snatched it up. I paid more for the hobbed M8 bolt than the whole bench! Now I'm looking for a vise and possibly a small drill press so that I can ream these plastic parts.

today I got some more kits in the mail, the 5 feet of nichrome wire, the hybrid extruder, and one of the stepper motors from Polulu. I picked up a 72" length of threaded rod in 5/16 at the hardware store for $5 and a hacksaw for $5, plus a 10 pc file set for $10. I'm almost ready to prepare the parts for assembly, but first I'm looking for a vise to secure the parts for reaming.

got the vise for $10 on craigslist last night. Today I started drilling out the extruder gear which needs an 8mm hole for the bolt. I realize that I need a new drill bit set today but for now I've drilled it with my 5/16 bit and it worked pretty good. I started by putting this gear in the vise but was afraid I'd damage the teeth so I clamped it next to the vise. I'm also going to pick up a precision file set today to get the small holes in the other parts.

after drilling, the bolt still did not fit into the hex hole on the top. It took about 10 minutes of filing all sides of this opening with the triangle file before I was able to press the bolt in there for a snug fit. My first part is a success! I'm very excited to be able to produce parts like this on my own.

Moving on to the main extruder body piece, I had to run out and pick up that extra 6 pc. file kit to ream the hole. After a few minutes the bolt fits snugly through. I also got that drill bit kit I was needing and I'm considering the idea that drilling these out may be faster. After finding all my scattered old tools in the shed and organizing them into my new workstation drawers, I see that I have a lot more than I realized as far as tools, I just didn't have the space to work. Organizing the work area for this project has been tremendous fun and I saved so much money finding used stuff I have enough to get the things I need like new drill bits and files. I got the email that Fleming CNC has shipped my Isaac with plexiglas build platform today and everything else I'm waiting on now has a tracking order except for the electronics.

Preparing the extruder for insertion of hardware, I drilled out the hole for the M8 bolt with a 5/16 bit but there were a lot of stringy edges around the hole this time because of the way this area was printed with just a very thin layer over the hole. Normally I don't get any of those stringy edges of plastic on this part. So I just used a little clipping tool to get rid of the strings and the bolt fits right in there. I'm still waiting on the hobbed bolt to arrive before finally assembling the extruder but I now have all the correct holes with the bolts fitting through. When I'm talking to people around town I mention the project and everyone is very interested and asks many questions. I can see that others feel the same excitement I do about this technology. A guy asked me to build him one but I told him I'm not in the business of doing that at this point and I encouraged him to check out the site and build one too. Many people feel that a 3D printer project is beyond their expertise and I don't mind letting everybody think I'm a genius for making one. Everybody I talk to immediately has ideas for what I could do with it and they ask me if I could print things for them. I am planning on sharing my progress on this project with my CAD teacher next week too and other students at school.

After filing the opening side edges on the holes for the bearings I was able to press them firmly in place. I put the bolt through the hole and saw that the gear is spinning nicely in there. Next up is to file out some edges to install the motor bolts.

I see that the problem isn't that I need to file out the holes, but rather that this part seems to accommodate a larger stepper motor in this slot. I'm using Polulu item #1209 stepper motor here. Using just two of the bolts I'm able to install the motor at an angle and I don't see why it shouldn't work this way. I'm wondering if there's another motor which would be preferable to use here?

Looks like you have a NEMA14 motor there instead of NEMA17. The torque is 1/3 that of the recommended high torque NEMA17's so you may struggle to extrude with it but you might get away with it.

Odd that you have to do so much filing. When I print that I only have to enlarge the bolt holes slightly with a reamer. The bolt head and the bearings are a press fit.

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[www.hydraraptor.blogspot.com]

The Polulu item #1209 stepper motor is a NEMA 14. It is what I used on my Mini Mendel. Phidgets.com has NEMA 17's at a good price, $14.65 US.

Thanks, I'm going to get that extra motor from phidgets. I have a 3 pack of NEMA 17's coming from ebay soon too. Wish the Polulu site was clearer on what I was buying. Today I went down to Lowe's and Home Depot and picked up most of the hardware I'm going to need. They don't go down to M3, the sizes start at M4 and I'm going to still need to locate some of the harder to find bolts like the M4 20mm and a few more of the 16mm that I took the last of. So far I've spent $55 on this hardware including the threaded rods and I think I should be able to get what I need for under $20.

I found all the extra stuff I'll need for hardware on amazon.com for better prices than I'm finding in store. I got all the rest of it for $76 with the free shipping over $25 deal and this way I'll have lots of extras left over. This brings it to about $215 total for all the hardware including bearings which saved me enough off the $266 (including shipping) botmill hardware kit I was first considering buying to make it worth it for me. I'm wondering if I'm jumping the gun now buying the electronics kit from them, I see that a new Gen 6 kit is to be made available in a few weeks at mendel-parts.org.

Edited 1 time(s). Last edit at 08/30/2010 12:08AM by jkelso.

The bearing kit for $79 from VXB came in just now. Another ebay purchase, everything was packed nicely and I got an extra 8mm bearing in there, thanks VXB! I've decided to order the electronics from a few sources like Makerbot and wherever I can find it. I've been waiting for 5 hours now from an email back from botmill confirming that they have the items in stock and asking when I can expect a tracking number. I haven't heard back, I suspect the deal is falling through with them. I've contacted paypal to let them know I'd like a resolution to my questions.

