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#51

Debbie K
Member
Joined: 15 July 2017
Posts: 37
Member
23 January 2018 07:50 am

J:

My coarse adjustment knob is threaded all the way through so this is not the problem. Closing the gap is the issue; as I am tightening the coarse adjustment knob it is unscrewing the bottom screw as I am having to tighten it down really hard to pinch the axle enough to keep the entire brake from rotating on it. I have to hold the bottom screw whilst tightening the knob with pliers to keep it from moving, and even then it seems to loosen as you are cutting a facet. It doesn't seem like that big of deal until you are cutting a stone with many different angles and then it is. I believe this is due to the inside of the brake being abraded over time and becoming too loose to tighten due to extremely close tolerances it was originally engineered to have.

I think before I make a new one, I'll try your fingernail polish approach to either the axle or the inside of the brake. I thought about using shellac or some thinned down metal epoxy, but the fingernail polish sounds easier.

Debbie

#52

johnful
Member
Joined: 27 December 2017
Posts: 26
Member
28 January 2018 02:56 am

Hi Debbie,

Got tired of waiting for the switch at Grainger to come in. I found a suitable one at Home Depot. It cost about $6.

1517068463_switch_front.jpg

1517068482_switch_back.jpg

I'll try wiring it up this afternoon and post some instructions.

J

#53

johnful
Member
Joined: 27 December 2017
Posts: 26
Member
28 January 2018 05:12 am

I think it's I'll need to mount the switch above the speed control. I need to check clearance before I drill a hole

1517076708_img_1037.jpg

#54

johnful
Member
Joined: 27 December 2017
Posts: 26
Member
28 January 2018 05:15 am

Hi Debbie,

More pictures of the hard stop.

1517076805_img_1035.jpg
1517076806_img_1036.jpg

Looks like a little lock washer on the bottom where the screw goes in and a rubber washer right below the coarse adjustment knob.

Does yours look like this?

J

#55

johnful
Member
Joined: 27 December 2017
Posts: 26
Member
28 January 2018 05:23 am

Hi Debbie,

Given that the screw turns when adjusting, you might be missing the lock washer. You should be able to find one at Lowes or Home Depot for a few cents. It'll stop the screw from turning as you adjust the knob on the other side. The rubber washer under the knob keeps it from vibrating loose. You could find one of those at lowes or Home Depot as well. I had to get one for the lap nut on mine as it was missing. No matter how tight I made the lap nut, it would loosen up in a few minutes. The rubber washer solved that.

J

#56

johnful
Member
Joined: 27 December 2017
Posts: 26
Member
28 January 2018 05:37 am

Hi Debbie,

This is a meh Sunstone I was testing with. Weak color and only a tiny bit of Schiller. It's just a 16 sided brilliant so I can test the accuracy of the adjustments to my machine. 600 mesh to rough it out, but you can see the cuts are dead on. I'll try and finish the pavilion today when I get done messing around with the switch.

1517078194_img_1039.jpg

#57

johnful
Member
Joined: 27 December 2017
Posts: 26
Member
29 January 2018 09:55 am

Hi Debbie,

I couldn't figure out where to put the switch. There's not much room. I'll try and find a smaller one.

Here's the sunstone. Excuse the bad iPhone picture. Turns out it had quite a bit of Schiller deeper in. The chiller runs in bands right across the crown ☹️ It has almost a tiger eye appearance as you tilt it. It winks at you. 8mm SRB unstacked mains.

1517180101_img_1045.jpg

1 user likes this post: Wally69

#58

Debbie K
Member
Joined: 15 July 2017
Posts: 37
Member
30 January 2018 04:53 am

Really pretty sunstone! I was looking at mine day before yesterday and saying to myself "and just where did you think you saw a sheen?" I think it would be more accurate to call mine feldspar.

I got so excited after looking at your post because my brake was indeed missing a lock washer. Went and found one, and yes, I put it on the right way so it would dig into the brake if it were trying to loosen. It still slipped when hand-tightened so I used the pliers and it still slips ever so slightly. So I'm back to trying fingernail polish on the inside or making a new one, but am waiting til Wednesday as I need to borrow some spring washer pliers from a friend; the standard one's pins are too large.

I bought some aluminum last week, When I take it apart I'm going to trace the part and get ready to make a new one as I don't have too much confidence that the polish will work. I might just go ahead a make the damn thing as I'll have access to the shop drill press, band saw and belt sanders.

When I had it apart before, the axle was as slick as glass. I thoroughly degreased it before I dimpled it but couldn't help thinking that sometimes rust might be your friend. If I make a new brake, I'm thinking about roughing it up with coarse sandpaper and making the hole in the brake slightly smaller.

Bummer about the switch. What about the real estate in the triangular shaped area in front of the motor? Water might be an issue, though.

I got bored doing nothing and carved this the other day just to keep my hand in. Not my best work, but I'm planning a really elaborate and large carving and have to get back in the habit. Dimensions are about 5/8" wide x 7/8" tall x 1/4" deep.1517248240_joan_s-amethyst.jpg

Debbie

Last edited by Debbie K (30 January 2018 05:06 am)

3 users like this post: Nena, 7.62marksman, Rockhound

#59

Wally69
Member
From: Sydney
Joined: 13 December 2013
Posts: 2,501
Member
13 February 2018 10:22 pm

Spare parts on eBay - no idea if this solves your problems

https://www.ebay.com.au/itm/Prismatic-F … Sw9vlagcGd


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