Poor Man's Digital Dentist Core XY build

I wouldnt do it any other way I like the solution, I also proposed a similar thing in one of my designs, but it was a double ended stepper & 2 shafts. Because the shaft is keyed I suppose that also helps as the shaft need not touch as long as the key engages.

Edited 3 time(s). Last edit at 08/11/2017 09:33AM by MechaBits.

Finally got the mill home and in place. I still have a lot of set up to do. I need to extend an existing 20amp 240v circuit so I can power the thing... and need to install the digital read out.

The mill and stand weighs around 1000lbs .

Was recently watching some Mill video's started to see the Grizzly thought ohh nice another we cant get in the UK, then I saw some bady YT reviews, will be interesting to see how you get on with it. Did you grab a bargin?

there are some people who won't accept less than a full sized knee mill from bridgeport or one of the other non-chinese companies. Im not an expert, but judging from what i've done thus far it's a capable machine. I mean, yeah, if you got room and money for a bridgeport go for it. A working bridgeport goes for around 4500 without tooling, and you need some heavy equipment to move it in to a newly built garage, because the one you have won't the adequate in terms of size c

they certainly look capable enough, is it manual on both x&y, any plans to upgrade, was it less than 2k? looks like spanking new one

It has power feed on the x-axis, I plan to add power downfeed on the head (not the spindle), I am currently working on installing dro. I don't think milling is very popular around here, there was nothing for sale except rust-bucket machines locally, though I expect that may have to do with the fact that most of the population is transient ( 4 larger military bases within 20 miles of me) and the fact that we live in a marine environment... I paid about $2700 for the machine. Add $1000 for tooling, $1000 for the dro (though I wish I had of gotten a nice set of magnetic dros instead of glass bead, looks a little easier to set up, and cheaper).

I already had a major screw up on it, I was using an endmill and for some reason I thought you could take cuts of any depth with an endmill (but you cannot) and ended up sliding the 100lb vice down the table, apparently I did not have the vice right enough, then the endmill stopped spinning because it got binded up in the material.. luckily I didn't have the end mill installed correctly in the collet so the collect kept spinnng, chewing up the end mill instead of the gearing on the machine. I'm starting a machine shop class at my community college next week

Once I get the dro installed I'll take some more pics, sadly I've only had a few hours to play with it over the past week because of work, and those weekend I'm going to see the eclipse...

Edited 2 time(s). Last edit at 08/19/2017 11:56AM by Qdeathstar.

Cool look forward to seeing some stuff from it, Have you seen the laser hole finder attachment, seems like a good device to make with 3D Printer, for mill.

that is a nice setup... how mich was the lathe?

Around 1900 €, but I think it is much cheaper in US (I think the equivalent is Grizzly 10x22). And you get more toys with it in the smaller price

Found this thread of a guy reworking hiz Grizz [www.cnczone.com]
I really want to get back into milling stuff but when you see the amount of extra work you might have to get involved with,
3D printings a breeze by comparison.

he is turning a milling machine into a cnc machine...

Yes I know...

On the subject of 3D printing being a breeze compared to milling, I had a dig around in the settings of cura the other night as I was thinking of trying some of the new stuff in it, but when I saw the amount of stuff I needed to configure...I thought nah,.. another time...
So 3d Printing obviously has enough depth & complexity if you want it, but you dont need as many extra tools jig's & stuff needed for milling, so that what i meant.

In 3D printing the mistakes are cheap, unless you have $$$ printer or $$$ materials (i.e no Statasys). Milling and lathing are expensive as I've recently discovered: money for tools, money for materials, lots of non-idle time spent and a huge mess to clean up.

and with me moaning about the price of cheap filament, you might have guessed there was no magic money tree in my back garden(what am i saying I dont even have a back garden & shed), thats why I dream of something compact & bijou to do small parts without much extra tooling, with a tiny endmill bit(I bet the cost on them mounts up)...who cares if it takes a few hours...something bigger needs so much more resources including the space for it & the time to devote to it, i'll be happy to just get one in the community to use, .

