I have seen some CNC routers driven by rack and pinion sets.
Just out of curiosity what would your thoughts be on making a rack out of say… oak or some similar dense hard wood.
i ask bc im nearing the completion of my CNC router which has and almost 30" x travel and im beginning to give more than serious thought to the next machine. i bought the rails for said next machine a while ago 5 foot long 5" cross section “V” type rails (TMT Speedy Rails) hard to find much info on them but i got them from an industrial surplus for $15 ea. it was too good to pass up.
back to the rack… ive got some oak hardwood floor boards i could use. im thinkin i could use dowel pins to align everything and mount them directly to the rails…
could be interesting… what are your thoughts?
Wood is unstable; the rack would probably lose its precision over a small amount of time.
I would guess it depends on your projected use, but agree with other posts, would probably wear our pretty quickly.
http://woodgears.ca/index.html
id be curious to see how long his gears tend to last…
if you’ve never seen his work or web site id suggest sending a few minuets looking around.
From what I saw from some previous research, a double helical gear and matching pinion would have the best motion. Else than that, the movement would be jerky and the gears may wear down faster.
You might have to have the pinion and gear be larger to increase the area that has contact and decrease the wear and tear.
I am not an expert. What I posted just seems logical to me.
To get any kind of precision, you are going to have to make your rack teeth 3-5mm in size. At that size, the wear only needs to be small to put your accuracy out.
If you are determined to use wood, make it the base for a rack made from 3GT belt. Glue the belt down and run your pinion on that
interesting thought on gluing the belt down. on second thought i have heard of ppl laying one belt down and feeding a second belt over it so that they engage tooth to tooth. it is then fed in an under over under config through the motors pulley. my main thought was to see about the viability of a wooden gear though. perhaps i could get enough accuracy and longevity out of it that so long as i check its accuracy periodically it may be worth having.
i think we are to often leaning towards what we see or think we understand rather than trying out something that may work just fine.
i have looked into some of the old ways machines used to be built in the 1800’s and earlier and found a lot of wood being used.
perhaps it will simply be a fun experiment.
It will work, but it won’t be accurate.
There’s a good reason they moved to milled metals from carved wood.