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3 Jaw Lathe Chuck

by bobwomble Jan 7, 2015
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It looks cool but it needs almost too much sanding/filing. Parts are 1mm off or more. I rather want something thats too loose than too tight. The 10mm hole is 9mm and the M16 is M15.

Gears and the spiral thingy work, but the rest is many hours work.


what is the maximum diameter to clamp in?

Could you add a file GEAR_RING without holes? I'd like to try print with SCROLL together, as one file. Or you could add already connected file.

SCAD file appears to be empty.. (never used scad, maybe i'm derping it up)

Looking at the warnings, i guess i have to install some libraries... (no idea)

Update 2:
Errors persist. Seems this was made with an older version of scad or something.. i honestly don't know.. :(

OpenSCAD 2019.05

Copyright (C) 2009-2019 The OpenSCAD Developers

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

Loaded design 'F:/DIY CNC/3D Printer Stuff/Mini_Torno Lathe/Chuck/files/4Jaw_Chuck_all-in-one1.SCAD'.
Used file cache size: 2 files
Compiling design (CSG Tree generation)...
DEPRECATED: The assign() module will be removed in future releases. Use a regular assignment instead. in file 4Jaw_Chuck_all-in-one1.SCAD, line 647
DEPRECATED: The assign() module will be removed in future releases. Use a regular assignment instead. in file C:/Users/ArcAiN6/Documents/OpenSCAD/libraries/TextGenerator.scad, line 119
DEPRECATED: The assign() module will be removed in future releases. Use a regular assignment instead. in file C:/Users/ArcAiN6/Documents/OpenSCAD/libraries/TextGenerator.scad, line 122
DEPRECATED: The assign() module will be removed in future releases. Use a regular assignment instead. in file C:/Users/ArcAiN6/Documents/OpenSCAD/libraries/TextGenerator.scad, line 125
Compiling design (CSG Products generation)...
Geometries in cache: 1810
Geometry cache size in bytes: 1055888
CGAL Polyhedrons in cache: 0
CGAL cache size in bytes: 0
Compiling design (CSG Products normalization)...
WARNING: Normalized tree is growing past 200000 elements. Aborting normalization.
WARNING: CSG normalization resulted in an empty tree
Normalized CSG tree has 0 elements
Compile and preview finished.
Total rendering time: 0 hours, 0 minutes, 1 seconds

The face housing model is wrong. There lost the nut cuts on the outer shell. And you'll figure this out after 14 hours of printing.. Nice.

BTW: these cuts should be located upper, at the same height as the cuts in the inner tube. Otherwise you'll need to long M4 bolts, about 80mm, which is hard to find.

this actually fills a bit of a need for me.
i often put things in the drill to have to use less effor to file something down or even sawing a screw short or something.

but i was limited to the max diameter of 10 or whatever it is.
this allows me to do it to bigger things

Beautiful design. I tried opening the scad file to make a few tweaks, and got several errors.
WARNING: Can't open library 'parametric_involute_gear_v5.0.scad'.
WARNING: Can't open library 'TextGenerator.scad'.
and a few others that seem to be related to the text module
Can you upload those missing items, or tell me how to get them?
When I open the model now, I only see the 3 jaws, nothing else.

This is a great design, works well. I would however like to point out that most if not all of the sanding and filing wouldnt have been necessary if the tolerances were correct. On top of the fact that a well dialed in printer/slicer can produce MUCH better supports than the ones you tried to include in the design.

Thank you for your comments, You are correct.
This design was primarily just so I could learn some openScad, and was also for my scratch built home made printer 4 years ago- (printers are better now), slicers did not have very good supports then, but you can remove them in the cad file.
Please feel free to modify the cad (where you can also change the tolerances).
Cheers Bob.

I got it printed and working with plenty of sanding and some lithium grease, honestly I would merely recommend removing those built in supports and reducing the diameter of the gear ring by like 1mm or 2 max.

Do they sell these (made from metal) that is meant to be used with a drill?

