J39 64859 Bachmann/Dave Bradwell

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PeteT
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J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Sun Nov 24, 2019 2:31 pm

I apparently posted about this project in my generally workbench thread in November 2017 :shock:

viewtopic.php?f=135&t=5186

It spent most of the intervening 2 years off the back of the back burner, for two reasons (aside from other projects, life, etc):
- Partially, as the Exactoscale wheels are actually J6 (crankpin in between) rather than J39 (in line) - and I needed to decide whether to continue with them, or consider the Ultrascale or Gibson options. In the end I am continuing with the Exactoscale route - and do like the way they work (so far).
- Secondly I was trying to overcomplicate the drive, and failing to figure out how to conseal the drive shaft under the footplate, not colliding with a loco-tender coupling, other detailing gubbins down there, how to get the gearbox sat down there at the right height to meet it, etc etc...

However, at Scaleforum this year I had a couple of chats with Mr B about it and decided to go back to basics - with the drive shaft out through the coal hole door, and into the firebox. Just like the real thing had the fuel inserted... I duly purchased a High Level Road Runner + 34:1, and have made a bit of progress since the end of September.

Some of this relates to Tim's gearbox tethering discussion - so thanks for having that, as while I was happy with the route I was going (same principle, not sure I'd concluded on the implementation) it may not have ended up quite as nice!

The loco chassis has a tight spot, but hopefully won't take much to sort. The tender underframe is sitting at the right height (it may not be in the photos, as I think the loco-tender coupling is sitting too high, so affecting how both loco and tender are sat) and so the plan is to finish the tender underframe build, as that will allow me to add pickups there.

The loco body (one of the era with a groove across the cab roof) will need a fair bit of detailing. Most of this is covered in the instructions & add on sheet, though 64859 (of Starbeck in 1958) had one of the handful of boilers with 4 washout plugs per side rather than 2 handholes (about a dozen had this, of the class totalling 289). I also need to work out how to replicate the removable steam chest front. The question is whether a couple of infill bits of plasticard will do the trick. My donor body also only has 1 mechanical lubricator, while my prototype had 2. Romford do these (Wakefield no 7), and I expect it will look different to the Bachmann one (better or worse I don't know!) but will get two so at least they look the same.

Tender wise I have a couple of good photos which show it to be a rivetted/none flared/NER braked 3500g group standard tender. What I can't tell from the photos I have (and neither the Green book nor Yeadon's register help with) is whether this tender will have been built with a scoop, kept it, just kept the dome, or been plated over, or never had one. Still - plenty to crack on with while I try and solve this one!

Oh, and yes the tender should have disc wheels. Hopefully Exactoscale will reintroduce these sometime soon. I went to raid my B1 kit but it appears I only bought the driving wheels for that! Ultrascale do them though so no biggie, and the spoked ones will do for now. I get the feeling they get more difficult to take in & out once the axlebox & spring castings are added though, which is the next step.

Anyway, if anyone has made it this far - I'll conclude with some photos:

Firstly the gearbox - all supplied by High Level, aside from 2mm bearings to use remote drive. I used Alan Gibson 4M65s for these.
20191009_205807.jpg


20191010_195619.jpg


The driving wheel assembly jig allows room for the hornblocks & gearbox, and the back to back gauge (not in photo, I only have 2 hands) has a slot which fits around them too. (I'm also aware that the final drive gear wasn't in place at this point, this was just testing the theory)

20191015_183132.jpg


This gearbox required a bit of the ashpan removing to fit:

20191123_165733.jpg


I put a bracket in the tender for the motor to attach to. The motor sits up slightly so I can put a rubber pad under the far end which will hopefully nullify any noise. No idea if this concept will work... hopefully won't be long before I find out!

20191124_122938.jpg


The shaft in the Ultrascale UJ is currently a short offcut - but even though this is the thinner of the 2 Ultrascale options 1/16" still looks pretty chunky! I'll probably prove the mechanism with this, but try and find some tube to sleeve a thinner drive rod.

I have filled the well tank with lead, and the stack of lead on the top fits under the drive shaft but needs a bit of fettling to allow the body to slide into place around it.

20191124_121752.jpg


20191124_122105.jpg


All being well it will not be another 2 years before the next installment...

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PeteT
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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Mon Nov 25, 2019 9:41 pm

I've sorted the running - the middle drivers weren't quite quartered. It is the only problem I've so far seen with the Exactoscale drivers (& alluded to in John McAleely's review in snooze 178 - though he didnt encounter it) is that the drivers can rotate slightly while being pushed home in the jig. I usually use the GW press with good results for both Ultrascale & Gibsons.

