Buying Dob Mount

[Hertford Stargazer]

I have a 300p tube that I'm looking to mount on a Dob base, are there and companies who will make a good quality Dobsonian mount? I already have one on order via a UK company but it's now a month over due and I'm on the verge of canceling through frustration (long story).

Admittedly I could make one, but don't really have the time at present and feel my finished product would never achieve a satisfactory finish and would probably collapse under the weight      
 

[andrew s]

You could try one of these http://www.orionoptics.co.uk/MOUNTS/dobsonianmount.html - regards Andrew

[Hertford Stargazer]

5 hours ago, andrew s said:

You could try one of these http://www.orionoptics.co.uk/MOUNTS/dobsonianmount.html - regards Andrew

Thanks for replying Andrew, thats what I already have on order and the cause of my frustrations lol.

A while back when I wasn't interested in such (typical how that always happens) I came across a company who supplied Dob mounts but I seem unable to find them again. I've even been through my browser history to locate the site but to no avail. 

 

[andrew s]

Yes it is a pity OO seem to have a problem with delivery times my new scope was delayed but I got it in the end.

Regards Andrew

[estwing]

43 minutes ago, Hertford Stargazer said:

Thanks for replying Andrew, thats what I already have on order and the cause of my frustrations lol.

A while back when I wasn't interested in such (typical how that always happens) I came across a company who supplied Dob mounts but I seem unable to find them again. I've even been through my browser history to locate the site but to no avail. 

 

What a surprise......Making a dob mount isn't that hard and searching on here could the inspiration to DIY ....probably be cheaper and quicker 

[faulksy]

6 hours ago, Hertford Stargazer said:

I have a 300p tube that I'm looking to mount on a Dob base, are there and companies who will make a good quality Dobsonian mount? I already have one on order via a UK company but it's now a month over due and I'm on the verge of canceling through frustration (long story).

Admittedly I could make one, but don't really have the time at present and feel my finished product would never achieve a satisfactory finish and would probably collapse under the weight      
 

i had a similar problem, so cancelled and ordered through ts optics, which they recommended

[Hertford Stargazer]

2 hours ago, andrew s said:

Yes it is a pity OO seem to have a problem with delivery times my new scope was delayed but I got it in the end.

Regards Andrew

Thats reassuring to know, I ordered late September and as the shortest day is fast approaching I'm beginning to get frustrated.

 

2 hours ago, estwing said:

What a surprise......Making a dob mount isn't that hard and searching on here could the inspiration to DIY ....probably be cheaper and quicker

Your right,  probably would of been cheaper and quicker.

 

3 hours ago, faulksy said:

i had a similar problem, so cancelled and ordered through ts optics, which they recommended

Thanks, if they have stock I'll cancel on Monday and order from them 

 

[John]

It was the price of the Orion Optics dob mounts that put me off placing an order for one for my OO 12" F/5.3 optical tube. With their reputation for flexible delivery times I would have been nervous about actually going ahead as well.

In the end a skilled fellow SGL member (Moonshane) built a great mount for me based on the OO design but consructed from 18mm Birch ply. He did a great job

 

[jetstream]

12 minutes ago, John said:

It was the price of the Orion Optics dob mounts that put me off placing an order for one for my OO 12" F/5.3 optical tube. With their reputation for flexible delivery times I would have been nervous about actually going ahead as well.

In the end a skilled fellow SGL member (Moonshane) built a great mount for me based on the OO design but consructed from 18mm Birch ply. He did a great job

 

Any pictures of how the rings attach to the bearings John? I'll be looking at this option myself.

[John]

1 hour ago, jetstream said:

Any pictures of how the rings attach to the bearings John? I'll be looking at this option myself.

Hi Gerry,

On each side of each tube ring I have a thing that OO call a radius block. This creates a flat surface that mounting plates etc can be bolted onto. I use washer spacers to make sure that the alt bearings are square with the recesses cut into the mount base. 

This was all Shanes design, not mine. It works really well though

Here is a photo of the radius block on one tube ring:

 

 

[jetstream]

Thanks John, did Shane make the radius blocks? The pictures and info are much appreciated.

[John]

42 minutes ago, jetstream said:

Thanks John, did Shane make the radius blocks? The pictures and info are much appreciated.

No Gerry, they are an Orion Optics item made of the same metal as the tube rings.

Having just looked at their website I realise that OO are calling these things trunnion blocks now.

 

[jetstream]

I thought they might be- here is the issue- I have stock rolled tube rings as supplied with the scope ( at least I think they are) and need some form of radius block to use as your dob mount does. My OO mount wont ship until the end of January...

[andrew s]

If you like a bit of DIY you could try wide "U" shaped metal instead of the trunnion blocks. If you want to fill in the gap you can use car/wood filler resin and shape it by putting sandpaper on the rings and rubbing it down. (Wear a mask if you do this.)