After printing, nothing fit. I didn't think I could ever make it work. After relatively little filing, lo' and behold, things started coming together. Tomorrow to the screw store. Pictures to follow.

I created a new STL file from the OpenSCAD file to print the housing without the "support structures". Whoever added the lines 185/186

translate ([0,0,32.5])
cylinder (h=8,r=(((chuck_center_hole+chuck_inner_thickness*3)-clearance)/2),$fn=res); ////DP: New feature

owes me 120g of formfutura TitanX!!! This adds a thicker base at the bottom of the centre bore, so the scroll/gear ring do not fit anymore.


Love it. Printed really well in ABS at 235/95, no enclosure.

What filament did you use for this? It may be quite dangerous if the plastic is not strong enough to resist the centrifugal forces of spinning it too fast. Introducing a workpiece and cutting on it will only make the problem worse. Maybe Nylon would be OK but I'd be very wary of PLA, ABS or PETG.

I printed it in ABS 235/95 at 100% infill. It is rock hard. I wouldn't hesitate to turn it at 500 rpm. I'd be very wary to turn it any faster, but that speed is useful for repairing tips and ferrules on pool cues. Also easy to get dialed in since the jaws are relatively soft. If they start to get worn, you can grind 'em again a couple of times then just print up a new set. You can be sure the first time I fire it up I will not be standing in the line of fire should it come apart. You can also be sure I will be wearing eye protection and "I" protection. After all, the surface speed of a 4" chuck at 500 rpm is only about 40 ft/sec. Enough to put an eye out perhaps but it wouldn't send out a piece that could penetrate a vital organ.

This looks very much like my 4" Sanou scroll chuck. Do you know if the jaws will fit a 4" Sanou?

I'm having issues with the supports on the face housing. I can't get them to slice properly in Cura. One set disappears completely while the others only show up half. Very weird. I've tried tweaking multiple settings but no luck.
Anyone have similar issue or tips to sort it out?

I have a round, ring shaped print and i'm looking for something to harness it to a drill to sand the outside. Can i use this model here to grab my print from the inside (push jaws outside insted of pusing to the inside)?

Niestety szczęki nie schodzą się w punkt.
1.2.3 przekładałem w różne gniazda i nie pasuje żaden układ.

Comments deleted.

I've discovered a great way to "grind" the jaws and bring the runout down to about zero - at least by eyeball (I don't have a dial test indicator). I'm using an 8mm shaft so I changed the model to have a smooth 8mm hole which I cleaned up with a reamer. Next I ran a long 8mm rod through the hole and lightly gripped it with the chuck's jaws. Next I mounted this hub: https://www.amazon.com/gp/product/B0777M7TXD Then I drilled holes for it in the backplate and secured it with M5 screws. This assures that the backplate is reasonably square to the shaft and roughly aligned with the jaws. Next I tightened the chuck jaws a little, mounted the shaft running through the chuck in a power drill and started spinning it (don't tighten the set screw on the hub before doing this)! The idea is to have the friction between the rod and the jaws create enough heat that they deform a little. Since they are gripping a shaft that is perpendicular to the backplate they will deform to a position that is perfectly centered.

I'm pretty stunned by the results. I have the chuck mounted on a 100mm/8mm rod gripping a 250mm/8mm rod spinning in a cordless drill and I don't see the tip of the rod wobbling at all.

how well does this work if scaled bigger? like if i want to make it 1.5 or 2x bigger? does the required hardware scale well? (im not familiar with metric hardware)


Firstly, thanks for sharing this design. Unfortunately tolerances very tight and we need more grinding works. Please add design files. Thanks...

The design file's have always been available, they are Scad.
If you require a different format, feel free to convert them.

Hi guys, I need to fit a round piece in my wall driller for sanding purposes. This piece has a 140mm diameter and I need this kind of chuck to hold it on drill. How may I scale this design withou modifing the required hardware too much to addapt for a 140mm diameter? Thanks!

The standard model combined with the reverse claws mentioned/linked lower down should do the trick for a 140mm diameter (that is 70mm radius) item...

