Bandsaw/Resaw help

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colinc

Established Member
Joined
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Location
South Derbyshire, UK
Hi,

I have posted an add in the wanted section but I thought I should add a post here too as someone may have the facilities to help us.

We are looking for a large bandsaw (or resaw) for resawing largish baulks of spruce into smaller sections for laminations. Am thinking of something like a Wadkin but any similar robust machine would be considered. Three phase is available.

The machine is for the workshop of the DH-88 Comet 'Black Magic' restoration group at Derby Airfield. The Comet is an important historic aircraft and is being rebuilt to flying condition by a group of volunteers and professional aircraft engineers. If anyone wants to see more information about it go here: http://www.cometracer.co.uk

Please advise if you have or know of anything available.

Also, if there is anyone relatively local who could help with or has the facilities for wood machining please do contact me. Our problem at the moment is that we have a number of large baulks of Sitka Spruce, some up to 40 ft long which need to be machined into 3/8" and 1/2" sections and then scarfed and laminated into the top and bottom booms of the wing spars. Ideally we need to find someone with a band resaw to do the initial cuts.

regards

Colin
 
Hi,

a resaw would be great but it's a bit beyond our budget and needs a lot of space. Having been looking at what's around I think an old Wadkin would be ideal for us. Am also looking out for some roller track to make an infeed and outfeed for it. 40ft x 10" x 8" is a big piece of wood to handle.

I want to run the widest/thinnest blade I can as the wood is very expensive so the least waste the better! Before anyone says it - I'll talk with Tuff-Saws about the blade, I have some really good ones from him that I'm using on my EB saw at home for cutting Sitka Spruce, which is quite a soft wood and seemed to clog the old blades.

I'll keep an eye on Ebay but would prefer to just buy one from someone I can go and talk to. I'm sure that with a bit of patience and by asking around something will turn up.

regards

Colin
 
Hi Colin, I'm no expert and this is all based on bits of info floating about rather than experience - and I know even less about Wadkins and the like. But 40ft long lengths of 10x8 in is getting into heavy stuff.

Be careful not to get stuck with a machine that will be too slow - you could end up spending an awful lot of time standing around. Ditto in respect of ability to maintain accurate tracking without lots of babying - you could equally lose a lot of time/reject quite a lot of wood.

Two other thoughts. (1) There's probably a lot to be said for running a carbide tipped blade like a Lenox. (they not only cut fast if you have enough power and last well, but also it seems give a better finish which might be significant on wood for high performance structural applications due to the side cutting ability of the teeth), and (2) power feeding may be a good idea too to deliver consistent results.

As said before, I was a bit shocked when I saw videos of how a serious band re-saw really performs - there's several clips on YouTube. Even what in cabinet making/joinery is considered a very large and heavy duty band saw is a bit of a toy by comparison - the real thing typically has many times as much HP, a much wider blade, power feeding and a set-up designed to perform (track wide blades etc) on that sort of application.

I guess what I'm saying is that (a) if you buy anything it'd need proven capability or better still testing first, and (b) there might be a lot to be said for hiring some time on the right re-saw. One risk with hiring is that you probably have high standards for what you need, and a careless operator not understanding this could do a lot of harm very quickly. Might there be an option to buy a band saw as well for smaller jobs?

The Comet by the way looks like quite a project. They were such a beautiful aeroplane, and very brave design in aerodynamic terms - those thin and pointy wing tips etc mean it must (?) surely have been a bit inclined to tip stall etc. Somebody at De Havilland was really pushing out the boat on wing plan forms in those days - even the likes of the Dragon Rapide was pretty daring.....
 
Hi,

it would be great to have access to somewhere with a resaw but I have tried without success to find anyone locally.

I have seen a resaw working and they do an impressive job but speed is not an issue on this job and the ability to be able to process our own material will provide greater flexibility. Am getting advice from various people now which is very helpful in finding the best way forward. Unfortunately funds are limited otherwise we would be looking for a powered resaw. The problem is that what gets spent on machinery can't be spent on raw materials, so if a big bandsaw will do the job, albeit more slowly, that seems a compromise we can live with.

The Comet is a very interesting aircraft but was designed and built very quickly and might have benefited from more development. Grosvenor House at Old Warden has was rebuilt to the original drawings and flies. Tom Watham's replica built in the USA had washout (decreasing wing incidence towards the tip) built in to reduce the risks of tip-stalling and so improved handling, and there are a number of other ways that the issues caused by the sharply tapering wing can be mitigated given the greater understanding gained since the 1930's. Of course, the Comet had just one design aim, to travel long distances as fast as possible to win that race - which Grosvenor House did! The team behind the restoration have done a lot of research and this promises to be a very interesting project to be involved in. The result should be a very sympathetic restoration but will incorporate a number of improvements and modifications that will make it better than when it originally left the factory.

