Results 1 to 17 of 17

Thread: Echolette pinch roller

  1. #1
    Twobie
    Join Date
    Oct 2019
    Posts
    9
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0

    Echolette pinch roller

    I got a Klemt Echolette a couple months ago and found some Dynacord pinch rollers being sold on Ebay and was wondering if this would work on an Echolette. The dimensions of the pinch roller on my Echolette are
    20mm OD x 7mm ID x 12mm long


    Some more details:
    I used a dental mirror to look at the bridge rectifier and since its selenium (B 300 C 70) I decided to put in a silicon type bridge rectifier (KBPC50-10) to substitute for it. I checked the motor capacitor and two filter capacitors with an analog ohm meter and capacitor tester. The motor works (both speeds, bridge rectifier disconnected during the test). After that I connected the silicon bridge rectifier in place of the selenium (left in place but disconnected) with a 250 ohm power resistor in series with the new bridge rectifier. With a variac and ammeter connected, I slowly brought up the voltage and figured it looked OK. I tested the tubes with a tube tester and they look OK. I put the tubes in and turned it on with a microphone connected via a home made adapter with a 3 pin DIN connector and phone jack and connected the output to an amplifier. It worked with the mic connected, but there was no reverb. I connected a jumper between two pins of a 3 pin DIN connector plugged into the remote control and the reverb worked with some problems with the tape I can discuss later. It seems that it was a bad connection at one of the pots which I fixed. More recently I replaced the roller on the spring biased arm with a new polyurethane roller. It works good in the slow speed when I put my finger on the pinch roller arm and push it toward the capstan. If I had a new pinch roller it might work better.

    Also, I used a 9 pin tube adapter/tester (ie. Pomona) between the tube and socket and checked the grid and plate voltages on some of the tubes which seem OK. There doesn't seem to be any bad interstage capacitors (no shorts).

    0 Not allowed! Not allowed!

  2. #2
    Twobie
    Join Date
    Oct 2019
    Posts
    9
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    I found this on a foreign Ebay website

    As stated this is a rubber tape pinch roller for a Dynacord Vintage Echo Chamber Type S62 although I suspect it will fit other Dynacord Machines from the same era It is 22 mms diameter x 9.5 mms thick with a 5 mm bearing
    Looks like they aren't equivalent.

    0 Not allowed! Not allowed!

  3. #3
    Old Timer
    Join Date
    Jun 2007
    Posts
    5,105
    Thumbs Up/Down
    Received: 90/0
    Given: 57/0
    Rep Power
    19
    You can have the original roller rebuilt with new rubber. I had two of them done last year by Terry in Michigan. Very nice work and fairly quick service as well.

    Where are you located?

    0 Not allowed! Not allowed!

  4. #4
    Twobie
    Join Date
    Oct 2019
    Posts
    9
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Some pictures of my Echolette. The roller on the spring biased arm was replaced with a polyurethane roller with a bearing.







    I'm in Maryland. If I had a new tire for the roller, I might be able to rebuild it myself. How much would it cost if Terry fixed it? There's some on Ebay (German seller) for about $60 a piece.

    0 Not allowed! Not allowed!

  5. #5
    Old Timer
    Join Date
    Jun 2007
    Posts
    5,105
    Thumbs Up/Down
    Received: 90/0
    Given: 57/0
    Rep Power
    19
    Quote Originally Posted by Toynbee View Post
    I'm in Maryland. If I had a new tire for the roller, I might be able to rebuild it myself. How much would it cost if Terry fixed it? There's some on Ebay (German seller) for about $60 a piece.
    Here's the link www.terrysrubberrollers.com.

    The cost was $35 plus shipping ($6), but check with him.

    0 Not allowed! Not allowed!

  6. #6
    Twobie
    Join Date
    Oct 2019
    Posts
    9
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    OK, thanks. Some pictures of the roller in my Echolette. It doesn't look that bad. It seems to be harder than a new pinch roller.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	rollertop-c.jpg 
Views:	11 
Size:	36.2 KB 
ID:	55483   Click image for larger version. 

