Member postings for Dave S

Drill 1mm and then make yourself a single flute drill from silver steel, also known as a d-bit.

Or make a 1.48mm spade drill. Watch makers use them, so a bit of Google in that direction will show you how to make them.

Dave

Thinking aloud a hydraulic transmission is a pump supplying pressurised fluid and a turbine turning because of that fluid.
When in a dead engine scenario the turbine ( still coupled to the wheels) becomes a pump and the pump

is a ‘turbine’ - I’m not a hydraulic transmission specialist but I suspect that is the reason for “no tow”.

If so then a couple of 3 way valves and a bypass loop would solve it - loop the input and output of the wheel end hoses together and isolate that loop from the main pump.
Now when the wheels turn they pump fluid around in a loop and the pump and associated bits and bobs are not connected. Should be a fairly straightforward install into the system, and no less reliable than the other hoses.

Not sure that is helpful, but who knows.

Dave

Don from Suburban tools does some good videos on YouTube.

Also check out the Abrasive Machining sub forum on Practical Machinist

Dave

Jim,

IIRC (it’s been a while) the spindle comes to pieces quite easily. I would take the back off and have a look at the index ring. It’s a fairly chunky piece and there is a good chance the dot mark place is on it.
It doesn’t actually matter where your mark is, as long as the index ring is halfway through the travel.
I returned the Chinese one I had as it arrived damaged, then I lucked into an actual S0 with loads of collets for not much more.

The Deckel head is the same, but IIRC there were detail differences.

Dave

the index dot indicates that the indexing ring is 90 degrees into the 180 degree travel.

That gives you the correct position when you line the flat of the d bit up with the pull out blade to rotate the back edge for grinding the relief.

There is probably an index notch that corresponds which you can use to lock it whilst making the marker.

Have you dismantled the spindle? It possible the index ring has a place for the dot on it, but the hole in the housing to view it hasn't been drilled.

Dave

Hobby Slicers are pretty 'general purpose''. The hollow things out because in general a machined design would be solid and that takes ages to print. Often a hollow thing is 'sufficiently not shit' to be useable - especially for the general 'landfill ready' prints a lot of people make.

If you reframe a little: if you were designing this as a set of castings you would model all the cores and wall thicknesses exactly as you want them.

Think of 3D printing as extremely slow casting process with a digital mould and maybe you need to do the design of the parts a little different.

When I did some design for a 3D printed prototype I did all the internal work in the CAD and sent the print out (this was 15 odd years ago) to get made as per design. These were SLS Nylon, but the principle is the same - if it needs to be a specific shape or wall thickness then the generic slicer hollow fill is unlikely to be the best option.

Dave

Might be easier to make new hoops for the horse end.

Dave

A small tube filled with grease over the part works well. Use this trick for watch parts - like balance staffs.

Dave

Yep uni flow is what I meant. Given a 3D printed piston and 3d printed cylinder there is likely to be quite a poor seal, so the compression isn’t likely to be good.
Multiple power cylinders should help with the light flywheel issue

Dave

As your printing it it is no more effort to make a twin or even 3 cylinder engine.

This simplifies the double acting issue by making it a sum of singles.

something like a 3 cylinder radial might work nicely.

Have each cylinder somewhat like a CO2 engine - input valve at the top, exhaust through a slot at the bottom.

vale can be a simple ball and seat or some sort of print in place flap, triggered by a pin extension on the piston.

wouldn't be a 'traditional' engine, but then isntt that the point?

Dave

I use a couple of sets of smaller diamond files from Arc for HSS (and carbide as it happens)

Dave

Yes to photos. I can’t picture what you made. Sounds useful

Dave

Surely the point is to make things?

I don’t think a cylindrical square will work for what I think I’ll need - as with the parallel faces I can square vertically and with another square horizontally at the same time.
Still if it turns out I need one I do know I can turn to under a tenth over 20” or so because not that long ago I had to…

Dave

Im building a CNC mill, and I think Ill need a chunkier square when I eventually get to the aligning stage.

I came across a webpage sometime ago (can't find it now of course) that showed how to make one from a chunk of cast iron. Not having a lump of iron the right sort of shape I poke about and found some thick walled steel box section. Hurrah, that'll do to try the process at least, and might even work for the intended job

To start the long edges are made parallel. Fortunately I have a reasonable surface grinder, so I slapped the box onto the mag chuck and started making sparks:

The weld seam was something like 0,004 lower that the edges. Not too bad.

I planned to rough grind and then finish, so once both sides had cleaned up I checked it on the surface plate.

 Basically zero movement on a 0.0001" DTI.

I was well chuffed

Now the long edges parallel It was time to rough in the ends. I hacksawed them roughly square, whacked it in a known OK grinding vice and made some more sparks:

Then with parallel ends that should be close to square it was back to the surface plate to measure up:

DTI on a surface gage rocked left and right for the high reading. Turned out to be leaning by about 0.007". For the first round of squaring up it was back to the grinder with some feeler gages:

0.003" under one side and clean up one end, then flip and make parallel (without the feelers).

At this point I left it to sit for a couple of days, partially to let it move if it was going to, and partially cos I have other things to do...

It did move, and the long sides were slightly out, something like 4 tenths IIRC. So I did a light set of finish passes on them. This is the start of one ( the beautiful dark corner):

Ended up back to basically as good as I can measure

Then another round of measure the squareness. I couldn't easily get the round part of the surface gage to touch and have the DTI at the height I wanted due to the way the angles worked out. Fortunately the surface gage has a V in the front, so one bearing later I have a round bumper again and I could measure over pretty much the full height.:

This time I needed an offset with precision in the tenths region, so I made a pair of gage block stacks with the required offset ( IIRC it was 0.2 on one side and 0.2014 on the other). The square was supported on these on the grinder, mag'd and clamped so I didn't get any ideas about flying away and then a fresh dress and a light grind and I cleaned up the ends.

The finished square has come out OK:

Its roughly 90 degrees - I calculated it to 89.996 / 90.004 based on the measurements. Ill check it again in a few weeks to see if it moves, but even if it does it'll likely be close enough for what I need.

Dave

Edited By Dave S on 11/05/2022 21:36:28

I would probably TIG or braze up the holes - but I have a TIG set and like to use it
Given it’s an oil tank if you do fibreglass it make sure it’s ok for continuous submerging in hydraulic oil.

JB weld might also be an option

Dave

Yes indeed. I was hoping to get the seals before having to strip the machine.
Currently I’m in the middle of a project where the grinder is the best machine for the job. Id rather not have it out of action for a long time while stripping and then procuring seals.

Still if no one knows then I guess that’s how it’ll go.
Dave

All I have is a photo of the parts manual, which has a very general description:

Of course the part numbers are no use unless you can get them from the apparently defunct J&S.

Given the cost of the wheel head oil Id rather not run a total loss system...

Dave

My elderly 540 has decided to start leaking from its wheel head.

It’s the plain bearing, uses super thin oil model.
Does anyone have the spec of the seals, or a lead on where to buy them?

Andmar suggested a seal place, but the info in the parts manual is apparently not sufficient.

Dave

I would put it in a box with filtered forced air cooling.

doesn’t need to be fancy filters, just something to stop the brass - a panel filter for a car engine might be what I’d use as I have them available. Even a pair of tights from swmbo over a tube would work.

Dave

What are you making a spindle for?
Is it for the Hobbymat lathe or are you using that lathe to make the bearings for something else?

Dave