Shop Made Tools

[rcaffin]

I've always thought we stand on the top of a pyramid of knowledge built by our predecessors, who had a smaller base of knowledge to use.
That may be true, but remember the lesson of the Bent Pyramid in Egypt.They started to build it following the Pharaoh's orders, but they soon found that the rock at the base could not take the load. It was crumbling. So they had to change the slope of the sides and truncate the height.
In the same way, what might have 'seemed like a good idea at the time' can now be seen as a bad idea. We don't use iron pipes any more: we use copper, PEX and nylon. The old idea should not be perpetuated.

To make things worse, the use of BSP has spread from the old iron pipes into many other areas where it now makes zero sense. It is even used in pneumatics, where I have to deal with 1/2" BSP, 3/8" BSP. 1/4" BSP and 5 millimetre fittings. Yeah, mixed units! I understand the 5 mm: it is standard metric.

Cheers
Roger

[mattthegamer463]

Made a solid toolpost mount over the last few days. Weighs about 9 lbs.



Sent from my SM-G960W using Tapatalk

[RichR]

Made a solid toolpost mount over the last few days. Weighs about 9 lbs.

Now that's solid. Nice job.

[quasi]

Now that's solid. Nice job.

yup Robin will be proud!

[bborr01]

Made a solid toolpost mount over the last few days. Weighs about 9 lbs.



Sent from my SM-G960W using Tapatalk

What was your motivation to mount it that way instead of just using it with a compound? Did you buy the lathe without one?

Brian

[The Metal Butcher]

Probably one of the three R's of machining.

Rigidity,

Rigidity,

or

Rigidity.

[Tim Clarke]

Yup. A nice hunk of iron. What kind of lathe is this?

[mattthegamer463]

Yup. A nice hunk of iron. What kind of lathe is this?

A Busy Bee Craftex 10x18. Pretty low horsepower so it doesn't need a solid post but it seemed like something to try.

Sent from my SM-G960W using Tapatalk

[ATW]

Pull down style low(ish) profile clamps

Needing to hold onto a lump of metal larger than the vice capacity got me looking for clamping solutions.

Initially I was drawn to Harold Hall (Model Engineers Workshop Projects) type 4 low profile clamps, but didn't like the idea of fixing into location by grub screw down into the machine table.

Further digging eventually led via eccentric clamps led me to Mitee Bite "Pitbull", the "Heavy Duty T-Slot Clamp" variant looking fit for the job - I'm glad I was sat down when I saw the price!

A bit of bar stock and a couple of hours of generating chips:


In action, with some stop blocks:



I was impressed how much holding power was generated, very little torque was required to get a very good grip on that lump of cast iron.

Whilst functionally ok, I wasn't that happy with pivot radii on the moving jaw:

to the naked eye from the other end of the workshop it looks good, and does provide two points of contact into the fixed block, examination with a radii gauge reveals it wasn't the radii I was aiming for or a very good arc.

I formed it using a corner cutting end mill using two passes to get the full circumference, with hindsight it was less than idea as it involved far too much eyeballing to get the setup.

Any suggestions on better techniques for cutting such a radii (2mm), the edge is 30mm long and the faces are 75deg to each other?

[Baz]

Don't you want just two points of contact along that vertex so filing some relief in the middle and leaving the corner 'as sawn' would do. Nice clamping action though.

[TGTool]

What is it specifically about the radius discrepancy that annoys you? At first glance it seems to me not especially relevant.

Thinking about different cases. If both pieces have sharp corners (inside and outside) I can see a couple liabilities though maybe not serious. The inside corner might crack and the outside corner get rolled over from the force against it. A crack is unlikely since the stress at that point is mostly compression and having the sharp outside corner round off changes nothing.

A radius on the pull down block, while eliminating the previous problems will also raise the contact point and changing the geometry of the factors generating force. Again, I think this is a negligeable problem. Even if it's a full round against a flat wall on the fixed block, so long as there's an angle on the work contact face the clamping action should work.

If you really want to get absolutely correct radii on the outside corner it will probably take a lot more work and analysis. If you have a corner rounding end mill, you'll need to establish whether the 2mm is exact. That is, could there be a tiny flat tangent to the runout of the curve. If you know it's exactly a 90 degree arc, then you can touch off vertically and horizontally and make the required moves with the machine dials, also assuming backlash and tool spring don't change anything.

All of which is a longwinded way of saying I think you're worrying too much over it and you have a very fine looking set of clamps.

[mattthemuppet]

those are very nice clamps ATW, I'll have to keep that in mind. Do the fixed "jaws" on the other side have a face perpendicular to the table surface or do they have a slight angle?

as for me, made a piloted reamer at the weekend to enlarge 3 bolt holes on my bike. Wanted to make sure the new hole was perfectly centered on the bolt axis.




worked out really well and left a good finish with exactly the same ID for all 3 holes.

[Bob La Londe]

Using tools I made in the past to make tools to use the tools to make the part to fix the tools to make your parts. LOL.

Little tail stock die holder used to thread handles on larger die holder. Fitting threaded and test fit.

[BCRider]

ATW, TGT is right. You don't really need any radius at all other than to avoid actual crushing or failure of the edge. Even just a somewhat generous deburring would be fine. There's really no need or gain by having a generously rounded heel. On the other hand it does not hurt the function of the clamp either.

I really like what you did there. Not exactly "low profile" due to what looks to be a 2cm or nearly 2cm height. But for many general items that won't fit in a regular vise easily low enough. Part of the "not exactly low profile" is due to the little shelf you did for the wedge block. But I like that since it saves the wedge block from possibly marking the mill's table. So very worthy of the slight extra height.

I suspect you'll have many opportunities to use those fine mill table clamps.

[Bob La Londe]

For another interesting edge clamp look at the Car Lane Tiny Vise. They make two versions (and multiple sizes). The regular one has a slot milled in the middle of a counter sink on both the top and bottom. There is a machined cone with a screw size hole that goes underneath. Then a countersunk head screw goes in through the top. Tightening the countersunk head machine screw moves the edge clamp towards the stock. The low profile version just has the slot and a single counter sink in the top for the counter sunk head machine screw. They would be very easy to make, but they can be purchased pretty inexpensively. I have used them on a variety of bases including to make an "infinity" vise so that I can mount nearly any size stock on my mill table. I think I have ten of the dual cone and ten of the single cone. I use them for odd applications all the time.