Thanks, after much sanding, it works pretty smoothly. I've added a printed 3/4x16 thread to the back plate inside the centre hole in OpenSCAD and mounted it to my wood lathe, just need to see how well it holds up. It certainly feels pretty solid.

Great design, do you have an editable format for the assembly? I would like to use the chuck as part of another design. A step or IGES of the assembly would be very helpful, if you have it. Thanks.

I found that the parts don't seem to be designed to fit together very well. Spent 20hrs printing this thing, I'm sure it would take 3 times that to get the parts to fit together properly. Used PLA, which normally prints parts very accurately on my 3d printer.

Why did you add the pillars in the t slots? A slicer would've just added supports there automatically

yup, I am sanding them as we speak and annoyed as shit by them.. I printed this in an ORANGE PLA that for some reason is notorious for stubborn to remove support. This particular PLA also has the best layer adhesion I have ever seen so it is a good fit for this project.. I just wish those integrated suports were not there! PAIN IN THE ASS

Maybe that would work now, however when i designed it print support was horrible and added support in areas not required.
You can remove the pillars by commenting them out in the Scad file.

Seems like some of the holes in the back plate are missing. Anyone knows if you should drill tehm out yourself?

is there a simple pdf which shows the dimensions of this design?

Добрый день. Классная вещь. Хочу распечатать. Уже распечатал несколько деталей. Вот только вопрос возник. А не могли бы вы переделать "rear_housing_10mm_hex.stl" под болт М8? А то у меня оси и втулки под размер 8 мм. Заранее спасибо.

Typically a chuck like this can take a very long rod ..so somehow it may be possible to have a geared system which allows a rod to be placed into the jaws and the drill mech to the side to allow that rod to be as long as needed...

Great part it would be very cool if you redesign the parts in the middle so that you can Thighten bigger diameters i hope you understand what i'm thinking about. if not look at the picture https://media.real-onlineshop.de/images/items/original/0a1422a6e10d1265d8597136bb413910.jpg :)

Kinda like these?


(As mentioned in the description!)

Reverse Jaw (1,2,3) for Lathe Chuck

Nice Model.
I need the other Jaws, to tighten outside.
Or can you give me the step from this Jaws?

Sorry i can't. You can edit the scad tho.

I just printed the chuck. Excellent design.
Here are my few observations:
1/ I could not make my slicer to slice the built in supports on face housing. So I went to included scad file and rendered my own stl without supports. I used Simplify for slicing and adding necessary supports. Printed just fine in about 8 hours on Prusa i3 MK2. What was my surprise when I saw reinforced part of inner bore on new face housing. Then I found new piece of code in scad file marked "////DP: New feature". That means I cannot use the original scroll part as its centre hole is small now. So I had to tweak the code for scroll a bit.
2/ I decided to tweak the drive gear part after I snapped the outer pin on one of them. I wanted to make a 3mm hole in the pin axis and glue piece of 3mm diameter filament in the hole to reinforce the pin. something like this, but using the filament instead of screw: http://www.thingiverse.com/thing:674853
However, now after exporting new drive gear, there is deeper and bigger grove around the gear (the one where the locking screw goes. I cannot make it more shallow. When I tweak the variable "pin_radius=(3+clearance);" to something like pin_radius=(2+clearance); the teeth simply disappear. I cannot find why.

Still have to assemble the chuck so I will see if this is a problem or not.

3 Jaw Lathe Chuck drive gear remix - reinforsment

Here is new code for drive gear:

module drive_gear(){
difference ()
difference ()
union ()
translate ([0,-14.1619,-23.44]) //([0,-16.1619,-23.44])
rotate ([90,0,0])
cylinder (h=7,r=8/2,$fn=res); //(h=5,r=8/2,$fn=res)center pin***
translate ([0,-40,-23.44]) //([0,-40,-23.44])
rotate ([-90,0,0])
bevel_gear ( //(14,42.4,352,0)
translate ([-25,-45,-54]) //([-25,-45,-54])
cube ([50,6,60]);
translate ([0,-38.98,-23.44]) //([0,-38.98,-23.44])
rotate ([90,0,0])
cylinder (h=11,r=31/2,$fn=res); // (h=9,r=31/2,$fn=res)outer pin
translate ([0,-40.5,-23.44])
rotate ([90,0,0])
cylinder (h=10,r=9.5/2,$fn=hex_res); //8mm hex key socket r=9.4 is a tight fit
translate ([0,-14,-23.44]) rotate ([90,0,0]) cylinder (h=20,d=3,$fn=res); // cutout for filament insert
rotate ([90,0,0])
cylinder (h=2,r1=7/2,r2=10/2,$fn=res); //chamfer hex socket
translate ([0,3.8,0]) //([0,5.8,0])
//translate ([0,0,-49]) //FOR TESTING ONLY
// outer_housing(); //FOR TESTING ONLY

Here is new code for scroll:

module scroll() {
translate([0,0,-4]) difference() {
intersection() {
translate ([0,0,-5]) cylinder(r=42,h=15,$fn = res);
union() {
translate ([0,0,4]) jaw_spiral();
translate ([0,0,-1]) cylinder (h=10,r=(((chuck_center_hole+chuck_inner_thickness*3)-clearance)/2),$fn=res); //NEW FEATURE
//translate ([0,0,-1]) cylinder(r=18,h=10);
translate ([-23,-10,4]) cube([10,20,10]);
rotate([0,180,-45]) translate ([0,0,4.8]) gear_screws_cutouts();

Where can i buy this chuck?

Try a local 3d hubs.

Printed the chuck "out of the box". Made no changes.

It needed a lot of sanding and filing but I got it to work.

Great Thingy!!

Hi, great job!

is it possible the STP for the Housings or just export the STL for the housing at best resolution to eliminate the lines from faces. It would be nice if you remove that supports there also/ the rectangles/ , so we can generate out supports for better quality.

Just saw this and think it's awesome! I'm wondering though at the built dimensions, what's the largest I can spin on it. I wanted to do something like a 7~8 inch square bowl.... Do you (or anyone else) have any experience trying that?

Comments deleted.

hey man, what allen key are you using to open and close the chuck? is it imperial? one size for me is small and the next is just a tad larger (metric). also, thank you very much for the design looks great!

M8, its a snug fit, As I noted on the details page I had slightly modified parameters to suit my printer.
If you find one size slightly to tight, maybe you could carefully heat it up and push it in to make it the correct size?

oh i didnt see that you noted it. yeah maybe the heat gun will be a good idea. thank you very much :)

Comments deleted.

Wow!!! I'll print it ASAP and connect it to a speed regulated AC/DC motor to build a mini-lathe. Of course I've to design a bearing tailstock for wider works.
Many thanks...

Very nice work! This is a great starting point for a lathe if the drill by itself isn't good enough.

Thanks, a lathe was the original plan, however my time has been otherwise occupied, maybe one day.

I have a problem with the scroll it breaks always, printed in ABS speed 50mm/s infill 50% honeycomb layer 0.12mm.
I think i print it again all in PLA and scale it at 200% so the scroll should not break i hope :/

The scroll is the weekest part and abs is prone to delamination.
Pla or nylon is better . Also I would use higher infill and a slower print speed. Good luck.

Has anyone made this just threaded for an actual lathe, or does it only take the bolt in order to connect it to a drill? I have a wood lathe, and this would be great for gently holding things I don't want to scratch while finish sanding them.

Not that I know of, it would just need a new back plate designed.
I don't have the time at the moment, perhaps someone might be able to post one.

Oh, I wouldn't expect you to do it for me. I just couldn't tell from the pictures if it was already threaded for a lath and could use a bolt, or only a bolt. Thanks for the quick reply. :)

I have just added the Scad file, very grateful to Durwin Pye for sorting it out, also you can change the number of jaws.
If anyone improves on it please let me know so as I can add it for everyone to enjoy.

Fantastic work!
There does appear to be another file missing though.
"WARNING: Can't open library 'TextGenerator.scad'. "
I guess a ref to http://www.thingiverse.com/thing:59817 is in order for easier access.

