Jump to content

WTB: Tobin Crystal Sync Motor for Bolex H16


 Share

Recommended Posts

Hi,

I've been searching for a crystal sync motor for my Bolex h16. I have scheduled a shoot in July and basically I've acquired all the necessary equipment except a crystal motor.

Here's what I did in order to find this gem:

1. Constantly search eBay --> No luck

2. Emailing rental houses and camera service companies (DuAll, Calkovsky Cinema and lot others, etc.) --> No luck

3. Asking individuals who might have one or are renting their motors. They're not selling and I cannot rent since mostly they're located in another continent. (I'm located in Helsinki, Finland) --> No luck.

4. I found NCS Products and their A-mazing Revolution crystal motor. I talked to the guy on the phone for 25 minutes. Incrediblely nice and friendly fellow but he told me he currently doesn't have any motors lying around and making one would take hell of a time. --> No luck.

My last attempt is to see anyone on this forum could help me out. Let's hope for some luck!

Link to comment
Share on other sites


if you can find a normal non-crystal brushed dc motor for the camera which works correctly or can get one made, then it would be possible for me to convert that normal motor to crystal sync using my existing crystal sync controller designs. If it does not need to be pretty and the system can be housed in a external box it should not take more than about 3 - 4 weeks to convert the motor if I can use my existing board designs and new circuit boards don't need to be made.

it is challenging for me to make precision mechanics because I don't have all the correct machining tools for it but if you would have a mechanically working non-crystal brushed motor system which needs to be converted to crystal, that conversion should work fine. So finding someone who can do the mechanics part and I could then handle the electronics here

Link to comment
Share on other sites

so you would need a mechanically fitting non-crystal motor and I can convert it to 12-speed crystal sync relatively easily with my existing circuit boards. There seems to be couple of non-sync bolex motors on ebay for sale which should work fine for this conversion. consult the forum which exact bolex motor model fits mechanically to your camera and I can take care of the crystal sync conversion when you got the suitable motor for it.

It is not possible for me to build the entire mechanics of the motor out of the scratch but converting a mechanically working motor to crystal sync is easily possible for me. I live in Turku, Finland so shipping would not be an issue

Link to comment
Share on other sites

42 minutes ago, aapo lettinen said:

if you can find a normal non-crystal brushed dc motor for the camera which works correctly or can get one made, then it would be possible for me to convert that normal motor to crystal sync using my existing crystal sync controller designs. If it does not need to be pretty and the system can be housed in a external box it should not take more than about 3 - 4 weeks to convert the motor if I can use my existing board designs and new circuit boards don't need to be made.

it is challenging for me to make precision mechanics because I don't have all the correct machining tools for it but if you would have a mechanically working non-crystal brushed motor system which needs to be converted to crystal, that conversion should work fine. So finding someone who can do the mechanics part and I could then handle the electronics here

Thank you for the reply. There are a few issues that concern me when it comes to DIY attempts.

1. I know nothing about mechanics and have never even seen one of these motors to at least have a ground level idea how it should work. I know a few folks who have studied mechanical engineering in Helsinki but unfortunately they haven't learned anything in their 5+ years of education.

2. The time limit is another factor. I have worked as a programmer before and experience tells me that 99% of the time, a new design/concept/project needs rigorous testing. I'm afraid that even if this DIY attempt succeeds in test environment, there's always a possibility that it fails during the shoot due to some unknown/unpredictable/untested condition. The shoot is scheduled in July because that's when there's the most amount of sunlight and my screenplay is around 90 pages with 70% exterior scenes. I'm hoping to use this time window effectively with no hiccups (at least the ones I can avoid.)

Having said that, let me ask around. Maybe I could find someone that could understand the mechanics. Do you have any specs of your circuit designs? What it needs and how it works? It could be helpful when I have to explain it to a mechanics engineer.

Link to comment
Share on other sites

39 minutes ago, Arash Tohidi said:

Thank you for the reply. There are a few issues that concern me when it comes to DIY attempts.

1. I know nothing about mechanics and have never even seen one of these motors to at least have a ground level idea how it should work. I know a few folks who have studied mechanical engineering in Helsinki but unfortunately they haven't learned anything in their 5+ years of education.

2. The time limit is another factor. I have worked as a programmer before and experience tells me that 99% of the time, a new design/concept/project needs rigorous testing. I'm afraid that even if this DIY attempt succeeds in test environment, there's always a possibility that it fails during the shoot due to some unknown/unpredictable/untested condition. The shoot is scheduled in July because that's when there's the most amount of sunlight and my screenplay is around 90 pages with 70% exterior scenes. I'm hoping to use this time window effectively with no hiccups (at least the ones I can avoid.)

