What did you do today (2015)

[John HinkleyParticipant @johnhinkley26699]

Finished all the machining and bits-gathering for the toolpost spindle (Mk2). Unfortunately I won't be able to get back in the workshop until Tuesday to screw it all together for a trial assembly as we have visitors over from the UK arriving tomorrow 'til then.

I can't decide how to lubricate the innards – probably whack some grease in and hope for the best! It won't be running for extended periods after all.

John

P.S. Already started CAD design of next project – an automatic boring and facing attachment. Such fun!

[Anonymous]

Posted by Muzzer on 11/03/2015 21:50:41:

Now you will have to tell us if they produce nuts that mate with the leadscrew

Oh, yea of little faith!

The answer is a qualified yes. The taps did cut a square thread, but it seems I didn't harden the first tap properly, so it is now a spiral flute tap. Fortunately the second and third taps cut cleanly producing nice short curls of swarf. Driving through 3/4" of bronze was hard work. I alternated between taps, each cutting a turn at a time to relieve the cutting forces. I drilled the central hole slightly larger than theory, but the thread depth is still about 95%. Here are the threads in the embryo nuts:

In order to get the external screws to mate properly I had to put them back in the lathe, reset the screwcutting, and shave a couple of thou off the flanks. Finally the nuts were split and tidied up:

The exercise has been most interesting and has ticked a few more boxes, such as can I cut a square thread and can I make useable taps.

Onwards and upwards now; the task this evening is to get the Britan set up to start churning out the 1/4" and 5/16" BSF studs I need for my traction engines.

Andrew

Edited By Andrew Johnston on 13/03/2015 18:56:35

[John Stevenson 1Participant @johnstevenson1]

Disappeared on a call of nature this afternoon and came back and these were thrown on the floor, always on a Friday 'play day'

Put the cup there for scale but thats a right brute so this is more not a what you did today but will it fit today ?

Gap out, big chuck on mitt greedy jaws fitted.

Close but got it.

I reckon a bit of blue – tak either side of the jaw will help it no end ?

Yup it is close but doable so not bothered as now got to source a bit of thick wall tube to graunch a 150mm bearing rung out of. Whatever it can wait until Monday.

[Ian PParticipant @ianp]

Well it certainly looks interesting John, but it not clear (to me) what needs doing to it as there is nothing obvious in the pictures.How big is the bearing OD?

Out of interest, what type of mount is your lathe chuck, and wouldn't the faceplate been more suitable than the welded on? jaw tips (and you could save on the Blu-Tak expenditure).

Ian P

[RobboParticipant @robbo]

"and you could save on the Blu-Tak expenditure"

 

Surely you would Blu-Tak the thing to the faceplate??

Edited By Robbo on 13/03/2015 19:55:02

[John Stevenson 1Participant @johnstevenson1]

Bearing is 150mm OD and has spun in the housing so if you turn it over with a bearing it it just falls out.

Chuck on this machines is A1-4 fitting, a lot of European machines use this fitting, same taper as a D1-4 but uses 4 thru bolts to clamp. Good design, never comes loose even under interrupted cuts.

Face plate on this machine isn't that big and wouldn't reach the outer holes plus messing about getting it to run true.

Job on Monday is to make the bearing ring first but leave the bore unfinished, bore out to fit the ring, remove and press the new ring in then back in the lathe for final size boring so it has to go in twice.

All those housings in the picture have got bad bores, in fact the mate to this, the squarer one is a ring missing as the bore is 126mm and the bearing is 120mm. This pair is wanted Monday PM, the other one, there is no rush for but seeing as it's also 120mm bore then it pays to do it at the same time.

[Ian PParticipant @ianp]

Re faceplate, this is just a suggestion that works for me. I have never ever used the original catchplate on my lathe so I reduced its thickness slightly to create a spigot and bolted a (maximum diameter) 12mm thick ali disk to it as a sacrificial faceplate.

Its now full of an assortment of tapped holes that I put in to suit the job in hand. I find the slots and holes in lathe faceplates never seem to be in the right position leading to lots dodgy looking setups that look like accidents waiting to happen.