OpenSCAD 3D Text Generator

hello :)
printed it out, great design!
everything fits so nicely :)

i can't wait for scad files release so i could tinker with it even more (scale, modify etc.)

btw, one can buy jaws/scroll/housing parts of "real" metal lathe chucks individually ,
the smallest jaws i could find locally are 50mm long , so just a little bigger than ones you use :)
It would be great to make different sizes versions allowing to either use metal parts, as part of plastic chuck, or
to use plastic parts (like jaws) into metal chucks :)

Has anyone used this to hold wood for wood turning? Looking to make a mini lathe to turn .75" x .75" x 4" blocks down and hoping this will be strong enough to take the hits when going from square to rounded.


During testing I had a piece of 20mm aluminum rod 1/2 pop out of the jaws and bash into my carriage several times until I managed to shut it down. No visible damage to the chuck.
But it would depend on many things, How well bonded your layers are, how true your chuck is setup ie: dead center no wobble, how sharp your tools are, using very small cuts, preparing your bits of wood, like round of the corners a bit before you start.
I have found that PLA is best as it is strong and rigid, no flex
ABS has flex .

Hi, are you trying to print this from ABS?
I tried to print face_housing from abs 3 times, but no succes, cracks and layer delamination in the middle of housing.
Jaws printed nicely.
Maybe i should try to print from PLA everything except gears and jaws?

I printed all parts in PLA as I find it is harder and more rigid than ABS.
I have found gears are best printed from PLA or Nylon as ABS is a bit too soft and tends to wear out faster.
As for cracks and delamination, That is classic print setting issues IE: check your heatbed, nozzle temps, fan speeds, yada yada etc etc

do you by any chance sell these chucks?

Hello Impala416,
To be honest, I had never thought about it, as It started as a personal challenge. I would have to look in to the amount of fillament required etc to see what the cost would be.
Also, what part of the world would I need to send to?


with a fixed price of 50-70$ you woud cover cost and labor. The time part is in fact the fun we Maker's get ^_^

That can be reduced(scaled)?

I haven't tried but others have check out the other comments below an the other makes like this one https://www.thingiverse.com/make:147075
Cheers Bob.

3 Jaw Lathe Chuck

I want to do this for a 4th axis cnc, for milling small of wax models.

This is awesome! Thank you for sharing

Comments deleted.

Awesome! Thank you very much for sharing this!
Do you know if it is possible to use it to drill 0,35mm hotends holes?

If you have the chuck perfectly centered, and take it very carefully, you should be able to, I haven't tried it myself, let me know how you get on.
PS I drill my nozzle's out by hand with a pin vice, after starting the hole with a 1mm drill in the drill press.
I doesn't take long and you have a better feel for what is happening.

Couldn't an alternative to the reversible teeth come from diamond-oid tracks on the bottoms of the teeth, instead of the specific curves it currently has? As long as they maintain angle and width in relation to the spiral for the spiral it should be flip-able.

I think that would work, Let me know how you get on, Bob

Do you think this would work at half scale?

80mm and if your printer have 0.3mm nozzel ,yes , would work. But you have to know - as much you are scaling down this item that mich you are loosing its load tech spec.

Also have a look at your g code as the face housing exterior wall is already pretty thin, so scaling it down will make it weaker and you will have to use smaller diameter screws , also you would need to calculate the reduced size of the hex key for the drive gears, other wise you could end up with no way of using the chuck.

Yes, you are absolutely right, I had only say that scale down is possible but did not went into the design details, sorry , my mistake.

Dear Bob, I have question to rear housing element (cap) - why it has so high vertical walls if scroll & gear ring abut to the drive gears? In my version I am going to cut those walls because they are creating additional friction force when I want to open or close chuck's jaws. I will leave only 2,5mm height.

