3D printing knowledge?

[crabber]

Any members on here that have experience or are experts in 3D printing?

I ask as I know absolutely nothing about these printers and have never even seen one. I need to make some gear wheels for an antique lathe, the original metal gears are almost unobtainable, replacement ones can be machined out of Delrin (a type of tough nylon) but this is a time consuming job.

So does anyone know if a gear could be 3D printed, what software would be needed, what material do 3D printers use, and how tough would it be?

[cosworth4x4]

I almost bought one a few month's back but was so confusing on the net with what they can do and what is available i gave it a miss , so hopefully someone comes back with more info.

[whompus]

I have a Creality CR-6 SE printer and no I am not an expert :-)

Yes a gear could be printed, the most common 3D printers can use PLA, TPU and PETG it will not be as strong or durable as Delrin but depending on the load requirements of the antique lathe.

I do my drawings in FreeCAD then use PrusaSlicer to create the 3d printer file, 3D printing is not a fast process.

What type of gears are you after Straight/Helical/Worm? Have you tried _http://lathes.co.uk

[crabber]

I suppose they would be called spur gears. All imperial sizes they are 16DP (diametral pitch, which is the number of teeth per inch of pitch diameter) they run outside of the gearboxes and drive the leadscrew for thread cutting. They are called change gears, presumably because of the need to swap them to cut the correct threads. I have a few that will cut imperial threads but need 8 more to have a full set including metric. the ones I need range from 21 tooth @ just under 2 inches diameter up to 127 tooth with just over 8 inches diameter. I could cut them on a mill but I have a low boredom threshold which would definitely be tested when moving a dividing head 127 times.
I have no idea what the materials are that you use on a 3D printer so I will look up PLA, TPU and PETG, so thanks for the info. Is there software that allows you to feed in the required dimensions, diameter thickness number of teeth etc which can then work out how to print?

[whompus]

Fully understand the dividing head issue, what lathe is it?

Have you tried HPCGears?

_https://www.hpcgears.com

[crabber]

It is a Colchester Bantam which I have recently bought to restore. I have had a much larger DeMoor lathe for many years which will cut all threads both metric and imperial just by selecting levers so change gears for the Colchester are not important I am just looking at options as it would be nice to have it doing all the things it should.
The standard steel gears are noisy and original ones that are available are expensive so I thought I may as well spend some money on a 3D printer if it were possible to make a gear that would work.
Unfortunately as I have no knowledge or experience of what they can do it is a bit daunting choosing something without asking for advice. I thought on here I may get impartial advice rather than from someone who is just looking for a sale!
I had not seen hpc gears website, it looks like they could make more or less anything I needed but if a printer would make them not only would I have the satisfaction of doing it myself but probably the printer would not cost as much as having a set of gears made.

[whompus]

There are some change gears for a Colchester Bantam on that well known auction site. The noise of the steel gears can be reduced by setting the gear backlash.

Apologies beforehand I have no idea if you have CAD skills or not.

There is a video on youtube that gives a rough guide for drawing gears in FreeCAD once your gear is drawn it is very simple to slice it for the 3D printer, I only use FreeCAD but no doubt all the expensive CAD packages have similar tools. _https://www.youtube.com/watch?v=bDLlQiTl5XI

3D printers are quite fun to play around with and make things you did not think you wanted or needed the prices start around £160 and go up into £1000's

Thingiverse and Cult3d is where people put up 3D files for people to download (free and paid) to give you an idea

_https://www.thingiverse.com/thing:204587

_https://cults3d.com/en/search?q=DP+gears

[crabber]

Thanks for the info above, just an update that my head hurts from trying to learn CAD programs having not used one before. I tried FreeCAD and although it has a spur gear template it is only in metric so uses module and not diametral pitch. Fusion 360 does have the English version and I have made a file of a copy of an existing gear minus the splines. I have sent this to the only person I know with a printer who will print it for me as "proof of concept" meanwhile if it works I have to get my head around making internal splines to make any further progress. Obviously I have no clue as to how this can be done.
I read somewhere that a .3mf was a suitable file to send but quite what it involves loading into a printer I have no idea, however the good news is that my friend says it does look like a gear and he is printing it for me.

[whompus]

The .3mf file is opened by something like PrusaSlicer then converted in that program to something the printer can read.

PrusaSlicer is free so download a copy and have a play around with some files from Thingiverse to see how things work.

CAD is a very steep learning curve no matter what version. Tinkercad is more friendly and highly recommended for beginners of 3D drawing and Printing

_https://www.tinkercad.com

[crabber]

Many thanks again for your continuing help. I got the proof of concept gear today made out of whatever the usual plastic is. It looks and fits OK so I thought I have nothing to lose I will try it under light load. Delighted to say it worked, the teeth seem to mesh nicely and it didn't disintegrate in my short test.
Hopefully you can see from the photo that the plastic cog is driven by a larger metal one so I think it did quite well to not break.

IMG_20220321_112635.jpgIMG_20220321_162701.jpg

As soon as I get time I will endeavour to learn how to insert splines and take it another stage further.