Ian P

[Anonymous]

Here's the prototype 1/4" BSF stud, after grinding tools and setting up the Britan:

Of course I need to thread t'other end, but I'll do that after I've done the 1st op on all the studs I need. For scale this stud is 31/32" long. Note the rounded end to the stud, the radius is all correct and proper at 1.25 times the nominal thread diameter. The stud lengths have been calculated assuming the old standard for thickness of BSW/BSF nuts, 1/4" in this case. However, I am not sticking to the old standard for the AF of the nuts. Instead I am between old and new at 11mm. That's because I happen to have an 11mm hex collet for the Britan. That should cause the rivet counters to choke on their tea and biscuits!

Andrew

[MuzzerParticipant @muzzer]

John H – looks like a fine kit of parts. Your design and what CAD environment did you use? What is the parentage of the various gears – did you make them yourself or modify std parts?

I'd love to see how this goes together so you must post further pictures. Is this going to be fairly noisy – I expect it's a high speed spindle if it's a toolpost attachment?

Murray

PS – I see you have an album showing progress to date. Looking forward to watching progress!

Edited By Muzzer on 14/03/2015 11:56:11

[mechman48Participant @mechman48]

Just a small mod that loads of members have done.. during weekly clean up got round to making locating strip for mill vice that's been on the toduit list for some time, the slot was already in the base so no machining needed but had to machine the bar to fit the slots as the vice slot was 14.2mm (?.. oddball size ) & the table T slots are 12mm, so a slight step needed.. but a snug fit in the end.

George

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, John S greedy jaws remind me of four I fitted to my Boxford faceplate a couple of years ago, to hold a couple of blank backplates for boring and screw cutting. The jaws enable the backplate to be set off the faceplate so not to run into it with the drill and boring bar.

It worked extremely well.

A few more photos can be viewed in this **LINK** for anyone who is interested.

Regards Nick.

[Neil WyattModerator @neilwyatt]

An early MEW featured some natty extension soft jaws, a simple design that could extend you chuck's grasp as much as you like, within the limits of reason and common sense.

Neil

[Involute CurveParticipant @involutecurve]

Started machining a Dry Sump system for a Ralt F3 car, I'm fitting a BMW M3 Engine into this car, the billet sump doubles as part of the chassis, billet size 600 x 485 x 62mm (its like machining a paving slab) this will require a couple of setups to finish and a wheely bin full of swarf…… below the main pockets roughed out.

[Bob Brown 1Participant @bobbrown1]

Looks nothing like any of the dry sumps I have used/seen, BDG and 2ltr red top to name a couple. They have all had a central channel with a windage tray above it, oil drained into the channel to be extracted by the scavenge pump via two outlets.

Nice job all the same.

Bob

[Clive HartlandParticipant @clivehartland94829]

I want to make a silencer for my new PCP air rifle, I am starting to collect the bits and have ordered 12" of 20 mm dia.HE 30 to make the ends and baffles. I have a sketch made out and have the 1/2" taps to cut the holding thread to fit the muzzle. The baffles start off with a 40 mm long chamber then a 26mm and then a 16 mm. I will add 2 x 10 mm baffles to make up the length. I already have 8" of 20 mm alu tube for the body and I will thread both ends internally to fit the attaching end and the front end will be removable. This may be a bit hit and miss (excuse the pun) as the chambers need to be that length to equal out the resonances of the sound made by the air. The pellet is not supersonic. I am making my own as the price of a good one is about £40. and hopefully it will reduce the sound report to zero.

Clive

[martin perman 1Participant @martinperman1]

Clive,

Are you making a tuned pipe similar to a two stroke silencer for your rifle, how will you calculate its length.

Martin P

[John HinkleyParticipant @johnhinkley26699]

Muzzer,

The gears are all homemade. They are my first attempt at gear-cutting using involute cutters from CTC Tools. Incidentally, also the first time I've used a rotary table! The whole lot was designed in QCAD. The first version was also two-speed, but used a toothed belt drive, speed changes acheived by swapping two of the pulleys. It was made on-the-fly, then drawn up in CAD afterwards. Consequently, when used on the lathe, it didn't have the versatility that I'd hoped for but works adequately for my needs (e.g. grinding the collet taper). The more compact version 2, has the spindle coming out the other side. In order to get the spindle direction reversed, I needed to use the gear train. It uses a 90watt sewing machine motor with primitive variable speed control. Max quoted rpm is 10,000, so yes, it will probably be very noisy, if not terminally explosive! More pictures to come as assembly and testing takes place.