MrArrow1961, The high walls act as a bearing surface against the back of the scroll gear, that is why the gear ring is a smaller diameter than the scroll gear
if you cut the wall off and tighten the chuck, the drive gears will take all load, this could lead to the ends breaking off the drive gears, Your remix using a 3mm screw as a pin may stop this , however the load will still be against the gears
There shouldn't be too much friction, I would suggest removing only a small amount say 0.25mm so that it wont bind, also check that the gear ring outer diameter is less than the inner diameter of the rear housing walls so it can turn freely.

Dear Bob, I had find video on russian which show chuck internal components. Cap has the wall like you had use, but that wall not for supporting the scroll gear. Yes the the drive gears will take all load and my suggested M3 screw will take the load.
See this video, sorry for russian language, language not changing the the mech parts. http://youtu.be/6Smb2Gjfz84

I will test the both versions with and without walls and will leave objective additional info.
Chuck parts load distribution are the following:
Frontal load jaws are taking and passing to the face housing. The scroll gear and drive gears with gear ring just under the load of protract of processing object and finally it is again on face housing part via drive gears.

I see in the video short walls, but that is a metal chuck, much stronger.
Thank you for the analysis of load distribution, it makes sense, I am not an engineer and get lost in some of that technical stuff sometimes.
I look forward to your test info on the different versions, maybe with lots of input from you, I or someone else we can refine the design into a better chuck.
PS sorry i missed your other post a couple of days ago, I printed all in PLA, for no other reason than its my cheapest fillament and I wanted to test it before posting the files, I plan to re print at some stage in Abs for housing and nylon for gears.

Thank you for comment dear Bob. We all here (I hope so) to help each other dear, no problem. I like your intention to print Abs for housing and nylon for gears. It is going to be the best combination, just make it with 100% infill, my suggestion dear!
I am moving a bit slow because the main big work load at Country Telecom DC, but Tests will be presented, promise!
After tests, if they are positive, I will take advantage to make 4 jaw chuck design, i need to dump my load and have some rest of the mind with such nice design :)

No hurry eh,
Ive been thinking a bit about a stronger housing, especially the rear housing, also using a 20mm hollow brass threaded tube for mounting instead of the 10mm hex bolt, but haven't quite figured out mounting options yet, anyone else got any ideas?

Dear Bob, see important recomendadtion in my next remix here

3 Jaw Lathe Chuck drive gear remix - reinforsment

I had thought about doing that originally, but I found my parts to be more than strong enough as they are, and I have really put them under some pressure.
I do find if I print parts faster than around 60mm/s they tend to get weaker, That could just be my printer though.
Also I have found that a good honeycomb infill is far stronger than solid infill.

60 mm/s holy cow... Thats pretty slow? How long did it take to print some of the parts. Post some print times.

Hi Bri113, it depends to your printer specs and slicing mode. It can be determined by you.
I had print out all with 100% infill.

Ok print times etc, using Slic3r 1.1.7- 0.4mm nozzle, home made hotend, home made Mendel90 with extruder mounted on X carriage and 3mm filament, (Lots of things here that limit print speed before even looking at slice settings).
3 top and bottom layers, 3 perimeters, 35% honeycomb fill, 50mm/sec perimeter, with exterior perimeter at 80% of that, 60mm/s infill, 50mm/s top solid infill 180mm/s non print moves, results in;
-Face Housing 8hours 48 min using 16.5m filament
-Gear ring 2 hours 11min using 3.854m filament
-3 Drive Gears 2 hours 20min using 4.258m filament
If I was to slice with Cura with above settings (except honeycomb infil) my print times would be faster still as it seems to slice differently .
I could speed that up even on my printer , however I would end up with less quality and a print result where parts may not fit together as well as they should, or as previously mentioned weaker parts.
Now I could print these parts out on my other printer which uses 1.75mm filament and has better bearings, much faster but my old trusty printer prints fine and Im not really in any huge hurry.
I would be interested in your printer and slicing settings and a photo of your prints to compare?

