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View Full Version : The Boxford 260VMC as you probably never seen it before!



rnr107
21-04-2012, 07:58 PM
Hi All,
I bought a 260VMC a little while ago and converted it to Mach3. The problem was, The door of my workshop is only 65cm wide.
far too narrow to get the 260VMC thru it.... :(

I thought, no problem, I'll just take the mill out of its enclosure.... Nah! Boxford had the brilliant idea to cement the base and the back of the mill to the enclosure! Call Boxford, How do I get the mill out of the cabinet? ==>> Not possible sir!

Well, this was enough for me to give it a go.
1- move the table along the Y axis to both extreme position to expose the 5 M10 cap head screws. Take these off.
2- Place a scissor jack between the base of the mill (with a large piece of wood to protect and distribute the pressure) and the cabinet side.
3- start turning the screw a little bit at the time, slowly but surely! Crack!!! it's off! :-)

5810

Now we have a 260VMC on the bench... :-) run a few test, run nicely!

Time to start the cleanup before doing anything serious with it...
First, full disassemble!

5811

5812

5813

I'll add some pictures of the electronic if any interest... :)

Laurent

Ricardoco
22-04-2012, 12:52 AM
Well i have more than a little interest, so post away i look forward to reading..

i2i
22-04-2012, 01:38 AM
check the feel of the ballscrews, they are the weak link on that machine. Any notching or play they'll need to be replaced, i did one years ago and used ground 14x5mm pitch screws, also you'll need to sort out homing switches/sensors. Is your spindle R8, 30 int or coventry?

i2i
22-04-2012, 01:40 AM
Well i have more than a little interest, so post away i look forward to reading..Nice to see you back again.

rnr107
22-04-2012, 10:28 AM
check the feel of the ballscrews, they are the weak link on that machine. Any notching or play they'll need to be replaced, i did one years ago and used ground 14x5mm pitch screws, also you'll need to sort out homing switches/sensors. Is your spindle R8, 30 int or coventry?

Hi i2i,
The spindle looks very much like the EasyChange itself but without the grove for the balls.
It was a pain to take off! See picture bellow:

58165817


Where did you get your ballscrew from? did the new ballnut attach to the existing holders or did you make some new ones?
My X axis has no play at all, the Z got some play between the nut holder and the nut but not between the nut and the screw... How does the nut hold onto the holder? Is it screw in? I don't seems to be able to tight it...
The Y axis got some play.

Something else, I find the spindle a bit stiff. Is it supose to spin freely? I mean if I take the gear on the top of the spindle in my hand and give it a good twist, is it supose to spin a few turns? Cause right not, I can turn it easly, but it won't spin multiple turns if you see what I mean... The cap head screw on the top is it used to load the bearings?

5818

Laurent

i2i
22-04-2012, 11:00 AM
i used a company called BXR Ballscrews in Bideford, ask for Gerry.

i2i
22-04-2012, 11:12 AM
the ballnuts screw into the holders so they must be tight, and i would expect the cap head screw locates the easychange holder. Preload on the bearings would be from a clamp nut above the bearings, which by the sound if it may be too tight, it's hard to judge without seeing it.

rnr107
22-04-2012, 01:19 PM
Well i have more than a little interest, so post away i look forward to reading..
Hi Ricardoco,
I'll post the electronic for you... :-) I followed your 260 build and I see you like all these electronic gagets! :-)

I2I,
I had a quick look at that ballscrew page, But they seems to have the type of nut I am looking for only in the rolled type of screw...

5819

rnr107
22-04-2012, 02:38 PM
Well i have more than a little interest, so post away i look forward to reading..

Here is the electronic...
Old stuff first:

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Then the new stuff... I wanted to use rack mount 19" enclosure so it can be bolted underneath my bench, but could not find one big enough, so had to split spindle electronic in one box and steppers electronic in an other.

58215822582358245825

Got these nice rack mount enclosures from work. They've got extra holes on the front panel... I guess I will have to patch these at some point.

Laurent

i2i
22-04-2012, 03:32 PM
extra holes = lights.......lol


if you're parting with the original electronics i would be interested.

rnr107
23-04-2012, 08:58 AM
if you're parting with the original electronics i would be interested.

Hi i2i,
Can you collect from Bradford West Yorkshire ?

Ta,
RNR

i2i
08-05-2012, 11:41 AM
i may be going to the harrogate show sunday, could we sort it out then.

rnr107
08-05-2012, 02:21 PM
Could do... :encouragement: Would you come to my place?
Which bit do you want? I have the original stepper drivers, transformer + big caps, various relays , control panel...
I kept the spindle driver as it works fine with Mach3.
What do you think it is worth ?

Laurent

i2i
08-05-2012, 05:36 PM
Hi Laurent, the drives, rack, psu +caps and b/recs are all i need, the rest is boxfords own, so too old to be used. I can come to yours either before or after the show. No idea on value, these are more for for spares for old machines.

rnr107
08-05-2012, 06:49 PM
Hi Laurent, the drives, rack, psu +caps and b/recs are all i need, the rest is boxfords own, so too old to be used. I can come to yours either before or after the show. No idea on value, these are more for for spares for old machines.