Poor Mans Digital Dentist just spent a few bob & has the space for it, can't be that poor, or the Dentist is extremely rich.

Edited 2 time(s). Last edit at 09/20/2017 10:55AM by MechaBits.

Here is an update



This is the mount for the idler pulleys. I was using printed abs but after a month of tension in the belt the abs want really holding up, plus, i had to use long screws because the abs was thick...




A view from underneath, showing some pocketed fasteners.



This is the base of the motor mounts. The slots are to allow sideways adjustment of the motor, so that i can keep the belts parallel and at 90 degrees. I will cut slots in the aluminum tubing to tension the belts.



Just another view from the underside...




I really enjoy milling, got a lot to learn but there is something satisfying about shaping metal into something,


Got a few pictures of the mill set up with dro as well. A lot of chips..

I think ebay. is the best bed to get tooling, I got some nice end mills that are much higher quality than the grizzly set i bought for about half the price.... i want to get a corner-radius end mill set and maybe a face cutting end mill asap, but maybe after i get my small lathe.








Edited 1 time(s). Last edit at 10/22/2017 04:50PM by Qdeathstar.

Those bellows on the linear guides are definitely worth it. I've noticed it on my bare mgn12 rails too
Maybe the shapeoko-v-wheels version has an advantage there?
I'm thinking of adding a "curtain" around my spindle, allowing me to attach a vacuum cleaner hose right where the chips come from.

Been a long while since I had a proper update. I can't believe it has taken this long to get the xy assembly right again, but other projects pop up... anyway, some pics:



This is one of the belt clamp for the effector, I machined it down to match the bearings, then notched out s bits round the corners so the belts had a place to lay, than drill/tapped a few holes to get everything to stay in place.



you can kind of see how it goes onto the effector here.



nothing like blue marking paint, but this is the mount for the dual aero extrudes. It will slide up into the belt attachment thing showed earlier. this way i can make everything modular for perhaps a laser etcher or if i need to the extra two inches a single extruder head...



easy sliding action, attaches with 4 m5 screws.



Here the belt clamp is in place. There is a screw that goes though the belt clamps to squeeze them together, then there is a screw on the bottom and top(pictured) that screws down to prevent side to side movement. It works nicely. however, i will have to keep an eye out for belt slippage because it's just the clamping force of an m5 screw that is squeezing the belts together to keep them in place.



I decided to rethino the y carriage and go with a larger rail with an extra bearing block like in the digital dentists design. I've notice the rail movement is smoother.



just another close up of the belt clamp



et cetera, the guiding bowden tubes fit through the slot down to the aero extruders.



looking good, might make a water cooler for the extruders, if i feel the need. A i noticed a difference with my cyclops on the delta, but there is a lot more surface area here so im probably good with just the fans.



overview..

Edited 1 time(s). Last edit at 12/28/2017 12:00AM by Qdeathstar.

Nice! When it it going to print?

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

who knows! I've got to rework the z axis, complete the wiring, and it should be ready to print. maybe before winter is over...

The Digital Dentist, what did you end up doing about driving the rhino stepper? Did you use the nema23 that came with it? What kind of driver did you use? I am planning to use a suite wifi which allows 2amps to the motor


nvm, found it.

Quote
the_digital_dentist
The stepper that came on the Rino is a 166 oz-in NEMA-23 motor, but with 30:1 reduction / torque multiplication, I think a NEMA-17 motor could do the job. It has an 8mm keyed shaft, and a couple rings with grub screws keep the shaft from sliding out of the gear box. I am running the motor at 1A, driven directly by the smoothieboard, and it doesn't even get warm.

Here's the Rino I bought- looks like he is still selling them: [www.ebay.com]
Here's the data sheet: [www.ondrivesus.com] These are the PF30-30ANM parts on page 3.
I don't know why he doesn't have the word "Ondrives" in the title somewhere- I was looking at these things on ebay for a couple weeks before I found his listing. "Rino" is used for a lot of different products.

