# Repairing my Record Power BS300 bandsaw



## sploo (8 Mar 2015)

A couple of months ago, I snapped the tensioning rod on my Record Power BS300 bandsaw. I'd just about gotten enough tension in the blade, and needed the saw for a project, so didn’t want to risk stripping it down immediately (on the assumption I might have difficulties getting it back together).

I’ve finally gotten around to fixing it, and it turned out to be a whole lot easier than I thought. I had a replacement rod from Record, but realised I could make my own - thus avoiding the weak link in their design. Hopefully this post might be useful to fellow BS300 owners.

Here's the starting point:








This shot shows the top of the tensioning rod. It turns out it’s just an 8mm threaded rod, with a short section turned to a smaller diameter and pinned into a sleeve that takes the plastic knob. The pinned link strikes me as an odd design, and it’s where mine snapped (hence the fact the sleeve and knob are not in this photo).







Here’s what it looks like with the wheel removed.







The actual tensioning cradle mechanism as a whole isn’t bad - it pivots on a rod, that allows a lever to quickly release the blade tension. In this photo you can just see the bolt in the back of the machine body (that pushes at the back of the cradle to adjust tracking).







The system appears pretty simple: at the bottom there’s a plate that compresses a spring, with a trapped nut (for the threaded rod). There’s the silver (aluminium, I guess) block with the wheel spindle, then a washer/tube/washer arrangement is held in place by two nuts that are locked together.

Here it is dismantled, along with the top sleeve and plastic knob not shown in the original image.







I realised that the sleeve just rests on the top of the black cradle (with a washer underneath), but there’s no tension on that part of the rod (mine snapped due to twisting movement). That meant I could just use an M8 threaded rod, and another pair of nuts (locked together) to rest on top of the cradle, and add a new handle/knob on the top of machine - thus I’d avoid using the original design with its weak link. I’ve just realised I’ve used a sentence with the words "nuts" and "knob" and wasn’t trying to be crude :mrgreen:.

I made new winder handle from a piece of oak. It has a tee nut on the bottom, and the dowel is loose, so can be spun.







The gap between the original pair of locked nuts and the bottom of the sleeve looked to be about 15mm, so I replicated that with the extra pair. The end result is pretty good, and much easier to tension than with the old round plastic knob.






There’s a reasonably large hole at the top of the machine (for the sleeve and knob), and it’s elongated to account for the fact the cradle could be tipped with the tracking bolt.







With no sleeve/knob in place I’d noticed that the machine does put a fair bit of dust out the top, so I put a thin plate over the hole with a section that fits into the hole (as the winder handle does cause the rod to wobble around a bit when being spun). I'm hoping that will reduce the lateral movement.











And finished...






A good clean and tuneup, and she's running sweetly again.


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## blackrodd (8 Mar 2015)

Good write up and pic sequence there Sploo, As you say, although Record were happy to replace the dodgy threaded bar,
There's possibly a weakness in anything made in a similar fashion, so make you're own!
The crank handle has to be an improvement, too! Regards Rodders


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## sploo (10 Mar 2015)

blackrodd":3cbool6r said:


> Good write up and pic sequence there Sploo, As you say, although Record were happy to replace the dodgy threaded bar,
> There's possibly a weakness in anything made in a similar fashion, so make you're own!
> The crank handle has to be an improvement, too! Regards Rodders


Thanks.

Well, they were happy to _sell_ me a replacement bar :wink: 

To be fair, the machine is 10 years old and it's the first time anything's gone wrong - but it does seem to be a weak point, so I haven't used it as I happened to have some M8 threaded rod to hand.

There's the small matter that the cause of the breakage was trying to tension a 3/4" blade, which they sell on their site for the BS300. Except that when I spoke to one of their guys to order the replacement tensioning rod, he told me he wouldn't recommend trying to fit a 3/4" blade to the BS300 ](*,)


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## woodpig (10 Mar 2015)

Nice job, I did something similar on my 300E.


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## sploo (10 Mar 2015)

woodpig":2nzt277n said:


> Nice job, I did something similar on my 300E.


Thanks.

I'm pretty certain they mentioned that they'd improved that part (which I took to mean the 300E). Is it very similar though?


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## woodpig (10 Mar 2015)

Looks similar, my post is here:

record-bs300e-upgrades-t54641.html

Old knob and spindle and new crank. I also added a thrust washer.






It still surprises me that record fit a small knob on a hard to move spindle to adjust the blade tension then fit a nice large hand wheel on the easy to move blade guard adjuster! Bonkers.


