Bridgeport Manual to CNC conversion...

[JAZZCNC]

Drive belts - HTD5mm x 15mm wide big enough?

They'll work ok but i'd be more inclined to go with 25mm for Mill with heavy bed.

[Davek0974]

They'll work ok but i'd be more inclined to go with 25mm for Mill with heavy bed.

Hmm, will have to check pulley dimensions will fit machining on shafts, there is a conversion kit which uses 1/2" belts, I thought that was a little weak so went for the 15mm size as i used before.

Will look into the 25mm size

[Davek0974]

Drive belts, just had a chat with a very knowledgeable guy and it seems HTD is the best option here, GT is better but more expensive all round. The backlash concern is valid but equates to approx 0.25mm linear which if i have my sums right on 5mm pitch screws and a 75mm pulley will give me an error of 0.0053mm - I think thats acceptable on a 30+ year old machine ;)


He did however strongly recommend going for 8mm pitch and 20-30mm wide belts.

Can't use 8mm pitch as you can't get the needed ratio in as the pulleys are so much bigger so will have to be 5mm pitch.

[Davek0974]

CSMIO unit on order, motors on order, ball-screws ordered, wallet crying :(

Panel controls...

With the Bridgeport you have to run in reverse when in low range, is there a way to have this done in Mach3 or will it still be a Hi/Low selector switch on the panel?

The VFD for main spindle, with the vari-speed mechanical system I'm not sure if i should try using the vfd as variable or leave it fixed at 50Hz, the top speed is limited to 3500rpm absolute max as it tends to wreck the spindle bearings above that and low down it probably would not have the torque needed, so stick with mechanical ?

Main spindle on/off manual control - would these buttons control Mach3 or would they control the vfd directly?

Just looking for ideas here.

[Davek0974]

Food for thought...

While waiting for the screws & motors to arrive, should I strip her down to the bones and clean / paint the old girl ;)

Would take a bit of effort as it would need space clearing to get the engine hoist in to lift the head, ram, collar, bed and knee off.

Could be useful as it would allow me to check for worn out bits, split lube pipes etc.. Would also make the build and wiring a cleaner job by getting rid of the grime and muck.

Hmm....

[komatias]

Food for thought...

While waiting for the screws & motors to arrive, should I strip her down to the bones and clean / paint the old girl ;)

Would take a bit of effort as it would need space clearing to get the engine hoist in to lift the head, ram, collar, bed and knee off.

Could be useful as it would allow me to check for worn out bits, split lube pipes etc.. Would also make the build and wiring a cleaner job by getting rid of the grime and muck.

Hmm....

Yes and get the knee saddle and table reground and turcited. Speak to slideway services, they quoted me by far the best price

[Davek0974]

Looking at replacing the mechanical speed control and back-gear with an AC servo motor, something like this...

http://www.aliexpress.com/store/prod...760988112.html

Should give full power across the board I think, also no loss in the drive belt and no changing gear for low speeds.

[Davek0974]

Yes and get the knee saddle and table reground and turcited. Speak to slideway services, they quoted me by far the best price

At £950 + VAT + transport there and back this will have to wait i'm afraid. I have chrome ways so that put the price up as well.