So, onwards with the tender underframe so I can get some pickups installed. I could do some flying lead tests, but actually having this separation between motor & gearbox allows me to build & debug the two separately, without said flying leads getting in the way.

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Will L
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Re: J39 64859 Bachmann/Dave Bradwell

Postby Will L » Tue Nov 26, 2019 8:35 pm

PeteT wrote:I've sorted the running - the middle drivers weren't quite quartered. It is the only problem I've so far seen with the Exactoscale drivers (& alluded to in John McAleely's review in snooze 178 - though he didnt encounter it) is that the drivers can rotate slightly while being pushed home in the jig...

Yes I've had that problem too and I have an explanation and a fix, see viewtopic.php?f=96&t=2932#p26669 see item 4 under "quibbles" near the end of what is quite a long post. I also have a supply of the correct size ball bearings (see fix) if anybody wants one or two.

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PeteT
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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Wed Nov 27, 2019 8:06 pm

Thanks Will, both for taking the time to do that review in the first place, as well as bringing it to my attention now!

The ball bearing technique does look like a good solution to the problem. I bought some a while ago, to experiment with in paint tins for shake/mixing purposes (an experiment I'm yet to carry out) but alas I've just dug them out & they are all but 3mm so too large for the tapered ends of the Exactoscale axles.

Therefore yes please to one of your spares.

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Will L
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Re: J39 64859 Bachmann/Dave Bradwell

Postby Will L » Wed Nov 27, 2019 10:39 pm

PeteT wrote:Thanks Will, both for taking the time to do that review in the first place, as well as bringing it to my attention now!

The ball bearing technique does look like a good solution to the problem. I bought some a while ago, to experiment with in paint tins for shake/mixing purposes (an experiment I'm yet to carry out) but alas I've just dug them out & they are all but 3mm so too large for the tapered ends of the Exactoscale axles.

Therefore yes please to one of your spares.

PM sent

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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Wed Nov 27, 2019 10:51 pm

On with the tender underframe - and trying to sort out the spring hangers, springs and axleboxes.

The hangers have pegs on the back of the casting, and the sideframes have holes to suit - however these appear to then end up too low. They hold the springs too low in relation to the spring stops, which also puts the axlebox too close to the bottom of the frame. Even without the spring hangers though, the axlebox sits too low down. Is the spring casting and axlebox supposed to be separated and mounted slightly closer together?

This isnt a criticism of the kit, as I fully expect it is something I have done rather than a designed in issue. There are different springs for the 4200g and 3500g tender, and I am pretty sure I have chosen the right ones - though this shouldn't affect the spring hanger to spring stop relationship anyway.

I have separated one spring from its axlebox, which does generally help the axlebox position. Comparing my images with the photo on Dave's website suggests the cast hangers are mounted slightly lower down on Dave's - mine seem to line up more with the centreline of the frame cutouts. But this would move them in the wrong direction (in relation to what I currently perceive as my problem!).

Apologies for the quality of images, but remember they are several times life size!

First two of the side I have attached the hangers to so far. The left hand casting is as supplied, the right hand one separated between spring & axlebox and sat closer together.

20191127_205332.jpg


20191127_205316.jpg


Then on the other side of the tender, so referencing the springs off the spring stops rather than hanger brackets - and firstly the casting as supplied still sits too low at the bottom:

20191127_205257.jpg
20191127_205257.jpg (191.89 KiB) Viewed 1493 times


But separated and sat closer together looks better.

20191127_205237.jpg
20191127_205237.jpg (192.23 KiB) Viewed 1493 times


Dave's hosted image for reference:
http://traders.scalefour.org/DaveBradwe ... er-lrg.jpg

So the question is, before I remove the pegs from the hangers and sit them all a tad higher, and detach the springs from axleboxes and mount these closer together - is this the right thing to be doing, or have I missed a trick somewhere?

Refering back to my first post, it also since occurred to me that Dave will do the lubricator casting himself - which is indeed true, on mould 23 for the K1.

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Re: J39 64859 Bachmann/Dave Bradwell

Postby davebradwell » Wed Nov 27, 2019 11:04 pm

I'll look into this Pete, although it will be late tomorrow, then I'll have to find the drawings. It looks as if my tender had the 4200 gal castings, probably because I hadn't done the correct ones at this time.

