Member postings for old mart

When you find a source of inserts, compare the price against the £15 that a bar and 10 inserts would cost on line.

They will be stronger and not be brittle like the ordinary cast iron., the Bisons are sg iron and I have drilled and machined them without the horrible black dust. You will have to make some dedicated clamps for it.

You need to post the maximum and minimum diameters that would be useful to you.

The SG iron ones are better if you don't mind the extra money, but having no swivel base is a shame. Lots of people seem to discount the value of the swivel base, but they are detachable and can come in handy. I have two, the other one came with the NOS 100mm Bison that matches exactly the one the museum already had. I have used both on occasion. The versatile vise could be clamped down using the flange round the sides if necessary.

Edited By old mart on 23/02/2021 16:31:50

I have looked for Hoybide without much success. The only likely looking candidates for your inserts all have proprietry codes which is no help at all if the original Hoybide information is missing. The shape is a combination of T and W type inserts which means that no common inserts will fit.

Unless somebody on the forum already has that H6 FR boring bar and knows the insert code, I fear you will be unlucky.

I have changed the leadscrew gears on the Smart & Brown model A to metric which were easy to buy and also because I chanced upon a 125/127 mod 1 gear on ebay. The seller told what diameter the gear was, so I was able to check it against the diameter of the 120 idler on the lathe. The teeth pitch and form were similar enough to have mixed and matched because the power through the train was not high,but I chickened out and the 3 original gears are in storage. The S & B gears are 24DP  20PA.

Edited By old mart on 22/02/2021 20:35:13

It's not a backplate that I would like to tackle making. To get the taper right, I would get a dti set exactly on the centre line and run it against the nose taper of the spindle to set the compound. That is the most critical part, the threads are easier. Google for drawings of the L00 size. You will probably have to get a cut length of cast iron of slightly bigger than your chuck diameter and drill and tap it to hold it on a faceplate.

Every source of this size seems to be very expensive wherever they come from. I would check out the backplate listings on ebay every day, you could be lucky.

I bought one of ARC's 125mm versatile vises as the 100mm Bison's did not open enough. It came with a removable rotating base, which can be invaluble on the odd occasions when it is needed. Their SG vises are nicer, but more expensive and do not have the rotating base.

The 125mm is about the limit for a Tom Senior bed, the 100mm would fit better. I can recommend the versatile, it is great value and not badly constructed.

If you can mask off the machined parts and just blast the painted areas, you will not do any damage. No trace of the abrasives must be left afterwards. The rust on machined areas can be removed with oily steel wool, much less likely to alter the dimensions.

The bit of angle is cut from a piece of channel section girder. I didn't bother to mill right across. The thickness tapers from the angle towards the edges. When girder sections are bolted together, special washers with a matching taper are used to level things up.

This picture may show the slight taper.

Edited By old mart on 21/02/2021 18:13:09

To get a reasonable size for the nut threads, measure the width of the slot first. If the slot was 12mm, for instance, 12 mm would be too big, so 10mm would the sweet spot. If you are starting from scratch, then metric is easier, much more freely available and metric lengths of studding are common. Studding is usually 8.8 medium tensile strength, which is ok for most work. Custom nuts can be a bit longer which spreads the loading in the slot better than bought ones.

I would also go for aluminium if I didn't have any steel to hand. It could be made slightly larger diameter without getting in the way. What luck to have the broken part easily removable.

I remember my father helping with a threshing machine being used for threshing wheat. The tractor was a Fordson major and the belt was extremely long. The threshing machine was made of wood and angle iron, and was used back in the fifties because it left the long straw for thatching.

A bit of hopeful news on the vaccine subject. There is a local care home that has 6 residents and 2 staff testing CO19 positive. None of them have so far shown any adverse symptoms. The all had their vaccinations at the beginning of January. The 2 staff have to quarantine. Testing is carried out twice a week.

I had exactly the same problem at the museum. The only way out was to make custom nuts. The advantage of making them is that they can be a much better fit than bought ones. I made them out of key steel. We have two mills, a rotary table, a lathe faceplate and a shaper cube, all different.

With the mounting plate off, the bars may be removable and new ones made. I would be wary of straightening them in situ if the plate is cast iron.

It can be done, but as already advised, the VFD must be isolated from the mains power before switching from one to the other. VFD's do not like switches between the VFD and the motor and if the VFD is off when the switchover is made it will not be adversly affected. The cables between the VFD, the switching and the motors should be screened.

I believe you can get small benchtop machines with MT2, but should you go for R8, an R8 to MT2 adaptor using a smaller diameter drawbar works well. I have R8 to MT2 adaptors for drawbar and for tanged tools such as drill chucks.

ARC Eurotrade have lots of adaptors to look at, as well as milling machines.

Edited By old mart on 19/02/2021 16:04:02

What type of tooling do you have? If it is R8, then be sure to get a machine that has that fitting to share your tools.