Isaac Mendel build
Posted by jkelso
|
Re: Isaac Mendel build October 12, 2010 02:46PM |
For some reason I've become addicted to watching this music video over and over. Just now, I finally realized that the shapes in the background form the letters "laroux". I had never noticed this before. I thought of repraps when I saw this because the answers never seem to be there until suddenly you figure it out and the answer was there all the time.
|
Re: Isaac Mendel build October 13, 2010 12:50PM |
Now with all systems go, I've been trying for the last hour to get the filament to move through the nozzle again. Finally, I had to take a hacksaw blade and cut off a bolt that was coming through too long to allow me to take off the bearing cap from the extruder. With the cap removed, I could see that there was a bent piece of chewed up filament stuck in there. Now I'm going to put it all back together and have another go at it.
|
Re: Isaac Mendel build October 13, 2010 02:09PM |
With the extruder now apart, I could find no cement clogging that inner hole. I've got the extruder heat ramping up right now and I'm going to hold the nozzle with some pliers and try to feed some filament down in there to see if it's a clog in the nozzle that's causing the problem.
|
Re: Isaac Mendel build October 13, 2010 04:47PM |
The thermistor wire came loose so I had to peel off all the tape holding it and resolder the wire on there and retape it. I got it ramped up to about 230C and used one pair of pliers to hold the nozzle and another pair to force the filament in there. It took great pressure and I could only see the slightest extrusion at first, then it jammed and nothing would come through. After looking more closely at the nozzle, the metal tip appears to be bent at an angle to the plastic end. I'm now going to take all the tape completely off and take another look at it. I guess I'll be ordering that other nozzle now, wouldn't be a bad idea to have them around. I'm wondering how long they are supposed to last. Maybe I can still get it working tonight though...
|
Re: Isaac Mendel build October 13, 2010 05:21PM |
After peeling off the tape, it is evident that the bend is the cause of this problem and that the nozzle is trash. I'll have one here in the next few days and I'm hopeful that this could be the last of my problems to work out and I'm ready to print..
|
Re: Isaac Mendel build October 19, 2010 02:38PM |
I've decided to try it again this time with the cement more carefully applied and now that it's drying I can see a clear hole through the tube. This apparatus may have gotten very hot for a long period during my testing phase when the temp value was disconnected. I believe that the high temps left on for a long time warped the nozzle. I'm wondering if the bolt that goes through the side is necessary. I've got more copper tube and I'm going to try taping this instead of globbing too much cement. Since I now have a working extruder board that senses temp values I'm hoping this won't warp this time. I'm going to wait until late tonight to start testing it, the cement has just been applied. I'm wondering if that bolt in the side is necessary to hold the nozzle in there.
|
Re: Isaac Mendel build October 19, 2010 10:03PM |
I wish you luck for tonights attempt. Fingers crossed 
|
Re: Isaac Mendel build October 20, 2010 12:04AM |
Well, since my last post I've reconsidered rushing into things, the cement still felt semi pliable. I put the bolt in the side and the nozzle shifted slightly but the hole through looks fine. I've decided that it needed more cement around there to hold the nozzle in better and give it more strength. I've spent more than 10 minutes holding a hair dryer over the cement as it's applied on. I'm going to keep drying the layers and applying more until it seems dry and holding firm in there. I think this could be more reliable and I'll wrap tape around it.
|
Re: Isaac Mendel build October 21, 2010 02:30PM |
It didn't seem to fit with 2 bolts, I'm hoping the fire cement will do the trick. One bolt puts the nozzle in there snug, the second bolt starts to push the nozzle into a bad angle and it seems like things are cracking using the 2nd bolt. I've not applied any more cement and it looks like it's holding very nicely so far. I cut another length of nichrome wire to 12 inches to achieve 6 ohms and I attached it to some lengths of coated wire and twisted them together. Then I bent the twist over one time so it holds better. I didn't use solder because I think it would melt with the heat anyway, the tape should help to hold the wires together.
Edited 1 time(s). Last edit at 10/21/2010 02:30PM by jkelso.
