Grampian Type D - Reconditioning

[jamesfabel]

Hey trolls

I have a Grampian feedback cutting head - type D

and i would like to recondition it - i have the original manual, which i will scan and upload to the repository if there is not already copy.

Wherein it refers to some items and materials that Im hoping someone with some insight can suggest modern equivalents

They are:

Silicone damping fluid - 'Dow Corning'

Absorbent washer

Sealing pads

Spacers

Cement - 'Goodyear Plio-bond'

I have the original of all above except the cement - i imagine they should be replaced, if there is a ideal solution.

The rest of the instructions are relatively straightforward, but if a troll out there knows of any tricks

Im all ears.

Cheers
Jamesfabel

ps. a couple of photos attached of the components as they were once removed.

pps. Im very interested in matching a Gotham amplifier to this - if anyone knows of where i can get one - please PM

[jts]

Would be interested in grampian D manual
Is possible to get copy? Or where to find?

[piaptk]

If you successfully wind a new saddle coil for this, I would be interested in buying a few. I don't have a coil form for it. Thanks!

[mrd]

Nice, I'd be interested in the manual too!

[emorritt]

I have the manual for this head; will scan it and post when I get home from work today.

[mrd]

I have the manual for this head; will scan it and post when I get home from work today.

Hi, any joy with this please - would really like a copy if possible!

[emorritt]

Sorry this took so long; here are the two pages of the tech literature that came with the Grampian head:

[mrd]

Sorry this took so long; here are the two pages of the tech literature that came with the Grampian head:

No problem, thanks for uploading!

[dubcutter89]

Thanks for sharing - BUT - I cannot view these images...why?

Regards
Lukas

[SueDenim]

Try these perhaps?

[dubcutter89]

They work - THANKS!!

[DavidS]

Hi, who has tried to rewind the coil for Grampian D head?

[Fela Borbone]

Hello,
I wounded saddle coils, for grampian replica, and is not really difficult. You have to wind them round first, around a cylinder (I used a marker) and with two rubber stops away from a 3mm gap. Then wind first the feedback with the thinnest wire you can get, and then, around hundred turns of thicker wire for the drive coil, When is done, carefully remove the rubber and tie around the coil some Teflon strip, or alike to keep the turns together.
Then bend it to a saddle shape around the armature. If is too big or too small, try with other cylinder diameter. Check resistance of the coils, and change number of turns or gauge if needed. This may take the whole afternoon, dont worry, relax and enjoy.
The "sweet spot" of resistance/gauge/number or turns ratio is wide, it don't have to be exact. Its more important that the coil fit perfect on his place, and don't protude too much outside the pole pieces, this will cause a big waste.
I'll try to find pictures, and check wich gauge I used, if I find n my notes....

[Fela Borbone]

]Hello again
Sorry for the delay,
Found no pictures, so make new ones.This is not a real Grampian, but a prototype inspired on it, and dimensions are not exactly the same, but similar.
I used here 100 turns of 0.25 thick enameled copper wire, what yields aprox 2 ohms DC resistance. I prefer high current(thick wire) few turns, as it brings less
inductance, with modern solid state amps, but others may have another choice. That's fine. The sweet spot is wide. Also I dont care too much about the "turnover point" in frequency where impedance overtakes resistance(lazyness and less headache), now that extra eq solves anything.Here some pic of the process that speak for themselves:

20241108_132412.jpg

20241108_140444.jpg

20241108_140731.jpg

20241108_140830.jpg

20241108_140935.jpg

20241108_141132.jpg

20241108_142106.jpg

Theres no feedback coil here, but if you wish, some 30-50 turns of the thinnest wire you can get will work.
I belive its winded first, close to the armature.The outside forming and insulation is made with PTFE plumbing tape.

[Fela Borbone]

Now, ver gently, the coil is formed to fit in the space in the polepieces. If the fit is not perfect, im sorry but you may have to start again with less or more turns.Is important that the coil is blocked and dont move.

20241108_142250.jpg

Then the ends are bendeb upwads so it fits the armature

20241108_142527.jpg

And everithing should fit. If coil protude too much, start again with a thinner marker to wind up the coil (I used a 12 mm diameter marker here)

20241108_142718.jpg

And that's it.Some tryal and error may be needed.

In my prototypes I prefer two coils instead of one (Phillips-Miller way), I can tell if this will benefit a Grampian too:

20241108_142755.jpg

...And finaly, a picture of my babies:

20241108_142903.jpg

[mrd]

That’s awesome, thanks so much! And those heads look beautiful!

[farmersplow]

A fantastic piece of work! I love it when a craft is used in this beautiful way!