screws couplings motor mounts - questions

[TrickyCNC]

screws 1st

I see the bigger players on here, recommending multi start screw for their machines.

Like a 2 start, or 5 starts etc.

are these still ballscrews and ball nuts ? or trapezoidal, with delrin nuts ? ACME ?

I cant find any suppliers here in the UK for a range/choice of multi start screws.

Next, is machining of the screws...

Are there common sizes for the machined end to fit the coupler and bearing.
Does the bearing need a lock nut behind it ? both sides of it ? How long is the bare coupling part ?

Couplings / motor mounts .... are they all a common size ? I am about to make my own motor mount, and want to make sure there is enough room for a standard coupler to fit. (I'll be making some kind of coupling myself to start with)

Thanks
Rich

[jckstrthmghty]

screws 1st

I see the bigger players on here, recommending multi start screw for their machines.

Like a 2 start, or 5 starts etc.

are these still ballscrews and ball nuts ? or trapezoidal, with delrin nuts ? ACME ?

I cant find any suppliers here in the UK for a range/choice of multi start screws.

Next, is machining of the screws...

Are there common sizes for the machined end to fit the coupler and bearing.
Does the bearing need a lock nut behind it ? both sides of it ? How long is the bare coupling part ?

Couplings / motor mounts .... are they all a common size ? I am about to make my own motor mount, and want to make sure there is enough room for a standard coupler to fit. (I'll be making some kind of coupling myself to start with)

Thanks
Rich

I believe they are refering to ACME leadscrew when talking about multi-start screws. Trapezoidal might mean in metric.

There are a few common sizes for motors couplers but 1/4" shaft for the motor side seems the most popular. On the screw size anything from 1/4" to 1/2" is common.

Motor mounts will vary since many builds are unique in thier own. Probably why standoffs are so popular. Easy to cut to length required.

[louieatienza]

I believe they are refering to ACME leadscrew when talking about multi-start screws. Trapezoidal might mean in metric.

There are a few common sizes for motors couplers but 1/4" shaft for the motor side seems the most popular. On the screw size anything from 1/4" to 1/2" is common.

Motor mounts will vary since many builds are unique in thier own. Probably why standoffs are so popular. Easy to cut to length required.

Check worldofcnc.com I've ordered in the past, good stuff... Also diagrams of bearing block/screw interface...

Now in the DIY community, some here have "machined" the ends for the bearings (check Gerry's build thread, I believe.) Others, like myself, rely on different ways to do it without machining. For example, I got one half of my motor coupler with an ID the same as my leadscrew, then a washer as a spacer, then the bearing. On the other side I have a bearing, shaft collar and threaded collar; I use the threaded collar to tension the screw, then lock both shaft collar and threaded collar in place. dumpstercnc sells threaded motor couplings and threaded rod couplings that make this pretty easy.

[TrickyCNC]

Check worldofcnc.com I've ordered in the past, good stuff... Also diagrams of bearing block/screw interface...

Now in the DIY community, some here have "machined" the ends for the bearings (check Gerry's build thread, I believe.) Others, like myself, rely on different ways to do it without machining. For example, I got one half of my motor coupler with an ID the same as my leadscrew, then a washer as a spacer, then the bearing. On the other side I have a bearing, shaft collar and threaded collar; I use the threaded collar to tension the screw, then lock both shaft collar and threaded collar in place. dumpstercnc sells threaded motor couplings and threaded rod couplings that make this pretty easy.

Thanks both.

Louie, that's the only place in the UK I can find that has multi start listed, but it describes them as Trapezoidal ! ? ... hence this thread

From the start of my time on the Zone, I was under the impression that everyone was using ballnuts/ballscrews. but as far as I can work out, these multi start screws aren't ?

I haven't paid too much attention, as I always intended to make some kind of belt drive (still going to explore this).

As for the coupling, I didn't know of such a variety . I just assumed you had to make your screw ends fit the coupler some how.

Anyway, I bought an antique (like at least 100 yrs old ! ) lathe a while ago, which I have never used (never used any lathe ! ) ... It should be fun figuring out how to use it, and machine my allthread. I only have skate bearings, so need to machine to fit them.

Rich

[HorridHenry]

Aluminium Profile Connection elements for Bosch Rexroth

Multistart screws? I think that might be the US term for self tappers?

[TrickyCNC]

Aluminium Profile Connection elements for Bosch Rexroth

?

Hi Horid

Thanks for the link, but they dont sell CNC stuff ??? and I'm not using ally profile .

Rich

[HorridHenry]

Zapp Automation Ltd - Stepper motors & Stepper Motor Drivers - Servo motors and Servo Motor Drivers - Ballscrews & linear motion products. :

[TrickyCNC]

Zapp Automation Ltd - Stepper motors & Stepper Motor Drivers - Servo motors and Servo Motor Drivers - Ballscrews & linear motion products. :

No Multi start screws there either

I have used Zapp for my electronics though.

[HorridHenry]

Linear Products : ABSSAC Power Transmission

http://www.wmh-trans.co.uk/Products/LEADSCREW_NUTS

[TrickyCNC]

Linear Products : ABSSAC Power Transmission

WMH Transmissions Ltd - Product List - LEADSCREW NUTS

haha ... I can google myself you know ;-)

But you can carry on if you like, I'll just use this thread as a reference later

I am looking for recommended suppliers that will deal direct with PITA newbie questions, and supply things on a one off basis .

The main reason for this thread though, is to get some answers to the questions I posted .

Thanks
Rich

[HorridHenry]

haha ... I can google myself you know ;-)

What have you found out about yourself?

[TrickyCNC]

the tamworth link seems usefull, thanks. not in relation to this thread though LOL, but a usefull link non the less