Bridgeport Interact 4 Series 2 to Acorn6 build

[richardb15]

I've done the CAD for the motor adaptor. The main reason for doing this is that a longer shaft motor was crazy lead time, and I'd still need to take it from 28mm to 32mm to fit the pulley, so I was going to have to do an adaptor whatever.

Fill CAD in section here:

Closer up of the shaft end, motor shaft is light blue, main spindle pulley is grey, brake sprocket is dark blue, adaptor in an attractive mauve colour:

Here is the adaptor by itself, split 4 ways so the pulley collet locking setup will grab it onto the motor shaft:

I'll stick some barstock in the CNC lathe and get this turned out with some nice tight fits

[richardb15]

Time to gather together the motor pulley and spindle brake gear, they need a good clean for sure!


I raided the wifes 4140 collection and snaffled some to make the spindle adaptor, so into the CNC lathe to make swarf


First job is turn the ODs, a 28mm and 32mm section, I think that is close enough to 32mm, I'll take that


After that turn it round and bore the 28mm ID to go over the 112 frame motor shaft:


With a keyway for the brake sprocket milled in and slots to allow the pulley taperlocks to lock the whole lot together I pressed the gear on:


Now I can mount the motor into the original cast iron carriage:


Then fit the new adaptor and belt pulley, it all went together very nicely. The spindle brake sits on the top of this assembly:


The motor fits nicely in the original position, just a bit more room for airflow which can't be a bad thing:


Finally I can loop the belt over, not tensioned in this pic of course:


After that I tensioned it up and fired up CNC12 and it once again has a spinny spindle! All is not completely happy though, the top spindle bearing sounds rough and the machine has a vibration above 2000rpm. I think the machine sat for a very long time not running and the belt has gone somewhat stiff, causing the vibration. I'll run it a bit and see but I may end up junking the multi-rib belt as even if its available, it will no doubt be crazy expensive. I can just fit taperlock 14M HTD pulleys and a toothed belt if I need to. That job can wait though, it spins so that will do for now.

Just waiting for the spindle locking petal thing to arrive along with a couple of ER40 toolholders then I can cut metal, getting close now.

[cnckeith]

wow, nice work!

[richardb15]

Time to turn the 3D printed stuff into real metal, 24hr turnaround from the local laser shop helps that!



A couple more mount hols drilled and some tacks saw the mock-up fitting nicely. I've probably over engineered the mount and rear brackets, but heyho



Taperlock pulleys make the belt stuff easy and I'd designed it to match centres to a standard belt length, 8M20 560



All welded up and in place I wired the motor into the cabinet. I know the motor mount bolts don't match, I need to buy some when I'm out next



After that time for a test


I'll make a swarf/coolant shield for the belt and motor next time I'm doing some sheetmetal. I also need to sort out a homeswitch for the W axis and calibrate it. Still waiting for the petal clamp to arrive, I'm eager to cut metal now!

[Muzzer]

I needed a bigger diameter shaft on the bigger motor I fitted to my Bridgeport clone. I removed the rotor, built it up with MIG (running beads around the circumference rather than lengthways to avoid distortion) and then turned it down to size with a fixed steady / rest and milled a new keyway. Was pretty quick and easy. In some situations this might be a good solution to consider.

[richardb15]

I needed a bigger diameter shaft on the bigger motor I fitted to my Bridgeport clone. I removed the rotor, built it up with MIG (running beads around the circumference rather than lengthways to avoid distortion) and then turned it down to size with a fixed steady / rest and milled a new keyway. Was pretty quick and easy. In some situations this might be a good solution to consider.

If I get issues that may be one way forward, but I'm not a fan of modifying standard fitment stuff, as if I ever need to change the motor in future I know a 112 frame will drop straight in.

More bits arrived:




I'm away with work now for a couple of weeks but when I get back I'll measure up the petal clamp and make sure it will work, sort the pullstuds then its time to get swarfy

[Coolidge62]

Love it keep the pics coming!

[richardb15]

I got a bit of time today to sort the petal clamp so with the drawbar out we can see the old and new ones



here with the new petal clamp on the old drawbar


and here in the machine looking up into the spindle, showing the petals working


So the good news is the BT40 petal clamp seems to work okay, but I think its about 3mm too far down, it locks off onto the pull stud, but only just. It should be about 3mm up into the 28mm parallel bore when locked to ensure its well in and locked, but its just on the edge. There is a 3mm spacer on the drawbar but when I took that off it went threadbound so thats more work than I had time for today. I think I need to shorten the top thread by 3mm and thread it down another 3mm to allow it all to close up. with the BT40 pull studs in the CAT40 toolholders the 40 taper *just* does not lock in by 0.2mm. The disc springs are supposed to have a few mm load on them when locked to ensure the tool is always pulled tight into the taper. Also the BT40 pull studs are 10mm shaft dia but the petal clamp when locked will take a 12.5mm (12.7?) shaft so I may end up making myself a few CAT40 (ANSI) pull studs as I think from memory they are half inch shaft and 3mm shorter than the BT40. Getting there.....

Me and my wife also spent an enjoyable couple of hours calibrating and dialling out backlash on the 4 working axes, its within a few microns over 10mm in all directions so that is near enough to start chewing metal once I've sorted the pull stud stuff. I think the fact the machine has not been used for years means there is sticktion going on, we'll just check the calibrations after a few hours running and make sure its holding good.

[Snap-On Phil]

Very nice. I have a Bridgeport Series 2 Interact 2. That I just did an Allin1DC on and very happy with it except for the lack of torque in reverse when trying rigid tapping my spindle stalls. Might need to switch out my variable speed pulley for a one speed setup I’m thinking.

[richardb15]

Very nice. I have a Bridgeport Series 2 Interact 2. That I just did an Allin1DC on and very happy with it except for the lack of torque in reverse when trying rigid tapping my spindle stalls. Might need to switch out my variable speed pulley for a one speed setup I’m thinking.

The Interact 4 uses the VSD and motor so no variable drive of course, a bit different to yours. My older mill had the variable drive that was always changing speeds and messing about so I junked it, used taperlock 8M pulleys and an induction motor and VSD, never looked back from doing that conversion.

It's been a while since I updated as I've been away with work, but back in the workshop last weekend. Next job was to sort the drawbar and petal clamp to work. I ended up removing the whole drawbar assembly including the belleville washer stacks. The reason is the petal clamp will insert from the bottom of the spindle but springs out in the tool indent, then won't come back out that way. The only way out is to pull the whole assembly out from the top. Anyway, it turns out there are about 100 belleville washers all stacked in alternating ministacks of 4 washers. Unfortunately the pics I took of this contraption seem to have vanished off my phone

I threaded the drawbar down another 1/4" on the top and shortened it so I can have some adjustment as it was threadbound. To adjust the petal clamp heights there is an adaptor in the top of the drawbar with a 5/8" BSW female thread and a grub screw of the same thread. The drawbar screws in then you tighten down the 5/8" grubscrew onto the top of the drawbar thread to lock it in place. I didn't work that out until I'd taken the whole thing apart.

With the petal clamp height set with the springs relaxed I could fire the air-hydraulic booster to operate the drawbar cylinder, but it was not happy. Instead of moving the cylinder down and compressing the belleville washers it just emptied the contents of the booster onto the workshop floor. Time to take the booster out and see what is going on