Member postings for CotswoldsPhil

Hi Chris,

Yes, a real can of worms.

Merry Christmas everyone

CP

As I have no intention of manufacturing QCTH's from scratch, I need to develop a test and modification method to satisfy my QCTH needs as it looks unlikely that I will be able to purchase pattern/clone holders from any source that have any chance of fitting correctly.

I wonder if the Bison originals would be loose on either a HBM or SOBA tool-post based on my findings?

CP

Edited By CotswoldsPhil on 24/12/2015 22:12:09

Hi Clive,

I'll try the round support method and see if I get any variation - thanks for the tip.

What I find difficult to understand is how any manufacturer can continue to put out such a wide variation in what is a standard product and that it appears to be acceptable to the distributors. Surely distributors have some say in the quality / conformance to specification of the product they sell.

CP

Edited By CotswoldsPhil on 24/12/2015 21:28:58

Hi All,

Prompted by this latest thread on QCTP compatibility issues, here is my experience of trying to find compatible holders to extend my usage of QCTH's at reasonable cost.

I have measured the relative position of the V seating to the working face of the locking t-slot of 11 Myford (T00) sized holders of different brands which I have purchased over the last year. My aim was to try and establish the most compatible pattern holder for my set-up at the least cost.

I appreciate that my measurement set-up (see photo below) is not to national standards, but it was repeatable.

The 2 holders which came with the Bison/Toolmex tool-post (and started this whole saga) were used as the reference point i.e. zero. These holders positively locked at approximately 50% on the clam-shell height adjuster. (all measurements shown below are + values in imperial units)

I have 3 holders sourced from the Midlands Exhibition last year; stamped "M" or "W" these gave relative measurements of 0.013, 0.008 and 0.012 providing reduced locking positions of 25,30 and 25% and just about OK, i.e. reasonably positive.

I took a punt on a 26mm / 2mm Carbide Parting Blade holder (HBM brand) from RDG and this measures 0.007 with a very positive 40% lock position. This holder has sorted all my parting-off woes - very pleased.

Based on this positive experience, I purchased a HBM HSS parting tool holder (for use as a screw-cutting tool with minimum grinding) This measured 0.020 with a not very positive 10% lock position.

Another HBM standard holder measured 0.023 with a not very positive 10% lock position.

Another HBM 1/2 inch tool holder, measured 0.015 with a not very positive 15% lock position, especially important as it is designed to hold a larger tool at centre height on the Myford.

These 3 holders are obviously made for the HBM tool-post but there is still a wide variation in my sample.

Foxed again; I took a punt on 2 holders from Axminster Tools (turned out to be SOBA brand when received), these proved to be even less compatible measuring 0.024 with hardly any locking action, and a whopping 0.038 with no locking action at all. Again these are designed to go with the SOBA tool-post but my very small sample, showed quite a large variation for a precision product.

All these additional holders are nicely hardened and ground but the variation is very wide, even within the same brand.

So, I have now collected 11 holders, of which, 6 are usable in my workshop, I'm really thinking I should go back to the 4 way tool-post and be done with it!

I seem to remember Jason mentioning a lick on a linisher to correct this incompatibility. My next step is to purchase a 1 inch wide linisher (I could do with one anyway) to hopefully fettle the working face of the t-slots in the non-compatible holders. Fortunately, every holder needs metal removed! I think I've worked out a method, but I'll report back later.

I hope this information may be of use to members. I have no connection with any of the companies/products mentioned and my purchase decisions were aimed purely at trying to find a source of holders compatible with my set-up at a reasonable price. In no way do I question the quality or suitability of the mentioned items in their designed configuration.

CP

Hi Paul,

If as John suggests a 10mm bolt or studding is sloppy in the chuck  then your option is to screw-cut the external 10mm thread to achieve a close fit.

CP

Edited By CotswoldsPhil on 18/12/2015 13:16:54

Hi Clive,

I don't do that much parting; perhaps because of past experience! and it has always been from the rear tool-post. It's only recently that I've started to extend the use of a QCTH instead of a 4 way tool-post; so I thought I would try the Insert Parting Holder version described above.

Based on the content of a long and detailed previous Thread about parting, I was very pleased how parting with the top-slide QCTH insert set-up behaved on my Super 7.

My rear tool-post is fitted with an Eclipse 5/16 inch parting blade; but the tool-post has a "boat" for height setting which means that if I extend/retract the (rather flimsy) blade to suit a particular job, I loose the height setting. A better way, perhaps, is to set the "boat" in its neutral position and install a correctly sized shim/packer to set the blade horizontal when on centre height.

My decision to purchase the QCTH version, as opposed to a block for the rear tool-post, was based on the height setting issues the rear tool-post "boat" presents unless I shim/pack as just described.

As a final note - if I was making a number of bolts or nuts I would use a freshly honed and height-set rear setup to save swapping tools. The parting tool would be ground to leave the pip on the waste.

When funds permit, I may purchase a block to install the 2mm / 26mm blade in the rear-tool-post now I know how well it performs.

Phil

I've just bought one of these tipped parting blade QCTH from RDG for my T00 sized Bison Toolholder - it fits my tool-post very well. It also reduces the overhang to a minimum compared to that described above when using a separate block installed in a standard holder. The tip is 2mm wide so has minimum waste.

**LINK**

Usual disclaimer - just a satisfied customer.

