Member postings for old mart

Welcome Ross, I'm afraid you will have to explain a bit better, I presume you have a mill. You could try googling milling collet systems, a picture will probably set you on the right track.

By the time you have flattened the stone, the surface contamination should be gone.

I have Kennametal carbide inserts made in the USA, UK, Germany and China.

I have just created two new threads with pictures, and in both, the text has been lost in amongst the pics. I tried to avoid the timeout problem.

I have no idea why the text got into the middle, or why the pictures are in reverse order.

I chose three chucks to use with the collar, a very good Chinese 125mm, a 5" Pratt Burnerd and a 6" four jaw Toolmex lightweight. I had to match up the rear of the backplates for interchangeability. The radial holes in the collar are for preloading it while the 6mm locking screws are tightened. The collar has to be slightly loose before the locking screws are tightened so it does not interfere with normal tightening of the chuck on the spindle.

Edited By old mart on 20/06/2019 21:11:17

The Smart & Brown model A that I use at the museum has a 1 3/4" X 8 threaded spindle. Here are some pictures of the locking collar that I made for it.

Edited By old mart on 20/06/2019 20:58:02

I have some pictures of the X axis nuts. The adjustable one will be fitted when casting has been cleaned, and the fixed one is awaiting the manufacture of a bush.

It turned up its toes as soon as I tried to add the second photo.

I have just wasted 3/4 of an hour creating a new thread and started adding photos when the whole lot disappeared. Any ideas where it went?

Did they have your bank account details for a direct debit?

Does your MT2 arbor have a male 1.5" X 18 thread? That size seems to be a standard for smaller boring heads. Arceurotrade sell replacement arbors with that thread. If so, the MT3 one could be replaced if you have to destroy it.

If there is a flange on the arbor where it screws into the boring head, a couple of flats could be milled in the flange to hold it securely in a vise. Then more torque could be applied to the head.

I like the way the cockpit cutouts have been made into the mudguards.

The 8BA is 0.086" od and the tapping size for 3/32"W is 0.070", it will end in tears. 1/8"W would be ok, as the tapping size is more than the od of 8BA @ 0.0984". 

Is there room to drill and tap to a larger size, and Loctite in a plug to d&t to 3/32W?

Edited By old mart on 19/06/2019 22:09:02

Get the bores hard anodised and ground, probably a costly option but better than chrome which would also have to be ground.

Sometimes just changing the speed a little will improve the cutting, reduce chatter or change the surface finish.

My car has a six speed box, I don't stay in third all the time.

 With carbide inserts, you have to take deep cuts with inserts designed for steel or the surface finish suffers. Using inserts designed for aluminium to finish steel allows very small depth of cut, useful when you are creeping up on the required size. They are sharp like hss.

Edited By old mart on 19/06/2019 21:44:54

I found the site www. inverter drive.com and was amazed at the sheer number of VFDs' they sell.

Picking one in the power range I was interested in I noticed a downloadable pdf with the installation and setting up instructions. It was amazingly comprehensive, even including details of how to wire a complete remote set of standard on off buttons, emergency stop and speed controlling potentiometer. I had been concerned about running a machine with only those rather small controls they have on the VFD box.

The tension type of Abrafile is not the original concept at all, back in 1959, at school we all were given an Abrafile which was about 1/16" diameter by 2" long in a little black wooden handle about 5/16" diameter by 1 1/2" long. Their main advantage over ordinary files was that they were bendy. I still have a few short bits and a 1/4" version with a plastic handle. I also have some of the tension versions.

I am thinking about using one of these VFD inverters to control a 3 phase 6 pole 3/4 hp electric motor. The motor runs at 900rpm and halving that would be useful. I have access to both single and three phase power.

The ebay listing on the UK site is : 223486597368.

Maybe thinking about an adjustable mandrel would be the better option. All of mine are eccentric too, probably not being British made is the reason.

I've made a little progress on the antibacklash for the X axis. I made a sleeve to be loctited into one of the bores in the cross slide with a 3/4" clearance hole for the leadscrew. Drilling 3/4" wasn't enough, I had to bore it out a few thou to give clearance. The end for the nut was turned down to just clear the casting and bored to about 1.2" diameter by 1 3/8" deep. I turned the nut down on a mandrel for concentricity, and ended up sizing the pair for a super fine thread. I chose 40tpi and started the female thread by undercutting the bottom 1/4" of the hole and used a left hand threading tool which I had made out of Densimet, spindle in reverse and cutting away from the chuck. The finest er16 inserts I had were 0.5mm, or 28UNF. I went for the 28, as the thread was a 1 off and cut 0.012" deep in 0.002" steps, then 0.001" steps, with a spring cut at the end.

The male was done using the same insert, and I started trying the fit when I got to 0.011" deep. The fit ended with about 0.001" clearance and a total of 1" length of thread contact. The end of the nut projecting from the sleeve got turned down, leaving a step for a locking collar held by two 4mm screws. I will use Loctite 628 on the sleeve- casting joint.