# An Induma (Bridgeport) head tilt disaster and subsequent repair



## Pacer (Oct 16, 2012)

Couple years ago I bought a Induma mill (an Italian copy of the Bridgeport) off Craig list along with a SB 10L lathe and a large shaper - all 3 were in really sad shape...

I had the ability to haul the Induma without tilting the head as is usually done for transport - which in hindsight I should have did, and made the relatively short trip home. On arrival at the shop and getting the machines off loaded, I needed to get them in the shop which meant I had to tilt the head on the mill in order to get it thru/under the shop door -- well, what the?? the mill head wont move?? My buddy and I puzzled on that for a bit and soon decided the head was gonna have to come off! On pulling the head it was quite obvious why the head wouldnt move! some one had cranked down on the four T bolts that allow the head to rotate so hard that 3 of the 4 had pulled the bolts thru the T slots! And to make matters worse, had drilled and tapped the head for studs! and remounted the head! Geez... (would sure make tramming a bit difficult...)

On top of this good news, on further examination of the head, I find the 'pinion' part of the nod had 3-4 of its teeth stripped! These problems and several others throughout the table and knee made me sit the mill over in the corner and seriously consider hauling it to the scrap yard.

I started the rebuild of the SB 10L and left the Indumas problems to be pondered in the back of my mind...

Discussing the T bolt problem with my buddy, he had seen this happen to a couple other BPs and them successfully repaired so we thought we would at least give it a try (nothing to lose!) I needed to find a hunk of round stock about 8" in dia and about 2" thick, so I started to prowl the scrap yard, and on about the 3rd trip I found a piece almost perfect. Thats it on the right of the damaged head tilt/nod casting where you can see the place where the original T bolts pulled thru, and where the studs were tapped in.




My scrapyard find already had a hole in it so I chucked it up in the lathe and faced one side, flipped it and faced the other side and cut the outer dim down to the needed 7 inch diameter (actually some millimeter, I dont remember exactly) then went to the mill and got the hole bored to the necessary size. I then carefully got the 'knuckle' casting trued up in the mill and milled all of the messed up T slot portion off down to a flat surface.

Shown here with the "donut" that will replace it beside the vise...




Then it was time to get the new T slots cut int the new 'donut' 




I ordered up some 3/8" 'low head' socket head cap screws from McMaster to attach the donut to the knuckle casting counterboring 5 places for them to allow the new T bolts to slide over the top of them. The new 1/2-13 T bolts also came from Mcmaster. 

And --- ta-daah -- what seemed ready for the scrap is now a quite nicely repaired and serviceable knuckle (the broken teeth on the knuckle nod part was built up with braze and also came out nicely) And after several other successful repairs on the tables/knee and a new paint job, the mill was actually a pretty nice machine!!


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## pdentrem (Oct 16, 2012)

That is how to turn a pig in a poke into, well I am not sure what to call it now!

Excellent work, and nice clear pics too!

Pierre


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## Hawkeye (Oct 17, 2012)

Maybe it's the silk purse from the sow's ear. Very nice work, Pacer.


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## walterwoj (May 8, 2020)

@Pacer I hate to restart this post but I have just purchased an induma mill like yours that I'm pretty sure has the same issue.  The head won't rotate and 2 of the bolts stick out more than they should.  I had a few questions for you... 

do you have any measurements/plans for the ring you made?

Is there any reason you couldn't make the t-slots on the lathe with the boring bar?

Did you cut teeth in the back of the ring to make the screw work?

If you didn't mill off the old t-slot could you just overlay the new ring over the old (I know this would make the screw non-functional) of would there be other clearance issues?

Does the screw still work on yours, post-repair?


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