my first build

[wires]

i have been trying to think how i could do that myself, that sounds simple enough. i have a bench grinder and vernier calipers.

i do know a friend of a friend who works in a tool making workshop, might see if i can call in a favour when the time comes.

being a noob i am not sure what a pillow block is. do you mean a small square of mdf with a hole for the bearing? you then make a hole larger than needed in the machine chassis so that the pillow block can be moved to line it up perfectly?

also, if i am going to get some thrust bearings i need to understand them a little. my understanding of thrust bearings is that they handle the load laterally along the length of the screw but they have no ability to handle side to side loads. do i need a ball bearing and a thrust bearing in each pillow block or am i missing something?

[irving2008]

...being a noob i am not sure what a pillow block is. do you mean a small square of mdf with a hole for the bearing? you then make a hole larger than needed in the machine chassis so that the pillow block can be moved to line it up perfectly?

A pillow block is just a bearing mounted in a carrier, usuall cast or pressesd steel with ears to bolt down with. you can buy them ready-made or, for this purpose, two 12mm id races mounted at equal height in some blocks of MDF screwed to an MDF base will suffice... its only to provide some support for the leadscrew while its being worked on so moderate accuracy only needed...

also, if i am going to get some thrust bearings i need to understand them a little. my understanding of thrust bearings is that they handle the load laterally along the length of the screw but they have no ability to handle side to side loads. do i need a ball bearing and a thrust bearing in each pillow block or am i missing something?

For the actual machine you need a bearing block which retains the leadscrew radially (ball race) and axially (2 x thrust bearing), alternately you'd use 2 x angular contact bearings but these are hard to find in small sizes. See the pic for a guideline

[wires]

ah i see. so if it is supported by thrust bearings either side of a ball bearing on the drive side of the screw there is no need for a thrust bearing on the other end, just another ball bearing. i think if i am going to go that complex on the machining of the ends of the screw i will just get someone with a lathe to do it right.

thanks for clearing that up for me, i was wondering how exactly i would do that. one more thing decided

[jonm]

hi wires
if you look at my build , i turned down 12x3 trapeziod screw
with a drill , grinder and file it turned out really well

i have the system 3+ board from diync also a power supply
support from roy is first class

i built my router from mdf to start with but i am now in the process of rebuilding in aluminium , should have went the alu route to start with

[Swarfing]

Sorry I totally missed the point of the cash flow issue and i can appreciate your position. I did explore the use of patio door rollers as slides. I buttered up a couple of window fitters to have a butchers at some old patio doors and i was pleasantly surprised at what i still believe to be a viable idea for a low budget machine? just a thought or you could just go for plain old Bronze bushes?

Paul

[wires]

that screw did turn out :heehee: good for you jonm, maybe i will tackle it myself.

as the design progresses i will be trying to source many of my parts localy. in doing that i will be visiting and looking for engineering supply shops. i have a few contacts who can advise me where to go. i think i will be beginning construction around end of january. that gives me plenty of time to go and see whats out there. i think its highly likely that i will find someone selling propper lead screws and some sort of propper linear bearings at a price right for me but at this stage i will not count on it.

i see your the point all of you make about getting the right stuff straight away but there are really two things stopping me from spending that sort of money right now...

*of course as mentioned there is the financial situation which is crap but there is no point crying about it. plenty of people in the same boat. the answer to that one is to just get on with it and dont let it get you down.

*more importantly is the fact that i dont yet fully realise the full potential of having a machine such as this and dont really know all the uses i will have for it and as such i dont want to buy expensive linear bearings only to find that i really need ones 200mm longer in the long run. i would rather build something cheap and then after using it decide if i need it more acurate or smaller or bigger...i do have the garage space to go for an 8' x 4' if i want.

i do have a quiet enough life, no kids yet, house is built and mostly finished so i can afford to spend a lot of time getting this finnished.

i promise there will be no more talk about budget or financial situation from now on. its depressing
you all know the brief at this stage. keep it simple, get it working and then with the experience of doing that decide if the specs are right for a better one.

does anyone have any ideas for coupling the motor to the screw? i see a lot of guys using propper couplers and some guys making their own.
where do you get your couplers?

i have been busy learning solidworks and trying to visualise my ideas, pretty cool bit of software. i will see if i can get the model finnished over next few days and get some pictures up.

cheers for all the help guys, i would be lost in design decisions without this forum.

[jonm]

v groove bearings on ebay 4 for £26