Dear Bob,
I am using 1,75 filament, my printer has special home made fast hotend which able to produce 1000mm/min https://www.youtube.com/watch?v=VsqaKwQl79o polymer if printer will be able to move at 3000mm/sec:) As far as hotend has no limits to reach low 300mm/sec printing speed it is producing not bad prints. Nozzle can be changed from 0,1 to 0,6mm, mean time I am on 0,35mm to have fast prints and good quality. temperature of printing also influencing to the item quality, As much it high that much printer printing fast, of corse T has max limits for each polymer.
To show my printer quality I prefere to print cube 50x50x50mm. Here is the results: http://s14.postimg.org/mau820ke9/test_cub_50mm.jpg.
Both objects were printout by using 0,2 mm layer and 200 mm/sec speed of printing via Cura. https://www.youtube.com/watch?v=_Mf26l3mp8Y
As I told you before I am producing my own ABS filament with very low self price as 4$ per 1kg, so I am able without any thinking use 100% infill and get almost 100% solid parts as it may come after molding/casting. As for example of my time for Face Housing at 100% infill - 11:30 hours

yea i may have to try and print my face housing at 100% infill because I printed at 35% and it turned out terrible... weak and fell apart. I am using 1.75 mm PLA on a Gen 5 Makerbot

Dear Bob, what polymer did you used for drive gears? PLA more hard but brittle, the ABS more elastic not so hard like PLA and not too much brittle.
Moreover, since drive gear printed in vertical position the polymer fiber structure lies in the horizontal direction and in the same direction it is under load and break the seam. If we will turn drive gear to 90 degrees to print then the force of the pressure will fall against the polymer fiber axis and can not break it.But at this case, we are forced to use the support structure that will decline the quality of printed gear teeth .This is not desirable. Therefore, I recommend using a metal screw in body of axis and print object vertically.
(Sorry for my poor English, hope I had explained all correct.)

Also was an tapping of the holes needed?

Don't tap the holes, run an appropriate drill through to clean the hole,(2.5mm drill for a 3mm bolt) then slowly screw the bolt into the hole which will cut the thread for you, if you wind the screw in to fast it heats up and melts the plastic, effectively striping the hole out. I have found with PLA that if you tap the holes, the tap seems to make the hole to big and you end up with a sloppy fit.

If u Form the thread with a threadformer(Not a threadcutter) or with a screw, you have to make the hole bigger then the regular hole for a M3 thread. 2,7mm will work better.

Whats a thread cutter? You mean a tap?? Like a tap and die set. Google it.

Also for example the picture with the blue jaws.... Is that showing reverse jaws or did you simple just spin the part around and insert it in the opposite direction?? I'm asking this because I see a remix with reverse jaws.

Hi, it is reverse jaws

I printed at .25mm and 35% infill on my Makerbot 5th gen desktop printer and the first part (face housing) did not turn out too good. I didn't print with raft or support. I will be trying some other parts on the parts list to see how they print. Any tips or print settings I could change for better parts? Thanks

Hello Bri113, Thanks for your feed back,
What specifically do you mean by "did not turn out to good"? What fillament are you using?
Have you had success printing other objects of a similar size in the same fillament at the same settings etc?
If you message me via "about bobwomble" and send me a photo that would be even better.

Cheers Bob.

What I mean by not good is it had holes in it, lots of sanding and cutting off material with an exact-o knife. I am going to re print the face housing. I printed the gears at 0.20mm and 35% infill and it turned out better. I think thats what I will use for the face housing. Can you post more pictures of how the chuck connects to the drill? Also what other things do you connect it to?

I was using 1.75mm PLA filament bought on eBay for about $20 for 2.2lbs... It seems to work just as well as the Makerbot filament. They say it voids the warranty on the print head but I've already opened mine many time to remove jams so I had already voided the warranty.

PS: Could you maybe post a video on Youtube of how the chuck works and how to assemble! It would be very helpful and I'm sure you would get many more people to print it!!!