DaveB

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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Wed Nov 27, 2019 11:13 pm

Thanks Dave - I may have got there with the hangers though. I noticed while looking at yours castings list that there are both 'long' & 'short' hangers. I've checked back through & only had 1 set in that kit, however I have a 4200g tender in the queue with the B1 - & this does have both.

It looks like the long ones are the right ones for this, so will keep me going (& if the short ones & the other springs are right for the 4200g then I'm sorted?).

That said, it still looks to my eyes that the axle box is slightly low if left attached to the springs & will the springs held up against the stops. I did have two sets of axlebox/spring castings with it, & am using the shorter one.

Thanks,
Pete

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Re: J39 64859 Bachmann/Dave Bradwell

Postby davebradwell » Thu Nov 28, 2019 5:47 pm

Short hangers are the right ones. Hang on a bit longer and I'll post results later this eve.

DaveB

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Re: J39 64859 Bachmann/Dave Bradwell

Postby davebradwell » Thu Nov 28, 2019 7:03 pm

This was a surprise as I always check the fit of parts before releasing kit. However, after investigating, I do need to own up to a number of small errors and I apologise for not spotting them before release. I haven't looked in the instructions where I sometimes confess my sins.

The first of these is that I cheated by using the axlebox that I made for my 4200 gallon tender rather than a new slightly smaller one. Measuring the dressed casting the hornguide is 0.2 too long. In fitting the smaller spring it is 0.5 too high, as PeteT has spotted. The 3500 gallon tender only used the short spring hangers and these appear to be about the same on both types of tender. The top of the hanger brkts could be moved up a little to achieve the 1.5 dimn, probably by enlarging the locating holes in the frames.

I have attached the GA - the best place to start - and the scaled values from this with the most significant errors highlighted.

You will get very close if you lower the spring on the whitemetal casting, lift the brass castings a little and in particular work on the fit of the spring end in the brass hanger. I believe I did just the last in checking the parts so ended up with the axlebox sat on the keep below the axlebox, the others can be done to choice according to your determination.

If anyone has any queries with my kits, please contact me and I will endeavour to give an answer, although digging out ancient drgs may sometimes be a challenge in itself.

DaveB

Img057.jpg
Img056.jpg

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PeteT
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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Thu Nov 28, 2019 7:23 pm

Excellent, thanks Dave. We all make mistakes...

As the GA shows, it is the slight gap between the bottom of the hornguide and the tie which makes it most noticeable. Not having the GA, than snippet and the sketch are very useful though, thanks. I'm sure I can work with these.

I'm pretty sure there isn't anything noted in the instructions -as you say you are pretty open where things need tweaking.

The GA does look to show the spring quite low in relation to the stops, but I'll look for the clearest photo and attempt to reproduce.

I have found no new angles of photos of 64859, but looking through others in the class both in books, and (usefull) the colour rail collection and (less usefully) the RCTS archive I think I have come to the conclusion that removing the tender dome at the same time as the scoop seems to have been the most common method (& if not, I can always glue it on if evidence comes to light :D - but sod it, I'm not putting it on one side to mature for another few years while trying to find illusive proof...).

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Re: J39 64859 Bachmann/Dave Bradwell

Postby davebradwell » Thu Nov 28, 2019 8:40 pm

Yes, I gave up investigating my tender dome and eventually put it on just to check if would fit. I have seen a photo of a Carlisle J39 going over the HL bridge and taken from above which showed plated over dome but the traditional photo viewpoint isn't helpful here. I suspect J39 tenders need a 10 volume work but there's no sign of a rush to write it.

Anyway, a positive outcome at least that will be useful to the other 38 owners of this tender. I've always been surprised that I've never sold any of the brass spring hangers - they were a pig to make and especially so because they both have to be the same length within not much.

DaveB

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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Thu Nov 28, 2019 10:18 pm

Indeed, to be honest most of the photos I have seen you're lucky to see dome/no dome let alone plated/never.

I suspect you're correct - though with the right author I'm sure it would make good reading! I get the feeling it would be considered marginally niche. I'm surprised only 39 have been released into the wild though - without a RTR option I would have thought more people would have them in the cupboard. If there is a 10% build rate then this will be about number 4! I'm sure I've seen evidence of slightly more than that though...

I've opened out the holes to 1mm & they seem to line up nicely. I really like the hanger castings, but 1 or 2 do have flash inside the top opening. This was proving troublesome the other day, but coming fresh to the issue today the lightbulb illuminated & I dug out the piercing saw blades to run through & this has worked well, with a 1/0.