Edited 1 time(s). Last edit at 10/21/2010 02:30PM by jkelso.
|
Re: Isaac Mendel build October 21, 2010 10:21PM |
that is good advice to know but too late for me to use now. I'll have to try that on the next one. I'm gonna get a new extruder body soon. For now I think this will be OK. I wound the nichrome wire around the nozzle about halfway down from the top and taped it. Then I wrapped the thermistor around and taped it more. I think this will work just as good as having that copper tube but we'll have to see, I've been wrong before. I think it will work this time though, don't see why not.
|
Re: Isaac Mendel build October 22, 2010 05:42PM |
With everything bolted up and ready to try again, I now have good motor control but the temp value is showing 158C at room temp and when I try to ramp it starts flashing between 875C and 158C. I think I'll try wrapping another thermistor around there with new wires to the extruder board after I unbolt the extruder body once again.
|
Re: Isaac Mendel build October 22, 2010 09:50PM |
I've got the extruder taken apart and getting ready to try another thermistor. The connect plug for the power supply had been sticking a lot and finally it just stuck together and would not budge apart. After yanking on it a bunch of times one of the wires pulled loose out of there. The whole apparatus was janky so I took out the connector and hardwired the power supply into the terminal connectors. I also zip tied the cord in 2 places so that it will not pull loose. I'm going to put the supply on a power strip with a switch so that I can turn it on and off without unplugging things. This should be more stable. I plugged it in to test it and nothing came on, I feared that I burned the boards accidentally then I tried it again and after a few seconds got the lights but got very worried for a moment.
|
Re: Isaac Mendel build October 22, 2010 10:43PM |
After tearing down the extruder halfway and getting the thermistor tape off I could see that wires were touching power supply wires that shouldn't have been. I retaped the thermistor on there and finally got an accurate reading. However, the heat would not ramp up so now I took it all apart and with the multimeter I can see that there is a broken connection somewhere in the tape, I'm getting no reading on the meter. This time I'll be more careful to tape everything up so that wires aren't touching and most importantly to test it before putting it back together. No more "oh, man!"
|
Re: Isaac Mendel build October 23, 2010 12:14AM |
At last, with the wires taped into there more carefully I now have a nozzle that heats up and displays the proper temp value. Now it should just be a matter of bolting things back up and giving it another try.
|
Re: Isaac Mendel build October 23, 2010 06:23PM |
With the extruder body bolted back on now, I'm finding that the opto endstop for the Z axis is too long so I cut it using a pair of needle nose pliers to hold it just above the cut and a pair of side cutters with a side to side motion until the piece falls off. Now I'm using the Home button in the reprap console to find the 0 for the Z axis. It came down against the platform slightly so now I'll adjust for that by tightening the gap in the bed springs.
|
Re: Isaac Mendel build October 23, 2010 08:32PM |
Hit another snag tonight, the nichrome wire does not have continuity any more. Somewhere between testing it and bolting it up the wire must have come loose. I'm going to solder them them time, I've been just twisting them together but the nichrome wire often seems to kink and break. It may need a new length of wire cut and rewrapped in there.
|
Re: Isaac Mendel build October 23, 2010 09:34PM |
After peeling off the tape I can see that the tape alone is never going to work. The wire needs to be encased in fire cement or done another way. I'm not sure I can get a picture of how you're doing it from the description alone. With the extruder removed I decided to go ahead and drill that 2nd hole to hold in the nozzle and I put the bolt in there. I'm going to try and use a method I saw on youtube to coat the wire with fire cement and then wrap it and apply more coats and heat with a torch or blow dryer between applications. I have copper tube too I may use it and make another nozzle more like the first one I made that warped.
|
Re: Isaac Mendel build October 23, 2010 09:56PM |
I started coating the wire and I'm going to put a thin coat around the nozzle and allow to dry for a while before wrapping it together.
|
Re: Isaac Mendel build October 23, 2010 10:16PM |
I looked at the heater block design A. Smith, it looks pretty good, where can I get one of those? Does it work with Wade's extruder? So the whole thing heats up? Not sure how it works from a quick glance...
I'm going to let this thin coat of cement dry until tomorrow or later tonight and I'll wrap the wire and apply more cement.
I'm going to let this thin coat of cement dry until tomorrow or later tonight and I'll wrap the wire and apply more cement.
Sorry, only registered users may post in this forum.