I only have experience with my home built mendel90, I don't see any reason why you would have any problems, but I would stick to settings that you have had success with in the past.
I have never used a raft, and the only support you need is built in to the design (on the face housing it is little hollow cubes at the bottom, should be pretty obvious)
The parts were designed for 0.25mm layer height as that is what I mostly use, different layer heights shouldn't cause too much of a problem, although It will slightly change the location of some parts in the z direction, nothing a file or sand paper wont fix. The problems you are having sound more like mechanical or slicer type settings to me.
Do you check your G code before you print? (I am guessing you can do that on you Makerbot s/w)

I connect at the moment to a battery drill with a 10mm bolt through the rear housing, see the photo above, And that seems to work very well, I have a few ideas for different methods, but am currently working on another project, so will have to come back to that at a later date.
One point to note, be very careful when removing the print supports from the face housing it is tricky.
I thought about posting a video, but haven't done that before, I will see what time allows.

Best of luck,

im printing one out now is ther an issue with the strength of the teeth on the jaw? would it be worth printing them on a 45* angle to increase strength?
kind regards

Hello dxhacksaw, I haven't had any problems with the jaws, but if you print them out at 45angle please let me know your results,
as you can see from the photos, I have filed out an alloy scroll gear and had no problems with the jaws.
I would say the week point of the chuck is the scroll thread, as it could snap off at the base of the thread if the jaws are over tightened.
Thanks for your interest,

This is brilliant. I was looking for a way to make a mini hobby lathe and this should work. If you upload your .scad files I can help clean up the code and possible make a 4-jaw remix. I agree with MrArrow1961, though, that you should finalize this "Thing" as is and then immediately start a remix or a new "Thing" that has some improvements like the jaw redesign and SAE rear housing. Just brilliant, though. Thank you for sharing your work.

Thanks dpye_bc,
I also have been looking at making a mini hobby lathe, and haven't found a suitable chuck, so i decided to make this one, now I am turning my attention to the rest of the lathe. I had a quick look at my scad files (there are many, and already I cannot remember how they go together ) I am the first to admit I am not good at organizing files or writing code (its all long hand) etc, but I am getting better (slowly). I will get on to it when I get a chance as I am keen on your 4 jaw . Bob

Dear Bob, thank you for grate discriptions regarding used materials and mentioning my name dear!
Can not understand why your nice desine not evaluated by site owners after so many likes, views and downloads...
Not fair!!!
I think this notification as "Hey! This thing is still a Work in Progress. Files, instructions, and other stuff might change! " inhibit them?

Hello MrArrow1961, I think its only fair to mention your name, your jaws are the only ones i have used so far and they work very well, both the flexi fillament and the nylon, I will load a photo of your jaws holding a cast aluminum scroll gear that I filled down and fitted to my chuck. (my first attempt at casting not perfect but it works)
you are correct about coefficient of friction although that stuff is way to technical for me to understand, I get the gist of it.
Your comment "Not Fair!!!" I dont mind as life is like that, lesson learned years ago.
Keep up the good work, Bob.

Here I had start some Jaw remix dear Bob. hope you will like it:)

Reverse Jaw (1,2,3) for Lathe Chuck

Dear Bob, very nice item and design !!! Are you printd it by using PLA or ABS?

Hello MrArrow1961,

Thanks for your comment, I printed it in PLA as it is a harder plastic and better for gears, ABS would wear away too fast.

ABS can be coated by super glue and become very hard, I am talking about natural ABS, not recycled one.Moreover ABS can resist more high temp. than PLA. In any way...
Thanks for info and desin again dear Bob. Based on that I will try to make other type of chuck jaw.I hope you understand what I mean as far as you are good mech. enginneer. Here it is http://s17.postimg.org/60az405r3/cats.jpg

Thats a good tip on treating ABS with super glue, I will try that.
Yes you are right about the ABS resisting higher temp, I might print the jaws out of nylon yet.
I had also thought about using the PLA as a mold for casing in aluminum but I am not to sure how that will go.

There are many video at youtube regarding molding via PLA etc. such parts surface need additional mech. processing, and it must be done by other cnc .But I prefer your way to use polymer in chucks to reach light weight and good balance. There is other idea to put in jaw nylon round rods at the point where it touching object. I will see. I will share if I will got positive result.