This guy sells the shafts: [www.ebay.com]
I asked him to make me an extra long one (I could have done it at the makerspace, but I don't know that it would have been cheaper by the time I acquired the shaft and key stock, tools, etc.). IRIC I paid him $20 or 25 to make the longer shaft.

My measurements of belt stretch include the shaft torsion, of course. I put the motor at the middle of the shaft so the torsion would be equal at both belts.

Edited 1 time(s). Last edit at 12/28/2017 09:24PM by Qdeathstar.

My bed and support weigh about 3.5 kg. The NEMA-23 motor that comes on the Rino, operating at 1A, lifts that plus 4kg of print mass (probably more- I never tried more) just fine. There's no need to change the motor or use an external driver.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

I gotta say with all the nice machining of parts, you're making mine look like the poor man's version of the machine.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

hah! Making chips is fun. Too bad the tools don't make the printer.

Quote
Qdeathstar
hah! Making chips is fun. Too bad the tools don't make the printer.

Why make a 3D printer then ? just put an extruder/hotend (or even a plasma torch) in the chuck and a heated bed on the mill table "et voila" !
Now you have a combined substractive/additive mfg machine.

Edited 1 time(s). Last edit at 12/30/2017 02:14AM by MKSA.

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

Getting closer.



I got the hot end together. I ended up using a dB-25 connector, plenty of wires for the dual hotends, stepper motors, thermistors, fans, and proximity sensor. I haven’t fully tested if the cable can handle the current, but worst case they do sell 20awg db12 cables that are a little more expensive that should be capable for 60w at 12v.



A picture of what it looks like unpopulated...



Mechanics endstops are the way to go...



I printed a little bundled for the air hoses and cables. Neat.



This seems like an easy way to provide heat for the chamber. 1800w hair dryer. We will see how it goes. But it’s got an fan, heater, and thermal overload protection built in....



I think I’m just about ready to wire everything up. Based on the 1800w hair dryer and 1000w bed heater, I am going to use a l14-20 cord to provide two 20 amp circuits to the printer... I have two contactors that will be used to control power to the unit.

Edited 2 time(s). Last edit at 01/22/2018 11:06PM by Qdeathstar.

Love the dB25
Cable management is always last on most lists.
Amazing how the Amp draw adds up after adding up all the accessories...

I don't think the PVC pipe is going to be too happy about the hot air from the hair dryer blowing through it. Is that air pump going to move enough air to actually cool the print?

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

The part cooler has worked excellent in my delta printer, so I have no reason to doubt it will work in the coreXY. As far as the pvc pipe I’m not sure how it will hold up, but I saw it on the internet so I decided to give it a try.... I don’t think it will be an issue, my target temp is around 60c. If worse comes to worse I can get some imc or maybe grey pvc that has a higher temperature tolerance.

Edited 1 time(s). Last edit at 01/23/2018 10:49AM by Qdeathstar.

I did a little more research, and what ive found out is that PVC turns soft at around 90c..... hair dryers dont get hotter than 60c according to what i read because that is the temperature at which the scalp burns, so to protect the manufacturers from potential lawsuits, they limit the temperature to that amount. I want to get the heat chamber up to about 60c, so maybe it won't work... but, i think if the hair dryer can get up to 60c and then my heatbed goes to 100c it should be close.... i'll have to test and see. The advantage of the hair dryer is that it was cheap...

If not i'll get one of those elements and use it, but it looks like they cost about 50 bucks.

You could always buy a rattle can of high-temp paint for BBQs and Exhaust pipes and coat the inside if the PVC elbow, or line it with aluminum foil.

A swept 90 degree elbow will also help (or 2x 45s), that sharp 90 will cause back pressure from buffeting, though not alot, it will heat up pretty fast I'd imagine.
One draw back is the swept 90 will put the hair dryer further from the chamber, unless you take a hack saw to it for an oval exhaust port... yea they don't sell couplings for that :p