Mendel-parts V9 extruder and hot end

I just received my V9 extruder kit today, so I took some pictures and took it apart!
It's interesting what has come with this kit. Obviously the barrel, heater and nozzle. But also aluminium plate, fan, spare wire for the fan, heater resistor, thermistor, 4 wires with molex plug already attached for connecting resistor and thermistor, bootlace ferrules, two sizes of wire shrink wrap, long bolts, springs, bearing idler axle and the filament driver pulley which fits directly on the motor shaft. The plastics are all those that make up the extruder housing, and the fan mount.

Things that aren't included: any other nuts, washers, bolts or bearings, and none of the printed parts that attach the aluminium plate onto the X-axis, ie all the bearing houses. That's okay for me, I have lots of spare nuts and bolts. The bearing mounts aren't a problem for me either; I'm building a Prusa, and the X axis bars look to be a different width apart than the Orca. I'm also going to use LM8UU bearings anyway. I'm going to print out Greg Frost's LM8UU X-carriage and see if I can mount the V9 on top, without cutting away too much aluminium!

Pictures: Kit as supplied


Hot end assembled. There is no break between barrel and nozzle like there was in V6; the nozzle bolts onto the end of the lower barrel:


Hot end disassembled - the barrel is an M6 thread, with a bore of 3.2mm. It was surprisingly tightly put together:


There are 3 PEEK parts, and no PTFE. The middle PEEK part is a thermal break between the upper and lower brass barrels, with a narrow section in the middle.

i suppose the lower PEEK piece is just a spacer, and the upper PEEK piece is larger for mounting purposes?

and what's the clear plastic piece on the top? just a temp cover, or an integral part?

I think the lower PEEK piece is for locking the barrel into the middle piece, and the upper PEEK piece locks in the upper barrel. The middle and bottom pieces are 12mm diameter, the top is a a bit wider at 16mm. The whole hot end simply bolts through a 6.5mm hole in the aluminium plate, with the extruder directly above it.
Yes, the clear plastic piece is just a temporary cover.
I'm in the process of mounting the whole lot on GregFrost's LM8UU x-carriage. I've had to cut down the aluminium plate and drill a couple of holes in it, but should be straightforward now, if only I had the right size bolts! I'll post pictures when it's done.

The lower and upper PEEK are for locking the two barrels in the core PEEK, it need to be well assembled (as for the nozzle) to don't leak but the design is quite simple and the thermal break (plus fan) works great, the upper part is just a little warm but you can hold it with you bare hand without problem

Except I've built mine, stuck it on the normal Mendel carriage, and it died half way through printing a raft, as I had the temperature too high. The thermal bead calibration was way off. Having opened it up, cleaned out the leaked PLA, and reassembled it, it now will not feed the filament through properly, just oozing some out & causing the NEMA to skip and judder. I suspect I need to dismantle it again and re-bore the whole thing.
*sigh* It's about the 5th hot end I've killed!

Hello,

Do you have a picture of this installed on your hotend V9 mendel?
I wonder if hotend V9 is mounted on a wade extruder?
Sorry for my English but I am French.

Fabian

It could be great to have some pictures of those mountings.

Regards,
Miguel

I tried mounting the mendel-parts V9 extruder on a Greg's linear bearing x-carriage. I had to cut some of the aluminium plate and drill four mounting holes. However, the weight with the motor on was all on one bar, which I felt wasn't going to work without distorting. I have since printed a Greg's hinged extruder, adapted to fit the V9 hot end. There will still be a piece of aluminium for the V9 to bolt to, I'll post pictures when it's mounted.

Hello Droftarts,

I just bought the same hotend and I'm quite new in this field. Could you describe me how did you wire up all the hot with the thermistor.. I'm really worried about don't brake something that looks like pretty good thing.. Thank you very much in advance. Any picture could be simply great for me

Regards,
Miguel

I gave up mounting the extruder as shown in the picture above. Too much weight on only one of the x-axis rods, it was bending a visible amount. I printed out a slightly modified Wade's Accessible Extruder with space for the v9 hot end, cut the aluminium plate and drilled three holes for mounting the extruder and hot end. Then I mounted this on the x-carriage I had already printed.

To wire up the thermistor and heater, I find it easiest to use Kapton tape and PTFE heat-resistant sheath. Black heat-shrink sheath/sleeving should be supplied with the mendel-parts kit. You should also have been supplied by M-P a molex plug with 4 wires attached (if you bought the same kit as me), brown, black, yellow and grey. If you have the M-P Generation 6 electronics, the wiring order is shown on the wiki page here: [reprap.org]
Brown and black go to the thermistor, yellow and grey to the heater. If you have different electronics, the order may be different! So please check!

