[RomanLini]

Those motors are only small, size 17 and 4.4kg-cm (61 oz-in).

They MAY do for a 10" by 9" machine (or any small machine) but you would need fine thread rod to get any decent torque, and you won't get a lot of speed.

I think before commtting to those tiny motors it would be worth looking at larger motors (at least size 23) because they won't cost that much more.

[mmcp42]

Roman
thanks for the reply
I was almost hearing you say that as I posted!
will look at the 23s and see what's cooking there

[RomanLini]

I guess that's like the CNC version of the "the force".

"Feel the force"... "Feel that you need bigger motors - empty your mind and see those bigger motors... "

"... then feel that you need more speed and more cutting power... and a vacuum dust extractor"

Well it's something like that.

[mmcp42]

@Roman yes I feel the farce oops force

few steps forwards and a few steps backwards today
started the actual building

Y support rails (Mk I as it turned out)

had to get larger tubing - worked sooo much better
built the Y supports and Y table

then found that the trucks on the Y table were lifting off at one end
had to "adjust the spacing" at one end with a couple of washers

now runs fairly freely in both directions

lots of extra holes in the Y table as, with larger tube, the trucks are closer together, so the holes were all in the wrong place

[RomanLini]

That's looking pretty solid!

I take it that is the base and moving table part? I'm not sure how big the table will be on top of that carriage but you might have a bit too much overhang for good rigidity.

If so, you could space the bearings further apart and reduce the moving table travel. Sometimes it's better to have a bit less travel and a lot more rigidity.

[mmcp42]

yup indeed
exactly as you describe

added the drive rod etc today
had to make more mods to the table due to the increased support rail size
may well go back and redo the table once the dust has settled
(or perhaps add a thin sacrificial MDF layer that I can mill flat)

but for now it does at least move backwards and forwards when you turn the screw

have glued and screwed all the wooden parts
tomorrow, when it's all dry, I'll araldite the drive nut in place
it's actually just a very thick nut - intended to connect two screwed rods together
seems to have almost no backlash

the actual table won't be much wider then what you see, so no worries there

they do say you do learn from your mistakes - I have learnt a helluva lot on this project! :devious:

[mmcp42]

ok, looking at motors again
will need them soon as the build is moving along nicely!

I'm minded to get these NEMA 23 steppers (after feedback from Roman!)
with these couplers

thoughts, opinions, contributions, donations, ...

[RomanLini]

They're nice motors and with double shafts so you can add handles, that's always useful.

With the couplings I'd prefer one piece couplings, the 2 piece ones like those can get slop and backlash especially after some wear.

Re the nut and gluing it in place it's good to have some adjustment. Like glue the nut to a piece of flat stock, then screw the stock onto the table in a way that the holes are a little enlarged so you can loosen the screws and align it and tighten the screws back up. Otherwise if you commit to gluing the nut and you get some binding it's going to be harder to fix.

I like to have alignment clearance on the stepper motor screws, and on the leadnut if possible.

PS. It's a shame you don't have more people commenting on your build. I think (like in my build thread) once you put "small" or "desktop" in the thread title most of the wood guys won't even look at the thread. They all like massive machines they can cut doors and walls on.

[CarveOne]

They're nice motors and with double shafts so you can add handles, that's always useful.

With the couplings I'd prefer one piece couplings, the 2 piece ones like those can get slop and backlash especially after some wear.

Re the nut and gluing it in place it's good to have some adjustment. Like glue the nut to a piece of flat stock, then screw the stock onto the table in a way that the holes are a little enlarged so you can loosen the screws and align it and tighten the screws back up. Otherwise if you commit to gluing the nut and you get some binding it's going to be harder to fix.

I like to have alignment clearance on the stepper motor screws, and on the leadnut if possible.

PS. It's a shame you don't have more people commenting on your build. I think (like in my build thread) once you put "small" or "desktop" in the thread title most of the wood guys won't even look at the thread. They all like massive machines they can cut doors and walls on.

Hey, I look at them all. Anything good can be scaled up.