A lot of hurdles to overcome yet - not least is maching these wing spars. However, the team working on the fuselage and the guys making the metalwork, undercarriage, engine mounts etc are making real progress. If anyone wants to come and take a look visitors are very welcome - pm me or make contact via the web site.

regards

Colin
 
It's an aeroplane that I've always had a soft spot for Colin - since an Airfix kit way back in the early 60s I think it would have been. I can imagine back in the day that washout wouldn't have been ideal from the point of view of drag, but that between that, the long nose and the low canopy putting one down on an unknown strip in the dark when dead tired must have been interesting.

I'm unfortunately on the wrong side of the Irish sea for a visit.

On saws. Again no hands on experience, just another thought. Axminster Tools have a couple of what they call 'resaw bandsaws' made by Europac in Taiwan (which reportedly are good machines - I spoke to a guy with one based up near Rochdale recently, but would still want to test though) available these days at reasonable money. http://www.axminster.co.uk/axminster-pl ... tomsection Albeit more than a used Wadkin or the like.
 
For the plain cussed awkwardness of moving 40 ft lengths through a resaw I think your most sensible option would be to find someone with one of the smaller and lighter mobile sawmills such as the Lumbermate, Woodmizer LT10 or LT15, or the Hudson Oscar. These are horizontal bandmills which travel along a relatively lightweight and simple track which can be extended ad nauseam to give any length of cut. In your case a pretty straightforward bit of steel fabrication would give you a full length of cut and the mill owner/operator would need to bring just the cutting head as and when it is required. You wouldn't have to purchase a bit of machinery that would be redundant most of the time and taking up space- just book the saw in for a day when required.

Interestingly David at NBBS is advertising a boatyard's mill second hand with a 35ft travel for £3500, that's the sort of thing I'm talking about. http://www.sawmillservices.co.uk/usedmills.html

wp10b1fe49_0f.jpg
 
Interesting - I was about to post the same suggestion about mobile mills. They are surprisingly accurate; a guy using one at a show in Dundee last year was taking boards less than 1/2" thick off a 12" by 12" by 14' baulk of Scots pine.
Don't know about Derbyshire, but there are several mobile mill operators up here in Scotland. Would have thought there must be some in the Midlands?
 
I would go with trying to get a mobile mill as well – handling timber of this size is no easy feat, more so if you haven’t got any experience of sawing large pieces.
If you can’t find a local sawmill then I would definitely look into getting a mobile mill coming to you.
The Axminster resaw looks a decent machine but with these machines the blades have to be serviced after every 4 hours of cutting so you would need a local saw doctor to look at the blades as well.
A service on a resaw blade requires it to be sharpened, tensioned and levelled and if not done correctly or regularly then it’s an expensive blade to replace!
Ian
 
This is one application where a cheaper/lightweight mobile mill (<£10,000) scores more highly than an expensive one (>£20,000), as it is far easier to fabricate a bed extension. The nice thing is that your wood never has to move once it is in position, so instead of having to move 22cubic ft of timber back and forth on an 80ft journey for every board, you only have to move a light frame with a petrol engine, a couple of wheels and a blade.....

Out of interest, why does the timber have to come in those sections, and what specs are there for 'aircraft grade' timber. I assume rings per inch, grain slope, knots, mechanical testing come into it?
 
Hi,

it would be a good idea to get in a mill if we were wanting to do the job in one go but we are proceeding carefully and will do the cutting over a period of time as we work out how best to do the laminating. We are not needing to rush at the job and time is not as important as in the average production environment.

As a result of posting the problem here we have had a couple of leads already which I'll follow up this week.

Wills asked about the sections and selection of wood. Sitka Spruce of the grade and quality for aircraft is fairly difficult to come across. We were able to source the baulks from a local importer from supplies that went mainly to mast makers. The alternative is to import from aircraft suppliers in the USA but for the quantity we need that is a very expensive option. I understand that most of the high quality wood is going to the Chinese musical instrument makers these days. The actual selection is covered by published specs and criteria includes density, rings per inch, straightness of grain, moisture content etc. Also we do strength tests to check the modulus of rupture and compressive strength. Here's a machine I built to test samples for brittleness http://i894.photobucket.com/albums/ac14 ... achine.jpg the big (22lb) weight get dropped onto a sample and if it doesn't break then it passes!

regards,

Colin
 
colinc":3phkqq0b said:
Hi,

I have posted an add in the wanted section but I thought I should add a post here too as someone may have the facilities to help us.