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## sploo (10 Mar 2015)

That does look sufficiently similar (in both the weak link and pain in the backside to tension stakes).

I'd seen your thread, but not the most recent updates. Love the new blade guides (and wishing I had a milling machine)!

I wonder (with regard to the blade guides) if a block of dense hardwood and some off the shelf bolts/machine screws + bearings would work sufficiently that it would make sense to attempt a replacement guide for my BS300. I've never liked the upper blade guide (which looks very similar to the BS300E original).


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## woodpig (11 Mar 2015)

Yes, wooden blocks work well apparently. Not sure on the best species though? Well worth a Google to see what other folks have used.


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## gidon (11 Mar 2015)

Good job _sploo_- did the same on my BS350 within a week of ownership. Used stainless steel rod for more strength. Seems such a stupid place to save money!

Gidon


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## Graham Orm (11 Mar 2015)

Nice job, thanks for the heads up, I own a BS300.


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## marcros (11 Mar 2015)

woodpig":1800y668 said:


> Yes, wooden blocks work well apparently. Not sure on the best species though? Well worth a Google to see what other folks have used.



lignum vitae


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## sploo (11 Mar 2015)

marcros":1zjvopab said:


> woodpig":1zjvopab said:
> 
> 
> > Yes, wooden blocks work well apparently. Not sure on the best species though? Well worth a Google to see what other folks have used.
> ...


Ah. I probably should have been more specific; I didn't mean wooden blocks instead of ball bearings, I meant a wooden block to carry the bearings (instead of a milled lump of aluminium).




gidon":1zjvopab said:


> Good job _sploo_- did the same on my BS350 within a week of ownership. Used stainless steel rod for more strength. Seems such a stupid place to save money!



The odd thing is: a threaded rod and an arm held on with nuts may actually be cheaper than their proprietary solution!




Graham Orm":1zjvopab said:


> Nice job, thanks for the heads up, I own a BS300.


No worries. Hope it's useful.


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## RichardG (15 Oct 2019)

Old knob and spindle and new crank. I also added a thrust washer






[As photo bucket no longer allows embedded images on free account I've added the image to the thread. RichardG]


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## Mission1979 (24 Oct 2021)

RichardG said:


> Old knob and spindle and new crank. I also added a thrust washer
> 
> View attachment 81683
> 
> ...


Hi Richard

I know this is quite an old thread but do you where I could get a crank handle like that?
I've stripped everything down today as it looks like the M8 thread is stripped at the bottom, also I don't think that the Record specced knob will fit on the top anymore as that looks worn. They forgot to send that with my order this week (bit annoying) and judging by the fact the locking lever for the bed is totally the wrong size M10 not M6 I'm guessing the specs have all changed over the years. 
I'm going to replace the M8 threaded bar completely and also use a thrust bearing when I reassmble. 
Regards 
Tim


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## RichardG (25 Oct 2021)

That's the belt tensioner so in theory record power may be able to supply a replacement. Alternative have a look here as they have a good selection of hand wheels

Standard Parts


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## MichaelChou (13 Nov 2021)

Mission1979 said:


> Hi Richard
> 
> I know this is quite an old thread but do you where I could get a crank handle like that?
> I've stripped everything down today as it looks like the M8 thread is stripped at the bottom, also I don't think that the Record specced knob will fit on the top anymore as that looks worn. They forgot to send that with my order this week (bit annoying) and judging by the fact the locking lever for the bed is totally the wrong size M10 not M6 I'm guessing the specs have all changed over the years.
> ...


I’ve just ordered this in 8x24x8:








Minature Series Metric Ball Bearings 603 - 699 2RS Sealed | eBay


Miniature Bearings with bore sizes of 3mm to 9mm. Our range of miniature bearings are suitable for many applications including Small motors. Miniature gearboxes.



www.ebay.co.uk




And this:








M6/8/10/16 Adjustable Thread Handle Female Clamping Knob Lever Machinery Ratchet | eBay


Sanitary Male NPT DN8~DN65 Pipe Thread Adapter Vacuum Flange Fitting Tri Clamp. KF-16/25 to 1 ~ 3/4" Male PT Pipe Thread Adapter Vacuum Flange Fitting Sanitary. Release the handle to reengage and tighten.



www.ebay.co.uk




And will just use some m8 bar. 
hope that helps


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## Mission1979 (14 Nov 2021)

MichaelChou said:


> I’ve just ordered this in 8x24x8:
> 
> 
> 
> ...


