Member postings for CotswoldsPhil

Julian,

Thanks for your photo - very informative. Especially how you use Thermalite blocks. What size of burner would you use for this job when you do light up? I'm looking to have a go at a Minnie TE sized boiler. I suspect that the boiler in your photo is a little larger.

Regards

Phil

Hi Brian,

You are in exactly the same place as I was a good few years ago. I'm now pondering whether I should try and complete the Minnie boiler I started in the 70's.

With this in mind, some good advice has just appeared in another thread on silver soldering which may be of interest:

**LINK**

Regards

Phil

Edited By CotswoldsPhil on 13/01/2016 09:48:03

Thanks John

I'll be doing that tomorrow I've knocked the can over quite a few times when attention has been more on the work.

Phil

Just picked up my order of 5 litres from Machine Mart. Ordered on their Vat free day, so saved quite a bit. Just a brush and an empty soup can (with cutting fluid in it!) for me. It should last me a couple of years.

Phil

Edited By CotswoldsPhil on 07/01/2016 15:41:06

A name change why?

We could look to the Oxford English Dictionary for a reason not to..

Following the usual definitions - model train, computer model etc.

Model - an exemplary person or thing (a model of self discipline), (model student) - model engineer?

Modelling - to fashion from clay, wax etc - metals? says nothing about methods or size.

Apologies if I have missed anything similar in earlier posts, if so, I must have been spending too much time in the workshop!

A change to miniature would also be a poke in the eye to the engineers out there who don't make miniature examples of real things. Even I make full-sized tools for my workshop.

Now then, the debate about CNC - I am perfectly happy with my workshop and machines, no electronics to be seen anywhere, apart from a simple DRO on the cross-slide, a 6 inch digital caliper and a calculator in the toolbox.

I'm also perfectly happy to read (with interest) about the exploits of those who invest in CNC for whatever reason, and the ways-and-means developed by those more interested in manual methods.

My workshop (and time on here) is a pass-time for me, my hobby.

Phil

Hello Brian,

That's quite a flame you will have there, based on what I remember of the Bullfinch torch I used.  It's going to consume about 3.5kg per hour.

Boiler making is I fear, a difficult and costly skill to acquire.

Phil

Edited By CotswoldsPhil on 05/01/2016 11:49:34

Bump: So that Brian's last post is not lost in the festivities. Happy New Year everyone.

Brian,

It looks like you find yourself in the same situation as I was about 40 years ago when I was attempting to make a Minnie boiler. No matter how I tried, I did not seem able to get the work up to temperature before I exhausted the flux, which was the correct high temperature type for C24, as it was then.

I still have the shell - throat-plate, barrel, thickening plates, and pump pad, which I managed to assemble and silver solder OK with some help at night-school using oxy / acetalene - (very scary - for me) - which gas do you turn off first?.

The firebox did not, however, want to be silver soldered by me with my propane set-up which was a Bullfinch 1250 / 38mm dia / 12.6 kw / consuming 907 grams of gas per hour and which also kept blowing out! I had a makeshift hearth with lots of coke (as suggested by Mr Mason in his book) to surround the work and conserve the heat.

I gave in and bought a boiler which may not be an option for you as the prices have increased quite a lot since I paid £25 at Reeves in the early 70's.

I did some research last year (Sievert and Bullfinch websites) into propane torches, hearths and methods in preparation for a second attempt. Apart from a lot of successful small test pieces, some more Sievert burners and remade firebox plates - no further progress.

Your Sievert 2941 / 28mm / 7.7 kw output is quite a bit smaller than I was trying to use. I'm not saying that this is not enough - I just don't know, those more skilled at this may say - why are you wasting so much gas.

Another bit of information to bear in mind is the maximum off-take possible from different sized bottles:
A 3.9kg bottle - 25000 btu or 7.3 kw :: 11kg bottle 50000btu or 14.6 kw. etc.

Silver soldering a boiler, even a small one, is a difficult and potentially costly skill to learn.

I hope someone will be along soon to offer some practical advice, which I will also gladly welcome.

Regards

Phil

Hi Geoff,

Thanks for your interest.

I thought it easier to dismantle and let some pictures do the talking.

This protrusion is in the way to use the boss on the rear of the spindle housing to hang the motor from.

Adding a close fitting, collar secured with a couple of grub screws, solved the problem. I used the original draw-bar collet spindle as a pattern, extending the pulley end and added an ER20 collet chuck at the business end.

The 2 existing end-float adjusting nuts now sit inside the new collar.

A thick washer spaces over the remaining thread and provides clearance for the pulley.

