[country kid]

Hey guys.
iv being hanging around and reading and reading and reading. iv come to design my own plasma machine, i live in Australia and of course were not allowed nice things. rack and pinion is incredibly expensive (600+$per meter) which from what i understand is the ultimate for direct drive machines. so my question to the brainy people on hear:
-next best drive system and linear support combo? what have you guys used and what were the pros/cons
-drive system? i was thinking direct drive steppers but whats the best option in terms or a driver system, geko drivers or a all in one board like the TB6560? pros and cons?
not looking to make a huge table 6 foot by 8 foot
cheers.

[4R8]

Not sure where you got the $600 quote from?

I got mine (MOD 1.0) from TEA Transmissions, enough for a dual drive 5x5 table with pinions for much less than that, cut to length and drilled to requirements.
Mod 1.0 rack is plenty big enough.

CNC & Cupcake world (weird combo, must be a husband and wife store) have since started stocking pre drilled rack and pinions.

2 mtrs MOD 1.0 Rack, $89 to your door. ($59 for the rack, 30 for postage)

2m length MOD 1.0 STEEL RACK CNC MACHINE ROUTER MILL PLASMA PINION DIY KIT | eBay

They also have MOD 1.0 pinions starting at $18.50 landed. ($9 for the pinino, 9.50 postage)

Obviously they'll also have a postage discount for multiple purchases too.

[country kid]

Who did you talk to at TEA mate? I spoke to them with me last machine and they quoted me 650$ for one 8" length... Might look into them again. What did uou use for runners/supports

[4R8]

wouldn't have a clue who, mod 3 might be that sort of price?
maybe they're now charging through the nose for drilling?

I'll have a hunt later for the invoice, I've got a few lots from them so sure I'll have one saved somewhere.

I recently purchased a metre from cupcake world which is pre drilled on the backside, quality is as good as the TEA stuff and packaged well.

[country kid]

Possibly because of drilling yer. oh well i will get onto them about it, what rails did you run with the rack drive?

[4R8]

what rails did you run with the rack drive?

oops, forgot to answer that part.

This table is still under construction, table and gantry is done, just building the belt reductions at the moment.
Using V-rails from TEA.

On the Y-axis, I'm using T-3 rails. 1500mm long (1 top, 1 bottom) @ $166.50ea + GST

On the X, I'm using T-2 rails rails. 1500mm long (1 top, 1 bottom, each side of the gantry) @ $95.69ea + GST

I plan on very light routing occasionally so went with the T3 on gantry but T2 would be ample for a dedicated plasma.

I've only got the invoice from this build for the rack and pinions which were undrilled as i'll use 3m tape to mount them this time. price for MOD 1 rack was $55.93/mtr (5 ordered)

as you can see, the rack is only a small const compared to the v-rail. Add the price of v bearings ontop of that and it sure adds up. You could probably float one side of the gantry on cold rolled flat and skate bearings to save cost.

I used VXB for the bearings.
V Groove Bearings:Ceramic,Miniature Ball Bearings.

[country kid]

mk cheers mate, i was looking at using 16mm fully supported rod this time around. i used V-rails on my last "table" more of an experiment... and it didnt work as well as id like.. but i might look into it again.. the rack drive would also act as a guid to some extend. any pictures on the setup?

[4R8]

It's a little further along now. Finalising reduction housings.
X motors mount within the channel so they're not hanging out and the rack is hanging in the same cavity.
Y motor is on top of the carriage vertically with the rack on the back of the gantry.
Get to finish the profile/shape on the gantry's side plates shortly.