John

[Ian PParticipant @ianp]

John, your toolpost spindle parts look really nicely made but did you really use gears just to reverse the rotation. Its a bit sledgehammer to crack a nut compared to fitting a reversing switch.

Ian P

[Involute CurveParticipant @involutecurve]

Bob, as depicted its only 20% done, it will have two scavenge ports and a windage tray, the base of the sump also acts as part of the aero system on this car, as well as tying the tub to the bellhousing / oil tank, I've made similar systems for Mugen powered F3 cars in the past, and also motorcycle engine powered Westfield and other Caterham types, one of the problems with the BMW engine is the exhaust will have to run down the side we need to pick the oil up from with very little room so we are locating the pickups and pump on the far side of the sump, but scavenging the oil from the nearside avoiding a lot of external plumbing, its as much about packaging and making it easy to work on the car as anything else.

[Keith LongParticipant @keithlong89920]

Ian

If the motor that John used came from a supplier in mid Wales then it most probably is like the one I've got – offset brushes so it won't run very well in reverse if at all, and the internal connections can't be got at easily. They are designed and sold as clockwise or anticlockwise rotation, as sewing machines don't really need to reverse electrically, normally done mechanically as it's usually only the material feed that reverses not the needle action.

[John HinkleyParticipant @johnhinkley26699]

Ian/Keith,

The motor was purchased on an internet auction site and came from deepest, darkest China (post free). Following a plea on this forum for a means to reverse the rotation, I tried a tip from Les Jones, but that didn't work – at least I couldn't make it work – so I resolved to do it the mechanical way. It was also an exercise in a different realm of machining for me to try. All grist to the mill (pun intended).

John

[Keith LongParticipant @keithlong89920]

John/ Ian

I suspect mine came from China as well – but stopped off in mid Wales for a holiday!

Mine is branded YDK – that seems to be the most common make of replacement sewing machine motor available, and most of the sewing machine sales and repair places use them. They seem a pretty good product for the price.

I used a standard 70 watt (from memory) motor to drive a cross-slide milling spindle and was quite impressed with what it achieved powering a 12mm diameter cutter through high density polythene quite happily and afterwards showing a great deal of promise when offered a bit of steel to chew at. The motor I've got here is the replacement for that as I fancied a bit more power – this one is rated at 120 watt so I'm expecting about twice the useful power of the previous motor.

They are definitely designed as one way machines though so if your planning a machining set up you need to think about the motor mounting to make sure that you get the rotation correct or use a crossed belt. Fortunately you can easliy get the standard round rubber sewing machine belts and the motor axis can be slightly skewed with respect to the spindle axis to avoid the belt rubbing on itself.

[Martin CottrellParticipant @martincottrell21329]

Took a trip up to the Warco open day today and was amazed at just how busy it was! I was after a new milling machine so took the opportunity to look at a couple of contenders before finally making up my mind. I then had to queue for about 20 minutes to pay for my purchase! I came away with a bootful of small tools and accessories & now I have just a few weeks to get rid of my old mill and make room for the new!

Martin.

[Gray62Participant @gray62]

Went to the Warco open day and unusually for me, came away with very little, although I did pick up a very nice genuine Dickson toolpost and 5 holders for very little beer tokens, needed a damn good cleanup as it was full of brass swarf but other than that is in perfect nick. Should fit nicely on the WM250.

[Clive HartlandParticipant @clivehartland94829]

Hello Martin, yes, the dimensions of the baffles are calculated to soften the sound and to allow dissipation of the air as the pellet passes through the system. The lengths of the baffles which will be like cups and have bleed holes are, 40 mm 26 mm , 16 mm, then I will make a couple spacers to allow it to screw up tight. The larger baffle is nearest the barrel and then descending in length outwards. If it does not reduce the sound print I can vary the lengths easily but the lengths given are about right. I seem to remember that it has to take out 16 barrel volumes to quieten it down. At the moment it makes quite a loud noise.This is a Walther Rotax, RM8 with an 8 pellet rotary mag. The barrel comes already threaded for the silencer. I am very pleased with it and it is nice and easy to shoot. Ive had 2 Squirrels already. The damned things are forever chewing up the bird baskets. Even the wire ones.

Clive

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