Name:	rollertop2-c.jpg 
Views:	9 
Size:	42.8 KB 
ID:	55484   Click image for larger version. 

Name:	rollerbottom-c.jpg 
Views:	9 
Size:	44.9 KB 
ID:	55485  

    0 Not allowed! Not allowed!

  7. #7
    Old Timer
    Join Date
    Jun 2007
    Posts
    5,105
    Thumbs Up/Down
    Received: 90/0
    Given: 57/0
    Rep Power
    19
    The center bearing looks to be serviceable, but there is a tape path indentation line along the outer surface. At least you don't seem to have a big dent in the roller from having the roller left in contact with the drive capstan.

    I'd try and clean up the surface of the roller first and see how the tape runs with just that much being done. Usually there are bigger issues to deal with that make the roller a last thing on my list. It's great to have the tape running smoothly, but if there is a problem with the electronics or the heads and there is no echo, that pretty much makes the roller a moot point.

    0 Not allowed! Not allowed!

  8. #8
    Twobie
    Join Date
    Oct 2019
    Posts
    9
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    I tried googling "pinch roller refurb" and found some interesting links. I have some Rubber Renue and I'm going to try some more of that.
    one video I found:
    https://www.youtube.com/watch?v=nATgx4uJcZI

    0 Not allowed! Not allowed!

  9. #9
    Twobie
    Join Date
    Oct 2019
    Posts
    9
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    I tried putting some of that Rubber Renue on the pinch roller, but it doesn't seem to do much. I noticed there were some lines or deformations in the roller which caused some slight bulges on either end. I read a thread on another forum, I think it was at tapeheads.net about someone putting a pinch roller in a lathe and worked on the pinch roller somehow. I decided to try putting my pinch roller on a bolt (with a short piece of brass tubing as a shim) and putting it in the chuck of a drill press and filing the bulges on either end. It seemed to improve the performance when put back in the Echolette, but I still had to push the pinch roller arm toward the capstan to get it up to speed. I tried putting a second spring on the pinch roller arm before and that seems to work.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	roller-lines-c.jpg 
Views:	10 
Size:	64.8 KB 
ID:	55560   Click image for larger version. 

Name:	roller-bolt-c.jpg 
Views:	10 
Size:	53.4 KB 
ID:	55561   Click image for larger version. 

Name:	roller-filed-c.jpg 
Views:	12 
Size:	42.9 KB 
ID:	55562  

    0 Not allowed! Not allowed!

  10. #10
    Old Timer
    Join Date
    Jun 2007
    Posts
    5,105
    Thumbs Up/Down
    Received: 90/0
    Given: 57/0
    Rep Power
    19
    If the last photo is the wheel after you have abraded it, you still have a few problems.

    The shiny section is still going to slip because there is still a depression where the tape touches the roller. When the depression is gone, the entire surface of the roller will have a clean new even color.

    I don't know what you are using to abrade the surface with, but it is tearing up the rubber. It should be clean and smooth or you will have tape speed problems caused by a too rough surface.

    0 Not allowed! Not allowed!

  11. #11
    Twobie
    Join Date
    Oct 2019
    Posts
    9
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    That glazing is more obvious after filing the bulges. I used a jeweler's file. I was thinking of filing the glazing off where the tape contacts it, but I probabbly need to be careful with it.

    0 Not allowed! Not allowed!

  12. #12
    Twobie
    Join Date
    Oct 2019
    Posts
    9
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    I bought 5 Neutrik Rean 3 pin DIN male connectors for $1.370 a piece recently from Allied Electronics. The price was lower than most Ebay sellers and they shipped it fast. They fit in the 3 pin jacks on the Echolette.