CarveOne

[mmcp42]

They're nice motors and with double shafts so you can add handles, that's always useful.

With the couplings I'd prefer one piece couplings, the 2 piece ones like those can get slop and backlash especially after some wear.

Re the nut and gluing it in place it's good to have some adjustment. Like glue the nut to a piece of flat stock, then screw the stock onto the table in a way that the holes are a little enlarged so you can loosen the screws and align it and tighten the screws back up. Otherwise if you commit to gluing the nut and you get some binding it's going to be harder to fix.

I like to have alignment clearance on the stepper motor screws, and on the leadnut if possible.

PS. It's a shame you don't have more people commenting on your build. I think (like in my build thread) once you put "small" or "desktop" in the thread title most of the wood guys won't even look at the thread. They all like massive machines they can cut doors and walls on.

thanks for the feedback
I'll look again at couplers

as for the nut - the plan is to glue it to a piece of flat stock that is in turn bolted to the table with adjustments - so I got that bit right!!!

PS
I do appreciate all the feedback you've given - cheers!
Not planning on anything that big, initially PCBs, then possibly 3D printing
but I can already see the second machine and I haven't finished the first yet!

[mmcp42]

Hey, I look at them all. Anything good can be scaled up.

CarveOne

welcome to the party, pull up a chair, grab a beer!

[Bubba]

I'm enjoying your thread and trying to use it to get some ideas for a small router I am building. Every time I think I have the design nailed, changes are made. Hopefully now all is in lockdown if I don't find more mistakes like I have int he past two days. Hope to start cutting parts this week!

[mmcp42]

I'm enjoying your thread and trying to use it to get some ideas for a small router I am building. Every time I think I have the design nailed, changes are made. Hopefully now all is in lockdown if I don't find more mistakes like I have int he past two days. Hope to start cutting parts this week!

cheers!

know how you feel
I decided to go with a tried and tested design
yet I'm still having to make changes to fit what I can get

[mmcp42]

had another good day in the garage
steps[forward] > steps[backwards]

big issue is using US plans with metric materials
I've now taken to offering parts up before cutting/drilling
making some headway

I've ordered 3 off NEMA 23 steppers - should be here any day
that means I can drill the remaining support holes and go for the final (mechanical) push

[RomanLini]

It's finally looking like a machine! Congrats.

It is a good feeling when it starts moving under it's own power. Then comes all that annoying alignment...

[mmcp42]

It's finally looking like a machine! Congrats.

It is a good feeling when it starts moving under it's own power. Then comes all that annoying alignment...

thanks : proud :

I've been trying to keep it square, flat, aligned as I go, but I expect I'll find out just how far out it is once I start aligning it properly!

The black block it's standing on is an old "granite" kitchen work top - so that's been my reference flat surface

sooooo pleased I managed to borrow a mitre saw
made cutting the wood so easy, and far more accurate than I could ever achieve by hand

already I'm seeing limitations in this machine, Mk II is already forming itself in my mind. Mk I could well find its first job is reproduction!!

[mmcp42]

a very nice man with a very nice van just knocked on my door!
now the possessor of 3 NEMA-23 steppers!

just need more than 5 minutes in a row to fit them!

[harryn]

Hi, I like your machine, its progress, and the learning I am doing from it.

That being said, I have a tendency to read the build logs section and forget about the builds that are posted in this section. Maybe someday I will figure out why some are posted here and others in the build section.

[Zygoat]

Because people (like me) screwed up and posted in the wrong place.

[mmcp42]

been working on the electronics recently (easier to fit in the lulls in the day job)

now - a question for you

I have three driver boards each 2" by 4" to be mounted in and old PC case
the power chip on each has a heat sink

new shiny PC power pack will supply the volts and amps

am I better blowing air over the heatsink and letting it find it's own way out of the enclosure?
OR
sucking air past the heatsink directly to the outside world?

(if pushed I could, of course, do both!)

supplementary
the heatsinks are plain finned aluminium
is there any merit in painting them (matt) black to aid heat dispersal?
OR
will the paint make it worse?

answers on a postcard please!