For the first time parting-off on my Super 7 did not involve rubber pants. I have previously only attempted parting-off within the capacity of an Eclipse 5/16 Tool-holder in a rear tool-post. But now, I can attempt, from the QCTH mounted on the top-slide, 60mm 2200 alloy which came away cleanly in small tight curls with a nice fizz.

CP

Don't think I have seen one of these mentioned yet. I bought this cir-clip tool to remove the cir-clip from the counter-shaft of a Super 7 - very positive screw action.

**LINK**

Or this which covers 40-100mm

https://www.machinemart.co.uk/shop/product/details/040217923

Phil

Edited By CotswoldsPhil on 16/10/2015 15:39:42

Neil, Ketan

The power meter you link to is very similar to the one I use on the lathe to watch the power consumption. Works very well - I generally keep it set to amps to see the current reading. But set it to kwh when I have the heating on overnight.

Phil

Either the spindle is running in reverse or the photo has been flipped horizontally. You can best see the orientation of the teeth at top left.

Phil

Yesterday I bored a 1/2 inch hole (biggest drill I had under 20mm) out to 20mm over 60mm with a 10mm Glandz boring bar fitted with a ground tip. The material was a block of 35mm EN3. It took a bit of time, small cuts and clearing a lot at the beginning - but it's done. The hole has now been lapped to fit a straight shank ER20 chuck for my tool grinder.

Setting the boring bar was a bit of a challenge at first as it is angled down to create clearance.

Regards

Phil

Is this why the Myford Super 7 has a bronze cone front bearing?

Phil

Clicked in wrong place

Edited By CotswoldsPhil on 22/09/2015 09:20:42

Hi Brian,

The longer gib must provide some support, Myford designed it that way - it just needs careful set up so that it does not skew the saddle. A facing test will confirm the correct setting - and or checking for equal gaps either side of the saddle at the rear.

Good luck with getting you machine back together again.

Phil

ega - Thanks for that. My machine's serial number is just before the change to wide-guide so that may explain the difference in dimensions.

Neil - Thanks for the article - which seems to advocate both narrow and wide guides being brought into use at the same time? unless I have interpreted it incorrectly.

John - Thanks for your observations on the logic behind narrow-guide.

Perhaps when I rework the spare saddle, I should insert a wear-strip of Turcite to the face of the narrow-guide and return the machine back to its original narrow-guide design. I always keep plenty of ISO68 on the bed, so lubrication is unlikely to be a problem. Any thoughts as to how a Turcite wear-strip might last in this configuration? Replacing the wear-strip would be reasonably simple once the narrow-guide face has been machined.

Phil

ega... Can you remember what thickness of shim was required on your machine? On mine it was 20 thou to create a small working clearance on the narrow-guide. There is a significant difference between Brian's saddle and the one on my machine; the spare saddle I have is <>30 thou similar to Brian's. However, the front space for the gib is <> 0.225 in both cases when adjusted correctly. I'm trying to establish what the manufacturing dimensions might have been.

I've added inserting a dowel to the gib on the todo list, sounds like a good idea.

Neil, My modified wide-guide saddle (with shim) moves sweetly along the bed, either pushed by hand or driven with the hand-wheel and I have never noticed and tightness / jamming. Neither does it appear to twist when you change direction.

Anyone know the book title which contains JAR's article? 

Regards

Phil

Edited By CotswoldsPhil on 19/09/2015 13:47:32

Well slow typing.  Neil beat me to the information. Thanks.

Edited By CotswoldsPhil on 19/09/2015 13:49:07

Hi All,

Has anyone else done the shim mod and want to tell us about it? What material did you use?

Regards

Phil

Morning Brian,

I don't know about different materials and wear - others more qualified may wish to comment.

However, the 1mm shim you propose should give you about 0.005 inch (there - mixed dimensions again!) clearance for the narrow guide face based on an average of the rear clearance measurements you obtained of 31 / 39 thou.

When you refit the apron you will hopefully have sufficient waddle room in the cap-screws to get the rack gearing and half nuts aligned. When I refitted the saddle I moved the apron as near the tail-stock as possible, engaged the half-nuts, made sure the apron was not skewed by reference to the mating edges of saddle and apron and tightened up the saddle. Moving the saddle back to the chuck end and reengaging the half-nuts did not show any significant movement of the lead-screw indicating that the apron was (most likely) aligned OK.

What this mod does is to move the saddle away from the operator restoring it to the designed position. With wear and adjustment, the saddle is slowing moving towards the operator and twisting. The important thing is not to introduce too thick a shim which will over compensate for the wear.

I'm no expert, this is all from the experience of making a simple mod to restore accuracy to a narrow-guide Super 7 or ML7 for that matter.

As I indicated in an earlier post my initial experiment was to test the feasibility of using Turcite with no machining. The 0.5mm temporary shim is still in place and working well, I bent a small lip at the tail-stock end to help locate it. I thought about adding a fixing screw, but the shim has never moved.

Phil

Edited By CotswoldsPhil on 18/09/2015 11:55:40

Hi All,

Please note I did not build a Matadore on a Unimat it was as I remember, a similar sized engine from a casting kit available at the time (late 60's) my Uncle obtained. I mentioned Matadore because I used Jones 605 2 stroke castings in it's construction, effectively using the Matador design to convert a Jones 605 to a lightweight 4 stroke.

The drawing I used was for a Matadore .60 Four stroke engine by D Giles - overhead valve not rotary. I'm looking at the drawing now, having retrieved it from the archive - wish I could find the actual engine though!

Phil

Hi Martin,

Yes, the milling column was a bit fiddly to set up but it was quite versatile.

Phil