Folks,
I recently two Akai reel to reel units; GX280D and GX285D. Both units use 7" reels. I could not afford a 10.5" reel machine, as these are selling close to $800 and up and I paid $350 for both my machines. I looked at purchasing an Akai EA-11 adapter kit, but decided that this was not the route I wanted to go. I went to work researching where I could mount the new reel hubs. I discovered quickly that I could not just move the old hubs and motors, as there were clearance issues with other component adjacent to where these components would be resituated. So I went to plan B, I would create a new set of NAB reel hubs that have two sets of roller bearings on a 8mm shaft that I would mount to the Tape deck chassis. I would remove the existing tape hubs and replace them with 48mm diameter pulleys. these low profile pulleys have a 3mm track for a rubber belt. The new NAB hubs also have a pulley. Mounting the axles for the NAB hubs was a royal pain! The upper left portion of the tape deck chassis resides the reel hub brake solenoid. So I remounted this unit to the other side of the chassis to gain 5mm of Z clearance. Still I had to drill the hole for the axle into the mounting bracket of this solenoid. So I now have the hubs and pulleys mounted with the belts installed. As mentioned in my initial post, I was concerned that the added Z-height might require remounting the tape heads a transports. However, it appears the alignment is still acceptable. I still have a lot of adjustments needed and eventually I will need to modify the front panel to accommodate the newly placed NAB hubs. This will be the last step, as so far all modifications can be removed and the original design still intact, but modifying the front panel is irreversible.
Now for the cost. I designed and printed all the pulleys and NAB hubs out of resin. They look professional. The only hardware that I did not have locally was the 688ZZ Deep Groove Ball Bearings Z2 8mm X 16mm X 5mm Double Shielded Carbon Steel, 5pcs for $6 on Amazon, 3mm assorted sizes of rubber belts, $5.50 on Amazon, AS-332 O-Rings, Nitrile Rubber O-Rings 2-3/8" ID 2-3/4" OD 3/16", 8 pcs $8 on Amazon. At the hardware store I spent $8 of various lengths of 5/16" bolts, nuts and washers. I still need to purchase a small length of steel or aluminum pipe or tube that I can use for a small outline Z-spacer for the 8mm (5/16") axles. I wasted a lot of 3D resin on failed design attempts so I calculate that this was the lion's share of the cost, ~$25. I estimate my total cost into this project is $66 including taxes. Update- I roached my brake solenoid plunger and it cost me an additional $35 to purchase a used one.
The EA-11 adapters are a kludge with no regard to stress loading. Most of the units I have seen on Ebay have either cracks or breaks in the casting that mount the hub axles. The casting are only part of the problem, the thin sheet metal outriggers, flexes under dynamic load placing an extraordinary amount of stress on the casting. The extend 50 mm away from the tape unit chassis on either side making them look awkward. My design brings these hubs back inward by 80mm each side, making the tape system look sharp and taking up less real estate. Last, the EA-11 are as rare as chicken teeth and ones that come up for sale are undesirable.
I am far from completion, as I still have adjustments to make. I still do not know if these 3mm belts will be reliable enough, maybe they will. I included a photo of my progress so far. I'll keep everyone apprised of my progress.
Regards,
Rickey
I recently two Akai reel to reel units; GX280D and GX285D. Both units use 7" reels. I could not afford a 10.5" reel machine, as these are selling close to $800 and up and I paid $350 for both my machines. I looked at purchasing an Akai EA-11 adapter kit, but decided that this was not the route I wanted to go. I went to work researching where I could mount the new reel hubs. I discovered quickly that I could not just move the old hubs and motors, as there were clearance issues with other component adjacent to where these components would be resituated. So I went to plan B, I would create a new set of NAB reel hubs that have two sets of roller bearings on a 8mm shaft that I would mount to the Tape deck chassis. I would remove the existing tape hubs and replace them with 48mm diameter pulleys. these low profile pulleys have a 3mm track for a rubber belt. The new NAB hubs also have a pulley. Mounting the axles for the NAB hubs was a royal pain! The upper left portion of the tape deck chassis resides the reel hub brake solenoid. So I remounted this unit to the other side of the chassis to gain 5mm of Z clearance. Still I had to drill the hole for the axle into the mounting bracket of this solenoid. So I now have the hubs and pulleys mounted with the belts installed. As mentioned in my initial post, I was concerned that the added Z-height might require remounting the tape heads a transports. However, it appears the alignment is still acceptable. I still have a lot of adjustments needed and eventually I will need to modify the front panel to accommodate the newly placed NAB hubs. This will be the last step, as so far all modifications can be removed and the original design still intact, but modifying the front panel is irreversible.
Now for the cost. I designed and printed all the pulleys and NAB hubs out of resin. They look professional. The only hardware that I did not have locally was the 688ZZ Deep Groove Ball Bearings Z2 8mm X 16mm X 5mm Double Shielded Carbon Steel, 5pcs for $6 on Amazon, 3mm assorted sizes of rubber belts, $5.50 on Amazon, AS-332 O-Rings, Nitrile Rubber O-Rings 2-3/8" ID 2-3/4" OD 3/16", 8 pcs $8 on Amazon. At the hardware store I spent $8 of various lengths of 5/16" bolts, nuts and washers. I still need to purchase a small length of steel or aluminum pipe or tube that I can use for a small outline Z-spacer for the 8mm (5/16") axles. I wasted a lot of 3D resin on failed design attempts so I calculate that this was the lion's share of the cost, ~$25. I estimate my total cost into this project is $66 including taxes. Update- I roached my brake solenoid plunger and it cost me an additional $35 to purchase a used one.
The EA-11 adapters are a kludge with no regard to stress loading. Most of the units I have seen on Ebay have either cracks or breaks in the casting that mount the hub axles. The casting are only part of the problem, the thin sheet metal outriggers, flexes under dynamic load placing an extraordinary amount of stress on the casting. The extend 50 mm away from the tape unit chassis on either side making them look awkward. My design brings these hubs back inward by 80mm each side, making the tape system look sharp and taking up less real estate. Last, the EA-11 are as rare as chicken teeth and ones that come up for sale are undesirable.
I am far from completion, as I still have adjustments to make. I still do not know if these 3mm belts will be reliable enough, maybe they will. I included a photo of my progress so far. I'll keep everyone apprised of my progress.
Regards,
Rickey
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