The motor mounting is a length of 4 * 1/2 inch alloy bar with a split clamp at the spindle end and air-fits to pretty it up a bit. This 1/4 hp small frame motor is secured at the business end; others may require a bit more thought. Finally, a couple of 3 step pulleys to suit the belt which is 6mm round-thane? or similar.

The motor can be rotated to a convenient position as required by each set-up.

When I got the Potts attachment it was just a well made ornament with a single 1/4 inch collet; now it has a new life.

Regards

Phil

Hello John.

I clamped the vertical block to the tool-post (as when in use) and scalloped out the seating for the spindle housing with a boring bar. It's all held together with 2 cap-head bolts (loctited) one each side of the tool-post hole. It's been like that for nearly 40 years and never moved.

The Potts is really robust design...

I agree.

I acquired a Potts milling attachment when a Super 7 came into my ownership about a year ago.

I remade the spindle to suit ER20 collets and managed to hang a 1/4hp small frame motor out the back or at the top as required. It has 3 speeds <>700, 1500 and 2840.

Phil

One day I'll get a post done first time!

Edited By CotswoldsPhil on 02/01/2016 15:59:51

Here is my cobbled together version of a tool-post spindle. It was driven for years by a flexible shaft from a remotely fixed 1/4hp motor (now driving my tool-grinding spindle) It can be used either way up and is always at centre height when mounted. It now has a 90 watt sewing machine motor (with basic speed controller) which is fine for drill spotting prior to transfer of the work to the drilling machine or perhaps engraving, but is not enough for milling, aside from the wrong type of taper mount chuck, it struggles with anything over 1/8 inch. Spindle speed is about 2000 rev based on the stated motor speed of 6000 revs.

I think Roderic Jenkin's suggested in another post that a 120 watt motor was the minimum.

It has also been mentioned to watch the direction of rotation. This motor was rotating in the wrong direction for my application, when received. It was a tricky/delicate, but not impossible job, to identify and swap the field coil connections inside the motor.

With regards to the usefulness of ready made ER20 straight shank chucks, I used one (from ARC - no connection) for an indexing head for my home made tool grinder which saved a lot of work. I lapped the shank and bore of the indexing head for a close running fit. Dry lubricated with graphite and it spins very freely without shake.

Phil

Edited By CotswoldsPhil on 02/01/2016 11:10:20

A final bit of information (for those not bored silly) about the dimensions of the Bison QCTP and compatible holders.

I decided (for reasons unknown) to rest an original Bison holder on 6 mm bars (instead of 1/4 inch as previous) to locate the bottom (working-face) of the t-slot relative to the V's. Working in metric, to my surprise, I got exactly 3.00 mm; is this a coincidence or designed?

Phil

My laptop, originally Win 7, is now 4+ years old - I did not like win 7 from the get-go after years of working with XP. I managed to collect all the drivers and install XP onto a replacement HDD in the laptop with some difficulty. I'll get to Win 10 shortly...

Teased by the Win 8 hype I eventually installed a fresh installation of Win 8, now 8.1 (following various updates) onto yet another HDD, I've run Office 2000, and Dreamweaver/Fireworks - (web authoring tools) and DCAD 3000 on win 8.1 with no trouble since then. They just need running in administrator mode. Win 8.1 appears to load very quickly, although a regular reboot via a forced power-down seems to improve things. What I don't like about Win 8/8.1 and most likely Win 10 is the regular heavy use of the CPU, HDD and fan following an update. It seems as though the intention is to shorten the life of the hardware.

I never liked Win 7 - I find it very slooow even compared to XP, so I eventually upgraded the original Win 7 OEM disk to Win 10 - I fell for the hype again! All seemed to work OK after a lengthy install. However, I've yet to try and install all my legacy applications and see how it turns out.

Perhaps I will be a convert, if I can use my legacy applications on win10 (they work on win8.1) I hate the perpetual (costly) upgrade path - if it ain't broke...

Phil

Hi Bazyle,

Well, well...

I was going to order a pack of 5 myself, fully expecting to fettle them as described above, looks like the linisher set-up will get some more use.

The 2 Soba holders I have (from a different source) are very well finished apart from a little edge breaking required on the tool slot.

Let me know how you get on - on my tool-post (Bison T00a) the difference between no clamp/tight as you describe, and nicely clamped is about 0.035 inch difference in the depth of the slot. Someone mentioned that a tolerance of 0.005 inch would be acceptable around a mean value for the tool-post. One holder which differs by 0.007 from the Bison clamps up very well, so I have left that be. Note: all my additional holders, except the one mentioned above, needed metal removed, I found none too loose.

I simply compared a well fitting holder (Bison original) to each clone holder to establish what had to be removed to make it fit.

