Member postings for old mart

Could you see the signs of the slipping? I don't think Loctite would work, it requires enough clearance to glue the joint, and a light push fit would just push the Loctite out of the way. The grubscrew approach may be your only solution. I don't know how thick the wall of the outer sleeve is, or whether the parts would be hardened.

This type of dti can have its lever moved to any point depending how it is set up. Breakages occur when the lever is forced sideways. Some of my Miyutoyo lever types have a groove in the stylus close to the threaded end to ensure it will fracture before the pivot bearings are damaged. So far, I haven't put this feature to the test.

The picture of the Dasqua doesn't seem to show the usual friction pivot, some close up photo's would help.

Edited By old mart on 02/02/2021 15:34:56

I confess to being one of the offenders, and appologise for my actions publically. Oven Man's post may be the reason contributing to my rants, it can be difficult when you cannot even go near the workshop to get on with your projects.

My new years resolution will be to reserve my rants for the Home Shop Machinist forum where they are quite low key.

I also have some made in China, it's not surprising that companies want to be a part of the huge economy there. I have Kennametal carbide inserts made there as well as in the USA, Germany and the UK. Sandvik are manufacturing in India.

5 stations would fit better in a smaller lathe such as a Myford.

When you look at a magnified BA thread, it is rather a strange shape with almost sine wave profile, somewhere in there is the 47.5 degrees.

The angle of Morse tapers is also rather mysterious, every size having a different angle.

Edited By old mart on 01/02/2021 18:36:46

**LINK**

Check whether the instructions for the VFD of your choice are as easy to understand as these.

Edited By old mart on 01/02/2021 18:23:00

The ring pushes off over the printing, back off the jaws underflush before pressing. There are marks on the jaws to help when refitting them in the correct order like the jaws in a scroll chuck.

Edited By old mart on 01/02/2021 18:10:09

I agree, you would need thicker aluminium than cast iron.

When I had a Fiat Panda multijet, I had two sets of wheels, alloys and steel. The alloys were 5J X 14 and the steels were 5 1/2 J X 14 and with the same size tyres on them, the steels were 1 Kg lighter each.

I would also tend to suspect a cracked outer ring, the interferance fit should be enough to prevent the tightening forces causing slippage.

I get my first jab on Wednesday, at a small disused surgery which has been re opened for CO19 innoculating. The car park is only about 12 cars capacity, so I won't know exactly what to expect.

I think that police, firefighters, refuse collectors and all NHS staff should be given priority, now that the over eighties have been vaccinated.

You will have to be careful to get the offset the correct ammount and don't forget to mark the point of maximum deflection to align the carb bodies. If you offset 1mm, then the boring bar will just give you the 2mm increase in diameter without cutting into the sensitive part of the bore. Double check the settings before cutting metal. Keep the depth of cut small, 0.002", 0.050mm and remove the swarf regularly.

 The boring still has to go in line with the original carb bore, but slightly eccentrically, so a four jaw independent chuck will do exactly what you want. When mounting the finished carbs, you will have to hand blend the offset bore to the inlet manifold, best done before final cleaning and assembling of the bodies.

Edited By old mart on 31/01/2021 20:21:40

The fit of the register should be a light push or no more than 0.003" , 0.075mm clearance. 4 jaw independents are often loaded with very offset work, and the speed will have to be reduced as the out of balance forces increase.

The bolts hold the chuck on the spindle and the register makes sure the body of the chuck runs reasonably true.

Edited By old mart on 31/01/2021 20:01:45

Peter, I certainly allowed a generous ammount of clearance for the bolts in the front mount, but probably didn't think at the time of fixed studs being hard to mount. It was probably because I had earlier mounted the new 6" lightweight Toolmex chuck on the backplate that the scrapped off PB had been screwed to using front mounting. That was for the Smart & Brown model A.

If you look closely at the pictures I posted, you will notice the plain ends of the studs which helps get the nuts started. Those nuts with built in washers are 12.9  6mm, as are the SHCS.

Edited By old mart on 31/01/2021 19:51:11

Edited By old mart on 31/01/2021 19:52:03

There are many styles and grades of carbide inserts. The common ones for steel cut best with more agressive use. Then you get close to the size and start to creep up on the size and the finish that was good deteriorates. Inserts for stainless steel can use smaller depths of cut, but the best finishing type are those intended for aluminium, they will cut down to 0.0005", 0.010mm. There are some types of mild steel which rarely seem to machine well, like pure aluminium.

I would keep the backplate material to cast iron rather than aluminium. There is nothing to stop you mounting and removing the chuck in two stages, separating the chuck from the backplate first. Make a wood base to fit under the chuck which sits on the bed with as close a fit as you can get. It will make fitting and removing the chuck easier and safer. Then a tube projecting about 4" either side of the chuck will provide a decent grip when lifting it.

N-D-I-Y, I have never thought of looking for my posting record until you mentioned it.

Clever design, your printer must be pretty large. Sealing the MDF is very important to retain its dimensions. What decides the pivot point, is it the COG of the tube assy?

Edited By old mart on 31/01/2021 17:44:47