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Author Topic: Bridgeport Knee Mill Conversion?  (Read 269148 times)

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Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #490 on: September 09, 2016, 04:10:33 PM »
PS2 seemed to disappear for a while but it seems to be back, certainly is on every recently bought mobo I have had.

One thing maybe to look at is the power options for your USB in Device manager, make sure windows can not sleep if it thinks it is inactive.

Hodo

Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #491 on: September 09, 2016, 04:15:18 PM »
In fact I just bought that mobo I pointed iout to you a wee while back, nice wee mobo which will be going in the lathe if I swap over to Mach4. Put win7 Pro on it, COA for £8 on eBay :)
Hood

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #492 on: September 10, 2016, 09:56:38 AM »
At last - the adaptor I have mucking about with for the last couple of months is finally done  ::) Admittedly it took so long as i was building the machine to make it and figuring out how to operate it but in the end, after ironing out all (so far) of the bugs in tooling, offsets, post-processing etc it really only took a couple of hours.

Its also the first part designed in Fusion 360, that was a learning curve!

It fits the mill snugly and as long as the high-speed spindle motor fits ok, should work beautifully, still got some jobs to clear before i can strip that down though.

Total cost in Z axis travel is 22mm - not bad i thought - that leaves me about 95mm to play with but on a small spindle with tiny tooling that should be ok i think.

Thanks for all help guys  ;) ;)

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #493 on: September 11, 2016, 08:45:45 AM »
I'm almost ready to move my smaller parts to my Bridgeport conversion from the mini-mill. The spindle mount adaptor is made and the wiring/programming should be good to go. The bed needs to be about 350mm x 450mm

Picture below of my mini-mill with a just-finished part still mounted, I need to make a sub-table to replicate the bed of the mini-mill on the Bridgeport.

So, what would i be looking at here? The existing bed is 15mm ecocast but is sitting on a 15mm slab of cast iron which is bigger than the sub-table. The Bridgeport has a relatively narrow table at 230mm so the sub-table will overhang, max rear overhang is 20mm so more to the front. The lump of MDF in the second picture is about the right size, sitting on the mill.

Now, I have about 5 parts i make occasionally, none in quantities big enough to deserve a custom fixture plate so the universal sub-table seems the best way forwards?

What sort of thickness here?
Would it need support arms underneath for the overhang?
How to mount easily onto the Bridgeport?
Better idea?

Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #494 on: September 11, 2016, 01:46:27 PM »
I originally made a plate to fit to the Chirons table, think it was 40mm thick and I used sections of it to make two full length supports so that it was raised up further as it needed to be 80mm above the surface so small tools would reach.
I now have a very nice Gerrardi vice which opens to 300mm so I rearranged the supports on the bottom of the plate and just clamp the whole thing in the vice when I use it.

Hood

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #495 on: September 11, 2016, 02:20:52 PM »
Nice :)

Tool reach not an issue here, just need to figure how thick to go, maybe 25mm?

Needs to be removed easy so don't want to go massively overboard especially as the biggest tool that will be run on it would probably b 6-7mm :)

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #496 on: September 12, 2016, 10:19:49 AM »
Ooh tapping-head time....

Will have some 6mm holes to tap soon, can play with my tapping head, not quite meant for CNC as its an auto-reverse model meant for pillar drills etc but hey-ho :)

It needs to feed in 5mm less that hole depth, then stop - the device will then feed that last 5mm and disengage the drive, you then feed out and the device reverses the tap out, it works very nicely in a manual BP ;)

On to CNC, the best way, after a lot of pi$$ing about seems to be to use a boring cycle with dwell and feed-out in Fusion360.

For testing purposes I chose an M6 tap with 1mm pitch, 500rpm and 500mm/min feed, 10mm deep blind hole.

I have been doing simulations etc and this is the code i get for two tapped holes...

Code: [Select]
(1)
(T10  D=6.1 CR=0. TAPER=118DEG - ZMIN=-5. - DRILL)
G90 G94 G91.1 G40 G49 G17
G21
G28 G91 Z0.
G90

(DRILL2)
M5
M9
T10 M6
S500 M3
G54
M7
G0 X0. Y0.
G43 Z28. H10
Z8.
G98 G89 X0. Y0. Z-5. R3. P4. F500.
X20.
G80
Z28.

M9
G28 G91 Z0.
G90
M30

I think it reads ok, it has the delay (exaggerated for testing) and will feed in and out.

Am i on the right track here?

I couldn't find any G89.. codes in Aspire, seems too advanced for it and has no boring, threading etc so Fusion360 is the best way i have, apart from hand-coding and i'm not at that stage yet.

Offline dude1

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Re: Bridgeport Knee Mill Conversion?
« Reply #497 on: September 12, 2016, 03:18:17 PM »
Dave post on the fusion forum the EE will say how to do it

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #498 on: September 12, 2016, 03:33:34 PM »
Already on there, amazing - they have since edited the post processor so it can use a tapping cycle but feed out and not rapid out - they are just doing a bit of fine tuning on it now :)

Great forum there.

Offline dude1

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Re: Bridgeport Knee Mill Conversion?
« Reply #499 on: September 12, 2016, 03:35:44 PM »
the keep it very professional