Cl300m Bearing and Belt Advice

Evening all, hope we'll and safe,

Excuse my absence (France, without a machine   . and thank you all for the deep hole drilling advice, I have it down to a tee

I'm after a bit of "what would you have done extra/done different" advice whilst replacing the bearings seeming the machine is going to be in bits.

Firstly Should I go angular contact or taper? I pretty happy with the machine, chunks out free machining, 1mm cuts no problem. My aim really is to improve finish (which is not acceptable in my opinion) and hopefully quite it down a bit. When the rpm's are cranked up it doesn't fill me with confidence!

Also in relation to finish and generally making the machine more smooth would I benefit from changing the running gear from toothed drive (which I'm not a fan of) to a v belt system? I'm not talking an external stepper arrangement just replacing the motor and spindle pullies. I have no idea if this even possible I haven't had the machine apart yet.

On a side note I fabbed up a 12v tool post drill today thank you member Neil Wyatt for the idea.

Regards,

Woody.

On a side note

Edited By woody1 on 29/09/2020 20:14:03

Hi Woody

General opinion for bearing is to replace with angular contact ball bearings. These are the same dimensions as the original bearings.

The toothed belt on low speed will give positive drive. Vee Belts do not perform well at low speeds and high loads and tend to slip.

An option is to use poly vee belts "J" section 4 ribs or overkill with 6 ribs is adequate for 300 watt motor.

Simple enough to fabricate pulleys from Aluminium or Cast Iron Keep the diameters the same as the original or propotionally bigger that will still fit under the guards.

Poly Vee belts perform quite well at low speed compared to vee belts.

Eric

Thanks for that I will look in to it. Do you think the poly belt conversion would be a worthwhile project or should I just stick with the toothed.

Thanks.

Hi Woody

The toothed belt runs smoothly when tensioned correctly and should cause no problems.

The gibs on the top slide and crossslide may require some attention to get better performance to the finish.

One mod I have done is to replace the adjuster screws with cup point socket head grub screws and a 4mm ball bearing to look like this " <o> " Lock up the gibs tight then remove one and with a 4mm drill in an eggbeater hand drill tidy up the dimple in the gib strip. Put ball in and tighten up the grub screw then repeat with the next adjuster screw.

Eric

Ordered, I have polished the gibs. Iv also ordered some nuts to make an anti backlash arrangement. As I said the machine chunks out material. It's just surface finish. I find myself juggling dimensions, i.e if I want 10mm I turn to 10.3 then get the Emery cloth out. Not ideal I know.