Having said that, let me ask around. Maybe I could find someone that could understand the mechanics. Do you have any specs of your circuit designs? What it needs and how it works? It could be helpful when I have to explain it to a mechanics engineer.

it would use the main circuit board of my Konvas 15epss v1.0 controller so the board is already tested and is working fine.

What I would need mechanically is a brushed dc motor with normal operating voltage of from 12v to 30v and it having a small encoder disc installed to its axle so that I can get tachometer pulses for the crystal sync electronics from it.  If the mechanics are made from the ground up this encoder disc need would need to be taken into account. If it is a used bolex motor I should be able to install some kind of encoder to it here but if designing a new motor one needs to reserve some room for the encoder sensor and a mounting point for the encoder disc on the axle. I would need from 5 to 20 pulses from the encoder per frame and I have some 10 slot encoder discs here which can be used if making completely new mechanics.

The original Bolex non-crystal motors should work for this application as long as the motor fits to your camera. I have never opened one because my bolex is an older model and cannot use any motors, but installing a encoder into the original motor should be relatively easy and I should be able to do it here easily. 

after there is the encoder installed and the motor operating voltage is correct it is pretty straightforward for me to control it with my existing crystal sync electronics. I would use a 12-speed crystal sync system with a rotary switch to select the speed and a non-crystal variable speed feature just like on my Konvas controller. No display or additional features because it would double the costs and time needed to build it. I think the basic 12-speed external box model with variable speed feature and no display would be something between 500 and 600 euros to make depending on how much effort it takes to install the encoder inside the motor

Link to comment
Share on other sites

  • 6 months later...

I know it's past your July timeframe for the specific need. If you are still interested, I make crystal sync units compatible with the Bolex EL/EBM cameras and ESM motor, which all have sync support built-in. You'd need to find an ESM motor. I posted a demo on YouTube a few months ago. My main sales avenue has been Facebook so far.

Link to comment
Share on other sites

46 minutes ago, Jason Thompson said:

I know it's past your July timeframe for the specific need. If you are still interested, I make crystal sync units compatible with the Bolex EL/EBM cameras and ESM motor, which all have sync support built-in. You'd need to find an ESM motor. I posted a demo on YouTube a few months ago. My main sales avenue has been Facebook so far.

I think there is one or two EBM motors on eBay at the moment if they are compatible with the OP's camera. My bolex is so old that it cannot be used with a motor so don't know about the compatibility stuff.

 

As an update to my previous posts, I don't have time and resources to build any kind of motor modifications for the Bolex cameras. I don't have time for a project like that anymore but I lack the money too because it is spent on other projects and I would need to purchase a newer generation Bolex for a project like this which is way too expensive to happen (including the spare parts needed would go over 2k easily for me plus the possible cnc machining costs which would be at least a grand). It is impossible to make a crystal motor for a camera without having at least one camera of the same model available for at least half a year and I am not going to buy any new cameras in the next two years so the Bolex motor is not gonna happen.

 

Jason, do you have any interest in modifying the older generation Bolex motors to crystal sync (those very basic motors which are easily available and affordable like under 100usd, for example the MC17 model and similar ones) ?  There has been some interest towards these and if you have a suitable camera to test them with, then it should be possible to make a kickstarter or similar to fund the project. Should be handy for those people looking for a budget crystal 16mm camera package because there is very little original crystal capable motors available for Bolexes anymore

Link to comment
Share on other sites

17 minutes ago, aapo lettinen said:

I think there is one or two EBM motors on eBay at the moment if they are compatible with the OP's camera. My bolex is so old that it cannot be used with a motor so don't know about the compatibility stuff.

Good point. I forgot to mention the ESM motors only work with the 1:1 shafts on M4, H16S4, RX4 and later. If OP has an 8:1 shaft Bolex, the ESM won't work.

Link to comment
Share on other sites

8 hours ago, aapo lettinen said:

Jason, do you have any interest in modifying the older generation Bolex motors to crystal sync (those very basic motors which are easily available and affordable like under 100usd, for example the MC17 model and similar ones) ?  There has been some interest towards these and if you have a suitable camera to test them with, then it should be possible to make a kickstarter or similar to fund the project. Should be handy for those people looking for a budget crystal 16mm camera package because there is very little original crystal capable motors available for Bolexes anymore

Maybe. I ordered an MCE17B on eBay for $27 USD that is untested and looks rough. We can take it apart to explore what might be required. If we're uninterested in the work, my brother in LA can use it for parts.

Edited by Jason Thompson
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...