The thermocouple sensor arrived in the mail today, everything looks nice and new in the sealed plastic. Also the 3 NEMA 17 stepper motors which I can see are much bigger than the NEMA 14 I accidentally ordered. After sending the dispute to paypal, they refunded my $206 to botmill within a few hours and I spent the money getting 3 stepper driver boards, a USB to TTL cable, and a 5lb roll of black plastic. I still need an extruder controller board, I'm wondering if these are available somewhere I'm not seeing.

@jkelso: Sounds inspiring... keep posting
Where are you located (presume USA)?

Denver, CO USA
I got an email back from gil mayron this morning finally, he said that his manager told him I canceled the order. I think it's odd that his manager had to tell him, all he had to do was check the email to know there was a problem. He apologized for the "confusion" and stated the order was going to ship out Thursday. I told him that the information would have been great to have yesterday. When dealing with a company with no phone number or physical address on the site, an email becomes critical to get my trust. Frustrated, I went on amazon.com and ordered $450 worth of arduino kits, electronics supplies, and soldering equipment. Then, I went on ebay and saw that someone now is offering 6 available complete Mendel electronics kits so I grabbed one of those too. I got an email back from gil offering me some free plastic and I told him I'd be happy to pay for an extruder board, which is really all I needed after ordering everything available from Makerbot.

Got an email back right away from gil again this morning. Suddenly, with a sale on the line, the lines of communication are wide open again. But, the offer of free goods didn't extend to the extruder board I said I needed more than the plastic. He asked if he could charge my paypal for $49.95 for the board and I told him I already picked up the whole kit off ebay and he sent back an email to keep in touch. I should send him a christmas card or something.

The hobbed M8 bolt came today, another ebay part from Daniel Ferrier, thank you. I was hoping I could find an Arduino project book at the library but it seems I'll have to order it. I picked up some other books that I might find interesting. I've thought about building my own green laser projector also and it uses many of the same components as the Mendel. I've soldered simple electronics kits together before but never experimented with the Arduino or engineered my own designs.

Have you had any luck comprehending the Y-carrage on the isaac, they seem to have changed it from the pictures i can find on the web? also, what number are you, i am 34?

I got a confirmation number from USPS but my Isaac hasn't shipped yet, it says 1 to 2 weeks backorder on the site. Today I've been working on getting the Wade's extruder together. It didn't come with any instructions so I looked at the Wade's extruder page on the reprap site. I had to redrill some of the holes again to make the bearing cap slide onto the 4 bolts. I realized that when I assembled it that the bearing did not spin properly and that there is a groove in there made to fit a rod that goes through the bearing. I fashioned one from a cut piece of 5/16 threaded rod and filed down the sides so that the cap could fit as flush as possible on there with the bearing inside. The kit did come with an extra M8 bolt, which I assume is meant to be cut for this purpose. the springs that came with the kit needed to be cut down to 1/3 the size, then a washer and finally the finger bolts. After some adjusting I finally managed to get some weed trimmer string to feed through the hole and I think it feels just right but it will need some more testing when the rest arrives.

The Isaac kit with plexiglas arrived today from Fleming CNC. Everything was packed great with a nice letter and I would recommend this kit to anyone. The parts are smooth and the holes are perfect. Brett has been very helpful in making my purchase and giving his best advice, the kit came sooner than I thought. I had a little problem opening the .stp file on their wiki page for the Isaac documentation, but I finally downloaded a STEP viewer and was able to get a 3D model of an Isaac that I can zoom in on and rotate. I'm not sure if it has everything down to the last nut and washer, but the model is a good starting point for assembling this.

yellowfrog, please contact me if you have any questions. I will be more than happy to write up a little text and tack some screen grabs of what the y-chassis should look like.

jkelso, awesome blog. There are very few good complete assembly blogs in the community, can't wait to see more. I read it every day!!!

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Isaac: a CNCed Mendel Derived RepStrap
FlemingCNC

Thanks, I like photography and I think detailing this build will be a lot of fun. I started off going to the flemingcnc site and clicked on the documentation link. Step 1 (I'm finally there!) is to put the belt drive gears on the stepper motors with an 8.5mm clearance from the motor to gear. First thing I noticed is that the shafts were too big for the hole. I rigged up a jig using rod coupling bolts to hold the gears in place and I used a 13/64 bit. It was right then that I patted myself on the back for not going with the cheaper bit set with less bits in it. The holes drilled out perfectly and I mounted them and tightened the little screws on the side with a hex wrench. On one of the gears I didn't tighten it enough and the whole thing fell apart when I went to drill, then I overtightened and creased the teeth on two of the gears but it didn't ruin them and it should still perform fine. At this point I realize that I need to go find some more accurate measuring device, I saw a little plastic card at home depot that is a guide for hole sizes and measurements. I may want to think about getting a caliper too. I have a Dremel tool on the way and I have been thinking of getting the attachment that works like a drill press for $40, although I could probably find a decent shop drill press on craigslist for about $80-$100 but for now the hand drill works just fine.

What size motor shaft do you have? The Makerbot motors were all 3/16, so that is what the pulleys are. If there are other standard NEMA 17 shaft sizes then I'd be happy to offer a different sized pulley, or drill them out on my drill press.

If you find that the pulley's are too messed up let me know, I'll hook you up with some replacements.

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Isaac: a CNCed Mendel Derived RepStrap
FlemingCNC