rack and pinion design

[eloid]

I almost figured out most of my design however would like to source
a gearhead that can do 7.2:1 or 10:1 reduction, Looking for something which will not break the bank. Do anyone have a good source for
th gear or planetary or harmonic gear boxes? I could probly make one
out aluminum but i dont have a cnc machine to cut out the bearing mounts
any suggestions is helpful.

[Al_The_Man]

I have picked up some deals on ebay such as Bayside item#330215790109.
Other makes are Gam Gear & NemaTrue from Parker.
All offer right angle also.
Al.

[Bobbyr70]

Ebay has quite a few gear heads. Parker bayside type. the bayside reducers are rather spendy but if you want quality you have to pay for it. I have purchased 4 bayside reducers in the 90 size from 100 - 350 dollar range. there are a few smaller ones available right now. Look for alpha reducers too. High quality cast steel housings, very pricey too. good luck. Atlanta sells precision gear reducers. I have a couple of 5:1 alble reducers if backlash is not a problem for you.

[eloid]

Originally Posted by Al_The_Man I have picked up some deals on ebay such as Bayside item#330215790109. Other makes are Gam Gear & NemaTrue from Parker. All offer right angle also. Al.

what a good spec for backlash? typical number that would be good for wood/ aluminum cnc machine

[eloid]

Originally Posted by Al_The_Man I have picked up some deals on ebay such as Bayside item#330215790109. Other makes are Gam Gear & NemaTrue from Parker. All offer right angle also. Al.

looking at bayside there web site is not the best for get part number
for gearhead , im looking for 7.2:1 to 10:1 gear head with good backlash
control in a nema 34 frame? Does any know where to cross ref this?

[eloid]

if you have a 2 stage gear box made from timing belts
both stage same ratio 50 teeth meshing with 20 teeth
this gives the one stage 2.5:1 ratio?
so since the are to stages back to back

You would calculation just stage1 x stage2= ratio
in the above case 2.5 x 2.5=6.25 or 6.25:1

[wcarrothers1]

ebay is the way to go for the planitarys. I got my thompson there from a guy for only like 75.00. Emailed him to see if they had my size and they did. So sorta was an off ebay thing but planitarys are the away to go vs multi belt reduction (if you ask me)

b.

[Al_The_Man]

Originally Posted by eloid looking at bayside there web site is not the best for get part number for gearhead , im looking for 7.2:1 to 10:1 gear head with good backlash control in a nema 34 frame? Does any know where to cross ref this?

It looks like Bayside is another company that Parker has eaten up!
The Bayside site used to be excellent reference and info, including a sizing program.
For a router table, the standard backlash model should be fine, these are between 20 & 30 arc-minutes, the very low BL are 8 to 10 A-m.
I was fortunate to get a catalogue from the original company.
For NEMA 34, they usually have 34 in the part #.
Al.

[eloid]

need advice, is module 2 to large of tooth size for a rack and pinion set up
im looking at a 1:1 printout the teeth. It look to course, I thinking module
1.0 or 1.5 is ok but want to try do a split pinion using http://www.atlantadrives.com/zerobacklash.htm

A split-pinion consists of two pinion halves and an axial spring pack. The pinions halves mesh with opposite tooth flanks on the same rack, eliminating the backlash. The axial spring pack is used to preload the rack & pinions to insure that no backlash develops during the operating cycle.

only problem idealy you got to get both pinions on one rack, no problem for module 2 side but the smaller size is a problem.

Question looking at the above link, what module size do u think that rack is?

a 20 pitch rack , is equivalent to what metic size