Thanks Michael 
I ordered some of those levers to replace the table mitre lock thing. 
Got the replacement knob for the tentioner from record and some new M8 bar. Used some thrust bearings to make turning much easier. 
Seems to do the trick, even put the pointer back on that was all mangled in the box of spares I got with the saw. Wondering if I should upgrade the guides to bearings now. 

Cheers

Tim


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## Mission1979 (10 Jan 2022)

Hi all. 

Right now I'm lost. 

I bought a new 1/4" blade and went to change it tonight, took tension off removed the 3/4" blade. Installed the new blade but it was loose ebem with the tension back on. Tried increasing the tension, bad idea in hindsight. Snapped my new M8 threaded bar. Anyway, I've made up a new bar, now I can't figure out if I've put it back together incorrectly but I can't figure how to set everything up again. 

If someone could post some photos and any tips and if there's any critical measurements I'd be really appreciative. 

I just don't know what I've done wrong, I'm sure the blades are the same length. 

Thanks in advance. 

Tim


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## RichardG (11 Jan 2022)

First don't use the pointer as a guide unless you have calibrated it, use your finger on the blade. I also can't quite believe that you could apply enough tension using the plastic hand wheel to snap a m8 threaded rod, a 10 inch wrench yes, hand wheel no. It could have been a faulty bit of rod?

I've sold my BS300 now but I'm sure you already know the assembly diagram is in the manual.


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## Mission1979 (11 Jan 2022)

RichardG said:


> First don't use the pointer as a guide unless you have calibrated it, use your finger on the blade. I also can't quite believe that you could apply enough tension using the plastic hand wheel to snap a m8 threaded rod, a 10 inch wrench yes, hand wheel no. It could have been a faulty bit of rod?
> 
> I've sold my BS300 now but I'm sure you already know the assembly diagram is in the manual.


Morning Richard

Well I think the threads failed and then the only thing to do was keep going until it snapped. 

I put it all back together last night with a new threaded bar and it works with the 3/4" blade, all tensioned nicely, swapped back to the 1/4" and it wasn't close to tight so I think the blade is too long. Not sure what the tolerances regarding lengths are, I appreciate the can only get it to nearest tooth but this will sit around the 3/4" albeit tightly. 

Guess I won't be doing curved cuts anytime soon. 

Many thanks 

Tim


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## RichardG (11 Jan 2022)

Morning Tim,

From my experience with the BS300 and speaking with Ian at Tuffsaws the biggest blade I ever used was 5/8, I think you'll be struggling to tension a 3/4 blade adequately. I found that a smaller blade well tensioned would always cut much better than an under-tensioned larger blade.

I did use high pressure (graphite?) grease on the threads which is designed for these sorts of jobs, if you would like to try some send me a PM and I'll send you a blob (not quite sure how to package a blob of grease but I'm sure I'll work something out, should slip through the post no problems!). 

I have had an issue with a blade being slightly long which is why you can't use the the tension gauge as it only really works when the blades are all exactly the same length which of course they're not. Also narrow cheap blades can stretch if run under too much tension. I'd measure it and then contact the supplier if over length.

Richard


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## Mission1979 (11 Jan 2022)

RichardG said:


> Morning Tim,
> 
> From my experience with the BS300 and speaking with Ian at Tuffsaws the biggest blade I ever used was 5/8, I think you'll be struggling to tension a 3/4 blade adequately. I found that a smaller blade well tensioned would always cut much better than an under-tensioned larger blade.
> 
> ...


Hi Richard. 

Mines the BS350, don't know if that makes a big difference but the 3/4 blade was doing a great job of cutting true through 3 x 4" hardwood do I think it can do the tension okay with the thumb at the upper door hinge pull test method. 

The 1/4 is brand new so definitely hasn't stretched. If the blade will sit around the larger one, even though its tight how much longer will it be? My head hurts from trying to figure it out. Feel like a bit of an silly person but I'm new to this. I got the larger blade set up really well from a quite neglected machine so I feel like I'm missing something obvious here. 

If you let me know the grease you use I'll aquire some through work, its kind of you to offer, might end up lubricating Royal mails machinery if it went wrong. 

Cheers 


Tim


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## RichardG (11 Jan 2022)

It's sold as Rocol ASP (anti scuffing paste). It's a dry film type so doesn't pick up dust with a very high molybdenum content rated for pressure up to 100,000psi.


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