Chipper blade change guide - Jensen

[Zedde]

Morning all. I have just taken delivery of my first chipper, an old Jensen A528. I am looking to learn how to do all the maintenance myself and am currently trying to find some information on blade changing. Would anyone have some good documentation that will help me out with this?, In my searching I noticed there is specific spacing and skew to measure when fitting blades. Is there any special spacers/devices I need or can buy to make the job easier?.

 

I have torque wrench and good set of tools available.

 

Thanks in advance for any info.

[maybelateron]

I'm not familiar with the A528, but I have a 2013 A540 (turntable). If you are referring to the spacing between the blades and the horizontal anvil this is set by fitting (increasingly thicker as the blades wear) shims. Available from Jensen dealers in a range of thicknesses.

 

I can't emphasise enough the importance of thoroughly removing all crud from the blade bolts hex recesses before trying to undo them. If the large allen key is not fully home in the hole it can round it off all too easily.

 

Hope this helps.

[Zedde]

Thanks for the info, So I need a set of these shims from Jensen then.

 

I havnt had chance to look at my specific chipper but found this in the A530 manual which I believe is the newer model and very similar (see attached pic).

 

So the spacer in the diagram would be the shim you speak of which you change size to keep the blade edge at a certain distance from anvil.......I don't see a specific measurement for what the spacing should be between blade edge and anvil edge tho, I would assume I use a feeler guage to check it and adjust the shim thickness till its the correct gap?.

 

Thanks for all info, I like to get things 100% in my head before I attempt anything :).

 

 

[WeFixIt]

Simple rule to follow
Minimum of 2 mm (thickness of a standard hacksaw blade) less than 2 mm runs the risk of blade to anvil contact, this gap should always be set with a new set of blades,

Bolts, nuts,locking washer and mounting points on flywheel should be cleaned spotless, all traces of rust removed and a thin layer of copper grease to help stop corrosion, rust build up behind blades causes them to crack!

Despite Jensen supplying shims with the chippers when new, I’ve found many owners don’t use them!
I would be interested to hear how many do?

[Zedde]

Thanks wefixit!. So you are saying most people don't even bother shimming/checking the correct gap unless they are fitting new blades?.

[WeFixIt]

Simple rule to follow
Minimum of 2 mm (thickness of a standard hacksaw blade) less than 2 mm runs the risk of blade to anvil contact, this gap should always be set with a new set of blades,

Bolts, nuts,locking washer and mounting points on flywheel should be cleaned spotless, all traces of rust removed and a thin layer of copper grease to help stop corrosion, rust build up behind blades causes them to crack!

Despite Jensen supplying shims with the chippers when new, I’ve found many owners don’t use them!
I would be interested to hear how many do?

Little bit of self correction new blades and anvil!

[WeFixIt]

Thanks wefixit!. So you are saying most people don't even bother shimming/checking the correct gap unless they are fitting new blades?.

What I was saying in the past 10 years I’ve only seen 3 Jensen chippers with shins fitted and I’ve seen quite a lot! Neither is that because they all had new blades fitted!

In Europe Jensen set the chippers with a wide gap at blade to anvil, when they were imported by Redwood they reset/reduced the gap for the UK market.
Therefore the gap produced by wear/resharpening has a bigger allowance before and issue of the gap being to big that shims are needed..

[PeteB]

What does it say in the Ops Manual? I'm sure the Jensen importer will be able to help with this? Try and ring Bill Johnston at TH White's and asking for the electronic version of it?

[WeFixIt]

This is what a Jensen manual says!

[maybelateron]

On my A540 the gap between the blade and anvil increases in size along the blade. From memory I think it is smallest near the centre (some weeks since last blade change, I change them every 50 hours). I imagine this applies across the range of Jensen chippers. I set the gap near the centre to be as tight as possible, and check that each of the 3 blades is clearing the anvil. This works fine and stops the chip being too coarse on high roller speeds.

 

I always turn or replace the anvil every other blade change. The anvil can be skimmed to restore a sharp corner.