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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Thu Jan 30, 2020 1:13 pm

2 steps forward, 1 back. My Ultrascale order arrived a week or 2 ago (only ordered late November, so under 2 months which included Christmas). This included the tender wheelsets for the J39, discs to replace the Exactoscale spoked ones I had allocated.

These are now installed and tender runs beautifully. I set up the middle wheelset with a 1mm axle and 2mm/1mm tube for the axle sleeve carrying the wheels - I'm not sure whether this should be necessary on the wheelbase of a tender, but I haven't managed to make it fall off yet while I could make that happen with the Exactoscales in place.

1 of the loco driving wheels has developed a wobble though. The axle looks square and well locked onto the wheels metal bush, it looks like the metal bush in the plastic wheelcentre has managed to loosen - which is annoying to say the least... hopefully I can fix this, seeing as I can't obtain a replacement so would mean swapping to either Ultrascale or Gibson GWR wheels.

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Re: J39 64859 Bachmann/Dave Bradwell

Postby Will L » Fri Jan 31, 2020 10:52 am

PeteT wrote:...
1 of the loco driving wheels has developed a wobble though. The axle looks square and well locked onto the wheels metal bush, it looks like the metal bush in the plastic wheelcentre has managed to loosen - which is annoying to say the least... hopefully I can fix this, seeing as I can't obtain a replacement so would mean swapping to either Ultrascale or Gibson GWR wheels.

If you look at this post you will see I have had this problem too, and how I got there. Read down to the section on problems I wasn't expecting. For me the easiest way out way to buy one new pair which you can't at the moment. The prognoses isn't good, but I did wonder if I could use something like superglue to set it solid again as they do pop back into place, at least in the early stages.

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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Fri Jan 31, 2020 11:46 am

Thanks Will - I thought I had relooked at your post, but evidently not.

Yes it is certainly worth trying to reseat it, and fix either with superglue or loctite. Nothing to lose at this stage, and everything to gain. The problems with doing so are getting it sat at the right lateral location as it looks to have knurled the plastic edge a bit - (though I can assemble a spare axle so this isn't too much of an issue). More of a concern is making sure it is perpendicular - but if I can find a rod to sit within it that should help give a longer length to both assess and peg into something to help align them.

I thought I was keeping a good eye on the crankpins while setting them into the jig, but must have allowed it to rotate or catch on the jig.

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Re: J39 64859 Bachmann/Dave Bradwell

Postby Edward45 » Tue Feb 04, 2020 4:33 pm

I have no experience with this make of wheel, but from what I can glean can't say that I'm overly impressed with the concept. However, when it comes to attempting to repair the wheel is it possible to vertically drill a hole in a suitable material to take the sub axle. With the wheel and the axle thus held in alignment epoxy might be a better adhesive to reaffix the stub axle.

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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Tue Feb 04, 2020 5:24 pm

I like the concept in some ways, but there are reasons other people have failed to improve on the standard Gibson/Ultrascale/Sharman methods.

I will persevere for the time bring though - they do look nice.

That is my plan - the largest fly in the ointment being that the boss on the rear (& same on the front) is proud of the wheel rim - & so any minor misalignment there will be magnified - so I think I will need to allow clearance for that so the wheel sits on the rim and square to the stub axle.

All fun & games...

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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Sun Feb 09, 2020 9:06 pm

These area groups bring together a lot of helpful people - & thanks to Morgan I now have 6 driving wheels back in place! Once the stub axle was carefully removed, the wheel was repaired with the use of a watchmakers lathe to hold the wheel & stub axle square in all planes while epoxied back together.

This now rolls around nicely, squarely & without falling off. With the rods on there is a tight spot to sort out, so that is the next job - & then onto tender pickups.

20200209_210532.jpg

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Re: J39 64859 Bachmann/Dave Bradwell

Postby DougN » Sun Feb 09, 2020 9:31 pm

Pete,

regarding the tight spot, have you opened the rods out to 1.6mm? recently I have been opening every rod to this and the last 2 engines rolled smoothly. If it needs any more it should only be a very small amount which a reamer should be able to remove the smallest amount.
Doug
Still not doing enough modelling

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Re: J39 64859 Bachmann/Dave Bradwell

Postby davebradwell » Mon Feb 10, 2020 10:51 am

If you enlarge coupling rod holes to compensate for an error the thing won't run as well as if you corrected the error and it had worn. The much used 0.1 clearance feels very worn to me. Before giving in why not try to track down the issue - it's probably a small error in centres and I find the jigging process doesn't work for me hence the system I use in later kits. First there should be running clearance in the coupling rod brgs and axleboxes and axle nuts not pinching rods - visible sideplay. Stand the thing on a flat surface and observe the level of the coupling rod at front and back centres noting which way you would twist a wheel to correct any slope. Axle ends are good reference point. Repeat on other side. Sit down with your notes and you can work out if it's rod centres that need a tweak or the quartering. After correction you'll probably still end up easing the bearings a little with a broach.

