Today I collected the tooltips that I had modified, and also fitted the vee belts, that had arrived in the post earlier in the week, to the Whatton Boring Bar. After struggling to get them onto the pulleys, and replacing the top cover, I fitted a new indexable tips to the short tool tip holder.

I centralised the bar over the liner and went to adjust the tip using the micrometer, and discovered the tooltip was not catching the micrometer anvil, because it cuts slightly lower now it misses the anvil tip. I will have to make a larger diameter adaptor to sleeve & cap over the anvil of the micrometer, which might add say 0.1” thick overall externally, to make reading the actual size easier. A bit of machined silvered steel to the rescue, aided by a helpful chap on a tool grinder down the road.



If you look at the picture above you can see the cutting edge is much lower than the centre line of the old carbide tip.



This is the 12mm square shank tool converted in the long holder with a 8mm square shanked version in the background. The original tip is in the foreground.



I started to machine the liner, and the motor never stalled at all, so finally a little success, and the first shallow cut was of a very good surface finish. Next I tried a slower roughing cut, and after about halfway down the liner, some strange swishing/grating noises started to reverberate from the bar. I couldn’t see what was happening, as the heavier cut was creating a fair amount of dust, (note to me, need a vacuum source to remove cutting dust). When I looked at the bore after the cutting process had finished, I had a perfect bore for about half the length of the liner, then a series of ridges or ringed undulations. :eek

I had to leave off at that point and sort out a few other jobs, but it would appear the back edge of the tooltip was catching the bore, which is easily remedied by grinding an increased taper behind the tooltip face, but more importantly & slightly worrying is the only way it could ring the bore was if the tooltip was moving. I am going to try with the longer tooltip holder to see if the short tool holder was rocking slightly, and therefore pushing into the liner. I will also double check the gigs that take up the play on the bar as it travels downwards. The latter wasn’t an issue before, but I have to check.

Anyway I am pleased that the motor/tooltip stall with the original carbide tipped tools isn’t repeating itself, just got to work on this new problem.

I recently bought an upgraded version of the original motor off eBay, a 370W or 1/2 horsepower with the correct baseplate. However when I tried to swap the motor over today, I discovered the increased height or length didn’t allow it to clear the main casting. I had to revert back to the old motor, but I did use the cush drive off the vacuum pump, which was more concentric than the old part, and the boring machine is much quieter, with less vibration.

I have been doing all the attempted cuts so far with a single belt, and really struggled to fit one belt let alone the two that are required. Today I managed to fit the sister belt, a Z16 428 Ld, 410 Li onto the double fee pulley. It was at this point I notice the other belt was slightly stretched and greasy. The frayed edges are a result of a woodruff key being fitted incorrectly by the previous owner, it should never had one, as it had a hardened circular pin, that located in a vertical keyway. The woodruff key grabbed and wore itself out, and caused the belt to run at an angle, so cutting the edges.




I cannot guarantee I will get the same, so I have ordered two new belts to replace the stretched one. I also have a novel way (new to me) of getting the vee belt onto the pulleys, which doesn’t involve taking the pulleys off and sliding them down the shafts, however I cannot tell you how, as it might mean a silly person could lose a finger. Suffice to say, I cannot turn the pulleys by hand to get the belt to fall into its respective groove without it needing some electrical assistance.

The tooltips were scheduled to be done today, but I am pleased they haven’t been done yet as I have bought another LH boring tool to convert, and so I don’t have to pay for another set up charge.



It’s 8mm square shanked, indexable and takes CCMT inserts, but I am having it shortened and made 5/16” round with a flat put on it to lock it off square in the boring head tooltip carrier.



Hopefully, I will be able to use them soon, within the first week of October, in the boring machine, and then get the test liner analysed for surface finish, squareness etc at the local engineering works. If all works out, I will be able to rebore Panhard liners in the future to very precise standards.