Drill/Mill Spindle brake (RF30)

**BillTodd** · 30-08-2009

In a bored moment (well a bored day) I thought I'd add a spindle brake to my MD500 drill/mill

...bloody marvellous - wished I done it years ago!

**Lee Roberts** · 30-08-2009

Looks like a winner Bill, now for my "still learning" question...

Why do you need a brake ?

**BillTodd** · 30-08-2009

Originally Posted by Lee Roberts

Looks like a winner Bill, now for my "still learning" question...

Why do you need a brake ?

I was born with only two arms ;)

It just means I don't need to use two spanners to tighten/loosen the ER32 chuck (especially useful with a 13-12 collect and a 1/2" drill 'cos the *ing thing keeps dropping down onto the work before I can get the collet closed down onto the bit)

**irving2008** · 30-08-2009

Originally Posted by BillTodd

I was born with only two arms ;)

It just means I don't need to use two spanners to tighten/loosen the ER32 chuck (especially useful with a 13-12 collect and a 1/2" drill 'cos the *ing thing keeps dropping down onto the work before I can get the collet closed down onto the bit)

Excellent idea Bill.. I was struggling today to hold the spindle still, the chuck in the quill and do the drawbar up...

Yours looks suspiciously like my MD30...

**BillTodd** · 30-08-2009

Originally Posted by irving2008

Yours looks suspiciously like my MD30...

It's a NuTool MD500-30, one of a huge number of 'RongFu 30' clones, which usually have '30' in the name somewhere to distinguish them from the much smaller '25' and 'square post 40' models

**BillTodd** · 31-08-2009

Here's the varispeed idea I'm playing with ATM

Basically it's mounting a Piaggio Scooter CVT on top off the existing pulleys (believe it or not they will fit inside the belt cover).

I'm not sure exactly what range the CVT will give (calculating the ratios it's not as simple as measuring the min/max diameters) but it should be at least a 3:1 range.

**BillTodd** · 12-09-2009

Well the CVT sort of works:

the back of fenner final drive belt just catches the post causing a horrible buzzing. I'll need to source a slightly longer CVT belt, so that the intermediate pulley arm can swivel out slightly to allow the belt to clear the post

[ame="http://www.youtube.com/watch?v=s5iAb3IL1Hc"]YouTube - RF30 CVT1[/ame]

**BillTodd** · 14-09-2009

Knocked up a new shaft for the intermediate pulley .

**BillTodd** · 19-09-2009

Finished! New belt arrived today - no more buzzing noise.

Changing the front belt I can get speeds from 175 to 1860 in four over lapping ranges.

Pulley Vmin - Vmax
1 == 548 - 1860
2 === 393 - 1409
3 ==== 290 - 977
4 ===== 175 - 633

**John S** · 19-09-2009

So basically if you only ran 1 and 4 you would have the whole range ?

What about doing just a two speed pulley using a 6 rib Poly vee belt drive and that way you could get the smaller pulley on the intermediate shaft a tad smaller without loosing wrap round as Poly vees' don't suffer from this like V belts and you could probably get to less than 100 rpm.

Mind you if you are on CNC then it's a different ball game to the manual owner who needs low revs for large cutters and boring.