You see it at exhibitions where the coupling rod is doing a jolly dance sloping one way on the up and the other when descending due to a quartering error or the rods have so much play in them that a wheel is running in advance.

DaveB

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Re: J39 64859 Bachmann/Dave Bradwell

Postby 45609 » Mon Feb 10, 2020 12:12 pm

PeteT wrote:These area groups bring together a lot of helpful people - & thanks to Morgan I now have 6 driving wheels back in place! Once the stub axle was carefully removed, the wheel was repaired with the use of a watchmakers lathe to hold the wheel & stub axle square in all planes while epoxied back together.

This now rolls around nicely, squarely & without falling off. With the rods on there is a tight spot to sort out, so that is the next job - & then onto tender pickups.


Hi Pete,

Thanks for the mention and really glad that the repaired wheel seems to be ok. I know you had an offer of a replacement but I enjoyed the challenge of trying to get the wheel running true again. I hope you don't mind but I have posted a few images below that give more detail.

The wheel you gave me had a displaced centre insert which made the wheel wobble a significant amount. The first task was to try and remove this insert without doing any further damage to the plastic part of the wheel. I put the wheel into a step collet on my watchmakers lathe and very carefully advanced the cutting tool into the corner between the stainless steel insert diameter and the rear face of the plastic wheel. Once I had exposed all of the metal flange I then clamped the insert diameter in a 1/8" collet in the lathe tailstock and gently pulled the insert from the wheel centre. I was actually surprised at how easily it came free.

Separate insert from wheel.jpg

I then proceeded to clean up both the insert and the hole in the wheel centre so that both would slide back together squarely leaving a little bit of an allowance for a thin film of epoxy (I used some Gorilla Glue 5 minute epoxy). Reassembly was the reverse of the extraction process and I left the wheel and insert in this position for a full 24 hours to make sure things had set hard.

Reset centre insert.jpg

The final step was to add a little more strength to the repair by gluing an additional brass washer to the rear face of the wheel. I know you were concerned about side play so after this had set hard I carefully machined the face of the brass washer back to make sure it was flush with the rear face of the tyre.

Strengthening washer.jpg

The final step was to turn the wheel around and remount by the insert in a 1/8” collet. I then used a 3.0mm diameter slot drill to clean out the front recess of any stray epoxy that had bled out of the joint. I did this whilst turning the lathe headstock by hand so that I could feel when all the glue had gone and to not starting to cutting away the metal insert.

Repaired front.jpg


Cheers…Morgan

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PeteT
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Re: J39 64859 Bachmann/Dave Bradwell

Postby PeteT » Tue Feb 11, 2020 5:25 pm

Thanks for the thoughts - I agree with Dave that it is very likely to be something of my doing in construction. I'm glad later kits use a slightly different method, as I did/do find that jigging based on the coupling rods only help horizontal alignment in one plane, and it is difficult to tell once things are clamped that they are all square in the other directions. There are also relatively few square edges on the frames to check against for square - though the eye is remarkably good at picking up on these things.

I understood with hand drawn artwork where drawing discrepancies come in - but with CAD produced artwork it is going to end up far more square if designed as one piece than I am going to fit it together squarely from 2 separate pieces (this is purely a comment of my tools/abilities rather than the designs as such).

It is a good point on the nuts too - I will make sure I check those before taking it apart to check the hornguides.

I'm sure an extra bit of slack would work around the issue - but I would prefer to find the route cause if I can. I'm not worried that I can't fix it, just need to find a bit of time with a clear head to sit down and work through it.

Thanks again Morgan - absolutely no issues with you sharing the details here! I'm sure they will be of interest to others.

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Re: J39 64859 Bachmann/Dave Bradwell

Postby Paul Hutfield » Thu Feb 13, 2020 1:15 pm

I agree with Pete, a fantastic summary and very useful.

Many thanks Morgan!


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