OK.... What about 10 quids and a look at my mill ? :congratulatory:

Laurent

i2i
08-05-2012, 07:21 PM
sounds good to me.

rnr107
08-05-2012, 10:24 PM
Cool... Deal!

Ricardoco
15-06-2012, 12:17 AM
Hi Ricardoco,
I'll post the electronic for you... :-) I followed your 260 build and I see you like all these electronic gagets! :-)

I2I,
I had a quick look at that ballscrew page, But they seems to have the type of nut I am looking for only in the rolled type of screw...

5819
Hi there, did you manage to source some new screws for your 260 or did make do with the old, i only ask as my Z spat its balls out and im using a old lead screw as a temporary measure, but will replace all with new machined screws if i can find a reasonable priced source...

Rick

i2i
15-06-2012, 12:29 AM
you could machine out the ballnut mounting plate to take a standard flanged nut, and put up with the slight loss of axis movement.

Ricardoco
15-06-2012, 12:35 AM
you could machine out the ballnut mounting plate to take a standard flanged nut, and put up with the slight loss of axis movement.
Hi i2i, if i cannot get some of those threaded ball nuts thats what i will do its not like you would lose much using a conventional nut ...

i2i
15-06-2012, 12:49 AM
you'd loose the thickness of the flange. The guy i got the set off for my 260 can't get the same nuts anymore, and even those were remachined to fit the threaded mounts.

I've just helped someone put a 14 x 5mm ground screw on a 240 lathe x axis and it worked well.

rnr107
15-06-2012, 08:33 AM
Hi there, did you manage to source some new screws for your 260 or did make do with the old, i only ask as my Z spat its balls out and im using a old lead screw as a temporary measure, but will replace all with new machined screws if i can find a reasonable priced source...

Rick

Hi Ricardoco,
I found a company that makes 14mm ballscrew with a threaded nut but these were only rolled ballscrews not ground. But the original ballscrews on the VMC260 are rolled, so....
http://www.mooreinternational.co.uk/category-6/FGI14X4.html

I keep my existing ballscrew for now, I can not detect much backlash so far, so should be OK untill I get enough money aaside to get some new ones...

An other option I found is a guy specialised in fixing damaged ballscrew. May worth a try?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=180485044327&ssPageName=ADME:X:RTQ:GB:1123


RNR

i2i
15-06-2012, 10:47 AM
wrong thread on the nut

rnr107
15-06-2012, 03:42 PM
wrong thread on the nut

Hummm.... I wonder, It should not be too dificult to make a new nut holder (with the right thread)?
Looks like a fairly simple shape and made of aluminium...


RNR

i2i
15-06-2012, 04:18 PM
is the original steel.??

Jonathan
15-06-2012, 05:15 PM
This is probably a bit far fetched, but I wonder if it would be possible to machine a thread on one of the cheap ballnuts from china? The grade of steel is clearly hard, but it does file so it may be possible to machine.

i2i
15-06-2012, 05:23 PM
that's the way i went for my 260.

rnr107
15-06-2012, 07:06 PM
is the original steel.??

Nope... It is a kind of aluminium alloy...



This is probably a bit far fetched, but I wonder if it would be possible to machine a thread on one of the cheap ballnuts from china? The grade of steel is clearly hard, but it does file so it may be possible to machine.

Hi Jonathan,
You would do that on a Lathe I guess. So would you first remove all the balls ?

RNR

Ricardoco
15-06-2012, 07:27 PM
Nope... It is a kind of aluminium alloy...




Hi Jonathan,
You would do that on a Lathe I guess. So would you first remove all the balls ?

RNR
Thanks for the link RNR, mine are steel and i would have opted for the repair but to be fair it really was fooked, i couldnt understand what was happening untill i had stripped everything down and by that time i had moved the Head up and down at least 20 times just to get it to go to the top so i could get the thing off... it was toast... i will replace all three with the threaded type like for like as i just dont have the time to mess around doing the other type with the machining..... I will let you know how i got on when its done but dont hold your breath as im building a gantry machine at the moment so it could be a while...

Rick

Woodfish
29-11-2017, 01:49 PM
Hi Laurent, I'm rebuilding a 260VMC, the electronics were replaced by Mach 3, but has been as its my first rebuild any other photos you have of it 'naked' would be of great help. Information on these things is as rare as rabbit horns and any that would help keep me from making mistakes would be most welcomed.
PS I have just rebuilt all three ballscrews, Scott Sayers from GMS Ball Ltd (scott1711@hotmail.com, 01903 264601) was really helpfiul and extremely knowledgable.

rnr107
09-12-2017, 12:26 PM
Hi Laurent, I'm rebuilding a 260VMC, the electronics were replaced by Mach 3, but has been as its my first rebuild any other photos you have of it 'naked' would be of great help. Information on these things is as rare as rabbit horns and any that would help keep me from making mistakes would be most welcomed.
PS I have just rebuilt all three ballscrews, Scott Sayers from GMS Ball Ltd (scott1711@hotmail.com, 01903 264601) was really helpfiul and extremely knowledgable.

Hi Scott,
Sorry for the delay... A bit busy these days. :-)
I sold this machine a while ago... But I may have some pictures or maybe I can answer some of your questions ?
What do you need? What's not working ?

RNR