Member postings for JasonB

You may see a few new topics and posts under those topics in the next day as a couple of things want setting up before this site is closed. Please just ignor them, most likely to be locked anyway.

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If you ae going to be doing a few then a cheapish broach and home made bush would be the answer I push 1/8" wide through without a press but anything bigger really needs one.

I bought a set of three - 1/16, 3/32 and 1/8 plus some bushes and they have seen a lot of work and been borrowed too.

I hope you think so Howard

We have been using a Mortons URL for testing but I think the existing one is likely to be used as it easy to search but passwords remembered in your device may not carry forward.

One other thought, classifieds will not carry over so if you have typed a long description for an item then copy it so you can past it into a new classified.

Nigel this is the adjustable sort I was talking of where the long cutting tool pivots and can be pushed out by a grub screw.

I just use a smaller dia shank and an HSS bit at right angles

Very similar concept to what a modern CNC machine will use just moving thetool up and down while slowly advancing the work

Or you can just mount a bit of square HSS in the toolpost and use that if metal is softer or length shorter

I always thought of a billet as a slice off a bar say a 1" thick slice from some 6" CI bar.

But it has become the norm of anything machined from the solid as opposed to a rough casting or fabricated. The US users above use it to mean cut from solid, they would not use it for a machined cast aluminium component. So a billet engine block will be from a solid piece not a machined casting or a wheel will be from solid round stock not a casting or forging.

No Chris said "a couple of thou" no full depth.

You can make tools that have a shank that fits the bore and a long tool that is pushed out by a grub screw to advance it but at 3/8" it is getting a bit tight to fit it all in. So by having say an 8mm or 5/16" shank and the tool sticking out almost all the remaining 1/16" you can put on a cut .

1/8" slot in a 3/8" bore is a bit wider than standard which is generally 1/4" the shaft/hole size so 3/32 would be usual for 3/8. Also 1" is getting a bit on the long side, I don't think standard broach bushes are that long but woul dneed to measure mine though I do make my own longer ones.

I have done 1" long is steel @ 3/16" wide but probably used about a 5/8" shank tool into a 3/4" bore but it is a lot of work and needs many passes including regular spring passes, the one on the left.

I've always had good resuls doing it by "hand" using the lathe carriage or mill's quill to feed the tool though now I mostly use cheapish broaches.

Your advance a couple of thou may be the problem I find 1 thou is the most I advance the tool by somethimes less, it's a case of lots of very fine cuts which won't deflect the tool as much as larger ones will

My usual tool is a boring bar type that holds an HSS tool at right angles that is ground like a zero top rake parting tool. Shank has always been smaller than the bore when using this type of tool so the cut can be put on.

J

PS how long is the slot?

Rather then do all the big bits and then be left with the small fiddly ones at the end I decided to do a few of those. First was the slide valve for which a small casting is supplied, this was cleaned up all over and then the slot for the valve nut milled. Unlike a lot of valves which have a second slot for the valve rod this one has a hole which is a bit larger than the rod to allow the valve to lift if needed.



The cast in cavity was tidied up with a 1.5mm milling cutter



The valve rod gland was turned and threaded then the slots for adjustment cut using the 5C indexer to space them out.



There are two fairly similar brackets for the valve linkages so I machined these at the same time so that the vice stop could be used which saves time centering up parts twice, the one with the forked middle fits onto the cylinder cover and the one with the single blade goes ontop of the spacing block under the cylinder.



The vertical valve link was drilled and a slot milled before using the CNC to give it it's final shape which is with full 1/4" dia bosses around the holes/slot and than thining to 3/16" between. A piece of thicker steel as also prepared and shaped on the CNC to give the rounded ends.



A quick test fit of the various parts using cap head screws which will be replaced with fitted bolts once the engine has been test run.



The big end casting was cleaned up, drilled and tapped and then screwed back together for final shaping and reaming of teh big end. I then made use of teh split arbor that I made for the trunion bearings to hold it while each side was turned down to leave a 1mm boss. An insert with a 0.8mm tip radius leaves a nice fillet in the corner.



I did not take a photo of the three glands that compress the packing around the trunions and piston rod as they are little more than top hat bushes with three 2mm holes in their flanges but there were machined at this time too.

There may be those who have been members for many years and signed up with an e-mail that they no longer use or can access. So if you are going to need a new password sending to you it would be best if you can open th ee-mail it is sent to.

If you go to settings and then "My Account" you will be able to see which e-mail the forum is usng for you

You can also set a new password there if you can't remember your current one as password ssaved on your device may no longer work on the new system.

I suggest looking at something around the SX2.7 size machine which will be a worthwhile step up from the SX1L and having the separate head raising screw avoids some of the backlash issues that the X2 siz emachine can have although the latest twin strut one does go some way to reducing that.

I did try the new forums search and it came up with what I wanted part way down the 5th page. Google gave it to me as the first item so not so useless in my book

Some of us are having nightmares testing it