Regards

Phil

Edited By CotswoldsPhil on 30/12/2015 14:05:50

Hi John,

I have no intention of touching the V's. The are nicely ground and accurate as far as I can measure. All my measurements have been to establish how much to remove from the working face of each clamping-t-slot (all 5 are different and too tight) to allow the clamp to operate in its correct position, which seems to be the opposite of your situation. The original Bison holders are a perfect fit, so redoing the clamp is a non-starter, I would then have 2 Bison holders that are too loose. My aim was to have all my clone holders clamp to the same position as the Bison's.

If you take a look at the linisher set-up (a couple of posts back) you will see the method I have used to relieve the slots. I set the measured discrepancy with a shim, in this case 0.0315 inch (the worst one) and conveniently the thickness of my ruler, between the fence I made and the holder when the working-face of the slot was just touching the belt. Everything was set-up square beforehand - table / platten / fence / belt tracking. I removed the shim and linished away, until it all sparked out, having turned the block over about a couple of times to even out any potential errors.

I've just completed the rest of the holders this afternoon (much less metal to remove) and all is now well in my workshop, having 11 usable holders, instead of a pile of scrap.

Phil

Hi Muzzer,

I'm not intending to make any holders, my aim was to check the dimensions of the 11 commercial holders I have, 5 of which don't fit my tool-post at all because the clamping slot is too shallow. Checking the width of the V's was just a side-show and proved that any poor fit was not due to manufacturing errors in the V's.

The only metal I'm cutting is to increase the depth of the existing slot to make them usable i.e. able to clamp-up positively. With the set-up shown, I've been able to establish how much needs to be removed from each errant holder to get them to fit.

Regards

Phil

Ye gads, I can think of better uses for £254.40 (inc vat) of beer tokens!

I once purchased a piece of electronic test equipment in an earlier life - price £888.88, true as I sit here. I can still remember the smile on the my bosses face when I was trying to justify the purchase.

I've used 21 tooth set up's to make 2 ER collet chucks with great success. The 21 tooth gears came from RDG when they were not £900 and some odd pounds.

Phil

Edited By CotswoldsPhil on 29/12/2015 11:42:08

Morning Clive,

It did not occur to me to check the 48mm at each end of the block / v to check for parallelism. I've still got the set-up so will take a peek. All very interesting this - I'm not a toolmaker, this is just a hobby for me.

Regards

Phil

I'm back with some more information which might be of interest.

Just managed to upload the 3 photos after 3 attempts...so here goes.

Clive Foster suggested that I use round bars to support the holders whilst measuring, I can report that all the measurements made on round bars were within a couple of thou of the first set, where I used ground square bars supported in matched v-blocks. (see earlier in the post)

This alternative set-up did allow me to check the location of the v's by measuring the width across the two bars (short lengths of 1/4 silver steel) and subtracting one diameter, the result (4 different makes of holders) was all within +0.03mm to +0.08mm of the 48.00mm stated specification for the T00 sized block.

I've just bought and modified a 1 inch linisher (from the big red and black tool-shed) to do the work (yes, the slot is 1 inch wide - how lucky is that) and so far have fettled the worst of my errent blocks so they now lock positively at <> 50% on the cam as per the original Bison blocks - result.

The linisher, as bought, needed a thinner belt platten to get the belt into the quite narrow groove, a guide/stop and suitable shims were required to set the cutting depth. A little piece cut-out of the side of the belt was needed to feed the block into position. The resultant simple grinding procedure was done from both sides to reduce any potential error. I know that the slots are not absolutely true, but the blocks were essentially scrap and now they clamp-up very well. Fitting a new abrasive belt, now that I have fixed the worst offender(s), should improve the precision of the slot as lighter cuts will suffice on the remaining holders.

My ruler just happened to be the correct thickness to set the depth of cut for this holder.

Based on potential savings over original Bison blocks, I'm quids in. Although I still wonder how manufacturers produce precision v groves to the tolerances shown above, but are unable to get the clamping slot anything like correct for a T00 QCTP, clone or otherwise. The worst case for me, needed the best part of 1 mm removed - the holder as delivered only just slid onto the block.

This is the holder that would only just slide into place - no locking action at all, now after grinding, a nice positive 50% lock position.

Michael G's remarks on what are acceptable quality levels rings true - here I am, happily sorting out a very obvious manufacturing error, the distributor being unaware unless they follow the forum.

When is a T00 QCTP not a T00 QCTP - when its a clone.

Phil

Edited By CotswoldsPhil on 28/12/2015 19:33:12

It's probably due to the design of the shop software - users will always find tricky ways around features.

Phil

It's been mentioned before - the supplier just inserts a 9 into the price when they are out of stock, and removes it when back in stock.

It saves deleting and re-inserting the item, so £57 becomes £957. I wonder if anyone has actually bought anything at the higher price?

Phil