We are looking for a large bandsaw (or resaw) for resawing largish baulks of spruce into smaller sections for laminations. Am thinking of something like a Wadkin but any similar robust machine would be considered. Three phase is available.

The machine is for the workshop of the DH-88 Comet 'Black Magic' restoration group at Derby Airfield. The Comet is an important historic aircraft and is being rebuilt to flying condition by a group of volunteers and professional aircraft engineers. If anyone wants to see more information about it go here: http://www.cometracer.co.uk

Please advise if you have or know of anything available.

Also, if there is anyone relatively local who could help with or has the facilities for wood machining please do contact me. Our problem at the moment is that we have a number of large baulks of Sitka Spruce, some up to 40 ft long which need to be machined into 3/8" and 1/2" sections and then scarfed and laminated into the top and bottom booms of the wing spars. Ideally we need to find someone with a band resaw to do the initial cuts.

regards

Colin
Hi Colin
Andy Harrison from Kettering http://www.aharrisonwoodturning.co.uk/Services.html had a Woodmizer for sale and also travels around with it doing demonstrations. May be worth a ring to see if he could provide the service or machine you need.
Regards Keith
 
colinc":33n8jo3g said:
Hi,
Wills asked about the sections and selection of wood. Sitka Spruce of the grade and quality for aircraft is fairly difficult to come across. We were able to source the baulks from a local importer from supplies that went mainly to mast makers. The alternative is to import from aircraft suppliers in the USA but for the quantity we need that is a very expensive option. I understand that most of the high quality wood is going to the Chinese musical instrument makers these days. The actual selection is covered by published specs and criteria includes density, rings per inch, straightness of grain, moisture content etc. Also we do strength tests to check the modulus of rupture and compressive strength. Here's a machine I built to test samples for brittleness http://i894.photobucket.com/albums/ac14 ... achine.jpg the big (22lb) weight get dropped onto a sample and if it doesn't break then it passes!

regards,

Colin

Fabulous! The reason I asked is that I was talking to someone earlier in the year about sourcing home grown timber for replicating some of the early 'planes built in this country. No doubt they were built at the time with US or Canadian spruce, but this chap seemed keen to go to the effort of poking around to find an equivalent in England. I'm sure it's possible as a technical exercise, despite the extra complication- I doubt it's a very commercial proposition for the long term...
If we do get the ball rolling I may have to come and pick your brains or present some samples to be atomised!
 
Wills,

if the idea is to build a flying replica then he will need to use either sitka spruce or douglas fir as these are really the only woods obtainable that are suitable. It isn't a technical exercise if he's looking, the only home grown wood that goes into aircraft would be ash block for hard-points, it's simply too heavy to use for the structure. Down-under hoop pine is a good equivelant.

By the way, when I say Sitka Spuce I mean the slow grown wood which is really only produced in north-west of the US/Canada, not the fast growing stuff in Scotland - it's as much about terroir as wine!

I can probably help sourcing either Spruce or DF as I think I now have a pretty good picture of the supply situation in the UK. If it's a non-flying replica then I'd go for DF as it's cheaper, easier to get and the rarer Sitka should be saved for something that is going to fly.

Happy to test anything, but not sure I can atomise it. Tell me more about the project and I can advise better.

If you want any documentation about aircraft wood, pm me.

regards,

Colin
 
Back to the bandsaw.......

We have been directed to a guy locally who wanted to sell a Stenner bandsaw he rebuilt, and a deal has been struck. It is a rather large piece of engineering and will allow us to make the first tentative steps in converting the wood. Built in the 1940's apparently.

All of the comments about using a portable mill have been takenon board and when we have the confidence to know how we want to convert the bulk of the wood we will probably call someone in. For now though this machine will allow us to progress things.

Here are a couple of pictures:

IMG_0102Medium.jpg


and

stenner.jpg


May I say thank you to the various people who have helped and advised on this issue, it is much appreciated. Once again I have asked Ian John (Tuffsaws) to help sort out blades for the job and based upon past experience I'm sure he will come up with the goods. (Another Tuffsaws plug from a satisfied user)

regards

Colin
 
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