Wiring up the heater: I do this with the heater block on it's own, separate from the rest of the hot end.
To fit the heater in the brass heater block, I just use kitchen silver foil wrapped around the heater. You have to experiment with the number of tight layers you put around the heater, but it needs to fit in the block as tightly as possible. I then wrap the whole block in a couple of layers of Kapton tape - go over all the holes and cut them out later - which holds the heater in place in case it slips. You should also have been supplied some bootlace ferrules; these are tiny tubes that crimp wires. Cut some heat-shrink sleeving (again supplied with kit, hopefully) to a bit longer than the wire coming from the heater, eg 4cm, and put it on the yellow and grey wires, then strip the ends of the wire to the length of the bootlace ferrule. Using one ferrule for each wire, put the end of the wire and one end of the heater in the ferrule and crimp/squash with pliers. Push the heat-shrink sheath down the wire so that it covers the ferrule and the heater wire right up to the block. Repeat for the other side.

Wiring up the thermistor:
This is fiddly as the thermistor and it's wires are tiny. Use Kapton tape to insulate each thermistor wire right up to behind the glass head. The wires MUST be insulated from each other. Leave some wire free at the end to either solder or use bootlace ferrules to attach to the Brown and Black wires (I always solder these), and put some heat-shrink sheath on the wire to cover the join and any exposed wire up to and over the Kapton tape insulation. To mount the thermistor in the block, again I just use Kapton tape to hold it in place.

Reassemble the hot end, cutting out the any place that the Kapton cover holes.

You can also use the guide here: [reprap.org]

I hope that helps. I'll post some pictures when I'm able to.

Edited 1 time(s). Last edit at 10/27/2011 04:54AM by droftarts.

Hello guys,

Thank you very much droftarts! that's a really helpful for me, just a quiestion more, doesn't the v9 aluminium (or any other part) fit to the "classic" Wade's extruder plastic set? (i mean this extruder set: image attached). I hope it fits

Regards,
Miguel

P.S. Waiting your great pictures

Hi Miguel, no it won't fit without some alteration. The v9 expects to bolt into an aluminium plate. The standard Wade's expects a 16mm (I think) round part, with two bolts. When I get home I'll take a photo of mine so you can see what I did. It's good to use the aluminium plate as it acts as a heat sink.

Hi,

Allright, thank you very much!

Miguel

Here are some pictures to show how it's mounted.

I can't believe how little spring force people get away with. I need two strong springs, easily strong enough to break that bracket. How on earth does a piece of squashed tubing work?

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[www.hydraraptor.blogspot.com]

Yes. I also tried this once and it didn't last long before the feed started slipping. I think you can only get away with this if you extrude very slowly and run the nozzle really hot to reduce the viscosity of the melted plastic.

Ha ha, sorry nophead and brnrd! It's sort of just for testing purposes, as I did't have any spare springs, so chucked in the piece of tubing to test the extruder and hot end were wired correctly. It extruded fine with the nozzle high above the bed. However, that said, it is quite thick-walled PVC tubing, and seems to have a strong compression on the filament; it was tough to feed in the filament initially. I intend to change it for springs or a bird nose/camming retainer, but perhaps I'll see how long it lasts. I was expecting to have to do it up so tight the sides compressed completely! Also, note the pictures show no filament in the extruder, so it will compress by a couple of mm. Oh, and there are two bolts, the back one isn't as visible; the tubing is compressed by both.

Hello everyone,

well, i tried to fit in the nozzle with kitchen silver foil wrapped around the it but it didn't work too well.. I got this sealany, whe do you think? could it work fine? I hope so.. I wait your expert answers thank you in advance to everyone.

Miguel

Nobody knows anything about that?

I'm not sure if people know what you mean by fitting the nozzle. Ftting to what? Where was the silver (aluminum?) foil used where you know want to use a silicone sealant? Perhaps you should post a photo. Usually aluminum foil is used to tightly fit the heating resistor to the heating block. On a push-fit hot-end like Adrian's, it can also be used between the nozzle and the heating block.

I would like to use that silicone instead of aluminium foil to fit the heat resistor to the heater block but I'm not sure if it will transmit all the heating energy to the block or it'll decrease this temperature transmit. Thanks

Hi Pikelo, I think the silicon adhesive you have will be okay. If you can put silver foil around the heating resistor, even one layer, so it is in contact with the heater block, it would be an advantage. Use a small amount of the silicon adhesive in each end to hold the resistor in place if the silver foil can't, and/or use kapton tape to hold the resistor and thermistor in place and insulate the block.

the silicone is an excellent insulator, so you dont want it between the resistor and block. on the ends to hold the resistor in should be fine though.

It's a better conductor than air though, so it is better than nothing.

My preferred option is glass rope adhesive. I think that is a lot more conductive than silicone and it is cheap and sets reasonably quickly.

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[www.hydraraptor.blogspot.com]

Hello, I'm new to the Reprap community so any help would be appreciated. I purchased a used mendel from ebay and I'm trying to back track everything the previous owner did. How ever I am confused with how the extruder I have mounts to the carriage. Is it the wrong kind or am I missing a piece? Ty in advance for any help.

I haven't looked at a Sells Mendel carriage in a while, but I think you have it mounted upside down on the x-axis rods. That looks like a Wade extruder. The two mounting holes 50 mm apart should match the mounting holes in the x-carriage. The x-carriage has 2 captive nuts on those holes and you have to get the M4 screws the right length so that it doesn't hit the x smooth rods.