Regards Andrew

[101nut]

One thing I found was that the OO mount is designed for OO tubes which are quite slim and metric. Therefore, despite their bases accepting "most manufacturer's tubes", a 10" (250mm) OO tube fits their 250mm mount but a Celestron 10" (254mm) tube wouldn't ...

AndyG

[jetstream]

4 hours ago, andrew s said:

If you like a bit of DIY you could try wide "U" shaped metal instead of the trunnion blocks. If you want to fill in the gap you can use car/wood filler resin and shape it by putting sandpaper on the rings and rubbing it down. (Wear a mask if you do this.)

Regards Andrew

The sanding is a nice solution Andrew, thank you.

[Hertford Stargazer]

On 02 December 2016 at 23:54, John said:

It was the price of the Orion Optics dob mounts that put me off placing an order for one for my OO 12" F/5.3 optical tube. With their reputation for flexible delivery times I would have been nervous about actually going ahead as well.

In the end a skilled fellow SGL member (Moonshane) built a great mount for me based on the OO design but consructed from 18mm Birch ply. He did a great job

 

Hi John, is the Birch Ply used for durability regarding damp? It's the prospect of warping that puts me off making a wooden mount.
 

[Moonshane]

Birch ply is very stable, strong and has very few voids. It's more expensive than standard ply but it's worth it to my eyes.

I stained John's with a water based stain and used a wax oil finish which dries hard. Like this one http://www.wood-finishes-direct.com/product/osmo-polyx-oil?gclid=CKPcwd-64tACFU6T7QodtzQO4w

In reality if you are happy to fill and paint, standard exterior grade plywood is fine as long as it is well sealed. My 16" dob base is getting on a bit and it great.

I regret to advise I don't even have time to make mine currently so cannot directly help anyone other than providing links as above etc. There are a few more on the site. just google moonshane and dob base and it usually works.

[Hertford Stargazer]

1 hour ago, Moonshane said:

Birch ply is very stable, strong and has very few voids. It's more expensive than standard ply but it's worth it to my eyes.

I stained John's with a water based stain and used a wax oil finish which dries hard. Like this one http://www.wood-finishes-direct.com/product/osmo-polyx-oil?gclid=CKPcwd-64tACFU6T7QodtzQO4w

In reality if you are happy to fill and paint, standard exterior grade plywood is fine as long as it is well sealed. My 16" dob base is getting on a bit and it great.

I regret to advise I don't even have time to make mine currently so cannot directly help anyone other than providing links as above etc. There are a few more on the site. just google moonshane and dob base and it usually works.

Thanks Moonshane. The DIY route is becoming more and more tempting I must admit. 
 

[John]

I can happily report that the birch ply mount that Shane made for my scope has passed it's 2nd birthday now and is looking and working just as well as it did when it was delivered. I've taken the scope to a number of star parties and outreach events and it's proved very robust and durable

 

[Marci]

On 03/12/2016 at 03:04, jetstream said:

I thought they might be- here is the issue- I have stock rolled tube rings as supplied with the scope ( at least I think they are) and need some form of radius block to use as your dob mount does. My OO mount wont ship until the end of January...

Not tried for this purpose - just pondering - but: FIMO oven bake polymer modelling clay from yonder bay-of-fleas. Soften, mould to scope, press other side to a flat / existing trunnion block, poke holes in for screws. Bake. Cheap n’ easy for experimentation!

[John]

23 minutes ago, Marci said:

Not tried for this purpose - just pondering - but: FIMO oven bake polymer modelling clay from yonder bay-of-fleas. Soften, mould to scope, press other side to a flat / existing trunnion block, poke holes in for screws. Bake. Cheap n’ easy for experimentation!

The weight of the tube is supported on these blocks. I don't know the dynamic characteristics of FIMO but would it support 10kg + ?

You might be able to make them from wood though.

[Moonshane]

They  would be easy to make in either soft, hard or plywood.

[Marci]

Presuming screwing thru scope rings into flats, you’re void filling to minimise leverage on the bolts and provide support under compression more than the fimo directly taking a great deal of lateral load weight...? For next-to-sod-all cost of fimo, buy some, try it n’ find out... just be gentle with letting go of the scope til certain it can take it!

[Timebandit]

3 minutes ago, Marci said:

Presuming screwing thru scope rings into flats, you’re void filling to minimise leverage on the bolts and provide support under compression more than the fimo directly taking a great deal of lateral load weight...? For next-to-sod-all cost of fimo, buy some, try it n’ find out... just be gentle with letting go of the scope til certain it can take it!

 

I can see where you are coming from. But personally I would not risk it as one big cost of damage to your scope if it goes belly up?

Personally I would stick to the tried and tested method of using either metal or a suitable wood to sort the mount problem out.

And you could then sleep at night knowing you scope is safely supported?