    0 Not allowed! Not allowed!

  13. #13
    Supporting Member The Dude's Avatar
    Join Date
    May 2010
    Location
    Sioux Falls, SD
    Posts
    6,260
    Thumbs Up/Down
    Received: 1,183/1
    Given: 915/1
    Rep Power
    16
    This won't always work. Sometimes the rollers are just passed it and nothing but replacement will work. That said, I've used a fine emery cloth in the past. Apply slight pressure to the roller as it spins. Low and slow. Be patient. You need to take enough off the outside that the entire surface looks the same- no high or low spots and no shiny spots or grooves. Also, you'll need to continue to apply the Rubber Renue and let it soak in until it no longer does. Don't wipe it off right away. Let it do its job and soak overnight if necessary. If there's a chance of the pinch roller surviving, this will work. If it doesn't, time for a new one. My $.02.

    0 Not allowed! Not allowed!
    Last edited by The Dude; 10-15-2019 at 02:29 AM.
    “Yeah, well, you know, that’s just, like, your opinion, man.”

  14. #14
    Old Timer
    Join Date
    Jun 2007
    Posts
    5,105
    Thumbs Up/Down
    Received: 90/0
    Given: 57/0
    Rep Power
    19
    You need to use the DIN connectors for the two mic inputs and the footswitch connector, as the 3rd input that is recommended for instrument use and the output have already been changed to 1/4" phone jacks.

    I don't know what sort of file you are using, but I suggest that the file be wide enough to cover the entire face of the rubber roller. In order to not distort the dimensions of the wheel, you need to try and remove the old rubber on the surface as evenly as possible.

    I would also suggest that you file the surface flat before you use the Renue product.

    0 Not allowed! Not allowed!

  15. #15
    New Member
    Join Date
    Oct 2019
    Location
    Indonesia
    Posts
    4
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Be sure to send a photo of the final result. I think it should turn out an amazing thing!

    0 Not allowed! Not allowed!

  16. #16
    Twobie
    Join Date
    Oct 2019
    Posts
    9
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    I'm waiting on some 6X20X6mm (20 mm OD) polyurethane rollers slowly making their way through China. I put a 6X17.8X7mm polyurethane roller on the spring biased arm (idler pulley?) and it turns easier than the original one. The 6X17.8X7mm polyurethane roller touches the metal washer of one roller which could be modified.

    Original roller shown top left (20 mm OD), 6X17.8X7mm polyurethane roller top right, 2 6X26X10mm polyurethane rollers and a teflon washer bottom in the picture. The polyurethane rollers have some kind of bearing in them which allows them to turn easier (they don't have ball bearings).
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	polyurethanepulleys.JPG 
Views:	6 
Size:	243.6 KB 
ID:	55618  

    0 Not allowed! Not allowed!

  17. #17
    Don't forget the joker g1's Avatar
    Join Date
    Feb 2010
    Location
    Canada, somewhere north of Fargo
    Posts
    11,631
    Thumbs Up/Down
    Received: 1,546/23
    Given: 3,925/11
    Rep Power
    22
    Quote Originally Posted by Toynbee View Post
    The polyurethane rollers have some kind of bearing in them which allows them to turn easier (they don't have ball bearings).
    626RS is a standard type sealed deep groove ball-bearing.

    0 Not allowed! Not allowed!
    Just because they don't have tubes doesn't mean they don't have feelings! - glebert

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Under rated cap in a pinch
    By Sowhat in forum Fun with computers
    Replies: 3
    Last Post: 07-27-2017, 12:41 PM
  2. EL84 tube clamp, in a pinch......
    By nevetslab in forum Maintenance, Troubleshooting & Repair
    Replies: 7
    Last Post: 10-02-2014, 10:58 PM
  3. Replies: 9
    Last Post: 12-04-2012, 02:57 PM
  4. Echolette B200
    By QJerry in forum Schematic Requests
    Replies: 3
    Last Post: 09-16-2010, 05:27 PM
  5. Cleaning Pinch Roller on a roland Space Echo?
    By boutiquedungeonla in forum Maintenance, Troubleshooting & Repair
    Replies: 4
    Last Post: 10-28-2008, 03:42 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •